Recognition of a single strand breaks in ds-DNA using a fluorescence probe amiloride
HU Liang-liang, ZHANG Wen-yan, LIU Bei, GAO Qiang*
(Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, College of Chemistry and Materials Science, Shaanxi Normal University, Xi′an 710062, Shaanxi, China)
Abstract:
Gap site in ds-DNA, which produced by a single strand breaks (SSBs), is a important DNA lesion. Fluorescence probe amiloride was found to selectively bind to gap site in ds-DNA with a binding constant (K11) about 105 mol/L at 15 ℃, and this binding was accompanied by significant quenching of its fluorescence. Efficiency of fluorescence quenching of amiloride was dependent on the base at gap site, and the most efficient quenching was obtained when the base at gap site was thymine (T). While no significant changes in the fluorescence was observed in the presence of normal duplexes, the fluorescent quenching of amiloride can be detection even by naked eyes after binding to gap site in ds-DNA.
KeyWords:
fluorescence; DNA single strand breaks (SSBs); amiloride; hydrogen bonding; recognition
