Post Hartree-Fock Studies of the Canonical Watson-Crick DNA Base Pairs: Molecular Structure and the Nature of Stability
Post Hartree-Fock Studies of the Canonical Watson-Crick DNA Base Pairs: Molecular Structure and the Nature of Stability
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经典 Watson-Crick DNA 碱基对的 Hartree-Fock 后研究：分子结构和稳定性本质
DOI：
10.1080/07391102.2005.10507018
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发表时间：
2005
影响因子：
4.4
通讯作者：
V. Anisimov
中科院分区：
文献类型：
--
作者：
V. Danilov;V. Anisimov
摘要采用二阶Møller-Plesset微扰法，在6- 31 G（d）和6- 31 G（d，p）基组上，对典型的Watson-Crick DNA碱基对进行了气相梯度优化。它被检测到，在MP2水平上的全几何优化导致本质上非平面螺旋桨扭曲和屈曲几何的G-C和A-T碱基对，而HF和DFT方法预测完美的平面或几乎平面的几何的碱基对。假设电子对的非平面性是由氨基氮原子的非平面化引起的，HF和DFT方法低估了这一点。这证明了在MP2水平的几何优化的重要性，以获得可靠的预测的电荷分布，分子的偶极矩和碱基对的几何结构。采用Morokuma-Kitaura和简化变分空间方法对分子间HF相互作用能进行分解，研究了Watson-Crick碱基对间的氢键作用.结果表明，氢键DNA碱基对的HF稳定性主要来源于静电相互作用。同时，计算的二级分子内相关对库仑能的修正表明，电子相关降低了静电项对A-T和G-C碱基对吸引相互作用的贡献.极化作用、电荷转移作用和色散作用也对碱的吸引能有较大贡献。
Abstract Gas-phase gradient optimization was carried out on the canonical Watson-Crick DNA base pairs using the second-order Møller-Plesset perturbation method at the 6–31G(d) and 6- 31G(d,p) basis sets. It is detected that full geometry optimization at the MP2 level leads to an intrinsically nonplanar propeller-twisted and buckled geometry of G-C and A-T base pairs; while HF and DFT methods predict perfect planar or almost planar geometry of the base pairs. Supposedly the nonplanarity of the pairs is caused by pyramidalization of the amino nitrogen atoms, which is underestimated by the HF and DFT methods. This justifies the importance of geometry optimization at the MP2 level for obtaining reliable prediction of the charge distribution, molecular dipole moments and geometrical structure of the base pairs. The Morokuma-Kitaura and the Reduced Variational Space methods of the decomposition for molecular HF interaction energies were used for investigation of the hydrogen bonding in the Watson-Crick base pairs. It is shown that the HF stability of the hydrogen-bonded DNA base pairs originates mainly from electrostatic interactions. At the same time, the calculated magnitude of the second order intramolecular correlation correction to the Coulomb energy showed that electron correlation reduces the contribution of the electrostatic term to the attractive interaction for the A-T and G-C base pairs. Polarization, charge transfer and dispersion interactions also make considerable contribution to the attraction energy of bases.
独特的三级和邻近相互作用决定了 Cis Watson-Crick A/G 碱基对的保守模式。
影响因子：
5.6
作者：
Sponer,Jirí;Mokdad,Ali;Sponer,JuditE;Spacková,Nad'a;Leszczynski,Jerzy;Leontis,NeoclesB
通讯作者：
Leontis,NeoclesB