高等学校化学学报 ›› 2016, Vol. 37 ›› Issue (8): 1460.doi: 10.7503/cjcu20160346

• 物理化学 • 上一篇    下一篇

精氨酸侧链和核酸碱基间离子氢键作用强度分析

李蕾, 黄翠英, 姜笑楠, 高希婵, 王长生()   

  1. 辽宁师范大学化学化工学院, 大连 116029
  • 收稿日期:2016-05-16 出版日期:2016-07-19 发布日期:2016-07-19
  • 作者简介:

    联系人简介: 王长生, 男, 博士, 教授, 博士生导师, 主要从事理论与计算化学研究. E-mail: chwangcs@lnnu.edu.cn

  • 基金资助:
    国家自然科学基金(批准号: 21173109, 21573098)和大连市领军人才项目资助

Ionic Hydrogen Bonding Between Arginine Side Chain and Nucleic Acid Bases

LI Lei, HUANG Cuiying, JIANG Xiaonan, GAO Xichan, WANG Changsheng*()   

  1. School of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029, China
  • Received:2016-05-16 Online:2016-07-19 Published:2016-07-19
  • Contact: WANG Changsheng E-mail:chwangcs@lnnu.edu.cn
  • Supported by:
    Supported by the National Natural Science Foundation of China(Nos.21173109, 21573098) and the Program for Leading Figures in Dalian, China

摘要:

采用MP2/6-31+G(d,p)方法优化得到了22个由精氨酸侧链与碱基尿嘧啶、 胸腺嘧啶、 胞嘧啶、 鸟嘌呤及腺嘌呤形成的氢键复合物的气相稳定结构, 使用包含BSSE校正的MP2/aug-cc-pVTZ方法计算得到了复合物的气相结合能, 通过MP2/6-31+G(d,p)方法和PCM模型优化得到了复合物的水相稳定结构, 采用MP2/aug-cc-pVTZ方法和PCM模型计算得到了复合物的水相结合能. 研究发现, 精氨酸侧链与碱基间的离子氢键作用强度与单体间电荷转移量、 氢键临界点电子密度及二阶作用稳定化能密切相关. 与中性氢键相比, 离子氢键作用具有更显著的共价作用成分. 研究还发现, 精氨酸侧链和碱基间形成的氢键复合物的稳定性次序可以通过氢键受体碱基分子上氧原子和氮原子的质子化反应焓变进行预测, 质子化反应焓变越负, 形成的氢键复合物越稳定.

关键词: 精氨酸侧链, 核酸碱基, 离子氢键, 结合能, 质子化反应焓变

Abstract:

The optimal structures of twenty-two hydrogen-bonded complexes composed of one charged arginine side chain molecule and one nucleic acid base in gas phase were obtained at the MP2/6-31+G(d,p) level. The binding energies in gas phase were evaluated at the MP2/aug-cc-pVTZ level including basis set superposition error(BSSE) correction. The optimal structures for these hydrogen-bonded complexes in water solvent were further obtained by using PCM model combined with the MP2/6-31+G(d,p) method. The binding energies in water solvent were evaluated by using PCM model combined with the MP2/aug-cc-pVTZ method. It is found that the ionic hydrogen bonding strength between the arginine side chain and one of the five nucleic acid bases highly correlates to the charge transfer between the two monomers, the electron density at the hydrogen bond critical point, and the second-order stabilization energy. Compared to the neutral hydrogen bond, the ionic hydrogen bond exhibits more significant covalent character. It is also found that the stability of the hydrogen-bonded complexes can be predicted according to the enthalpy change of the protonation reaction of the nucleic acid bases. The more negative the enthalpy change of the protonation reaction, the more stable the hydrogen-bonded complexes.

Key words: Arginine side chain, Nucleic acid base, Ionic hydrogen bond, Binding energy, Enthalpy change of protonation reaction

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