https://scholars.lib.ntu.edu.tw/handle/123456789/377349
標題: | Assaying the binding strength of G-quadruplex ligands using single-molecule TPM experiments | 作者: | Liu, S.-W. Chu, J.-F. Tsai, C.-T. Fang, H.-C. Chang, T.-C. Li, H.-W. HUNG-WEN LI |
關鍵字: | G-quadruplex; G-quadruplex binding ligand; Single molecule tethered particle motion | 公開日期: | 2013 | 卷: | 436 | 期: | 2 | 起(迄)頁: | 101-108 | 來源出版物: | Analytical Biochemistry | 摘要: | G-quadruplexes are stable secondary structures formed by Hoogsteen base pairing of guanine-rich single-stranded DNA sequences in the presence of monovalent cations (Na+ or K+). Folded G-quadruplex (G4) structures in human telomeres have been proposed as a potential target for cancer therapy. In this study, we used single-molecule tethered particle motion (TPM) experiments to assay the binding strength of possible G4 ligands. We found that individual single-stranded DNA molecules containing the human telomeric sequence d[AGGG(TTAGGG)3] fluctuated between the folded and the unfolded states in a 10 mM Na+ solution at 37 °C. The durations of folded and unfolded states were single-exponentially distributed, and in return the folding and unfolding rate constants were 1.68 ± 0.01 and 1.63 ± 0.03 (s-1), respectively. In the presence of G4 ligands, such as TMPyP4, DODCI, BMVC, and BMVPA, the unfolding rate constant decreased appreciably. In addition, combining the Cu2+-induced G4 unfolding and TPM assay, we showed that BMVC and TMPyP4 are better G4 stabilizers than DODCI. The capability of monitoring the fluctuation between the folded and the unfolded state of G4 DNA in real time allows the determination of both kinetic and thermodynamic parameters in a single measurement and offers a simple way to assay binding strength under various conditions. ? 2013 Elsevier Inc. All rights reserved. |
URI: | http://www.scopus.com/inward/record.url?eid=2-s2.0-84874943220&partnerID=MN8TOARS http://scholars.lib.ntu.edu.tw/handle/123456789/377349 |
DOI: | 10.1016/j.ab.2013.01.021 | SDG/關鍵字: | DNA; DNA sequences; Positive ions; Rate constants; Folding and unfolding; G-quadruplexes; Hoogsteen base pairing; Kinetic and thermodynamic parameters; Particle motions; Secondary structures; Single-stranded DNA molecules; Telomeric sequences; Ligands; copper; guanine quadruplex; ligand; single stranded DNA; article; binding assay; controlled study; ligand binding; measurement; molecule; priority journal; single molecule tethered particle motion; telomere; thermodynamics |
顯示於: | 化學系 |
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