Evidence for glycosidic bond rotation in a nucleobase peroxyl radical and its effect on tandem lesion formation |
| |
Authors: | Hong In Seok Carter K Nolan Greenberg Marc M |
| |
Institution: | Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218, USA. |
| |
Abstract: | Nucleobase peroxyl radicals are the major reactive intermediates formed in DNA when the biopolymer is exposed to gamma-radiolysis under aerobic conditions. The major reaction pathways for the peroxyl radical (1) derived from 5,6-dihydro-2'-deoxyuridin-6-yl involve pi-bond addition to or hydrogen atom abstraction from the adjacent nucleotides to produce tandem lesions. The ability to independently generate 1 at a defined site in DNA enabled us to probe its reactivity by varying the local DNA structure. The effect of DNA structure variation reveals that 1 reacts from its syn- and anti-conformations in competition with trapping by thiol. These experiments also reveal that tandem lesions will be produced as a mixture of diastereomers, which could impact their biological effects. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|