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化学学报
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化学学报 ›› 2010, Vol. 68 ›› Issue (08): 753-759. 上一篇    下一篇

研究论文

鸟嘌呤四链体中K＋移动路径的预测

王华荣，刘翠，杨忠志*   

  1. (辽宁师范大学化学化工学院 大连 116029)
  • 投稿日期:2009-09-11 修回日期:2009-11-24 发布日期:2009-12-28
  • 通讯作者: 杨忠志 E-mail:zzyang@lnnu.edu.cn
  • 基金资助:

    国家自然科学基金

Prediction of the Exchanging Route of K＋ in Guanine-Quadruplex

WANG Hua-Rong, LIU Cui, YANG Zhong-Zhi   

  1. (Chemistry and Chemical Engineering Faculty, Liaoning Normal University, Dalian 116029)
  • Received:2009-09-11 Revised:2009-11-24 Published:2009-12-28

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结合鸟嘌呤四链体(G4)的结构特点, 取G4中的一个K＋与一片g-tetrad (g-tetrad-K＋)为研究对象, 和一个K＋与两片g-tetrad (1,2-g-tetrads-K＋和2,3-g-tetrads-K＋)为研究对象. 为g-tetrad-K＋, 1,2-g-tetrads-K＋和2,3-g-tetrads-K＋三体系中的K＋设计了几种移动路径, 来探讨G4中K＋与g-tetrad的作用. 首先分别应用从头计算MP2/6-31G(d,p)和ABEEMσπ/MM(σπ水平的原子键电负性均衡原理融入到分子力学)方法, 对g-tetrad-K＋中K＋移动过程中体系的结构和能量变化进行了详细研究. 结果表明ABEEMσπ/MM方法能够准确地描述g-tetrad-K＋体系的结构、结合能等性质. 为了更接近实际体系, 进而用ABEEMσπ/MM方法预测了更大的体系: 一个K＋和两片g-tetrad. 由于体系较大, MP2方法无法计算其结合能. ABEEMσπ/MM方法对g-tetrad-K＋, 1,2-g-tetrads-K＋和2,3-g-tetrads-K＋体系中K＋移动而产生的结合能变化表明: 如果吸收足够的能量, G4中K＋最容易沿α方向移出.

关键词: 平面G-四方结构, 钾离子, 从头计算, ABEEMσπ/MM

Considering the configuration characteristic, this paper takes K＋ and one g-tetrad (g-tetrad-K＋) as studied object, together with K＋ and two g-tetrads (1,2-g-tetrads-K＋ and 2,3-g-tetrads-K＋) in guanine-quadruplex structure (G4) as studied object. We have designed several moving routes for K＋ in g-tetrad-K＋, 1,2-g-tetrads-K＋ and 2,3-g-tetrads-K＋ three systems to explore the interaction between g-tetrad and K＋. First, ab initio [MP2/6-31G(d,p)] and ABEEMσπ/MM (Atom Bond Electronegativity Equalization Method at σπ level fused into Molecular Mechanics) methods have been used to investigate the changes of structure and energy, when K＋ moves in g-tetrad-K＋. The results indicate that ABEEMσπ/MM can accurately describe the properties of the g-tetrad-K＋ system structure and energy. To approaching the practical system, ABEEMσπ/MM has been used to explore the bigger system K＋ and two g-tetrads, which is too big to calculate the interaction energy using MP2. The changes of the interaction energy from ABEEMσπ/MM, when K＋ moves in g-tetrad-K＋, 1,2-g-tetrads-K＋ and 2,3-g-tetrads-K＋ systems indicate that if absorb enough energy, it is easiest for the K＋ in G4 moves out of the cavity along the α direction.

Key words: guanine-tetrad, potassium ion, ab initio, ABEEMσπ/MM

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