ABEEMσπ／MM力场模型下的多肽构象  

An ABEEMσπ/MM Model for the Polypeptide Conformations

作　　者：张强[1] 张霞[2] 

机构地区：[1]复旦大学生命科学学院,上海200433 [2]渤海大学化学化工学院,锦州121000

出　　处：《化学学报》2008年第3期289-294,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(No.20633050);博士后科学基金(No.20070410689)资助项目

摘　　要：在ABEEM/MM蛋白质浮动电荷力场模型的基础上,加入孤对电子和π电荷位点,从而能够体现多肽和蛋白质分子中一些重要的各向异性极化性质,允许非化学键方向的电子转移和极化.利用从头计算数据拟合模型相关参数.计算得到的小分子团簇结合能、偶极矩、氢键键长等性质与从头计算结果符合很好.该经典极化模型力场能够重复量子场下丙氨酸二肽、丙氨酸四肽、甘氨酸三肽的各稳定构象,其稳定性顺序与精密从头计算结果相一致,其结构和能量性质较以往模型有一定提高,并优于其他力场模型.An ABEEM/MM （the atom-bond electronegativity equalization method fused into molecular mechanics） model that explicitly includes the lone pairs and conjugate π fluctuating charges was employed to study the peptide conformations. The non-bond direction charge transfers were allowed in some important cases. With the optimized parameters from the alanine dipeptide, the dipole moment, the binding energies and the hydrogen bond lengths of the molecule clusters calculated by the ABEEM/MM model agree well with the corresponding ab initio results. The improved model provided more reasonable structures and conformational potential for the alanine dipeptide, alanine tetrapeptide and glycine tripeptide than the previous model and other models listed in this paper. For the alanine tetrapeptide and glycine tripeptide, the RMS deviations for conformational energies and key dihedral angles are 2.89 kJ/mol, 6.4° and 2.01 kJ/mol, 8.7° from the ab initio LMP2/cc-pVTZ（-f）//HF/6-31G＊＊ and MP2/6-31G＊＊//HF/6-31G＊＊ data respectively.

关 键 词：原子键电负性均衡结合分子力场方法(ABEEMσπ/MM) 多肽构象 各相异性极化 浮动电荷 

分 类 号：O629.72[理学—有机化学]