化学学报 ›› 2003, Vol. 61 ›› Issue (9): 1503-1507. 上一篇    下一篇

研究论文

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

晏利琴;宋钦华;黑晓明;郭庆祥;俞书勤   

  1. 中国科学技术大学化学系;中国科学技术大学化学物理系
  • 发布日期:2003-09-15

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

Yan Liqin;Songn Qinhua;Hei Xiaoming;Guo Qingxiang;Yu Shuqin   

  1. Department of Chemistry, University of Science and Technology of China;Department of Chemical Physics, University of Science and Technology of China
  • Published:2003-09-15

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 > 290 nm) 辐照下,主要通过双光子电离生成的光合电子(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。

关键词: 色氨酸, 环丁烷 P, 胸腺嘧啶, 二聚体, 三重态, 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 deteimining the splitting percentage of the dimer. It was revealed that 1,3-dimethylthymine dimer was mainly splitted by e_(aq)~- resulted from Lwo-photon ionization of Trp and its peptides under irradiation with light (λ > 290 ran) . 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.

Key words: TRYPTOPHAN, CYCLOBUTANE P, THYMINE, DIMER, TRIPLET, PYROLYSIS

中图分类号: