Generation of Guanine鈥揟hymine Cross-Links in Human Cells by One-Electron Oxidation Mechanisms
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- 作者：Guru S. Madugundu ; J. Richard Wagner ; Jean Cadet ; Konstantin Kropachev ; Byeong Hwa Yun ; Nicholas E. Geacintov ; Vladimir Shafirovich
- 刊名：Chemical Research in Toxicology
- 出版年：2013
- 出版时间：July 15, 2013
- 年：2013
- 卷：26
- 期：7
- 页码：1031-1033
- 全文大小：199K
- 年卷期：v.26,no.7(July 15, 2013)
- ISSN：1520-5010
文摘
The one-electron oxidation of cellular DNA in cultured human HeLa cells initiated by intense nanosecond 266 nm laser pulse irradiation produces cross-links between guanine and thymine bases (G*-T*), characterized by a covalent bond between C8 guanine (G*) and N3 thymine (T*) atoms. The DNA lesions were quantified by isotope dilution LC-MS/MS methods in the multiple reaction-monitoring mode using isotopically labeled [15N, 13C]-nucleotides as internal standards. Among several known pyrimidine and 8-oxo-7,8-dihydroguanine lesions, the G*-T* cross-linked lesions were detected at levels of 0.21 and 1.19 d(G*-T*) lesions per 106 DNA bases at laser intensities of 50 and 280 mJ/cm2/pulse, respectively.