类弹性蛋白多肽的分子动力学研究  

Molecular dynamic simulation of elastin-like peptide

作　　者：张光亚[1] 陈智山[1] 李红春[1] 黄凯宗[1] 

机构地区：[1]华侨大学生物工程与技术系,福建厦门361021

出　　处：《计算机与应用化学》2011年第4期399-402,共4页Computers and Applied Chemistry

基　　金：国家自然科学基金资助项目(20806031);福建省自然科学基金(2009J01030)项目;华侨大学高层次人才科研启动项目(10BS220)

摘　　要：类弹性蛋白多肽因其具有特殊的相变性质,故而在重组蛋白纯化方面展现出良好的应用前景,对其发生相变的机理进行研究具有重要意义。本文利用同源建模的方法构建了类弹性蛋白多肽的三维结构并进行能量优化,之后采用分子动力学模拟手段,在300K～400K间5个不同温度下,对含有100个氨基酸残基的类弹性蛋白多肽[KV8F-20]各进行了6ns的模拟。模拟过程中,类弹性蛋白多肽发生疏水缩聚,初始结构变得更加紧凑,且温度越高折叠程度越大。水分子在类弹性蛋白多肽的相变行为中起到关键作用。经分析,结果发现疏水作用与水的排出在类弹性蛋白多肽发生相变过程中起到关键作用,类弹性蛋白多肽随着温度的升高,在疏水作用驱动下,其构象折叠程度因疏水缩聚而变得更大。此外,比较不同温度下蛋白的缩聚程度,推断类弹性蛋白多肽在375K左右发生相变,这与实验观测的结果基本吻合。据此,推测该类弹性蛋白多肽变温度范围约为95℃～102℃。这对后续调控类弹性蛋白多肽的相变具有指导作用。The elastin-like peptide（ELP） is temperature sensitive biopolymer composed of a Val-Pro-Gly-Xaa-Gly pentapeptide repeat,it undergoes change from an extended to folded conformation at the transition temperature.This feature make it be a reliable and simple non-chromatographic tag for purification of the recombinant protein.In this paper,the 3D structure of ELP was constructed by means of homology modeling and then the molecular dynamic simulations for 6 ns of the temperature-dependent folding and unfolding of the peptide were carried out.The ELP used here contained 100-residues[KV8F-20]with explicit water molecular.Simulations were performed at five different temperatures between 300 K and 400 K. Hydrophobic collapse was observed during the simulation process,and the beginning conformation became tighter upon heating.Water was critical to the inverse temperature transition and ELP-associated water was divided into several categories.This inverse temperature behavior has been attributed to hydrophobic effect and expulsion of water molecular associated with the peptide.As the temperature increased,the water was driven out and the hydrophobic effect became stronger,and thus the ELP flocculated.In addition,by comparing the aggregation of ELP at different temperature, we found that the transition temperature of the ELP is near 375 K,which was agreed with the experimental results to some extent.So we suggested the transition temperature of the ELP was between 95℃to 102℃.These results will be helpful for the regulation of the ELP transition behavior.

关 键 词：类弹性蛋白多肽 分子动力学模拟 相变温度 疏水作用 

分 类 号：Q617[生物学—生物物理学]