补骨脂素-UVA对端粒DNA的直接作用及其原子力显微镜研究  

Direct Effects of Psoralen-photosensitization on Telomeres and its Studies of Atomic Force Microscopy

作　　者：曹恩华[1] 陈艾[1] 张晓嫣[1] 孙雪光[1] 秦静芬[1] 刘大格[2] 白春礼[2] 

机构地区：[1]中国科学院生物物理所,中国北京100101 [2]中国科学院化学所,中国北京100080

出　　处：《激光生物学报》2001年第1期1-6,共6页Acta Laser Biology Sinica

基　　金：中国科学院"九五"重大基础支持项目! (KJ 95 1 AL 5 0 2 0 2 )

摘　　要：HeLa细胞DNA ,经Rsal(12 5 0U)和HinF1(12 5 0U)内切酶酶解、Bio gelP 2柱分离 ,得到端粒DNA。原子力显微镜 (AFM)的直接观测结果表明在UVA照射下 ,补骨脂素可结合到端粒DNA的特殊位置 ,其光交链产物随照射时间增长而增加。与此同时 ,P5 3表达和端粒酶活性发生变化。纯化的端粒DNA片段在AFM下呈带尾的T 环结构 (T loop)。按其高度判断T 环部分为双链DNA结构 ,T 环与尾部交接处具有三链或四链结构特征。DNA from HeLa cells was cleaved with Rasl and Hinf ,and then purified by Bio-Gel P-2 column.Results showed that upon near-UV-irradiation,psoralen could be targeted to the repetitive sequences of telomeres and the psoralen cross-linking products increased with increase of irradiation time.At same time,the changes of the expression of P53 oncogene and telomerase was were observed. Large duplex loops (T-loop) with a tail were observed directly by AFM.The loop-tail junction position was assumed to be a tri-or tetra- strand DNA structure according to its apparent height.

关 键 词：补骨脂素 HELA细胞 端粒DNA T-LOOP 原子力显微镜 

分 类 号：Q58[生物学—生物化学] Q6－33