荧光探针氨氯吡咪对DNA双链中单链断裂损伤的识别研究  

Recognition of a single strand breaks in ds-DNA using a fluorescence probe amiloride

作　　者：胡亮亮[1] 张文艳[1] 刘蓓[1] 高强[1] 

机构地区：[1]陕西省生命分析化学重点实验室,陕西师范大学化学与材料科学学院,陕西西安710062

出　　处：《陕西师范大学学报（自然科学版）》2010年第6期49-52,共4页Journal of Shaanxi Normal University：Natural Science Edition

基　　金：国家自然科学青年基金资助项目(20805029);陕西师范大学校级重点资助项目(995427)

摘　　要：将氨氯吡咪选择性地嵌入ds-DNA中单链断裂损伤所形成的缺口位点,并通过氢键与缺口位点处的碱基结合从而导致氨氯吡咪荧光猝灭,据此建立了荧光检测DNA单链断裂损伤的新方法.氨氯吡咪荧光的猝灭程度与缺口位点处碱基类型相关,当缺口位点处的碱基为T碱基时,荧光猝灭程度最大.荧光滴定实验表明氨氯吡咪和存在缺口位点的ds-DNA是1∶1结合,结合常数为105mol/L数量级.在正常ds-DNA和存在单链断裂损伤的ds-DNA的溶液中加入氨氯吡咪,在紫外灯照射下通过目视法即可分辨出二者荧光强度的不同.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.

关 键 词：荧光 DNA单链断裂损伤 氨氯吡咪 氢键 识别 

分 类 号：Q657.3[生物学—生物物理学] TQ937[化学工程]