色氨酸及其肽对cis-syn型1,3-二甲基胸腺嘧啶二聚体的光敏化裂解作用  

Photosensitized Splitting of Cis-syn 1,3-Dimethylthymine Dimer by Tryptophan and Its Peptides

作　　者：晏利琴[1] 宋钦华[1] 黑晓明[1] 郭庆祥[1] 俞书勤[2] 

机构地区：[1]中国科学技术大学化学系,合肥230026 [2]中国科学技术大学化学物理系,合肥230026

出　　处：《化学学报》2003年第9期1503-1507,共5页Acta Chimica Sinica

基　　金：国家自然科学基金 (Nos.30 0 0 0 0 36 ;2 0 2 730 66);高等学校博士学科点专项科研基金资助项目

摘　　要：通过荧光猝灭实验和测定二聚体裂解程度的辐照实验 ,研究色氨酸 (Trp)及其二肽色氨酰苯丙氨酸 (Trp Phe)对cis syn型 1,3 二甲基胸腺嘧啶二聚体 (DMTD)的光敏化裂解作用 .结果表明 ,色氨酸及其二肽在较强光 (λ >2 90nm)辐照下 ,主要通过双光子电离生成的水合电子 (e-aq)导致二聚体裂解 ,其次 ,通过激发单重态与二聚体间的电子转移导致二聚体裂解 .另外一导致二聚体裂解的可能途径 :色氨酸残基激发三重态与二聚体间的电子转移光敏化二聚体裂解 .Photosensitized splitting of cis-syn 1,3-dimethylthymine dimer by tryptophan and its peptides (Trp-Phe) was studied based on the fluorescence quenching experiments and irradiation experiments determining the splitting percentage of the dimer. It was revealed that 1, 3-dimethylthylmine dimer was mainly splitted by e(aq)(-) resulted from two-photon ionization of Trp and its peptides under irradiation with light (lambda > 290 nm). Moreover, the excited singlet state of Trp and its peptides can transfer an electron to the dimer and make it splitted. In addition, the excited triplet state of Trp can also transfer an electron to the dimer and make it splitted.

关 键 词：色氨酸 肽 cis-syn 1 3-二甲基胸腺嘧啶二聚体 光敏化裂解 DNA光复活 DNA光解酶 光复合酶 

分 类 号：O621.2[理学—有机化学]