物理化学学报 >> 2015, Vol. 31 >> Issue (6): 1007-1014.doi: 10.3866/PKU.WHXB201504171

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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

李敏杰, 刁玲, 寇莉, 李重杲, 陆文聪   

  1. 上海大学化学系, 创新药物研究中心, 上海200444
  • 收稿日期:2015-02-09 修回日期:2015-04-17 发布日期:2015-06-05
  • 通讯作者: 李敏杰 E-mail:minjieli@shu.edu.cn
  • 基金资助:

    国家自然科学基金(21273145)资助项目

Hydroxyl Radical Reaction with the Guanine-Cytosine Base Pair: A Density Functional Theory Study

LI Min-Jie, DIAO Ling, KOU Li, LI Zhong-Gao, LU Wen-Cong   

  1. Innovative Drug Research Center, Department of Chemistry, Shanghai University, Shanghai 200444, P. R. China
  • Received:2015-02-09 Revised:2015-04-17 Published:2015-06-05
  • Contact: LI Min-Jie E-mail:minjieli@shu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21273145).

摘要:

为了解决年龄衰老、基因突变和癌症等问题, 理解DNA的氧化损伤机理非常重要. 本文利用密度泛函方法和极化连续介质模型在液相条件下研究了羟基自由基夺取鸟嘌呤-胞嘧啶(GC)碱基对上5 个氢原子的反应机理. 研究结果表明, 所有的脱氢反应路径都是放热过程, 热力学上五个脱氢反应路径形成自由基的稳定性顺序是(H2b-GC)·>(GC-H4b)·>(GC-H6)·>(GC-H5)·~(H8-GC)·, 其中H2b反应路径的能量变化最大, 说明该反应平衡时的转化率最高. 动力学上, 相对于反应复合物的局部反应能垒大小顺序是H2b

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

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 all the abstraction reactions in GC base pair were thermodynamically 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 all 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 following order: H2b

Key words: DNA oxidative damage, Hydroxyl radical, Guanine-cytosine base pair, Reaction mechanism, Density functional theory

MSC2000: 

  • O641