一种获取三肽构象系综的可靠量子化学方法  

A Reliable Computational Method for Obtaining the Conformational Ensemble of Tripeptide

作　　者：陆茜雅 汝啸 林子敬[1] LU Xiya;RU Xiao;LIN Zijing(Department of Physics,University of Science and Technology of China,Hefei 230026)

机构地区：[1]中国科学技术大学物理系,合肥230026

出　　处：《低温物理学报》2023年第4期183-197,共15页Low Temperature Physical Letters

基　　金：Project supportedby the National Natural Science Foundation of China(Grant Nos.12074362&12374017).

摘　　要：三肽是蛋白质的基本组成模块,具有重要生理功能.解析其结构对于更大的肽及蛋白质研究具有重要意义.基于二面角组合规则,结合键旋转手段,提出一种获取三肽构象系综的从头算量子化学方法.使用该方法对八个目标三肽的势能面进行彻底搜索,将所得结果与以前的预测方法及蛋白质数据库(PDB)提取的结构进行比较.结果表明,新方法搜索到了最完整的三肽构象系综.此外证明了PDB结构存在缺陷,遗漏了大部分中低能区的重要构象.将新获取的三肽结构用于红外光谱研究,理论结果与实验数据符合得更精准.Tripeptide is a basic building block of proteins and has important physiological functions.Analyzing the structure is of high significance for the study of larger peptide/protein systems.An ab initio method for tripeptide structure prediction based on the combination rule of dihedral angles combined with bond rotations is developed.The method is used to conduct thorough searches on the potential energy surfaces of 8 representative tri peptides.The results are compared with a few previous methods and that deduced from the Protein DataBank(PDB).Th comparison shows that the new method provides the most complete conformational ensembles of the tri peptides.It is also demonstrated that the results from the PDB are unreliable and miss a large portion of conformations in the low and middle energy regions.The newly obtained tripeptide conformations are further used in IR spectra study and provide a much improved agreement with the experimental data.

关 键 词：肽结构预测 三钛 量子化学计算 构象系综 红外光谱 

分 类 号：O641.121[理学—物理化学]