合理预测甘氨酸-α-多肽构象稳定性的有效途径  

Effective Scheme for Determining the Conformation Stability of Glycine-α-Polypeptide

作　　者：李晓静[1] 王长生[1] 

机构地区：[1]辽宁师范大学化学化工学院,辽宁大连116029

出　　处：《辽宁师范大学学报（自然科学版）》2005年第1期79-82,共4页Journal of Liaoning Normal University:Natural Science Edition

基　　金：国家自然科学基金资助项目(20173025);辽宁省教育厅基金资助项目(2004C019)

摘　　要：使用B3LYP/6 31G*方法,优化得到了甘氨酸多肽分子 CH3CO(NHCH2CO)nNHCH3(n=1,2,3)的 18 个稳定构象.对构象中存在的非键作用进行了分析,确定了影响构象稳定性的主要非键作用,并估算了相关非键作用的能量.将之应用于判断二肽、三肽、四肽分子构象的相对稳定性,得到了满意的结果.该方法和 B3LYP/6 31G*方法得到的相对能量的线性相关方程为:y=0.887 3 x+0.647 3, 相关系数为R=0.939 7,最大偏差为 3.5 kJ/mol,标准偏差为1.47 kJ/mol.The geometrical structures of CH_3CO(NHCH_2CO)_nNHCH_3 (n=1,2,3) were optimized at B3LYP/6-31G~* level and 18 conformers were obtained. The non-covalent bond interactions in these conformers were analyzed and the main non-covalent bond interactions, which play very important roles in determining the conformation stability of glycine polypeptide, were found to be the O…H interactions and H_N…H_C interactions. These non-covalent bond interaction energy parameters were determined and were used to estimate the glycine polypeptide conformation stability. It has been found that the B3LYP/6-31G~* relative energies of the di-, tri-, and tetra-peptides’ conformers can be well reproduced from the non-covalent bond interactions by using this set of parameters. The linear correlation equation between our method’s relative energies and the B3LYP/6-31G~* ones is y = 0.887 3x + 0.647 3, the correlation coefficient is R = 0.939 7, the root-mean-square deviation S is 1.47 kJ/mol, and the maximum deviation is 3.5 kJ/mol.

关 键 词：B3LYP 构象稳定性 大偏差 相关系 二肽 线性相关 能量 多肽 甘氨酸 CH 

分 类 号：O641[理学—物理化学] O211[理学—化学]