偶氮苯调控DNA解链的机理研究  

Mechanism research of melting of DNA duplex by photoisomerization of azobenzene

作　　者：袁帅[1] 王丹[1] 白明泽[1] 魏照林[1] 蒙平[1] 豆育升[1] 

机构地区：[1]重庆邮电大学计算化学研究所,重庆400065

出　　处：《重庆邮电大学学报（自然科学版）》2009年第6期821-824,共4页Journal of Chongqing University of Posts and Telecommunications(Natural Science Edition)

基　　金：国家自然科学基金(20773168);重庆邮电大学科研启动基金(A2006-81)

摘　　要：采用半经典动力学模拟的方法研究了偶氮苯、2-甲基偶氮苯及2,6-二甲基偶氮苯3种分子的光致异构化反应,上述3种偶氮分子结构由反式变为顺式的时间顺序是偶氮苯2-甲基偶氮苯2,6-二甲基偶氮苯,说明光致异构化反应的活化能顺序是偶氮苯2-甲基偶氮苯2,6-二甲基偶氮苯。这就意味着2,6-二甲基偶氮苯发生光致异构化反应必须吸收足够高能量形成活化分子,从而克服过渡态能垒。较高的能量状态决定了分子在过渡态的热力学稳定性降低,因此反式的2,6-二甲基偶氮苯在过渡态更容易失活,形成顺式异构体。模拟结果解释了2,6-二甲基偶氮苯对DNA解链过程调控效率最高的实验现象。Semiclassical dynamics simulation was used to research photoisomerization of azobenzene, 2-methyl azobenzene and 2, 6-dimethyl azobenzene. The isomerization time which arranges as azobenzene 〈 2-methyl azobenzene 〈 2, 6-dimethyl azobenzene indicates that the sequence of activation energy of above three azo molecules is azobenzene 〈 2-methyl azobenzene 〈 2, 6-dimethyl azobenzene. It suggests that 2, 6-dimethyl azobenzene must absorb energy high enough so that overcomes energy barrier of transition state. Consequently trans-2, 6-dimethyl azobenzene facilitates deexeitation in transition state and forms eis isomer. The resuhs explain the experimental phenomenon that 2, 6-dimethyl-azobenzene regularizes melting of DNA duplex most effectively.

关 键 词：偶氮苯 甲基衍生物 光致异构化 DNA解链 动力学模拟 

分 类 号：Q632[生物学—生物物理学]