中文摘要：

选取氮甲基乙酰胺（N-Methylacetamide,NMA）和DNA碱基为研究对象,应用ABEEMσπ/MM方法研究了NMA与碱基之间形成的二聚体的几何构型、电荷分布及结合能等性质,并进行了相应的从头算（abinitio）MP2水平研究,在B3LYP/6-311＋＋G（d,p）水平下对结构进行了优化.将2种方法的研究结果进行比较发现,所获得的构型、电荷及结合能之间具有很好的一致性,NMA与DNA碱基相互作用的强度大小依次为：鸟嘌呤〉胸腺嘧啶〉胞嘧啶〉腺嘌呤,且证明了ABEEMσπ/MM模型的参数具有很好的可转移性.

英文摘要：

DNA replication,repair and recombination must depend on the interaction with the protein.N-methylacetamide（NMA） is one of the typical units in protein.Taking NMA and the bases in DNA as the stu-died objects,the interaction properties including geometry,charge distribution and binding energy of these NMA-base complexes were investigated in terms of the ABEEMσπ/MM method and the ab initio MP2 method.The geometry optimizations were performed at the B3LYP/6-311＋＋G（d,p） level.The results of ABEEMσπ/MM and ab initio methods were compared.The results of ABEEMσπ/MM and ab initio methods have good agreement.The order of relative binding ability of interaction between NMA and DNA bases holds： guaninethyminecytosineadenine.The parameters of ABEEMσπ/MM have good transferability.This study provides a solid foundation for the research of interaction between the protein and nucleic acid via the ABEEMσπ/MM model.