An analysis of the interactions between nucleic acid bases: Hydrogen-bonded base pairs
An analysis of the interactions between nucleic acid bases: Hydrogen-bonded base pairs
复制标题
核酸碱基之间相互作用的分析：氢键碱基对
DOI：
10.1021/jp021805r
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发表时间：
2003
影响因子：
2.9
通讯作者：
S. M. Cybulski
中科院分区：
文献类型：
--
作者：
R. R. Toczyłowski;S. M. Cybulski
用二阶Miller-Plesset微扰理论(MP2)和6-31G*(0.25)基组和修正的Aug-cc-pVDZ基组对32个核酸氢键碱基对进行了计算。C-S对称性的络合物是由刚性单体构成的，这使得我们可以根据质心分离和欧拉角对它们的几何结构进行紧凑的参数化。研究了相互作用能及其分量与极小值附近的小几何变化的关系。虽然色散能和感生能也起着重要作用，但静电能和交换能是整个相互作用能中最重要的组成部分。交换能虽然在极小值时通常不是最大的，但它是单体在络合物平面内旋转的最各向异性分量。对电子相关分量的分析表明，吸引色散能的影响在很大程度上被对交换能的排斥关联修正所抵消。
Thirty-two nucleic acid hydrogen-bonded base pairs have been examined using second-order Miller-Plesset perturbation theory (MP2) and the 6-31G*(0.25) and modified aug-cc-pVDZ basis sets. Complexes of C s symmetry have been constructed from rigid monomers which allowed us to use a compact parametrization of their geometry based on the center of mass separation and Euler angles. The dependence of the interaction energy and its components on small geometrical modifications around the minima have been examined. The electrostatic and the exchange energies have been found to be the most important components of the overall interaction energy, although the dispersion and the induction energies also play important roles. The exchange energy, while typically not the largest in magnitude at the minima, is the most anisotropic component for rotations of the monomers in the plane of the complex. The analysis of the electron-correlated components reveals that the effect of the attractive dispersion energy is to a large degree canceled out by the repulsive correlation correction to the exchange energy.