Noguera M, Branchadell V, Constantino E, Ríos-Font R, Sodupe M, Rodríguez-Santiago L
Departament de Química, Universitat Autonoma Barcelona, Bellaterra 08193, Spain.
J Phys Chem A. 2007 Oct 4;111(39):9823-9. doi: 10.1021/jp073858k. Epub 2007 Aug 31.
The binding of first-row transition metal monocations (Sc+-Cu+) to N7 of guanine and N7 or N3 of adenine nucleobases has been analyzed using the hybrid B3LYP density functional theory (DFT) method. The nature of the bonding is mainly electrostatic, the electronic ground state being mainly determined by metal-ligand repulsion. M+-guanine binding energies are 18-27 kcal/mol larger than those of M+-adenine, the difference decreasing along the row. Decomposition analysis shows that differences between guanine and adenine mainly arise from Pauli repulsion and the deformation terms, which are larger for adenine. Metal cation affinity values at this level of calculation are in very good agreement with experimental data obtained by Rodgers et al. (J. Am. Chem. Soc. 2002, 124, 2678) for adenine nucleobases.
使用杂化B3LYP密度泛函理论（DFT）方法分析了第一排过渡金属单阳离子（Sc⁺-Cu⁺）与鸟嘌呤的N7以及腺嘌呤核碱基的N7或N3的结合情况。键合的本质主要是静电作用，电子基态主要由金属-配体排斥作用决定。M⁺-鸟嘌呤的结合能比M⁺-腺嘌呤的结合能大18-27千卡/摩尔，该差值沿这一排逐渐减小。分解分析表明，鸟嘌呤和腺嘌呤之间的差异主要源于泡利排斥和变形项，腺嘌呤的这些项更大。在此计算水平下的金属阳离子亲和值与Rodgers等人（《美国化学会志》2002年，124卷，2678页）获得的腺嘌呤核碱基的实验数据非常吻合。
