Photosensitized splitting of cis-syn 1,3-dimethyluracil dimer by tryptophan and its peptides  

作　　者：HEIXiaoming SONGQinhua LIJing GUOQingxiang 

机构地区：[1]DepartmentofChemistry,UniversityofScienceandTechnologyofChina,Hefei230026,China

出　　处：《Progress in Natural Science:Materials International》2004年第5期453-458,共6页自然科学进展·国际材料（英文版）

基　　金：Supported by the National Natural Science Foundation of China (Grants No. 30000036, 20273066) ; Special Fund for Doctoral Programme of the State Education Commission of China (2000035821)

摘　　要：Photosensitized splitting of cis-syn 1,3-dimethyluracil dimer by tryptophan (Trp) and its peptides (Trp-Tyr and Trp-Phc) is studied by fluorescence quenching experiments and irradiation experiments. It reveals that 1, 3-dimethyluracil dimer is mainly split by eaq- resulting from two-photon ionization of Trp and its peptides under irradiation with light (λ >290nm). Moreover, the excited singlet state of Trp and its peptides can transfer an electron to the dimer, which splits and gives two pyrimidines. In addition, because of its lower oxidative potential, the excited triplet state of Trp-Tyr can also split the dimer via transfering an electron to the dimer.Photosensitized splitting of cis-syn 1,3-dimethyluracil dimer by tryptophan (Trp) and its peptides (Trp-Tyr and Trp-Phe) is studied by fluorescence quenching experiments and irradiation experiments. It reveals that 1,3-dimethyluracil dimer is mainly split by eaq^- resulting from two-photon ionization of Trp and its peptides under irradiation with light ( λ > 290 nm). Moreover, the excited singlet state of Trp and its peptides can transfer an electron to the dimer, which splits and gives two pyrimidines. In addition, because of its lower oxidative potential, the excited triplet state of Trp-Tyr can also split the dimer via transfering an electron to the dimer.

关 键 词：TRYPTOPHAN cyclobutane dimethyluracil dimer DNA photoreactivation. 

分 类 号：Q345[生物学—遗传学] Q523