物理化学学报 >> 2014, Vol. 30 >> Issue (2): 257-264.doi: 10.3866/PKU.WHXB201312031

理论与计算化学 上一篇    下一篇

水环境对GC和AT碱基对质子转移的影响

吴颖曦, 王红艳, 林月霞   

  1. 西南交通大学物理科学与技术学院, 成都610031
  • 收稿日期:2013-09-10 修回日期:2013-12-03 发布日期:2014-01-23
  • 通讯作者: 王红艳 E-mail:hongyanw@home.swjtu.edu.cn
  • 基金资助:

    国家自然科学基金(10974161,11174237),国家重点基础研究发展规划项目(973)(2013CB328904)和四川省科技厅应用基础项目(2013JY0035)资助

Aqueous Solution Effects on the Proton-Transfer Processes of GC and AT Base Pairs

WU Ying-Xi, WANG Hong-Yan, LIN Yue-Xia   

  1. School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031, P. R. China
  • Received:2013-09-10 Revised:2013-12-03 Published:2014-01-23
  • Contact: WANG Hong-Yan E-mail:hongyanw@home.swjtu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (10974161, 11174237), National Key Basic Research Program of China (973) (2013CB328904), and Application Basic Program of Sichuan Province, China (2013JY0035).

摘要:

采用B3LYP/DZP++的方法研究了第一水化层作用和连续化处理的水溶剂作用对鸟嘌呤-胞嘧啶(GC)碱基对和腺嘌呤-胸腺嘧啶(AT)碱基对质子转移反应的影响. GC和AT碱基对在连续化水溶剂作用下,均发生单质子转移(SPT1)和分步的双质子转移(DPT),而在第一水化层5 个水分子的作用下(GC·5H2O,AT·5H2O)或同时考虑第一水化层作用和连续化水溶剂作用(GC·5H2O+PCM,AT·5H2O+PCM)时,GC和AT碱基对的质子转移均只得到单质子转移反应(SPT1). 单质子转移过程中的活化能变化情况表明:第一水化层对GC和AT碱基对结构和质子转移影响较大,水环境对碱基对的作用主要发生在第一水化层.

关键词: 密度泛函理论, 碱基对, 质子转移, 第一水化层, 连续化的水溶剂作用

Abstract:

The effects of the first hydration shell and the bulk solvation effects on the proton-transfer processes of guanine-cytosine (GC) and adenine-thymine (AT) base pairs are studied based on density functional theory, using the B3LYP method and DZP++ basis set. The proton-transfer mechanisms of the GC and AT base pairs in bulk solvation are first single-proton transfer (SPT1) and stepwise double-proton transfer (DPT). When only the first hydration shell surrounded by five water molecules (GC ·5H2O, AT· 5H2O), or both the first hydration shell and bulk solvation effects through polarizable continuum model (PCM) (GC·5H2O+PCM, AT·5H2O+PCM) are considered, only the first single-proton-transfer mechanism (SPT1) is found. The proton- transfer activation energies of the GC and the AT base pairs show that the majority of the hydration effects come from the first hydration shell through hydrogen- bond interactions, therefore the first hydration shell greatly influences the base pair structures and proton-transfer mechanism.

Key words: Density functional theory, Base pair, Proton-transfer, First hydration shell, Bulk solvation effect

MSC2000: 

  • O641