研究者詳細 - 佐藤　しのぶ

論文 - 佐藤　しのぶ

分割表示 >> ／全件表示140 件中 1 - 140 件目

Cyclic anthraquinone derivatives, unique G-quadruplex binders, selectively induce cancer cell apoptosis and inhibit tumor growth 査読有り国際誌

Fukuda H., Zou T., Fujii S., Sato S., Wakahara D., Higashi S., Tseng T.Y., Chang T.C., Yada N., Matsuo K., Habu M., Tominaga K., Takeuchi H., Takenaka S.

PNAS Nexus 2 ( 7 ) 2023年07月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Cyclic anthraquinone derivatives (cAQs), which link two side chains of 1, 5-disubstituted anthraquinone as a threading DNA intercalator, have been developed as G-quartet (G4) DNA-specific ligands. Among the cAQs, cAQ-mBen linked through the 1, 3-position of benzene had the strongest affinity for G4 recognition and stabilization in vitro and was confirmed to bind to the G4 structure in vivo, selectively inhibiting cancer cell proliferation in correlation with telomerase expression levels and triggering cell apoptosis. RNA-sequencing analysis further indicated that differentially expressed genes regulated by cAQ-mBen were profiled with more potential quadruplex-forming sequences. In the treatment of the tumor-bearing mouse model, cAQ-mBen could effectively reduce tumor tissue and had less adverse effects on healthy tissue. These results suggest that cAQ-mBen can be a potential cancer therapeutic agent as a G4 binder.

DOI： 10.1093/pnasnexus/pgad211

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85174723246&origin=inward

Naphthalene Diimides Carrying Two β-Cyclodextrins Prefer Telomere RNA G-Quadruplex Recognition 査読有り国際誌

Zou T., Sato Y., Kaneyoshi S., Mano K., Yasukawa R., Nakano Y., Fujii S., Sato S., Takenaka S.

Molecules 27 ( 13 ) 2022年07月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Newly synthesized naphthalene diimide carrying two β-cyclodextrins (NDI-β-CyDs) showed improved specificity for the parallel G-quadruplex structure alongside the hybrid G-quadruplex structure. Specifically, the highest binding affinity of NDI-β-CyDs for the telomere RNA G-quadruplex was observed. The binding simulation indicated that β-cyclodextrins might be available for loop nucleobase inclusion under its complex.

DOI： 10.3390/molecules27134053

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85133131763&origin=inward

Cyclic ferrocenylnaphthalene diimides as a probe for electrochemical telomerase assay 査読有り国際誌

Kaneyoshi S., Eguchi N., Fujimoto K., Fujii S., Sato S., Takenaka S.

Journal of Inorganic Biochemistry 230 2022年05月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Novel cyclic naphthalene diimides, 8 and 12, containing ferrocene in the cyclic linker were synthesized as G-quartet (G4) specific electrochemical ligands via the reaction of 1,1′-ferrocenedipropanoic acid and the terminal amine moieties of naphthalene diimides with varying linker lengths. The redox potentials of 8 and 12 were ca. 0.2 V (vs. Ag/AgCl), and the background current in an electrolyte was successfully suppressed. Both 8 and 12 bound to TA-core, representing human telomere G4, with K = 4.4 and 38 × 105 M−1, respectively. The current response of 12 to an electrode immobilized with G4 was the highest among the acyclic derivatives, suggesting its potential application in electrochemical telomerase assays.

DOI： 10.1016/j.jinorgbio.2022.111746

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85124248729&origin=inward

Electrochemical telomerase assay with ferrocenylnaphthalene diimide as a tetraplex DNA-specific binder 査読有り国際誌

Sato S., Kondo H., Nojima T., Takenaka S.

Analytical Chemistry 77 ( 22 ) 7304 - 7309 2005年11月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Spectroscopic studies revealed that ferrocenylnaphthalene diimide (1) can bind to tetraplex DNA at high potassium ion concentration. The tetraplex DNA was stabilized by the binding of 1, and this effect was larger than that of any other tetraplex stabilizers, which are known as a telomerase inhibitor. Quantitative analysis with circular dichroism and a quartz crystal microbalance strongly suggested a 3:1 binding stoichiometry of 1 to the tetraplex DNA. The telomere sequence could be extended by telomerase with the telomerase substrate primer on the surface of an electrode as proven by an increased current signal of 1 bound to the tetraplex DNA formed on the electrode. This is the first example of electrochemical detection of telomerase activity without relying on PCR. © 2005 American Chemical Society.

DOI： 10.1021/ac0510235

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=27944476426&origin=inward

Electrochemically active DNA ligands for gene detection: present and future 招待有り査読有り国際誌

Takenaka S., Sato S.

Analytical Sciences 2025年01月

担当区分：筆頭著者記述言語：英語掲載種別：記事・総説・解説・論説等（学術雑誌）

Electrochemical gene sensing methods are gaining attention as diagnostic chips. Here, we review the electrochemically active DNA ligand-based sensing methods. Various DNA ligands have been reported in these studies, among which metal complexes, methylene blue, and ferrocenyl naphthalene diimide (FND) have been studied in detail. DNA probe immobilized electrodes have been created, hybridization reactions on the electrodes with target DNA fragments have been performed, and electrochemical gene detection has been possible using these DNA ligands. An example of the realization of this system is the successful and accurate cancer diagnosis using FND to examine abnormal methylation of the hTERT gene, providing reassurance about the system's reliability. In addition, electrochemical detection of PCR products has been realized using the current decrease due to the double-stranded DNA binding of methylene blue although it is a signal-off system. A naphthalene diimide derivative with ferrocene and β-CD, FNC, increased the current upon double-stranded DNA binding. Using these FNCs, the detection of PCR products in a homogeneous system was realized. Electrochemical qPCR was realized with these ligands. Since FNDs also bind strongly to tetraplex or G-quadruplex (G4) DNA, we succeeded in electrochemically detecting telomerase activity, which is known as a cancer marker, using FNDs to detect the amount of telomeric DNA elongation, which is its substrate, as the amount of G4 DNA. This technique has realized compassionate cancer diagnosis from oral swab fluid. It is known that G4 is also present in viral genome RNA, and a viral testing method using G4 is expected to be a potential alternative to PCR. The first example was the electrochemical detection of novel coronaviruses using incFND as an RNA G4 ligand.

DOI： 10.1007/s44211-025-00745-5

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=105000634216&origin=inward

Biotinylated cyclic naphthalene diimide as a searching tool for G4 sites on the genome 査読有り国際誌

Fujii S., Sato S., Hidaka R., Takenaka S.

Analytical Sciences 40 ( 5 ) 943 - 950 2024年05月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

A biotinyl cyclic naphthalene diimide (biotinyl cNDI) (1), in which biotin is introduced on the cyclic linker chain of cNDI with high G-quadruplex (G4) specificity, was synthesized. 1 was used for binding analysis to G4 DNAs such as c-myc, c-kit, CEGF, or TA-core. The results showed that 1 bind to G4 DNAs with high affinity and, especially, two molecules of 1 bind to c-myc DNA from top and bottom of G4 site at K = 3.9 × 10−6 M−1 without changing the G4 structure. As a pulldown assay, 1 and streptavidin magnetic beads could be used to recover a c-myc DNA or 120-mer DNA fragment having single c-myc sequence. The qPCR results for the 120-meric DNAs showed that more than 50% of genomic DNA fragments could be recovered by this pulldown assay. The results obtained here might allow the recovery of G4-containing DNA fragments from genomic DNA to analyze the true G4 present in the genome. Graphic abstract: (Figure presented.)

DOI： 10.1007/s44211-024-00551-5

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85190388136&origin=inward

Novel analytical technologies contributing to clinical and pharmaceutical research fields 招待有り査読有り国際誌

Takenaka S., Sato S., Hamase K., Hayama T.

Analytical Sciences 40 ( 5 ) 2024年05月

Synthesis of cNDI-Peptide-Dimer as a G4 Cluster-Selective Binder and its Interaction with G4 Dimer 査読有り国際誌

Ono K., Sato S., Takenaka S.

ChemistrySelect 9 ( 16 ) 2024年04月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

The amino acid unit carrying cyclic naphthalene diimide (cNDI) was synthesized by linking the amino moiety of cNDI as a G4-specific ligand with the γ-carboxylic acid moiety of Fmoc-Glu. cNDI-peptide-dimer, 1 was synthesized by peptide synthesizer using this unit. 1 exhibited an extremely strong binding constant of the order of 108 M−1 with telomeric G4 dimer, probably due to cooperative stacking of the its two G4 planes. It also showed an IC50 at the nM level by the TRAP assay. The results obtained here are expected to enable the design of peptide ligands with multiple cNDI sites targeting the G4 cluster by using the amino acid units of cNDI.

DOI： 10.1002/slct.202401062

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85190644415&origin=inward

Evaluation of the accuracy of hTERT gene aberrant methylation using electrochemical hybridization assay and liquid-based cytology in screening for oral squamous cell carcinoma 査読有り国際誌

Haraguchi K., Sato S., Habu M., Yada N., Hayakawa M., Sasaguri M., Yoshioka I., Tominaga K., Takenaka S.

Electroanalysis 35 ( 8 ) 2023年08月

記述言語：英語掲載種別：研究論文（学術雑誌）

In order to improve the survival rate of oral squamous cell carcinoma (OSCC) patients, a reliable diagnostic method for early OSCC detection is required that is minimally invasive, less burdensome to the patient, and has high sensitivity and specificity. Therefore, we performed the detection of abnormal methylation at three locations in the hTERT promoter region of oral exfoliated cells by employing the ferrocenylnaphthalene diimide (FND)-based electrochemical hybridization assay (FND-EHA) using three types of DNA probe-immobilized electrodes. We also performed liquid cytology using oral exfoliated cells and compared these obtained data to evaluate whether FND- EHA can be used as an OSCC screening system. The results showed a good correlation between this method and conventional OSCC screening, and cytology. In addition, FND-EHA was also able to determine samples that had been ambiguously determined by liquid cytology. This indicates that FND-EHA may be useful as an OSCC screening system.

DOI： 10.1002/elan.202200564

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85151618064&origin=inward

ウイルス検査としてのPCRの原理と限界招待有り査読有り

佐藤しのぶ

化学と教育 ( 日本化学会 ) 71 ( 1 ) 8 - 11 2023年01月

Fluorescence Imaging of Extracellular Potassium Ion Using Potassium Sensing Oligonucleotide 招待有り査読有り国際誌

Sato S., Ohzawa S., Sota K., Sakamoto N., Udo A., Sueda S., Matsuda T., Nagai T., Takenaka S.

Frontiers in Chemistry 10 2022年07月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Potassium-sensing oligonucleotide, PSO, a conjugate of a quadruplex structure-forming oligonucleotide with a peptide incorporating a Förster Resonance Energy Transfer (FRET) chromophore pair, has been developed for fluorescent detection of potassium ion (K+) in aqueous medium. PSO 1 could be introduced into cells for real-time imaging of cytoplasmic K+ concentrations. To perform fluorescent imaging of K+ on the cell surface, we synthesized twelve PSO derivatives with different types of peptide types and lengths, and oligonucleotide sequences including thrombin-binding aptamer (TBA) sequences with FAM and TAMRA as a FRET chromophore pair, and evaluated their performance. 1 was shown to respond selectively to K+, not to most ions present in vivo, and to show reciprocal fluorescence changes in response to K+ concentration. For the peptide chains and oligonucleotide sequences examined in this study, the PSO derivatives had Kd values for K+ in the range of 5–30 mM. All PSO derivatives showed high K+ selectivity even in the presence of excess Na+. The PSO derivatives were successfully localized to the cell surface by biotinylated concanavalin A (ConA) or sulfo-NHS-biotin via streptavidin (StAv). Fluorescence imaging of extracellular K+ upon addition of apoptosis inducers was successfully achieved by 1 localized to the cell surface.

DOI： 10.3389/fchem.2022.922094

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85134682077&origin=inward

Replication Control of Human Telomere G-Quadruplex DNA by G-Quadruplex Ligands Dependent on Solution Environment 査読有り国際誌

Takahashi S., Bhowmik S., Sato S., Takenaka S., Sugimoto N.

Life 12 ( 4 ) 2022年04月

記述言語：英語掲載種別：研究論文（学術雑誌）

The human telomere region is known to contain guanine-rich repeats and form a guaninequadruplex (G4) structure. As telomeres play a role in the regulation of cancer progression, ligands that specifically bind and stabilize G4 have potential therapeutic applications. However, as the human telomere sequence can form G4 with various topologies due to direct interaction by ligands and indirect interaction by the solution environment, it is of great interest to study the topologydependent control of replication by ligands. In the present study, a DNA replication assay of a template with a human telomere G4 sequence in the presence of various ligands was performed. Cyclic naphthalene diimides (cNDI1 and cNDI2) efficiently increased the replication stall of the template DNA at G4 with an anti-parallel topology. This inhibition was stability-dependent and topology-selective, as the replication of templates with hybrid or parallel G4 structures was not affected by the cNDI and cNDI2. Moreover, the G4 ligand fisetin repressed replication with selectivity for anti-parallel and hybrid G4 structures without stabilization. Finally, the method used, referred to as quantitative study of topology-dependent replication (QSTR), was adopted to evaluate the correlation between the replication kinetics and the stability of G4. Compared to previous results obtained using a modified human telomere sequence, the relationship between the stability of G4 and the effect on the topology-dependent replication varied. Our results suggest that native human telomere G4 is more flexible than the modified sequence for interacting with ligands. These findings indicate that the modification of the human telomeric sequence forces G4 to rigidly form a specific structure of G4, which can restrict the change in topology-dependent replication by some ligands.

DOI： 10.3390/life12040553

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85128462524&origin=inward

Electrochemical Method for G-quartet RNA Detection of COVID-19 Based on Cyclic Ferrocenylnaphthalene Diimide 査読有り国際誌

Kaneyoshi S., Murakami S., Ikeda T., Fujimoto K., Fujii S., Sato S., Takenaka S.

Electroanalysis 35 ( 4 ) 2022年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

To develop an electrochemical detection method for COVID-19, we have investigated the interaction between RG-1, a characteristic parallel four-strand RNA component of the COVID-19 genome, and cyclic ferrocenylnaphthalene diimides carrying different linker lengths 1 and 2, which bind to RG-1 more strongly than cyclic naphthalene diimide 3 that lacks a ferrocene moiety. In particular, the binding affinity of 1 having short one showed the highest binding affinity to RG-1, and the redox current of 1 increased in the presence of RG-1 using a glassy carbon electrode. This increasing current of 1 in the presence of c-myc as a parallel G4 DNA or single-stranded RNA was lower than that in the presence of RG-1. Several RG-1 was electrochemically detected at the nanomolar level by 1.

DOI： 10.1002/elan.202200427

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85142493726&origin=inward

Substituent effects of cyclic naphthalene diimide on G-quadruplex binding and the inhibition of cancer cell growth 査読有り

Fukuda H., Sato S., Zou T., Higashi S., Takahashi O., Habu M., Sasaguri M., Tominaga K., Takenaka S., Takeuchi H.

Bioorganic and Medicinal Chemistry Letters 50 2021年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Interaction of cyclic naphthalene diimide derivatives (cNDIs), 1–4, with TA-core and c-myc as G-quartet (G4) DNA was studied under dilute or molecular crowding condition. Binding study for TA-core based on an isothermal titration calorimetry showed that 1–4 has 106 M−1 order of binding affinity with the following order: 1 > 4 > 2 > 3 under both conditions. Meting temperature (Tm) of TA-core obtained from the temperature dependence of circular dichroism spectra shows that TA-core was most stabilized by 4, which is in agreement with the result of PCR stop assay and the stabilization effect for 1–3 was correlated with their binding affinity under dilute condition. 3 showed specific growth inhibition of cancer cell line Ca9-22 at <0.03 μM of IC50, with no inhibitory effect against normal bone marrow cells. 3, which has highest value of ΔH/ΔG, shows the highest inhibition ability for Ca9-22, carrying a highest expression level of telomerase mRNA.

DOI： 10.1016/j.bmcl.2021.128323

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85113595432&origin=inward

Chemical Modulation of DNA Replication along G-Quadruplex Based on Topology-Dependent Ligand Binding 査読有り

Takahashi S., Kotar A., Tateishi-Karimata H., Bhowmik S., Wang Z.F., Chang T.C., Sato S., Takenaka S., Plavec J., Sugimoto N.

Journal of the American Chemical Society 143 ( 40 ) 16458 - 16469 2021年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Ligands that bind to and stabilize guanine-quadruplex (G4) structures to regulate DNA replication have therapeutic potential for cancer and neurodegenerative diseases. Because there are several G4 topologies, ligands that bind to their specific types may have the ability to preferentially regulate the replication of only certain genes. Here, we demonstrated that binding ligands stalled the replication of template DNA at G4, depending on different topologies. For example, naphthalene diimide derivatives bound to the G-quartet of G4 with an additional interaction between the ligand and the loop region of a hybrid G4 type from human telomeres, which efficiently repressed the replication of the G4. Thus, these inhibitory effects were not only stability-dependent but also topology-selective based on the manner in which G4 structures interacted with G4 ligands. Our original method, referred to as a quantitative study of topology-dependent replication (QSTR), was developed to evaluate correlations between replication rate and G4 stability. QSTR enabled the systematic categorization of ligands based on topology-dependent binding. It also demonstrated accuracy in determining quantitatively how G4 ligands control the intermediate state of replication and the kinetics of G4 unwinding. Hence, the QSTR index would facilitate the design of new drugs capable of controlling the topology-dependent regulation of gene expression.

DOI： 10.1021/jacs.1c05468

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85116545860&origin=inward

An electrochemical protease assay using ferrocenylpeptide for screening of periodontal disease 査読有り国際誌

Sato S., Nagata S., Shimamoto J., Okinaga T., Ariyoshi W., Usui M., Nakashima K., Nishihara T., Takenaka S.

Bunseki Kagaku ( 公益社団法人日本分析化学会 ) 70 ( 3 ) 199 - 206 2021年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Porphyromonas gingivalis, known as an anaerobic gram-negative bacteria, is associated with the progress of a periodontitis. Since gingipain (gp), a specific protease secreted from its bacteria, is its main pathogenicity, gp has been utilized as a marker of the periodontitis. Here, an electrochemical protease assay using a ferrocenylpeptide probes was applied to the detection of gp activity; the probe was cleaved with its protease activity and current peak decreased by the released ferrocene part to balk solution. A series of ferrocenylpeptides as specific substrates of Arg-gp (Rgp) and Lys-gp (Kgp) was synthesized: FRC and FKC having cysteine residue; FRSS and FKSS having lipoic acid; FRpra and FKpra having propargylglycine; FRDE and FRDK having cysteine and D-type amino acid. The electron transfer rate constant of all of ferrocenylpeptide immobilized on a gold electrode were estimated by Lavirons analysis. The obtained electron transfer rate constant were 400-3500 s-1, where fastest one of 3500 s-1 was obtained from FRC immobilized electrode. Peak currents of these electrodes were decreased after the treatment of a sample containing Porphyromonas gingivalis. The detection limits of Porphyromonas gingivalis were 1.0×107, 5.0×106, 3.3×106, 5.0×106, and 5.0×106 cells, for FRPra- FKPra-, FRC-, FRDE-, and FRDK-immobilized electrodes, respectively. FRDE- and FRDK-immobilized electrodes were applied for patients suffering from periodontitis. It was successfully classified between the patients and healthy peoples using the FRDK-immobilized electrode. These results suggest that gp activity is connected with a clinical condition of periodontitis, and it is expected to be applied to a periodontal disease screening.

DOI： 10.2116/bunsekikagaku.70.199

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85105520390&origin=inward

Electrochemical sensory detection of: Sus scrofa mtDNA for food adulteration using hybrid ferrocenylnaphthalene diimide intercalator as a hybridization indicator 査読有り国際誌

Kusnin N., Yusof N.A., Abdullah J., Sabri S., Mohammad F., Mustafa S., Ab Mutalib N.A., Sato S., Takenaka S., Parmin N.A., Al-Lohedan H.A.

RSC Advances 10 ( 46 ) 27336 - 27345 2020年06月

記述言語：英語掲載種別：研究論文（学術雑誌）

© The Royal Society of Chemistry. In this study, an electrochemical DNA biosensor was developed based on the fabrication of silicon nanowires/platinum nanoparticles (SiNWs/PtNPs) on a screen-printed carbon electrode (SPCE) for the detection of Sus scrofa mitochondrial DNA (mtDNA) in food utilizing a new hybrid indicator, ferrocenylnaphthalene diimide (FND). The morphology and elemental composition of the SiNWs/PtNPs-modified SPCE was analyzed by field emission scanning electron microscopy (FESEM) combined with energy dispersive X-ray spectroscopy (EDX). Cyclic voltammetry (CV) was used to study the electrical contact between the PtNPs and the screen-printed working electrode through SiNWs, while electrochemical impedance spectroscopy (EIS) was used to measure the charge transfer resistance of the modified electrode. The results clearly showed that the SiNWs/PtNPs were successfully coated onto the electrode and the effective surface area for the SiNWs/PtNPs-modified SPCE was increased 16.8 times as compared with that of the bare SPCE. Differential pulse voltammetry used for the detection of porcine DNA with FND as an intercalator confirmed its specific binding to the double-stranded DNA (dsDNA) sequences. The developed biosensor showed a selective response towards complementary target DNA and was able to distinguish non-complementary and mismatched DNA oligonucleotides. The SiNWs/PtNPs-modified SPCE that was fortified with DNA hybridization demonstrated good linearity in the range of 3 × 10-9 M to 3 × 10-5 M (R2 = 0.96) with a detection limit of 2.4 × 10-9 M. A cross-reactivity study against various types of meat and processed food showed good reliability for porcine samples.

DOI： 10.1039/d0ra03585h

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85089305701&origin=inward

The interaction of cyclic naphthalene diimide with G-quadruplex under molecular crowding condition 招待有り査読有り国際誌

Zou T., Sato S., Yasukawa R., Takeuchi R., Ozaki S., Fujii S., Takenaka S.

Molecules 25 ( 3 ) 2020年02月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020 by the authors. G-quadruplex specific targeting molecules, also termed as G4 ligands, are attracting increasing attention for their ability to recognize and stabilize G-quadruplex and high potentiality for biological regulation. However, G4 ligands recognizing G-quadruplex were generally investigated within a dilute condition, which might be interfered with under a cellular crowding environment. Here, we designed and synthesized several new cyclic naphthalene diimide (cNDI) derivatives, and investigated their interaction with G-quadruplex under molecular crowding condition (40% v/v polyethylene glycol (PEG)200) to mimic the cellular condition. The results indicated that, under molecular crowding conditions, cNDI derivatives were still able to recognize and stabilize G-quadruplex structures based on circular dichroism measurement. The binding affinities were slightly decreased but still comparatively high upon determination by isothermal titration calorimetry and UV-vis absorbance spectroscopy. More interestingly, cNDI derivatives were observed with preference to induce a telomere sequence to form a hybrid G-quadruplex under cation-deficient molecular crowding conditions.

DOI： 10.3390/molecules25030668

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85079081249&origin=inward

Cyclic Naphthalene Diimide with a Ferrocene Moiety as a Redox-Active Tetraplex-DNA Ligand 査読有り国際誌

Kaneyoshi S., Zou T., Ozaki S., Takeuchi R., Udou A., Nakahara T., Fujimoto K., Fujii S., Sato S., Takenaka S.

Chemistry - A European Journal 26 ( 1 ) 139 - 142 2020年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Cyclic naphthalene diimides (cNDIs), with a ferrocene moiety (cFNDs) and different linker lengths between the ferrocene and cNDI moieties, were designed and synthesized as redox-active, tetraplex-DNA ligands. Intramolecular stacking was observed between ferrocene and the NDI planes, which could affect the binding properties for G-quadruplexes. Interestingly, the circular dichroism spectrum of one of these compounds clearly shows new Cotton effects around 320–380 and 240 nm, which can be considered a direct evidence of intramolecular stacking of ferrocene and the NDI. Regarding recognition of hybrid G-quadruplexes, the less rigid structures (longer linkers) show higher binding affinity (106 m−1 order of magnitude). All new compounds show higher selectivity for G4 during electrochemical detection than noncyclic FND derivatives, which further identifies the redox-active potentiality of the cFNDs. Two of the three compounds tested even show preferential inhibition of cell growth in cancer cells over normal cells in a low concentration range, highlighting the potential for bioapplications of these cFNDs.

DOI： 10.1002/chem.201903883

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85076108396&origin=inward

Naphthalene diimide carrying four ferrocenyl substitutes as an electrochemical indicator of tetraplex DNA aiming at cancer diagnosis 査読有り国際誌

Sato S., Kajima A., Hamanaka H., Takenaka S.

Journal of Organometallic Chemistry 897 107 - 113 2019年10月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 Elsevier B.V. Naphthalene diimide carrying four ferrocenyl substituents, tFND1 and tFND2, were newly synthesized to expect the improved binding affinity for tetraplex DNA and specific electrochemical signal generation. tFND2 shows the 1:2 binding to tetraplex A-core DNA, which has a part of human telomere sequence based on circular dichroism spectra, and the current increase of tFND2 on the tetraplex DNA-immobilized electrode was 13.5-times higher than that on the single stranded DNA-immobilized electrode. When applied to an electrochemical telomerase assay (ECTA) for HeLa cell, tFND2 shows the quantitative change around 0.1–50 cells/μL and the detection limit of 0.1 cells/μL for HeLa cell.

DOI： 10.1016/j.jorganchem.2019.06.028

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85068254217&origin=inward

Cyclic Naphthalene Diimide Dimer with a Strengthened Ability to Stabilize Dimeric G-Quadruplex 査読有り国際誌

Takeuchi R., Zou T., Wakahara D., Nakano Y., Sato S., Takenaka S.

Chemistry - A European Journal 25 ( 37 ) 8691 - 8695 2019年07月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim A new type of dimeric cyclic naphthalene diimide derivatives (cNDI-dimers) carrying varied linker length were designed and synthesized to recognize dimeric G-quadruplex structures. All of the cNDI-dimers exhibited a high preference for recognizing G-quadruplex structures, and significantly enhanced the thermal stability of the dimeric G-quadruplex structure over the cNDI monomer by increasing the melting temperature by more than 23 °C, which indicated the strengthened ability of cNDI dimers for stabilizing dimeric G-quadruplex. cNDI dimers also showed a stronger ability to inhibit telomerase activity and stop telomere DNA elongation than cNDI monomer, which showed an improved anticancer potentiality for further therapeutic application.

DOI： 10.1002/chem.201901468

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85069767525&origin=inward

Electrochemical Aberrant Methylation Detection Based on Ferrocenyl Naphthalene Diimide Carrying β-cyclodextrin, FNC 招待有り査読有り国際誌

Sato S., Nishi Y., Takenaka S.

Electroanalysis 31 ( 10 ) 1988 - 1993 2019年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Electrochemical detection of the specific gene carrying aberrant methylated cytosine was achieved by ferrocenyl naphthalene diimide carrying β-cyclodextrin (β-CD), FNC, coupled with the probe-DNA-immobilized electrode. The five CpG sites in a 24-base sequence were selected as the target DNA on the CDH4 gene, which is associated with colorectal cancer. When methylated and unmethylated samples hybridized with the DNA probe (HS-M24) immobilized on the electrode, an increased current signal was observed in the electrolyte containing FNC and correlated with the amount of target DNA. Furthermore, an increase in current (115 %) was observed when the PCR product of 105 bp was hybridized on the HS-M24-immobilized electrode, whereas a background level of current increase was observed in the case of unmethylated product. Such large discrimination ability might be due to the inter- and/or intra-complex formation of ferrocene with β-CD of FNC on the surface of the electrode.

DOI： 10.1002/elan.201900282

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85068916620&origin=inward

がん診断電気チップの開発

佐藤しのぶ, 竹中繁織

Bio Clinica ( 北隆館 ) 2019年01月

新規フェロセン化ナフタレンジイミドを用いる均一溶液中でのシグナルオン型電気化学的DNase I検出査読有り

佐藤しのぶ, 福瀧修司, 竹中繁織

分析化学 ( 公益社団法人日本分析化学会 ) 68 ( 12 ) 953 - 960 2019年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

<p>A simple DNase I detecting method was achieved under a homogenous medium containing DNA duplex and a newly synthesized ferrocenylnaphthalene diimide derivative (FND) carrying alanine (<b>1</b>) or alanine-lysine residue (<b>2</b>) as an electrochemical indicator. The binding affinity of <b>1</b> or <b>2</b> with double stranded DNA was 10<sup>5</sup> M<sup>−1</sup> or 10<sup>6</sup> M<sup>−1</sup> order, which was estimated from a Scatchard analysis calculated by its absorption change upon the addition of calf thymus DNA (CT-DNA). It was expected that <b>1</b> or <b>2</b> intercalated to double stranded DNA with a threading mode and electrostatic interaction of the linker ammonium cations of <b>1</b> or <b>2</b> with phosphate anions of the DNA duplex backbone. The largest current increase after a DNase I treatment was observed under the mixture in a ratio of [<b>3</b>]:[CT-DNA-bp] = 10 : 1 (bp: DNA concentration per base pair), where the distance between the bound ligands is expected to a 10 bp or 34 Å theoretically. When considering to be ca. 30 Å of DNase I size and decreasing of the current increase under an increased amount of <b>3</b>, DNase I required over ten base pairs to access and digest with the DNA duplex. The current increase in the case of a mixture of 10 μM <b>1</b> or <b>2</b> and 100 μM CT-DNA was obtained 340 % or 640 %, respectively, after being treated with DNase I (final concentration: 2.0 × 10<sup>−3</sup> U μL<sup>−1</sup>), which might be derived from an apperarent molecular weight or diffusion coefficient of the ligand bound DNA duplex and the detection limit of DNase I in the case of <b>1</b> or <b>2</b> was 2.0 × 10<sup>−5</sup> or 2.0 × 10<sup>−9</sup> U μL<sup>−1</sup>, respectively, where the detection limit for <b>2</b> was 10<sup>4</sup>-times higher than that for <b>1</b>.</p>

DOI： 10.2116/bunsekikagaku.68.953

その他リンク： https://ci.nii.ac.jp/naid/130007783471

口腔がん早期発見のための剝離細胞診を応用した自己検診システムの開発:—適切な細胞採取法の検討— 査読有り

早川真奈, 土生学, 原口和也, 矢田直美, 佐藤しのぶ, 竹中繁織, 冨永和宏

日本口腔診断学会雑誌 ( 日本口腔診断学会 ) 32 ( 3 ) 191 - 196 2019年01月

記述言語：日本語掲載種別：研究論文（学術雑誌）

Previous studies conducted by our group confirmed that the electrochemical telomerase assay （ECTA） is sufficiently sensitive to detect oral cancer from the cells obtained by exfoliation from the whole oral cavity. In this study to develop a self-screening system for oral cancer using this method, we examined the optimal method for self-collection of exfoliated cells from the whole oral cavity.<br>First, an interdental brush, a conventional silicone brush for the cervix, a newly developed silicone brush for the oral cavity, a sponge brush used in our previous studies, and a gargle were tested for exfoliation from the oral cavity in ten healthy volunteers. Cells exfoliated from the oral cavity were collected by a single examiner, to prevent inter-examiner variation.<br>Then, exfoliated cells were collected from the same ten healthy volunteers by the same manner and stained using papanicolaou.<br>Finally, to mimic self-examination for oral cancer, another ten healthy volunteers were instructed on how to perform a specially-made protocol for collecting exfoliated cells from their oral cavity with a sponge brush, which had been evaluated in the initial study as the most efficient method. All subjects collected a sufficient number of cells comparable to conventional methods of exfoliative cytology.<br>In conclusion, the self-screening system for detecting oral cancer using ECTA with the cell collection protocol described herein could be promising.

DOI： 10.15214/jsodom.32.191

その他リンク： https://ci.nii.ac.jp/naid/130007742331

超分子相互作用を利用したDNAバンドリング

佐藤しのぶ, 開健亮, 竹中繁織

ナノ学会会報 ( ナノ学会 ) 2018年11月

がん診断電気チップの開発

佐藤しのぶ, 竹中繁織

Medical Science Digest ( ニュー・サイエンス社 ) 2018年10月

Membrane-based microwave-mediated electrochemical immunoassay for the in vitro, highly sensitive detection of osteoporosis-related biomarkers 査読有り国際誌

Kim H., Sato S., Takenaka S., Lee M.

Sensors (Switzerland) 18 ( 9 ) 2018年09月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. Highly sensitive and multiplexed in vitro detection of osteoporosis-related biochemical markers were carried out based on the membrane-based microwave-mediated electrochemical immunoassay (MMeEIA), where we can dramatically reduce the sample preparation time by shortening the incubation time of conjugation to obtain sensitive detection based on three dimensional conjugation of antibodies with target antigens in nylon membrane disk. C-terminal cross-linked telopeptide of type I collagen (CTx), Osteocalcin (OC), parathyroid hormone (PTH), and N-terminal propeptide of type I collagen (P1NP), which can be utilized to monitor the progress of osteoporosis, were quantified using their corresponding antibody immobilized in membranes. Coefficient of variations in this intra-and inter-assays were within 8.0% for all markers. When compared with data obtained from clinically used standard equipment (Roche modular E170), their coefficients of determination, R2 values, are mostly more than 0.9. They show that the results obtained from MMeEIA are in good agreement with that from the conventional clinical instruments.

DOI： 10.3390/s18092933

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85053077302&origin=inward

Synthesis of peptide-human telomere DNA conjugate as fluorometric imaging reagent for biological sodium ion 招待有り査読有り

SATO Shinobu, IMAICHI Yuuki, YOSHIURA Yukiko, NAKAZAWA Koji, TAKENAKA Shigeori

Analytical Sciences 2018年01月

Cyclic perylene diimide: Selective ligand for tetraplex DNA binding over double stranded DNA 査読有り国際誌

Vasimalla S., Sato S., Takenaka F., Kurose Y., Takenaka S.

Bioorganic and Medicinal Chemistry 25 ( 24 ) 6404 - 6411 2017年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2017 Elsevier Ltd Synthesized cyclic perylene diimide, cPDI, showed the binding constant of 6.3 × 10 6 M −1 with binding number of n = 2 with TA-core as a tetraplex DNA in 50 mM Tris-HCl buffer (pH = 7.4) containing 100 mM KCl using Schatchard analysis and showed a higher preference for tetraplex DNA than for double stranded DNA with over 10 3 times. CD spectra showed that TA-core induced its antiparallel conformation upon addition of cPDI in the absence or presence of K + or Na + ions. The cPDI inhibits the telomerase activity with IC 50 of 0.3 µM using TRAP assay which is potential anti-cancer drug with low side effect.

DOI： 10.1016/j.bmc.2017.10.014

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85032346666&origin=inward

The methylation status and expression of human telomerase reverse transcriptase is significantly high in oral carcinogenesis 査読有り国際誌

Haraguchi K., Yada N., Sato S., Habu M., Hayakawa M., Takahashi O., Sasaguri M., Takenaka S., Yoshioka I., Matsuo K., Tominaga K.

APMIS 125 ( 9 ) 797 - 807 2017年09月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2017 APMIS. Published by John Wiley & Sons Ltd Telomerase activity is present in most cancers and is tightly regulated by the expression of human telomerase reverse transcriptase (hTERT). Hypermethylation in the promoter region of hTERT contributes to the regulation of hTERT expression. In this study, we investigated the methylation and expression of hTERT in oral squamous cell carcinoma (OSCC), oral leukoplakia, and normal oral mucosa. Furthermore, we investigated the significance of hTERT to the clinicopathological findings of OSCC. 35 OSCC, 50 oral leukoplakia (epithelial dysplasia n = 25, squamous cell hyperplasia n = 25), and 10 normal oral mucosa samples were investigated through methylation-specific PCR. Immunohistochemistry was analyzed in 35 OSCC, 50 oral leukoplakia, and 4 normal oral mucosa samples. The methylation and expression of hTERT increased from normal oral mucosa to oral leukoplakia to OSCC. In OSCC, all samples were methylated. However, partial methylation (20%) or unmethylation (80%), but never complete methylation, was observed in normal oral mucosa. Additionally, hTERT expression correlated with cervical lymph node metastasis. These results suggested that the methylation and expression of hTERT is high in oral carcinogenesis and may play an important role in oral cancer. hTERT expression may also be predictive of cervical lymph node metastasis.

DOI： 10.1111/apm.12723

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85026680211&origin=inward

Oral Cancer Screening Based on Methylation Frequency Detection in hTERT Gene Using Electrochemical Hybridization Assay via a Multi-electrode Chip Coupled with Ferrocenylnaphthalene Diimide 査読有り国際誌

Haraguchi K., Sato S., Habu M., Yada N., Hayakawa M., Takahashi O., Yoshioka I., Matsuo K., Tominaga K., Takenaka S.

Electroanalysis 29 ( 6 ) 1596 - 1601 2017年03月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, WeinheimFerrocenylnaphthalene diimide-based electrochemical hybridization assay via a multi-electrode chip was applied to detect the methylation frequency in the promoter region of human telomerase reverse transcriptase (hTERT) gene for clinical samples from tissues, local exfoliated oral cells from a lesion, or from entire oral cavity after their methylation specific PCRs. These methylation frequencies were increased with cancer progress as the following order: healthy volunteers, oral leukoplakia as precancerous lesion, and oral squamous cell carcinoma (OSCC). Operating characteristic analysis of the obtained current data doesn't only give excellent discrimination ability of OSCC, but also of oral leukoplakia from healthy volunteers for all samples. Sensitivity and specificity was 95 % and 90 %, respectively, which is a comparable with methods in practical use.

DOI： 10.1002/elan.201700028

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85016606923&origin=inward

Ferrocenyl naphthalene diimides as tetraplex DNA binders 査読有り国際誌

Sato S., Takenaka S.

Journal of Inorganic Biochemistry 167 21 - 26 2017年02月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016Seven ferrocenyl naphthalene diimide (FND) ligands were synthesized. Each had a higher affinity for tetraplex DNA than for either single- or double-stranded DNA. The FND binding affinities were > 105 M− 1 in 0.10 M AcOH-AcONa or AcOH-AcOK (pH 5.5) containing 0.10 M NaCl or KCl. The FNDs with the highest binding affinities for tetraplex DNA showed 23- or 8-times higher preference for tetraplex DNA than for single- or double-stranded DNA, respectively. The current signals generated from the seven FNDs bound to the tetraplex DNA immobilized on the electrode were found to correlate with the binding affinities of these ligands for the tetraplex DNA. Furthermore, using the telomerase repeat amplification protocol assay, the FND ligands could be categorized into three groups: (a) inhibiting both telomerase and Taq polymerase, (b) inhibiting telomerase alone, and (c) inhibiting neither telomerase nor Taq polymerase.

DOI： 10.1016/j.jinorgbio.2016.11.020

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84999007166&origin=inward

Cyclic ferrocenylnaphthalene diimide derivative as a new class of G-quadruplex DNA binding ligand 査読有り国際誌

Islam M., Sato S., Sato S., Shinozaki S., Takenaka S., Takenaka S.

Bioorganic and Medicinal Chemistry Letters 27 ( 2 ) 329 - 335 2017年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016 Elsevier LtdTo identify an effective ligand that binds to a G-quadruplex structure but not a double-stranded DNA (dsDNA), a set of biophysical and biochemical experiments were carried out using newly synthesized cyclic ferrocenylnaphthalene diimide (cFNDI, 1) or the non-cyclic derivative (2) with various structures of G-quadruplex DNAs and dsDNA. Compound 1 bound strongly to G-quadruplexes DNAs (106 M−1 order) with diminished binding to dsDNA (104 M−1 order) in 100 mM AcOH-AcOK buffer (pH 5.5) containing 100 mM KCl. Interestingly, 1 showed an approximately 50-fold higher selectivity to mixed hybrid-type telomeric G-quadruplex DNA (K = 3.4 × 106 M−1 and a 2:1 stoichiometry) than dsDNA (K = 7.5 × 104 M−1) did. Furthermore, 1 showed higher thermal stability to G-quadruplex DNAs than it did to dsDNA with a preference for c-kit and c-myc G-quadruplex DNAs over telomeric and thrombin binding aptamers. Additionally, 1 exhibited telomerase inhibitory activity with a half-maximal inhibitory concentration (IC50) of 0.4 μM. Compound 2 showed a preference for G-quadruplex; however, the binding affinity magnitude and preference were improved in 1 because the former had a cyclic structure.

DOI： 10.1016/j.bmcl.2016.11.037

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85006944078&origin=inward

Electrochemical hybridization assay for methylation detection of the hTERT gene connected with oral cancer screening 査読有り

Sato S., Haraguchi K., Hayakawa M., Tominaga K., Takenaka S.

Bunseki Kagaku ( 公益社団法人日本分析化学会 ) 66 ( 6 ) 437 - 443 2017年01月

担当区分：筆頭著者記述言語：日本語掲載種別：研究論文（学術雑誌）

© 2017 The Japan Society for Analytical Chemistry. The human telomerase reverse transcriptase (hTERT) gene is encoded as a catalytic unit of telomerase. Since the methylation pattern of the CpG islands in the promoter region of hTERT gene is related with cancer development, this should serve as a suitable cancer marker. Electrochemical hybridization assay was applied to this detection using ferrocenylnaphthalene diimide (FND) as a hybrid indicator. Ten different 24-meric DNA probes were designed and immobilized on the individual electrodes of multi-electrode chip, which can hybridize with sample DNAs carrying different methylation patterns: M0, M1, M1', M2, M2', M3, M3', M4, M4', or M5, where number refers to the number of methylated cytosine of CpG islands in the promoter region of hTERT gene. Aiming for simple diagnosis of oral cancer, the total exfoliated oral cells as clinical samples were obtained from oral cancer patients (oral squamous cell carcinoma, OSCC), oral leukoplakia as precancerous lesion, and healthy volunteers. The clinical samples were amplified by a methylation-specific polymerase chain reaction (MSP) with bisulfite treated genome DNA from the total exfoliated oral cells and hybridized with 10-probe DNA immobilized multi-electrode chip. The current increase ratio of M4, M4', M5 probe for detecting methylation was increased with cancer progress according to the following order: healthy volunteers, oral leukoplakia, and OSCC. Receiver operatorating characteristic curve of the obtained data gave the threshold values in the case of the detection of OSCC from all samples to obtain 91 % of the accuracy rate for total exfoliated oral cells using 96.6 % of the threshold values.

DOI： 10.2116/bunsekikagaku.66.437

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85023753097&origin=inward

Water-soluble porphyrinoids as G-quadruplex binders and telomerase inhibitors 査読有り国際誌

Ikawa Y., Katsumata S., Sakashita R., Sato S., Takenaka S., Furuta H., Furuta H.

Journal of Porphyrins and Phthalocyanines 20 ( 8-11 ) 1041 - 1048 2016年08月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016 World Scientific Publishing Company.Water-soluble derivatives of three kinds of expanded porphyrins (N-fused pentaphyrin, hexaphyrin, and heptaphyrin) were synthesized and their binding ability to G-quadruplex (G4-) DNA and the inhibitory effects on enzymatic telomere extension were investigated. While expanded porphyrins increased the melting temperature of G4-DNA more effectively than the regular porphyrins, a porphyrin isomer (N-confused porphyrin) showed the highest inhibitory effect on telomerase activity.

DOI： 10.1142/S108842461650053X

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84980318049&origin=inward

DNA methylation detection based on difference of base content 招待有り査読有り

Sato S., Sato S., Ohtsuka K., Ohtsuka K., Honda S., Sato Y., Takenaka S., Takenaka S.

Journal of Physics: Conference Series 704 ( 1 ) 2016年04月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Methylation frequently occurs in cytosines of CpG sites to regulate gene expression. The identification of aberrant methylation of certain genes is important for cancer marker analysis. The aim of this study was to determine the methylation frequency in DNA samples of unknown length and/or concentration. Unmethylated cytosine is known to be converted to thymine following bisulfite treatment and subsequent PCR. For this reason, the AT content in DNA increases with an increasing number of methylation sites. In this study, the fluorescein-carrying bis-acridinyl peptide (FKA) molecule was used for the detection of methylation frequency. FKA contains fluorescein and two acridine moieties, which together allow for the determination of the AT content of double-stranded DNA fragments. Methylated and unmethylated human genomes were subjected to bisulfide treatment and subsequent PCR using primers specific for the CFTR, CDH4, DBC1, and NPY genes. The AT content in the resulting PCR products was estimated by FKA, and AT content estimations were found to be in good agreement with those determined by DNA sequencing. This newly developed method may be useful for determining methylation frequencies of many PCR products by measuring the fluorescence in samples excited at two different wavelengths.

DOI： 10.1088/1742-6596/704/1/012015

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84964886512&origin=inward

Electrochemical approaches to the study of DNA/drug interactions 招待有り査読有り

Sato S., Takenaka S.

Methods for Studying Nucleic Acid/Drug Interactions 241 - 259 2016年04月

電気化学的手法によるDNA/薬剤相互作用解析

佐藤しのぶ、竹中繁織

DOJIN News ( DOJINDO ) 156 1 - 4 2016年03月

電気化学的口腔癌診断法の開発：フェロセン化ナフタレンジイミド誘導体を利用した電気化学的テロメラーゼ検出

佐藤しのぶ、竹中繁織

化学とマイクロ・ナノシステム学会誌 ( 一般社団法人　化学とマイクロ・ナノシステム学会 ) 15 ( 1 ) 7 - 12 2016年03月

Diagnosis of Periodontal Disease from Saliva Samples Using Fourier Transform Infrared Microscopy Coupled with Partial Least Squares Discriminant Analysis 査読有り国際誌

Satoshi FUJII, Shinobu SATO, Keisuke FUKUDA, Toshinori OKINAGA, Wataru ARIYOSHI, Michihiko USUI, Keisuke NAKASHIMA, Tatsuji NISHIHARA, and Shigeori TAKENAKA

Analytical Sciences 32 ( 2 ) 225 - 231 2016年02月

記述言語：英語掲載種別：研究論文（学術雑誌）

Diagnosis of periodontal disease by Fourier transform infrared (FT-IR) microscopic technique was achieved for saliva samples. Twenty-two saliva samples, collected from 10 patients with periodontal disease and 12 normal volunteers, were pre-processed and analyzed by FT-IR microscopy. We found that the periodontal samples showed a larger raw IR spectrum than the control samples. In addition, the shape of the second derivative spectrum was clearly different between the periodontal and control samples. Furthermore, the amount of saliva content and the mixture ratio were different between the two samples. Partial least squares discriminant analysis was used for the discrimination of periodontal samples based on the second derivative spectrum. The leave-one-out cross-validation discrimination accuracy was 94.3%. Thus, these results show that periodontal disease may be diagnosed by analyzing saliva samples with FT-IR microscopy.

DOI： 10.2116/analsci.32.225

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84959323786&origin=inward

Specific metallization of double-stranded DNA using reducing group-labeled intercalator 査読有り国際誌

Himuro T., Araki R., Sato S., Takenaka S., Yasuda T.

IEEJ Transactions on Sensors and Micromachines ( 一般社団法人電気学会 ) 136 ( 10 ) 425 - 431 2016年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016 The Institute of Electrical Engineers of Japan.We demonstrated that the DNA metallization technique using reducing group-labeled intercalator molecules permits dsDNA (double-stranded DNA) molecules to be specifically metallized while not permitting metallization of ssDNA (single-stranded DNA) molecules. First, dsDNA and ssDNA molecules were stretched on a mica surface using spin-coating technique, and metallization process was conducted. AFM observation showed that only dsDNA molecules were metallized, resulting in formation of nanowires with a diameter of about 11 nm. Secondly, dsDNA and ssDNA molecules were stretched and immobilized between two microelectrodes. Impedance analysis showed that the electrical conductivity of only dsDNA was drastically increased after the metallization process.

DOI： 10.1541/ieejsmas.136.425

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84990849846&origin=inward

2G17 部分的金属被覆DNAを用いたDNA分解酵素センサの開発査読有り

村上太理, 氷室貴大, 櫻田一歩, 佐藤しのぶ, 竹中繁織, 安田隆

バイオエンジニアリング講演会講演論文集 ( 一般社団法人日本機械学会 ) 2016.28 ( 0 ) _2G17-1_ - _2G17-3_ 2016年01月

記述言語：日本語掲載種別：研究論文（学術雑誌）

We developed a microdevice for detection of Deoxyribonuclease (DNase), which is a candidate biomarker for acute myocardial infarction. DNA metallization process using intercalator molecules labeled with reducing groups permits double-stranded DNA to be specifically metallized while not permitting metallization of single-stranded DNA. Using this process, we metallized DNA complexes consisting of single strands and double strands, and fabricated partially-metallized DNA nanowires. In this paper, multiple partially-metallized DNA nanowires were immobilized between two electrodes in a microchannel, and DNase detection was achieved by measuring the increase in impedance between the electrodes after DNA cleavage by DNase. The use of partially-metallized DNA nanowires having much smaller impedance compared to non-metallized DNA generates a drastic increase of impedance after their cleavage and therefore permits much higher sensitivity. The experimental results showed a definite correlation between DNase concentration and impedance increase rate in range of 10^<-6> to 10^<-1> unit/μl of DNase. The present study will make DNase detection more simple, rapid, sensitive than conventional fluorometric and electrochemical detections.

DOI： 10.1299/jsmebio.2016.28._2g17-1_

その他リンク： https://www.jstage.jst.go.jp/article/jsmebio/2016.28/0/2016.28__2G17-1_/_pdf

A Selective G-Quadruplex DNA-Stabilizing Ligand Based on a Cyclic Naphthalene Diimide Derivative 査読有り国際誌

Md. Monirul Islam, Satoshi Fujii, Shinobu Sato, Tatsuo Okauchi & Shigeori Takenaka

Molecules 20 ( 6 ) 10963 - 10979 2015年06月

記述言語：英語掲載種別：研究論文（学術雑誌）

A cyclic naphthalene diimide (cyclic NDI, 1), carrying a benzene moiety as linker chain, was synthesized and its interaction with G-quadruplex DNAs of a-core and a-coreTT as a human telomeric DNA, c-kit and c-myc as DNA sequence at promoter region, or thrombin-binding aptamer (TBA) studied based on UV-VIS and circular dichroism (CD) spectroscopic techniques, thermal melting temperature measurement, and FRET-melting assay. The circular dichroism spectra showed that 1 induced the formation of different types of G-quadruplex DNA structure. Compound 1 bound to these G-quadruplexes with affinities in the range of 10<sup>6</sup> -10<sup>7</sup> M<sup>-1</sup> order and a 2:1 stoichiometry. Compound 1 showed 270-fold higher selectivity for a-core than dsDNA with a preferable a-core binding than a-coreTT, c-kit, c-myc and TBA in the presence of K<sup>+</sup> , which is supported by thermal melting studies. The FRET-melting assay also showed that 1 bound preferentially to human telomeric DNA. Compound 1 showed potent inhibition against telomerase activity with an IC<inf>50</inf> value of 0.9 μM and preferable binding to G-quadruplexes DNA than our previously published cyclic NDI derivative 3 carrying a benzene moiety as longer linker chain.

DOI： 10.3390/molecules200610963

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84938241127&origin=inward

Erratum: Cooperative binding of ferrocenylnaphthalene diimide carrying β-cyclodextrin converts double-stranded DNA to a rod-like structure (Bioconjugate Chemistry (2015) 26:3 (379-382) DOI: 10.1021/bc500535n) 査読有り

Sato S., Umeda Y., Fujii S., Takenaka S.

Bioconjugate Chemistry 26 ( 4 ) 2015年04月

Cooperative Binding of Ferrocenylnaphthalene Diimide Carrying β-Cyclodextrin Converts Double-Stranded DNA to a Rod-Like Structure 査読有り国際誌

Shinobu Sato, Yuta Umeda, Satoshi Fujii, Shigeori Takenaka

Bioconjugate Chem. 26 ( 3 ) 379 - 382 2015年03月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Ferrocenylnaphthalene diimide carrying β-cyclodextrin (β-CD), 1, intercalated into double-stranded DNA with a binding affinity of K = (6.6 ± 0.8) × 104 M-1 and a binding site size of n = 4, with a high positive cooperative parameter of ω = 14. β-CD and ferrocene moieties of the compound contributed to the formation of the intermolecular inclusion complex on DNA. Binding of 1 resulted in conversion of the DNA duplex to a rod-like form, which was cleaved upon adamantylamine addition. (Figure Presented).

DOI： 10.1021/bc500535n

その他リンク： http://pubs.acs.org/journal/bcches

Detection of deoxyribonuclease using site-specifically metallized DNA 査読有り

Himuro T., Murakami T., Sato S., Takenaka S., Yasuda T.

MicroTAS 2015 - 19th International Conference on Miniaturized Systems for Chemistry and Life Sciences 1652 - 1654 2015年01月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

© 15CBMS-0001.We newly formed partially-metallized DNA nanowires, and used them for detection of deoxyribonuclease (DNase), enzyme for nonspecific DNA cleavage, which is a candidate biomarker for acute myocardial infarction. In this paper, we developed an original technique for site-specific metallization of DNA complexes consisting of single and double strands. Then, multiple DNA nanowires were immobilized between two electrodes in a microchannel, and DNase detection was achieved by measuring the increase in impedance between the electrodes after DNA cleavage by DNase. When DNase solutions of various concentrations were introduced, we succeeded in obtaining a definite correlation between DNase concentration and impedance increase rate in the range of 10-6 to 10-1 unit/μl.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84983325945&origin=inward

Ferrocenylnaphthalene Diimide-Based Electrochemical Detection of Aberrant Methylation in hTERT Gene 査読有り

Shinobu Sato, Toshiro Saeki, Tomoki Tanaka, Yusuke Kanezaki, Mana Hayakawa, Kazuya Haraguchi, Masaaki Kodama, Tatsuji Nishihara, Kazuhiro Tominaga, Shigeori Takenaka

Applied Biochemistry and Biotechnology 174 869 - 879 2014年07月

Metallization of double-stranded DNA triggered by bound galactose-modified naphthalene diimide 査読有り国際誌

Kohei Komizo , Hideyuki Ikedo , Shinobu Sato, Shigeori Takenaka

Bioconjugate Chemistry 25 ( 8 ) 1547 - 1555 2014年07月

記述言語：英語掲載種別：研究論文（学術雑誌）

Naphthalene diimide (NDI) derivatives bearing galactose moieties through different spacers, NDI-DS1 and NDI-DS2, were synthesized by the click reaction of the acetylene derivatives of NDI with galactose azide. They bound to double-stranded DNA with threading intercalation, as confirmed by the topoisomerase I assay and circular dichroism spectroscopy. The binding affinities of these ligands were on the order of 105 M-1 with several-fold higher affinity for double-stranded DNA than for single-stranded DNA. The silver mirror reaction on the double-stranded DNA bound to these ligands afforded silver nanowires that were converted to gold nanowires. In the atomic force microscopy measurements, the increased height of DNA areas on a mica plate was observed in the case of double-stranded DNA after NDI-DS2 treatment and subsequently silver mirror reaction, whereas the increased height of DNA areas was not observed in the case of single-stranded DNA after the same treatment. © 2014 American Chemical Society.

DOI： 10.1021/bc500263b

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84906335840&origin=inward

Highly sensitive nuclease assay based on chemically-modified DNA or RNA 査読有り国際誌

Shinobu Sato, Shigeori Takenaka

Sensors 14 ( 7 ) 12437 - 12450 2014年07月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Nucleolytic enzymes are associated with various diseases, and several methods have been developed for their detection. DNase expression is modulated in such diseases as acute myocardial infarction, transient myocardial ischemia, oral cancer, stomach cancer, and malignant lymphoma, and DNase I is used in cystic fibroma therapy. RNase is used to treat mesothelial cancer because of its antiproliferative, cytotoxic, and antineoplastic activities. Angiogenin, an angiogenic factor, is a member of the RNase A family. Angiogenin inhibitors are being developed as anticancer drugs. In this review, we describe fluorometric and electrochemical techniques for detecting DNase and RNase in disease. Oligonucleotides having fluorescence resonance energy transfer (FRET)-causing chromophores are non-fluorescent by themselves, yet become fluorescent upon cleavage by DNase or RNase. These oligonucleotides serve as a powerful tool to detect activities of these enzymes and provide a basis for drug discovery. In electrochemical techniques, ferrocenyl oligonucleotides with or without a ribonucleoside unit are used for the detection of RNase or DNase. This technique has been used to monitor blood or serum samples in several diseases associated with DNase and RNase and is unaffected by interferents in these sample types. © 2013 by the authors; licensee MDPI, Basel, Switzerland.

DOI： 10.3390/s140712437

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84904158086&origin=inward

Design of tetraplex specific ligands: cyclic naphthalene diimide 査読有り国際誌

Yugo Esaki, Md. Monirul Islam, Satoshi Fujii, Shinobu Sato, Shigeori Takenaka

Chemical Communications 50 ( 45 ) 5967 - 5969 2014年04月

記述言語：英語掲載種別：研究論文（学術雑誌）

Cyclic naphthalene diimide 1 bound to hybrid-type tetraplex DNA from 5’-AGGG(TTAGGG)3-3’ (K = 8.6 × 106 M−1) with 260-fold greater affinity than binding to a double stranded oligonucleotide consisting of 5’-GGG AGG TTT CGC-3’ and 3’-CCC TCC AAA GCG-5’ (nK = 3.3 × 104 M−1) with 0.5 μM of IC50 for telomerase activity. © 2014 The Partner Organisations.

DOI： 10.1039/c4cc01005a

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84899993177&origin=inward

Interactions of cyclic and non-cyclic naphthalene diimide derivativeswith different nucleic acids 査読有り国際誌

Izabella Czerwinska, Shinobu Sato, Bernard Juskowiak, Shigeori Takenaka

Bioorganic & Medicinal Chemistry 22 ( 9 ) 2593 - 2601 2014年03月

記述言語：英語掲載種別：研究論文（学術雑誌）

Recently, strategy based on stabilization of G-quadruplex telomeric DNA by small organic molecule has been realized by naphthalene diimide derivatives (NDIs). At the same time NDIs bind to DNA duplex as threading intercalators. Here we present cyclic derivative of naphthalene diimide (ligand 1) as DNA-binding ligand with ability to recognition of different structures of telomeric G-quadruplexes and ability to bis-intercalate to double-stranded helixes. The results have been compared to non-cyclic derivative (ligand 2) and revealed that preferential binding of ligands to nucleic acids strongly depends on their topology and structural features of ligands. © 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.bmc.2014.03.034

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84899419213&origin=inward

ヒトテロメアDNAを用いたナトリウムイオン蛍光イメージング試薬（SSO）の開発

今市悠貴, 古賀晴香, 中澤浩二, 佐藤しのぶ, 竹中繁織

ナノ学会会報 ( ナノ学会 ) 12 73 - 77 2014年02月

ヒトテロメアDNAを用いたナトリウムイオン蛍光イメージング試薬（SSO）の開発" 今市悠貴, 古賀晴香, 中澤浩二, 佐藤しのぶ, 竹中繁織招待有り査読有り

今市悠貴, 古賀晴香, 中澤浩二, 佐藤しのぶ, 竹中繁織

ナノ学会会報 12 ( 2 ) 73 - 77 2014年02月

Electrochemical telomerase assay for oral cancer screening 査読有り国際誌

Tominaga K., Hayakawa M., Sato S., Kodama M., Habu M., Takenaka S.

World Automation Congress Proceedings 38 - 42 2014年01月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

© 2014 TSI Press.Telomerase has long been known as a cancer marker. As an easy-to-perform oral cancer screening system, we established a new electrochemical telomerase assay (ECTA) method that is superior to a telomerase repeat amplification protocol assay, a popular method for detection of telomerase activity. In the present study, we employed 3 types of clinical samples to examine the sensitivity and specificity of ECTA. Three types of samples were obtained from 44 oral squamous cell carcinoma patients and 16 healthy volunteers; exfoliated cells from the whole oral cavity, exfoliated cells from local lesions, and tissue samples from lesions. Telomerase activity was determined in the samples using ECTA. The increase in current in the oral cancer group was significantly higher than that in the healthy volunteer group for each sample type, while there were no significant differences among the 3 sample types in the oral cancer group. The sensitivity and specificity of ECTA was 94.6% and 88.6%, respectively. Our novel ECTA method showed excellent detection of telomerase activity and is consider applicable as an oral cancer screening system.

DOI： 10.1109/WAC.2014.6935647

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84908890493&origin=inward

1C14 2本鎖DNAの特異的な金属被覆によるナノワイヤの形成とその電気的特性の評価(OS14-1:バイオMEMS(1))

荒木遼, 氷室貴大, 池堂英幸, 佐藤しのぶ, 竹中繁織, 安田隆

バイオエンジニアリング講演会講演論文集 ( 一般社団法人日本機械学会 ) 2014 ( 0 ) 73 - 74 2014年01月

Development of a membrane-based microwave mediated electrochemical ELISA method for TNF-α detection in patients with periodontitis 査読有り国際誌

Irmina DIALA, Shinobu SATO, Michihiko USUI, Keisuke NAKASHIMA, Tatsuji NISHIHARA, Shigeori TAKENAKA

Analytical Sciences 29 ( 9 ) 927 - 930 2013年09月

記述言語：英語掲載種別：研究論文（学術雑誌）

The tumor necrosis factor-α (TNF-α) is implicated in periodontal disease, and there was an attempt to quantitate it by a membrane-based microwave-mediated electrochemical enzyme-linked immunosorbent assay (MMeELISA) using p-aminophenyl phosphate (pAPP) with an over-all time of 1.5 h. A differential pulse voltammetric signal increased linearly with an increase in the amount of TNF-α with a detection limit of 0.48 pg mL-1. This bio-sensing platform revealed a significant difference in the TNF-α level between GCF samples from periodontal patients and healthy volunteers. © 2013 The Japan Society for Analytical Chemistry.

DOI： 10.2116/analsci.29.927

その他リンク： https://www.jstage.jst.go.jp/article/analsci/29/9/29_927/_pdf

Electrochemical Detection of Duplex DNA Using Intercalation-Triggered Decomplexation of Ferrocene with β-Cyclodextrin 査読有り国際誌

Hirotomo Takenaka, Shinobu Sato, Shigeori Takenaka

Electroanalysis 25 ( 8 ) 1827 - 1830 2013年08月

記述言語：英語掲載種別：研究論文（学術雑誌）

The redox peak of ferrocenylnaphthalene diimide used as a threading intercalator shifted positively due to the formation of its complex with β-cyclodextrin. This complex collapsed upon the addition of double-stranded DNA, and its redox potential shifted negatively. This behavior was applied for the homogenous detection of a polymerase chain reaction (PCR) product from Porphyromonas gingivalis, which is important for the diagnosis of periodontal disease, and its quantitative detection was achieved with a detection limit of 2.7nM. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOI： 10.1002/elan.201300211

その他リンク： http://onlinelibrary.wiley.com/doi/10.1002/elan.201300211/abstract

Naphthalene diimide carrying two cysteine termini at both imide linkers as a molecular staple 査読有り国際誌

Shinobu Sato, Kosuke Yamamura, Shigeori Takenaka

Electroanalysis 25 ( 8 ) 1831 - 1839 2013年08月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Naphthalene diimide (1) carrying cysteines at the termini of amide substituents were synthesized to act as a molecular staple of double stranded DNA. Since 1 is able to bind to double stranded DNA with threading intercalation, the complex of 1 with double stranded DNA can be topologically immobilized on a gold surface through the S-Au linkage as confirmed by cyclic voltammetric experiment. Ferrocenyl-double stranded 23-mertic oligonucleotide, dsFcODN, was immobilized on gold electrode with 1.0×1012 molecules cm-2 when electrode was treated with 2.0μM dsFcODN and 4.0μM 1 for 1h at room temperature. The coverage density was similar to that obtained for the terminal thiol-modified oligonucleotide. Compound 1 was applied to detect the 321-meric PCR product of P. gingivalis, which is important in the diagnosis of periodontal disease. This experiment, coupled with the use of ferrocenylnaphthalene diimide, FND as electrochemical indicator for double stranded DNA, resulted in quantitative detection of PCR product within the range of 10pgμL-1-10ngμL-1 (15nM-15μM). The 1 and FND established a simple and rapid detection method of double stranded PCR product with a detection limit of 10pgμL-1 (15nM). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOI： 10.1002/elan.201300209

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84881536112&origin=inward

電気化学的遺伝子検出における超分子形成査読有り

Shinobu Sato, Shigeori Takenaka

BUNSEKI KAGAKU 62 ( 7 ) 627 - 635 2013年07月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Gene detection based on electrochemical techniques has been gaining much attention in recent years, not only because it provides simple and rapid methods for measurement and detec t ion, but al so for the eas ines s of downs i z ing the ins t rumentat ion. Ferrocenylnaphthalene diimide, which forms a pseudo-catenane complex with double-stranded DNA, has been developed to be used in an electrochemical detection system for doublestranded DNA coupled with a DNA probe-immobilized electrode. To improve the performance of electrochemical gene detection, FND or its derivatives, which can form a supramolecular complex, have been under development. Here, we review an electrochemical DNA or DNA-related enzyme detection technique based on supramolecular complex formation. © 2013 The Japan Society for Analytical Chemistry.

DOI： 10.2116/bunsekikagaku.62.627

その他リンク： https://www.jstage.jst.go.jp/article/bunsekikagaku/62/7/62_627/_pdf

Electrochemical DNA Detection Using Supramolecular Interactions

Shinobu Sato, Shigeori Takenaka

Analytical Scieces ( The Japan Society for Analytical Chemistry ) 28 ( 7 ) 643 - 649 2013年07月

Electrochemical RNase A Detection Using an Electrode with Immobilized Ferrocenyl Deoxyribooligonucleotide Containing Cytidine Residue 査読有り国際誌

Shinobu Sato, Shigeori Takenaka

Electroanalysis 25 ( 7 ) 1652 - 1658 2013年07月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

A ferrocenyl deoxyribooligonucleotide (FcODN(rC)) with contiguous cytosine bases and a single ribonucleotide, cytidine, was immobilized on a gold electrode, and this electrode was used to detect RNase A. RNase A activity in a solution was assessed using cyclic voltammetry, and it was found that the current response of the sensor electrode decreased with increasing enzyme concentration. An extremely low detection limit of 1.0×10-11gmL-1 RNase A was observed, with 15-90% changes in the current signal. RNase activity can be an indicator of a number of diseases; therefore, this probe has great potential for applications in medical diagnostics. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOI： 10.1002/elan.201300126

その他リンク： http://onlinelibrary.wiley.com/doi/10.1002/elan.201300126/abstract

Nanowire formation using specific metallization of double-stranded DNA 査読有り

Himuro T., Araki R., Ikedo H., Sato S., Takenaka S., Yasuda T.

17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013 3 1466 - 1468 2013年01月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

We demonstrated that the DNA metallization technique using reducing group-labeled intercalator molecules permits dsDNA (double-stranded DNA) molecules to be specifically metallized while not permitting metallization of ssDNA (single-stranded DNA) molecules. First, DNA molecules were electrostatically stretched and immobilized between two electrodes in a microchannel. Next, naphthalene diimide molecules labeled with reducing groups were specifically intercalated into the double strands of DNA molecules, and reduction of silver ions along the DNA molecules caused DNA metallization with silver. By using this technique, we succeeded in formation of nanowires having high conductivity and no parasitic capacitance.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84907358065&origin=inward

2D14 ナノチャネル中での単分子DNAの金属被覆によるナノワイヤの形成(OS9-1:バイオMEMS(1))

氷室貴大, 池堂英幸, 佐藤しのぶ, 竹中繁織, 安田隆

バイオエンジニアリング講演会講演論文集 ( 一般社団法人日本機械学会 ) 2013 ( 0 ) 375 - 376 2013年01月

TELOMERASE INHIBITION ASSAY BASED ON CHRONOCOULOMETRY 査読有り

Shinobu Sato, Shigeori Takenaka

XX IRT - 20th International Roundtable on Nucleosides, Nucleotides and Nucleic Acids 2012年08月

Development of electrochemical telomerase assay (ECTA) aiming at cancer diagnosis and drug discovery 査読有り

S. Sato, K. Mori, M. Kodama, M. Habu, T. Nishihara, K. Tominaga, S. Takenaka

The Second Asian Chemical Biology Conference, ACBS2012 2012年07月

フェロセン化ナフタレンジイミドと電極チップを利用したテロメラーゼ測定：電気化学的舌癌診断査読有り

佐藤しのぶ, 森久美子, 遠藤浩, 兒玉正明, 土生学, 西原達次, 冨永和宏, 竹中繁織

分析化学 61 ( 3 ) 243 - 250 2012年05月

担当区分：筆頭著者記述言語：日本語掲載種別：研究論文（学術雑誌）

Telomerase is an enzyme that elongates repeated six bases of TTAGGG of the telomere DNA, and is known to be expressed in tumor cells, but not in normal cells. For this reason, this enzyme is expected to serve as a new tumor marker. The telomerase activity has been detected by the telomerase repeat amplification protocol (TRAP), which involves a tedious polymerase chain reaction (PCR) and gel electrophoresis. We have been developing an electrochemical telomerase assay with ferrocenylnaphthalene diimide (FND) as an electrochemical indicator. Where telomerase activity is present in the sample, the telomerase substrate (TS)-primer immobilized on the electrode is elongated to form a telomeric repeat sequence; the resulting products form a tetraplex DNA. FND binds to the tetraplex DNA thus formed to give rise to an electrochemical signal whose magnitude reflects the telomerase activity. We tested saliva, oral epithelial cells, and solid tumor for telomerase activity for diagnosis of tongue cancer using disposable electrode chips coupled with a FND derivative. The samples were lysed, and supernatants (2000 and 200 ng of protein) were used in TRAP and the FND-based electrochemical assay with Osteryoung square wave voltammetry (SWV). In both assays, all of the samples from a solid tumor turned out to be telomerase-positive. However, the telomerase activity was detected at a higher rate, even in saliva and oral epithelial cells in the latter assay than in the former. In conclusion, the FND-based electrochemical telomerase assay was more sensitive than TRAP in terms of the detection of cancerous samples taken from tongue cancer patients. This electrochemical method will enable early diagnosis of tongue cancer in clinical dentistry. © 2012 The Japan Society for Analytical Chemistry.

DOI： 10.2116/bunsekikagaku.61.243

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84859127629&origin=inward

Structural Optimization of a DNA-Peptide Conjugate Aiming at Potassium Ion Sensing Agent in Living Cells 査読有り

Shinsuke Ohzawa, Keiichi Ohtsuka, Shinobu Sato, Shigeori Takenaka

Peptide Science 405 - 406 2012年04月

Electrochemical Detection of Periodontal Disease Using Protease Assay ）査読有り

Shinichiro Nagata, Takeshi Ohshima, Keiichi Ohtsuka, Shinobu Sato, Masato Nagayoshi, Chiaki Kitamura, Tatsuji Nishihara, Shigeori Takenaka

Peptide Science 407 - 408 2012年04月

Electrochemical Detection of DNA Duplexes Using Ferrocenylnaphthalene Diimide Derivaives in Homogenous Solution 査読有り

Hirotomo Takenaka, Shinobu Sato, Shigeori Takenaka

Peptide Science 409 - 410 2012年04月

Chronocoulometric telomerase assay 査読有り

S. Sato, S. Takenaka

5th International Symposium of Nanomedicine 2012年03月

PCR-free telomerase assay using chronocoulometry coupled with hexaammineruthenium(III) chloride 査読有り国際誌

Sato S., Takenaka S.

Analytical Chemistry 84 ( 3 ) 1772 - 1775 2012年02月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

An electrochemical method based on chronocoulometry coupled with hexaammineruthenium chloride (RuHex) is proposed for simple and rapid assay of telomerase without relying on PCR and gel electrophoresis. Thus, DNA extended by telomerase in extracts of as small as HeLa cells on the TS primer-immobilized electrodes was quantified successfully. This method is suitable for quick screening of drug candidates which inhibit telomerase. When 10 compounds were tested, the multiplicity of extension (x in (TTAGGG) x) varied from 11 to 0, suggesting that there is more than one mechanism of inhibition. IC 50 values of telomerase inhibitors TMPyP4 and PIPER were determined as 5.5 and 15μM, respectively, though their mechanisms of inhibition are different. This method is capable of discriminating two possible mechanisms of telomerase inhibition: direct binding of inhibitors to telomerase and indirect inhibition through their binding to the quadruplex generated by telomerase. As this method is easy and quick to run, it will be useful for high-throughput screening of drug candidates which inhibit telomerase. © 2011 American Chemical Society.

DOI： 10.1021/ac202233m

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84856708012&origin=inward

Detection of an aberrant methylation of CDH4 gene in PCR product by ferrocenylnaphthalene diimide-based electrochemical hybridization assay 査読有り国際誌

Shinobu Sato, Masato Tsueda, Yusuke Kanezaki, Shigeori Takenaka

Analytica Chimica Acta 715 42 - 48 2012年02月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Hybridization behavior of 24-meric and 105-meric single stranded DNAs derived from CDH4 gene related to cadherin cell-adhesive protein was tested with 24-meric DNA probe in a ferrocenylnaphthalene diimide (FND)-based hybridization assay. Hybridization efficiency in this system was also clarified using chronocoulometric (CC) measurement with Hexaammineruthenium (III) probe (RuHx). This is first example to calculate hybridization efficiency of PCR product with a DNA probe immobilized on the electrode. Although hybridization efficiency was really small for the PCR product as expected (20% for 105-meric PCR product), PCR products carrying aberrant methylation were discriminated from the wild one due to the electrochemical signal of FND. It was possible since FND possessed high preference for double stranded DNA, especially on the electrode. When applied to aberrant methylation detection for the fragment of CDH4 gene, this system can discriminate over 0.5ngμL -1 sample DNA, which is superior to bisulfite sequencing or MSP and COBRA assays. © 2011 Elsevier B.V.

DOI： 10.1016/j.aca.2011.12.010

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84855669982&origin=inward

PCR-free telomerase assay using Chronocoulometry coupled with RuHex 査読有り

Shinobu Sato, Shigeori Takenaka

Analytical Chemistry 84 1772 - 1775 2012年02月

Formation of a single metallized DNA nanowire in a nanochannel 査読有り

Himuro T., Ikedo H., Sato S., Takenaka S., Yasuda T.

Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012 1879 - 1881 2012年01月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

We present a novel fabrication process of a single silver nanowire using metallization of a DNA molecule. First, we introduced a single λDNA molecule into a nanochannel by capillary force. Then, the λDNA molecule was stretched and immobilized by applying an AC voltage between two electrodes that were placed 15 μm apart. Next, naphthalene diimide molecules labeled with reducing groups were intercalated into the λDNA so that the reducing groups were arrayed along the λDNA strand. Finally, the λDNA was metallized with silver using treatment with Tollens' reagent and reduction of silver ions along the λDNA, which resulted in formation of silver nanowires. The electrical property of the fabricated nanowire was evaluated with the complex impedance plot. As a result, an equivalent circuit for the nanowire was found to be expressed as the series connection of a resistance and several parallel RC circuits.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84901752528&origin=inward

Electrochemical detection of PCR products in homogeneous solution with naphthalene diimide having ferrocene and β-cyclodextrin 査読有り

Shinobu Sato, Hirotomo Takenaka, Sadayoshi Watanabe, Shigeori Takenaka

The 38th International Symposium on Nucleic Acid Chemistry, ISNAC2011 2011年11月

Naphthalene diimide having zinc(II) dipicolylamine complexes can bind strongly to human telomere DNA 査読有り

Shinobu Sato, Yusuke Fukunaga, Sadayoshi Watanabe, Shigeori Takenaka

The 38th International Symposium on Nucleic Acid Chemistry, ISNAC2011 2011年11月

Electrochemical DNA analysis with a supramolecular assembly of naphthalene diimide, ferrocene, and β-cyclodextrin. 査読有り国際誌

Watanabe S., Sato S., Ohtsuka K., Takenaka S.

Analytical chemistry 83 ( 19 ) 7290 - 7296 2011年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Naphthalene diimide 1 bearing ferrocene and β-cyclodextrin (β-CD) was prepared. Its half-wave potential at 420 mV shifted 40-50 mV upon addition of an excess of adamantylamine, suggesting that the ferrocene of 1 is included in the cavity of β-CD intramolecularly to form a pseudocyclic structure. This unique architecture is retained even where 1 is bound to calf thymus DNA to give rise to a catenane-like structure. Morphology of the DNA complex with 1 was further explored by atomic force microscopy to reveal that the DNA strand tends to bend as the amount of 1 on it increases. Presumably, intermolecular, yet intrastrand, inclusion of ferrocene into β-CD is responsible for this phenomenon. The resulting globular structure reverted partially by the addition of adamantylamine. At a low ratio of 1 to DNA, a novel reduction peak appeared at 320 mV in the differential pulse voltammograms of 1 at the expense of the 420 mV peak. The peak current of the former was proportional to the DNA concentration, thereby enabling quantitation of DNA in a signal-on way. Likewise, a polymerase chain reaction (PCR) product of 754 bp was analyzed successfully with a detection limit of 13 nM.

DOI： 10.1021/ac200989c

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84856244304&origin=inward

Electrochemical DNA analysis with a supramolecular assembly of naphthalene diimide, ferrocene and beta-cyclodextrin 査読有り

Sadayoshi Watanabe, Shinobu Sato, Keiichi Ohtsuka, Shigeori Takenaka

Anal. Chem. 83 7290 - 7296 2011年08月

PCR-free electrochemical telomerase assay 査読有り

K. Mori, S. Sato, K. Tominaga, S. Takenaka

Third International Meeting on G-Quadruplex and G-assembly 2011年06月

Nuclease activity detection using ferrocenyloligonucleotide-immobilized electrode 査読有り

S. Sato, S. Ohtsuka, S. Takenaka

ICAS2011 2011年05月

cancer diagnosis using FND-based electrochemical telomerase assay 招待有り査読有り

Shinobu Sato

Asian International Symposium 2011年03月

Discrimination of phosphorylated double stranded DNA by naphthalene diimide having zinc(II) dipicolylamine complexes 査読有り国際誌

Sadayoshi Watanabe,Keiichi Ohtsuka,Shinobu Sato,Shigeori Takenaka

Bioorg. Med. Chem. 19 ( 3 ) 1361 - 1365 2011年02月

記述言語：英語掲載種別：研究論文（学術雑誌）

Discrimination of phosphomonoesters and phosphodiesters of DNA was attempted with naphthalene diimide carrying two zinc-dipicolylamine (Dpa) units (1). The binding constant of 1 for a self-complementary octanucleotide was 1.3 × 106 M-1, while the value for the phosphorylated counterpart was 4.8 × 106 M-1. This fourfold increase in the binding constant seems to stem from higher affinity of the terminal monophosphate over the phosphodiesters of DNA as the fourth ligand for the metal in 1. Likewise, the binding constant of 1 for DNase I-treated calf thymus DNA (average size 200 bp) was twice as large as that for untreated DNA (1 kb), possibly because the terminal phosphate groups are five times abundant in the former. These findings provide a clue to developing a system where phosphomonoesters generated upon DNA nicking are discriminated specifically from intact phosphodiesters. © 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.bmc.2010.10.056

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=79551477073&origin=inward

FND-based electrochemical telomerase assay aiming at tongue cancer diagnosis

Shinobu Sato

第三回バイオセンシング技術に関する日韓シンポジウム(3rd JKBT) 2010年12月

DNA immobilization on the gold electrode using naphtalene diimide derivatives having dithiolane or cysteine moieties 査読有り

Kosuke Yamamura, Shinobu Sato, Shigeori Takenaka

PACIFICHEM2010 2010年12月

Electrochemical detection of double stranded DNA in homogenous solution using new naphthalene diimdie having ferroccenes located adjacent to triazole parts 査読有り

Sadayoshi Watanabe, Keiichi Ohtsuka, Shinobu Sato, Shigeori Takenaka

PACIFICHEM2010 2010年12月

Electrochemical detection of aberrant methylated genes by using ferrocenylnaphthalene diimide 査読有り

Shinobu Sato, Yusuke Kanezaki, Shigeori Takenaka

PACIFICHEM2010 2010年12月

Electrochemical detection of nuclease activity with ferrocenyloligonucleotide-immobilized electrodes 査読有り

Shinobu Sato, Katsuya Fujita, Shota Ohtsuka, Shigeori Takenaka

PACIFICHEM2010 2010年12月

Electrochemical detection of telomerase activity using ferrocenylnaphthalene diimide 査読有り

Shinobu Sato, Kumiko Mori, Yusuke Fukunaga, Ryota Fujikawa, Kazuhiro Tominaga, Tatsuji Nishihara, Shigeori Takenaka

PACIFICHEM 2010 2010年12月

Electrochemical detection of aberrant methylated genes by using ferrocenylnaphthalene diimide 査読有り

Sadayoshi Watanabe, Shinobu Sato, Shigeori Takenaka

ISNAC2010 2010年11月

Tongue cancer diagnosis by FND-based electrochemical telomerase assay 査読有り

Yusuke Fukunaga, Shinobu Sato, Kumiko Mori, Hiroshi Endo, Kimio Morimoto, Kazuhiro Tominaga, Tatsuji Nishihara, Shigeori Takenaka

ISNAC2010 2010年11月

Tris-intercalator based on the naphthalene diimide skeleton: Its synthesis by Click chemistry and DNA interaction 査読有り

Keiichi Ohtsuka, Yasuhiro Hadano, Shinobu Sato, Shigeori Takenaka

ISNAC2010 2010年11月

Electrochemical detection of aberrant methylated gene using naphthalene diimide derivative carrying four ferrocene moieties 査読有り国際誌

Shinobu Sato,Masato Tsueda,Shigeori Takenaka

J. Organomet. Chem. 695 ( 15-16 ) 1858 - 1862 2010年07月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Naphthalene diimide derivative, F4ND, carrying four ferrocene moieties was synthesized as a new hybridization indicator for electrochemical gene detection using DNA probe-immobilized electrode. F4ND could bind to double stranded DNA with threading intercalation mode despite the existence of such bulky substituents. As result, an improved binding affinity due to slower dissociation from double stranded DNA was observed. F4ND could be used for electrochemical discrimination between methylated and unmethylated PCR product of CDH4 gene coupled with methylation specific DNA probe-immobilized electrode under the optimum condition. Synthesized naphthalene diimide derivative, F4ND, carrying four ferrocene moieties could bind to double stranded DNA with threading intercalation mode and be used for electrochemical discrimination between methylated and unmethylated PCR product of the bisulfate reated CDH4 gene coupled with methylation specific DNA probe-immobilized electrode. © 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jorganchem.2010.04.034

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77955424559&origin=inward

Naphtalene diimide derivatives having dithiolane or cysteine moieties as double stranded DNA-immobilization reagent on a gold surface 査読有り

Shinobu Sato, Kousuke Yamamura, Shigeori Takenaka

Asian Chemical Biology Conference 2010(ACBC2010) 2010年06月

Reliable ferrocenyloligonucleotide-immobilized electrodes and their application to electrochemical DNase I assay 査読有り

Shinobu Sato,Katsuya Fujita,Masanori Kanazawa,Kosuke Mukumoto,Keiichi Ohtsuka,Shigeori Takenaka

Analytica Chimica Acta 645 30 - 35 2010年04月

Selective immobilization of double stranded DNA on a gold surface through threading intercalation of a naphthalene diimide having dithiolane moieties 査読有り国際誌

Shinobu Sato,Akinori Hirano,Shigeori Takenaka

Analytica Chimica Acta 665 ( 1 ) 91 - 97 2010年04月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Newly synthesized naphthalene diimide 1 having two dithiolane moieties at its substituted termini bound to double stranded DNA by threading intercalation and the resulting complex was immobilized on the gold surface through a dithiolane-gold linkage as revealed by quartz crystal microbalance (QCM) experiments. DNA with 20-meric double stranded and 24-meric single stranded regions was indirectly immobilized on the gold electrode using this characteristic of 1. Hybridization efficiency was 92%, a value higher than 50% for a thiolated oligonucleotide under identical conditions. When this electrode was subjected to hybridization with a 124-meric target DNA in the presence of ferrocenylnaphthalene diimide (FND) as an electrochemical hybridization indicator, a large current increase was observed deriving from FND bound in the double stranded region newly formed between the probe and target DNA. © 2010 Elsevier B.V.

DOI： 10.1016/j.aca.2010.03.008

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77951205333&origin=inward

Immobilization of a naphthalene diimide-DNA complex on the gold through dithiolane moieties. 査読有り国際誌

Sato S., Ohtsuka K., Takenaka S.

Nucleic acids symposium series (2004) ( 53 ) 147 - 148 2009年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Naphthalene diimide 1 having two dithiolane moieties at its substituted termini was newly synthesized to immobilize double stranded DNA through dithiolane moieties of 1. Double stranded DNA could be immobilized on the gold surface of a quartz crystal microbalance (QCM) chip after binding 1. Once immobilized, the complex will serve as a hybridization marker based on its frequency decrease. QCM experiments showed that a DNA duplex with a 24-meric single stranded region also could be immobilized on the gold surface of a QCM chip and subsequent frequency decrease was observed after hybridization with a 24-meric complementary DNA, but not with non-complementary DNA, indicating specific hybridization. This result reveals that 1 provides a new immobilization method for intact DNA on gold and that the immobilized DNA can hybridize with target DNA.

DOI： 10.1093/nass/nrp074

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=77952484530&origin=inward

Immobilization of a naphthalene diimide-DNA complex on the gold through dithiolane moieties 査読有り

Shinobu Sato,Keiichi Ohtsuka,Shigeori Takenaka

Nucleic Acids Symposium Series 53 147 - 148 2009年11月

Reliable ferrocenyloligonucleotide-immobilized electrodes and their application to electrochemical DNase I assay 査読有り

Sato S., Fujita K., Kanazawa M., Kanazawa M., Mukumoto K., Ohtsuka K., Takenaka S.

Analytica Chimica Acta 645 ( 1-2 ) 30 - 35 2009年07月

記述言語：英語掲載種別：研究論文（学術雑誌）

A ferrocenyloligonucleotide (FcODN) having contiguous cytosine bases was immobilized effectively and reproducibly on a gold electrode furnished with a self-assembled monolayer (SAM) having an N-hydroxysuccinimide-activated carboxylic acid. The resulting electrode was used as a sensor chip in DNase I assay. Thus, the current response of the modified electrode decreased upon addition of DNase I, demonstrating that the phosphodiester bonds of FcODN were cleaved. The DNase I activity assessed by Δi defined as (i0 - i)/i0, where i0 and i represent the current before and after DNase I treatment, respectively, was found to be reproducible with a standard deviation not greater than 9%. The DNase I can be quantitated in the range of 10-5 to 10-3 units μL-1 with a detection limit of 10-5 units μL-1 with this sensor chip. The current signal of the FcODN electrode was stable to storage in Biopak water up to 16 days with a 30% signal decrease over this period. DNase I activity in human sera was also determined successfully with this sensor chip. © 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.aca.2009.04.047

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=65749083875&origin=inward

Electrochemical detection of deoxyribonuclease in microliquid 査読有り

Sakata Y., Hirokawa S., Sato S., Takenaka S., Yasuda T.

Proceedings of Conference, MicroTAS 2009 - The 13th International Conference on Miniaturized Systems for Chemistry and Life Sciences 305 - 307 2009年01月

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

This paper presents a novel microdevice which detects deoxyribonuclease (DNase) electrochemically. The present device can be applied to diagnoses of diseases such as acute myocardial infarction and monitoring of DNase-free water used in genetic research. The device consists of a PDMS reservoir for storing a sample liquid and several microelectrodes including working electrodes where ferrocenyloligonucleotides (DNA strands carrying ferrocene molecules) are immobilized. DNase detection is achieved by the current reduction between before and after ferrocenyloligonucleotide cleavage by DNase. Experimental results showed a definite correlation between DNase concentration and the current reduction rate in the range of 10-4 to 10-1 unit/μl of DNase I. © 2009 CBMS.

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84901770145&origin=inward

Synthesis of naphthalenediimide having two beta-cyclodextrins at both of its substituent termini. 査読有り国際誌

Ohtsuka K., Sato S., Watanabe S., Komizo K., Takenaka S.

Nucleic acids symposium series (2004) ( 52 ) 717 - 718 2008年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Naphthalenediimide (1) carrying two beta-cyclodextrins (beta CDs) was successfully synthesized by click chemistry between pentynylnaphthalenediimide and azido beta CD. Absorption spectra of 1 showed hypochromic and red shifts upon addition of sonicated calf thymus DNA as a double stranded DNA. Kinetic studies showed its slow association with and dissociation from calf thymus DNA. These results suggested that 1 can bind to double stranded DNA by the threading mode, where one of the beta CD is required to go through adjacent base pairs of double stranded DNA. If this is proven, beta CD is one of the largest groups ever reported which can go through a DNA duplex for threading.

DOI： 10.1093/nass/nrn362

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=78649400207&origin=inward

Synthesis of a perylene diimide derivative having two ferrocene moieties as an electrochemical indicator for human telomeric DNA tetraplex. 査読有り国際誌

Fujikawa R., Watanabe S., Ohtsuka K., Sato S., Takenaka S.

Nucleic acids symposium series (2004) ( 52 ) 241 - 242 2008年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

A water-soluble perylene diimide derivative carrying two ferrocene moieties, FPD, was synthesized in two steps as an electrochemical indicator for human telomeric DNA tetraplex. Spectrophotometric binding studies of FPD with AG(3)(T(2)AG(3))(3) revealed its specific binding to tetraplex DNA in 10 mM MES and 1 mM EDTA (pH 6.25) containing 0.10 M KCl. Cyclic voltammograms of AAT CCG TCG AGC AGA G(T(2)AG(3))(4) in an electrolyte containing 20 mM FPN showed single oxidation and reduction peaks based on the ferrocene moieties. The peak current for the oxidation process increased linearly with the scan rate, suggesting the effective concentration of FPN on this electrode.

DOI： 10.1093/nass/nrn122

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=78649441658&origin=inward

Synthesis of a naphthalene diimide derivative having four ferrocene moieties as an electrochemical DNA hybridization indicator. 査読有り国際誌

Sato S., Tsueda M., Watanabe S., Ohtsuka K., Takenaka S.

Nucleic acids symposium series (2004) ( 52 ) 239 - 240 2008年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

A new naphthalene diimide derivative carrying four ferrocene moieties, F(4)ND, was synthesized by the reaction of trimethylammoniummethylferrocene with the terminal amino moieties of two imide substituents of naphthalene diimide. Spectrophotometric binding studies of F(4)ND with calf thymus DNA showed its high affinity of 2 x 10(5) M(-1) in 10 mM MES buffer and 1 mM EDTA (pH 6.25) containing 0.10 M NaCl. The Osteryoung square wave voltammetry (SWV) of a DNA probe-immobilized electrode before and after hybridization with target DNA gave a larger peak current in an electrolyte containing F(4)ND than that containing FND carrying two ferrocene moieties. The current peak difference between mismatched and fully matched DNA was also greater with F(4)ND than that with FND.

DOI： 10.1093/nass/nrn121

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=78649433967&origin=inward

Electrochemical assay for deoxyribonuclease I activity 査読有り国際誌

Sato S., Fujita K., Kanazawa M., Mukumoto K., Ohtsuka K., Waki M., Takenaka S.

Analytical Biochemistry 381 ( 2 ) 233 - 239 2008年10月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

A thiolated oligonucleotide having three ferrocenes was immobilized on a gold electrode through the sulfur-gold linkage. This electrode showed a current response based on the redox reaction of the ferrocene moieties and this response was decreased after treatment with deoxyribonuclease I (DNase I), suggesting the disappearance of the ferrocene moieties on the electrode by the DNase I digestion. A linear correlation between i0 and i, which are current peaks before and after DNase I treatment, respectively, was observed and this slope was decreased with increase in the amount of DNase I. No current decrease was observed in the presence of EDTA or RNase A instead of DNase I. These results suggested that the current decrease responded specifically to the amount of DNase I and this electrode could be used for an electrochemical DNase I assay. Under the optimum conditions of DNase I digestion at 37 °C for 30 min, a quantitative analysis could be achieved in the range of 10-4-10-2 units/μl of DNase I. © 2008 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.ab.2008.07.014

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=50049089446&origin=inward

Synthesis of naphthalenediimide having two β-cyclodextrins at both of its substituent termini 査読有り

Keiichi Ohtsuka,Shinobu Sato,Sadayoshi Watanabe,Kohei Komizo,Shigeori Takenaka

Nucleic Acids Symposium Series 52 717 - 718 2008年09月

Synthesis of a perylene diimide derivative having two ferrocene moieties as an electrochemical indicator for human telomeric DNA tetraplex 査読有り

Ryota Fujikawa,Sadayoshi Watanabe,Keiichi Ohtsuka,Shinobu Sato,Shigeori Takenaka

Nucleic Acids Symposium Series 52 241 - 242 2008年09月

Synthesis of a naphthalene diimide derivative having four ferrocene moieties as an electrochemical DNA hybridization indicator

Shinobu Sato,Masato Tsueda,Sadayoshi Watanabe,Keiichi Ohtsuka,Shigeori Takenaka

Nucleic Acids Symposium Series 52 239 - 240 2008年09月

Linker effect of ferrocenylnaphthalene diimide ligands in the interaction with double stranded DNA 査読有り

Shinobu Sato,Shigeori Takenaka

Journal of Organometallic Chemistry 693 ( 7 ) 1177 - 1185 2008年04月

Electrochemical Assay for deoxyribonuclease I Activity 査読有り

Shinobu Sato,Katsuya Fujita,Masanori Kanazawa,Kosuke Mukumoto,Keiichi Ohtsuka,Michinori Waki,Shigeori Takenaka

Analytical Biochemistry 381 233 - 239 2008年04月

Electrochemical RNase detection using ferrocenylnaphthalene diimide. 査読有り国際誌

Kanazawa M., Sato S., Ohtsuka K., Takenaka S.

Nucleic acids symposium series (2004) ( 51 ) 323 - 324 2007年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

To develop a conventional RNase detecting system, an RNA electrode was constructed by the immobilization of poly(A)+RNA from mouse kidney on the glassy carbon electrode. Electrochemical measurement using this RNA electrode in the electrolyte containing ferrocenylnaphthalene diimide (1) was carried out and showed the electrochemical signal depending on the amount of the immobilized RNA. After this electrode was treated with water, the differential pulse voltammetric (DPV) measurement was subsequently conducted in the electrolyte containing 1. When RNase is contained in the water, the electrochemical signal decreased with an increase of the amount of RNase. This is derived from the decreasing amount of RNA on the electrode by RNase. In DPV measurement, the concentration of RNaseA was linear in the range of 10(-10) - 10(-8) M and the amount of RNase in the tap water could be estimated.

DOI： 10.1093/nass/nrm162

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=42949174711&origin=inward

Searching study for the suitable ferrocenylnaphthalene diimide derivative in the electrochemical telomerase assay. 査読有り国際誌

Sato S., Ohtsuka K., Takenaka S.

Nucleic acids symposium series (2004) ( 51 ) 85 - 86 2007年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Interaction of ferrocenylnaphthalene diimide 1 with the tetraplex oligonucleotide, AGGG(TTAGGG)3, which is a part of human telomere sequence, was studied in 0.1 M AcONa-AcOH (pH 5.5) containing 0.1 M NaCl coupled with 22-meric single and double stranded oligonucleotides using spectrophotometric titration experiment to search for the more suitable tetraplex DNA-binding ligand to achieve the electrochemical telomerase assay. CD spectra and polyacrylamide gel electrophoresis revealed that this tetraplex oligonucleotide kept to the single conformational structure of basket type G-quadruplex under these conditions. Scatchard analysis showed that 1 can bind to the tetraplex oligonucleotide with the binding constant of 10(5) M(-1) order, which was the highest value among the other oligonucleotides. Binding number of 1 for these oligonucleotides were ca. 2, 11, and 3 for tetraplex, double stranded, and single stranded oligonucleotides, respectively. These values were reasonable when considering with the binding mode of 1 as a threading intercalator.

DOI： 10.1093/nass/nrm043

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=42949147091&origin=inward

Ferrocenylnaphthalene diimide-based electrochemical ribonuclease assay 査読有り

Kanazawa M., Kanazawa M., Sato S., Ohtsuka K., Takenaka S.

Analytical Sciences 23 ( 12 ) 1415 - 1419 2007年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Messenger RNA (mRNA) poly(A)+RNA (from mouse kidney) was immobilized on a N-hydroxysuccinimide(NHS)-activated carboxylic acid modified electrode prepared by the treatment of a gold electrode with 3,3′-dithiodipropionic acid, followed by NHS and 1-ethyl-3-(3- dimethylaminopropyl)carbodiimide (EDC). An electrochemical measurement using this mRNA electrode was carried out in an electrolyte containing ferrocenylnaphthalene diimide (1), and showed an electrochemical signal based on 1 concentrated on immobilized mRNA. After treating this electrode with water containing varied amounts of ribonuclease A (RNase A), the current peak based on 1 decreased with increasing in the amount of RNase A with a linear correlation in the range of 0.2 - 10 pg of RNase A. 2007 © The Japan Society for Analytical Chemistry.

DOI： 10.2116/analsci.23.1415

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=38449083466&origin=inward

The ferrocenyl-naphthalene diimide-based electrochemical ribonuclease assay 査読有り

Masanori Kanazawa,Shinobu Sato,Keiichi Ohtsuka,Shigeori Takenaka

Analytical Science 23 ( 12 ) 1415 - 1419 2007年12月

Electorochemical RNaseA detection using ferrocenylnaphthalene diimide 査読有り

Masanori Kanazawa,Shinobu Sato,Keiichi Ohtsuka,Shigeori Takenaka

Nucleic Acids Symposium Series 51 323 - 324 2007年11月

Searching study for the suitable ferrocenylnaphthalene diimide derivative in the electrochemical telomerase assay 査読有り

Shinobu Sato,Keiichi Ohtsuka,Shigeori Takenaka

Nucleic Acids Symposium Series 51 85 - 86 2007年11月

Direct modification of mRNA by ferrocenyl carbodiimide and its application to electrochemical detection of mRNA 査読有り

Mukumoto K., Nojima T., Sato S., Waki M., Takenaka S.

Analytical Sciences 23 ( 1 ) 115 - 119 2007年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Ferrocenyl carbodiimide (1) could be used for the direct labeling of synthetic RNA and expressed mRNA in vitro with the electrochemically active ferrocene moieties. These RNAs modified by 1 could be detected electrochemically coupled with a DNA probe-immobilized electrode. After hybridization of 1.1 Kb mRNA modified by 1 with the DNA probeimmobilized electrode, the peak charge observed by an Osteryoung square wave voltammetry (SWV) measurement correlated well with the concentration of mRNA, having a detection limit at the sub nanogram level. 2007 © The Japan Society for Analytical Chemistry.

DOI： 10.2116/analsci.23.115

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=33847775205&origin=inward

Direct modification of mRNA by ferrocenylcarbodiimide and its application for electrochemical detection of mRNA 査読有り

Kosuke MUKUMOTO,Takahiko NOJIMA,Shinobu SATO,Michinori WAKI,Shigeori TAKENAKA

Analytical Sciences 23 ( 1 ) 115 - 119 2007年01月

Electrochemical detection of DNase I activity. 査読有り国際誌

Fujita K., Kanazawa M., Mukumoto K., Nojima T., Sato S., Kondo H., Waki M., Takenaka S.

Nucleic acids symposium series (2004) ( 50 ) 307 - 308 2006年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

DNase I in one microl of the water could quantitate electrochemically with the detection limit of 0.01 units (ca. 20 pg) by using the ferrocenyl oligonucleotide-immobilized electrode prepared by thiolated oligonucleotide and ferrocenyl carbodiimide as a simple labeling reagent of redox unit.

DOI： 10.1093/nass/nrl153

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=36048955665&origin=inward

Linker chain effect of ferrocenylnaphthalene diimide derivatives on a tetraplex DNA binding. 査読有り国際誌

Sato S., Kondo H., Takenaka S.

Nucleic acids symposium series (2004) ( 50 ) 107 - 108 2006年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Spectrophotometric binding studies of a series of the naphthalene diimide derivatives, 1-7, carrying different chains with a human telomere oligonucleotide, d(TTAGG)(4) was carried out in 0.1 M AcOK-AcOH buffer (pH 5.6) and 0.1 M KCl. Under this condition, this DNA could exist as the mixture of two-type tetraplex structures and these derivatives could bind to this DNA with strong affinity of 10(6) M(-1). The effect of the linker chain is not so large in those binding affinity, but the ligand 5 having piperazine skeleton in the linker chain had relative higher affinity for this tetraplex DNA than other derivatives. Large hypochromic effect of these derivatives upon binding to the tetraplex DNA suggested that the binding mode of these derivatives might contribute the stacking interaction between the naphthalene diimide and guanine tetraplex planes.

DOI： 10.1093/nass/nrl053

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=36048995908&origin=inward

Electrochemical detection of DNase I activity 査読有り

Katsuya Fujita,Masanori Kanazawa,Kosuke Mukumoto,Takahiko Nojima,Shinobu Sato,Hiroki Kondo,Michinori Waki,Shigeori Takenaka

Nucleic Acids Symposium Series 50 307 - 308 2006年11月

Linker chain effect of ferrocenylnaphtalene diimide derivatives on a tetraplex DNA binding 査読有り

Shinobu Sato,Hiroki Kondo,Shigeori Takenaka

Nucleic Acids Symposium Series 50 107 - 108 2006年11月

Ferrocenylnaphthalene diimide-based electrochemical detection of methylated gene 査読有り

Shinobu Sato,Hiroki Kondo,Koji Hokazono,Tatsuya Irie,Takashi Ueki,Michinori Waki,Takahiko Nojima,Shigeori Takenaka

Analytica Chimica Acta 578 ( 18 ) 82 - 87 2006年09月

Electrochemical detection of telomeric quadruplex DNA using ferrocenyl naphthalene diimide. 招待有り査読有り国際誌

Sato S., Kondo H., Nojima T., Takenaka S.

Nucleic acids symposium series (2004) ( 49 ) 237 - 238 2005年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Ferrocenylnaphthalene diimide (FND) could strongly bind to the synthetic telomere DNA, 5'-CAT GGT GGT TTG GGT TAG GGT TAG GGT TAG GGT TAC CAC-3', at 0.1 M KCl. The binding affinity of FND for the telomere DNA was ten times higher than that for calf thymus DNA under the conditions employed. Circular dichroism spectra suggested that the telomere DNA can form a tetraplex structure and FND can bind to it. Oligonucleotide extended by telomerase on the electrode could also be detected electrochemically by using FND, thereby suggesting the possibility that telomerase activity may be detected electrochemically.

DOI： 10.1093/nass/49.1.237

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=39049181510&origin=inward

Electrochamical detection of telomeric quadruplex DNA using ferrocenyl naphthalene diimide 査読有り

Shinobu Sato,Hiroki Kondo,Takahiko Nojima,Shigeori Takenaka

Nucleic Acids Symposium Series 49 237 - 238 2005年09月

Supramolecular complex formation by β-cyclodextrin and ferrocenylnaphthalene diimide-intercalated double stranded DNA and improved electrochemical gene detection 招待有り査読有り

Sato S., Nojima T., Waki M., Takenaka S.

Molecules 10 ( 6 ) 693 - 707 2005年06月

記述言語：英語掲載種別：研究論文（学術雑誌）

Ferrocenylnaphthalene diimide 1 can bind to double stranded DNA (dsDNA) by the threading intercalation mode and the resulting complex was stabilized further by β-cyclodextrin (CD) by forming a supramolecular complex. These complex formation processes were studied by spectroscopic, viscometric, and electrochemical means in the absence or presence of β-CD, Quantitative analysis by quartz crystal microbalance (QCM) and electrochemical experiments strongly suggested a 2:1 binding stoichiometry for β-CD to 1 threading-intercalated to the dsDNA-immobilized electrode. Owing to this supramolecular complex formation, electrochemical DNA detection based on 1 was improved considerably. © 2005 by MDPI.

DOI： 10.3390/10060693

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=27944470330&origin=inward

Supramolecular complex formationby be-ta-cyclodextrin and ferrocenylnaphthalene diimide-intercalated double stranded DNA and improved electrochemical gene detection 査読有り

Shinobu Sato,Takahiko Nojima,Michinori Waki,Shigeori Takenaka

Molecules 10 ( 6 ) 693 - 707 2005年06月

Electrochemical Telomerase Assay with Ferrocenylnaphthalene Diimide as a Tetraplex DNA-Specific Binder 査読有り

Shinob Sato,Hiroki Kondo,Takahiko Nojima,Shigeori Takenaka

Analytical Chemistry 77 ( 22 ) 7304 - 7309 2005年04月

Electrochemical gene detection based on supramolecular complex formation by ferrocenyl-β-cyclodextrin and adamantylnaphthalene diimide bound to double stranded DNA 査読有り国際誌

Sato S., Nojima T., Takenaka S.

Journal of Organometallic Chemistry 689 ( 25 SPEC. ISS. ) 4722 - 4728 2004年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

Adamantylnaphthalene diimide 1 was synthesized as a highly selective double stranded DNA (dsDNA) binding reagent. The binding studies with sonicated calf thymus DNA as a model of dsDNA revealed that 1 can bind to dsDNA by the threading mode, where the two adamantyl moieties are located in the major and minor grooves of dsDNA separately and the complex of 1 with DNA duplex was stabilized by capping of the adamantyl moieties of 1 bound to dsDNA by β-cyclodextrin. The adamantyl moieties of 1 could be incorporated also into the cavity of ferrocenyl-β-cyclodextrin (Fc-β-CD), resulting in the formation of a supramolecular complex. When this complex is formed on the DNA probe-immobilized electrode, electrochemical DNA detection was feasible: the electrode hybridized with target DNA gave rise to a current peak corresponding to the ferrocene oxidation upon treatment with 1 and Fc-β-CD. © 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jorganchem.2004.08.039

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=12144268399&origin=inward

Electrochemical gene detection by using adamantyl naphthalene diimide coupled with ferrocenyl-beta-cyclodextrin. 査読有り国際誌

Sato S., Nojima T., Kondo H., Takenaka S.

Nucleic acids symposium series (2004) ( 48 ) 103 - 104 2004年12月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

The adamantyl moieties of adamantylnaphthalene diimide (AND) can be incorporated into the cavity of ferrocenyl-beta-cyclodextrin even where they are bound to double stranded DNA by threading intercalation. When this ternary complex is formed on the DNA probe-immobilized electrode, electrochemical DNA detection is feasible: the electrode hybridized with target DNA gave rise to a current peak corresponding to the ferrocene oxidation upon treatment with AND and ferrocenyl-beta-cyclodextrin (Fc-beta-CD).

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=36049032772&origin=inward

Electrochemical gene detection by using adamanthyl naphthalene diimide coupled with ferrocenyl-beta-cyclodextrin 査読有り

Shinobu Sato,Takahiko Nojima,Hiroki Kondo,Shigeori Takenaka

Nucleic Acids Symposium Series 48 103 - 104 2004年11月

Electrochemical gene detection based on supramolecular complex formation by ferrocenyl-β-cyclodextrin and adamantylnaphthalene diimide bound to double stranded DNA 査読有り

Shinobu Sato,Takahiko Nojima,Shigeori Takenaka

Journal of Organometallic Chemistry 689 ( 25 ) 4722 - 4728 2004年04月

SNP analysis by using ferrocenyl naphthalene diimide (FND)-based electrochemical hybridization assay (EHA). 招待有り査読有り国際誌

Sato S., Maeda Y., Nojima T., Kondo H., Takenaka S.

Nucleic acids research. Supplement (2001) ( 3 ) 169 - 170 2003年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Ferrocenylnaphthalene diimide (FND) having double-stranded DNA preference was used as an electrochemical hybridization indicator and applied to the electrochemical hybridization assay (EHA) coupled with a DNA probe-immobilized gold electrode. The effect of DNA probe length and the position of SNP (single nucleotide polymorphism) site on the DNA probe were studied in the SNP analysis concerned with the side effect of an anticancer drug, irinotecan. SNP analysis was achieved with high precision when a DNA probe carrying the SNP site near the terminus of a DNA probe was used in the EHA.

DOI： 10.1093/nass/3.1.169

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0142181155&origin=inward

Binding of threading intercalator to nucleic acids: thermodynamic analyses. 査読有り国際誌

Torigoe H., Sato S., Yamashita K., Obika S., Imanishi T., Takenaka S.

Nucleic acids research. Supplement (2001) ( 2 ) 55 - 56 2002年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

The constant melting temperature upon the change in the oligonucleotide concentration showed that the oligonucleotide d(CGCTTTGCG) formed a intramolecular hairpin rather than a duplex with an internal loop. We examined the thermodynamic properties of the interaction between the threading intercalator, naphthalene diimides designated as NDI, and a series of hairpin oligonucleotides, d(CGCTnGCG) (n = 3, 4, 5, and 6) designated as CGCn. A complex with a molar ratio of 1:1 was formed between NDI and CGCn. Because the observed negative entropy change was unfavorable for the binding of NDI to CGCn, the binding was driven by the large negative enthalpy change. All of the thermodynamic parameters for the threading intercalation were not significantly changed by the difference in the loop length n. The stem region rather than the loop region of CGCn is mainly involved in the binding of NDI.

DOI： 10.1093/nass/2.1.55

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0041818280&origin=inward

Synthesis of adamantyl naphthalene diimide and its interaction with double stranded DNA. 査読有り国際誌

Sato S., Nojima T., Takagi M., Kondo H., Takenaka S.

Nucleic acids research. Supplement (2001) ( 2 ) 213 - 214 2002年01月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）

An adamantyl naphthalene diimide derivative (AND) was synthesized as a highly selective double stranded DNA binding reagent. The binding studies with sonicated calf thymus DNA revealed that AND can bind to double stranded DNA by the threading mode, where the two adamantyl moieties are located in the major and minor grooves of DNA duplex separately. In the presence of beta-cyclodextrin (beta-CD), the complex of AND with DNA duplex was stabilized by capping of the adamantyl moieties of AND by beta-CD. In other words, beta-CD serves as a stabilizer for the complex of AND with DNA duplex to result in an enhanced selectivity of AND for double stranded DNA over single stranded DNA.

DOI： 10.1093/nass/2.1.213

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0042318756&origin=inward

Ferrocenyl naphthalene diimide can bind to DNA·RNA hetero duplex: Potential use in an electrochemical detection of mRNA expression 査読有り

Sato S., Fujii S., Yamashita K., Takagi M., Kondo H., Takenaka S.

Journal of Organometallic Chemistry 637-639 476 - 483 2001年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

The novel ferrocenyl naphthalene diimide derivative 1 was synthesized by the condensation reaction between ferroceneacetic acid and terminal amino moieties of two imide substituents of naphthalene diimide. Stopped-flow analysis of the ligand 1 and DNA interaction revealed the following results: (i) the ligand binds to double stranded DNA more strongly than to single stranded DNA; (ii) the ligand does not have a bias against DNA sequence; (iii) the ligand can bind to the DNA·RNA hetero duplex more strongly than to the DNA·DNA duplex. These properties of 1 make it a suitable ligand for analysis of not only DNA but RNA. In fact, a current due to 1 was observed at 269 mV in the differential pulse voltammetric analysis of dA20-immobilized electrode in an electrolyte containing 1. The current increased markedly upon hybridization with polyU, whereas no current increase was obtained for polyA. Since the DNA·RNA hetero duplex is formed between sample RNA and DNA on the electrode, 1 may be used for the electrochemical detection of mRNA expression. © 2001 Elsevier Science B.V.

DOI： 10.1016/S0022-328X(01)00951-2

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0035803726&origin=inward

Analysis of the complex of oligonucleotide duplexes with ligands by MALDI-TOF mass spectroscopy 査読有り国際誌

Yamashita K., Sato S., Takamiya H., Takagi M., Takenaka S.

Chemistry Letters ( 7 ) 680 - 681 2001年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

The peaks for a complex of DNA-interacting ligands naphthalene monoimide (NMI), naphthalene diimide (NDI) and ethidium bromide and groove binding ligand Hoechst 33258 with a duplex of oligonucleotide 5′-CCCCGGGG-3′ were observed successfully in MALDI-TOF mass spectroscopy. The appearance of the peak of the complex depended on both the binding mode (classical intercalation, threading intercalation, or groove binding) and the duplex structure (fully matched or mismatched).

DOI： 10.1246/cl.2001.680

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0035635145&origin=inward

Analysis of the Complex of Oligonucleotide Duplexes of with Ligands by MALDI-TOF Mass Spectroscopy 査読有り

Kenichi Yamashita,Shinobu Sato,Hiroki Takamiya,Makoto Takagi,Shigeori Takenaka

Chemistry Letters 30 680 - 681 2001年04月

Ferrocenyl naphthalene diimide can bind to DNA-RNA hetero duplex: potential use in an electrochemical detection of mRNA expression 査読有り

Shinobu Sato,Satoshi Fujii,Kenichi Yamashita,Makoto Takagi,Hiroki Kondo,Shigeori Takenaka

Journal of Organometallic Chemistry 637639 476 - 483 2001年04月

Linker chain effect of ferrocenyl naphthalene diimide on a double stranded DNA preference. 査読有り国際誌

Sato S., Takamiya H., Yamashita K., Takagi M., Kondo H., Takenaka S.

Nucleic acids research. Supplement (2001) ( 1 ) 269 - 270 2001年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Naphthalene diimide derivative 1 carrying two 3-(ferrocenyl-methylamino)-propyl substituents was synthesized as a new hybrid indicator for electrochemical gene sensing. Ligand 1 showed a preference for double stranded DNA four-times larger than 2 previously described. The peak potential of 1 shifted 30 mV toward the negative side from that of 2, thereby shortening the time required for gene detection.

DOI： 10.1093/nass/1.1.269

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0042704862&origin=inward

Ferroceneacetyl naphthalene diimide as a new electrochemical ligand for DNA sensing. 査読有り国際誌

Sato S., Yamashita K., Takagi M., Takenaka S.

Nucleic acids symposium series ( 44 ) 171 - 172 2000年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

New electrochemically active DNA ligand 1 was synthesized by the connection of ferroceneacetic acid at the terminal amino moieties of two imide substituents of naphthalene diimide. Electrochemical experiments in aqueous solution containing DMSO showed that the selectivity for double stranded DNA of 1 has increased from that of ligand 2 previously reported. The peak current of 1 shifted toward the negative side from that of 2, thereby shortening the time required for gene detection.

DOI： 10.1093/nass/44.1.171

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=0141670229&origin=inward

　前のページ-次のページ　

1