物理化学学报Issue(6)：1007-1014,8.DOI:10.3866/PKU.WHXB201504171
羟基自由基和鸟嘌呤-胞嘧啶碱基对反应的密度泛函理论研究
Hydroxyl Radical Reaction with the Guanine-Cytosine Base Pair:A Density Functional Theory Study
摘要
Abstract
To address problems such as aging, mutation, and cancer, it is of great importance to understand the damage mechanism of DNA induced by hydroxyl radical. In this study, the abstraction reaction mechanism of hydroxyl radical with guanine-cytosine (GC) base pair in aqueous phase under the polarized continuum model (PCM) has been explored by using density functional theory (DFT). The results indicated that al the abstraction reactions in GC base pair were thermodynamical y exothermic, and the stability of dehydrogenation radicals decreased in the order of (H2b-GC)•>(GC-H4b)•>(GC-H6)•>(GC-H5)•~(H8-GC)•. The reaction energy of H2b abstraction pathway was the lowest among al investigated pathways, thus indicating that the reaction conversion of (H2b-GC)•was the highest. In the five hydrogen abstraction pathways, the local energy barriers with respect to the corresponding reactant complexes increased in the fol owing order:H2b<H4b<H5<H6<H8, thereby suggesting that the H2b abstraction pathway was the most rapid. Thus, H2b abstraction process was the most likely favorable reaction pathway. Another compatible pathway would be the H4b abstraction, fol owed by H6 and H5 abstraction pathways in thermodynamics and in kinetics. H8 abstraction process was the least favorable pathway, as consistent with the formation of hydroxylation adduct observed experimental y rather than the hydrogen abstraction radical.关键词
DNA氧化损伤/羟基自由基/鸟嘌呤-胞嘧啶碱基对/反应机理/密度泛函理论Key words
DNA oxidative damage/Hydroxyl radical/Guanine-cytosine base pair/Reaction mechanism/Density functional theory分类
化学化工引用本文复制引用
李敏杰,刁玲,寇莉,李重杲,陆文聪..羟基自由基和鸟嘌呤-胞嘧啶碱基对反应的密度泛函理论研究[J].物理化学学报,2015,(6):1007-1014,8.基金项目
The project was supported by the National Natural Science Foundation of China (21273145).国家自然科学基金(21273145)资助项目 （21273145）
