Kinetics and mechanism of electron-induced splitting of a cyclobutane pyrimidine dimer with or without an electron acceptor  

作　　者：晏利琴 宋钦华 黑晓明 王文锋 郭庆祥 

机构地区：[1]Department of Chemistry, University of Science and Technology of China, Hefei 230026, China [2]Laboratory of Radiation Chemistry, Shanghai Institute of Nuclear Research, Chinese Academy of Sciences, Shanghai 201800, China

出　　处：《Science China Chemistry》2003年第5期439-444,共6页中国科学（化学英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(Grant No.30000036);Special Fund for Doctoral Program fromthe Ministry of Education of China and Foundation of University of Science and Technology of China.

摘　　要：Utilizing a pulse radiolysis equipment with time-resolved optical detector, kinetic processes of electron-induced splitting of cis-syn 1,3-dimethyluracil cyclobutane dimer (DMUD) in aqueous solution were investigated in the presence or absence of riboflavin (RF) or flavin adenine dinucleotide (FAD). It has been observed that the cyclobutane pyrimidine dimer reacting with hydrated electron splits spontaneously to give a monomer and a monomer radical anion, and the anion transfers one electron to RF or FAD. From the buildup kinetics of radical species, the rate constants of electron transfer from the monomer radical anion to RF and FAD have been determined. On the basis of comparison of the interactions between DMUD and hydrated electron in the presence and absence of RF or FAD, a chain reaction process in the absence of RF or FAD has been demonstrated.Utilizing a pulse radiolysis equipment with time-resolved optical detector, kinetic processes of electron-induced splitting of cis-syn 1,3-dimethyluracil cyclobutane dimer (DMUD) in aqueous solution were investigated in the presence or absence of riboflavin (RF) or flavin adenine dinucleotide (FAD). It has been observed that the cyclobutane pyrimidine dimer reacting with hydrated electron splits spontaneously to give a monomer and a monomer radical anion, and the anion transfers one electron to RF or FAD. From the buildup kinetics of radical species, the rate constants of electron transfer from the monomer radical anion to RF and FAD have been determined. On the basis of comparison of the interactions between DMUD and hydrated electron in the presence and absence of RF or FAD, a chain reaction process in the absence of RF or FAD has been demonstrated.

关 键 词：CYCLOBUTANE pyrimidine dimer  pulse radiolysis  riboflavin  FLAVIN adenine dinucleotide  electron transfer  DNA photoreactivation. 

分 类 号：O631[理学—高分子化学]