SARS病毒E蛋白的计算机模拟的初步研究

Preliminary Computer Simulation of Spatial Structure of SARS Coronavirus E-protein

以粗粒化的多肽链模型进行了 SARS病毒包膜中 E蛋白的计算机模拟 ,描述了该蛋白质空间构象的概貌 .首先扩展了多肽链的 HP模型 ,使之能够用于研究在水或脂环境下蛋白质折叠的行为 ,并且考虑了全部氨基酸残基疏水相互作用能的差异 .相关格子链的 Monte Carlo模拟显示了很高的计算效率 .模拟再现了蛋白质的 coil-globule转变 ,验证了蛋白质序列分布的重要性 .结果表明 ,在水环境中 ,E蛋白质空间结构由紧致的疏水内核和部分向外延伸的亲水片段组成 ;在脂环境中 ,中部疏水片段会成为向外延伸的环 ,而当两侧紧致的亲水片段分开时 ,则形成桥 .

The HP coarse-grained model has been applied to study three-dimensional spatial structures of a protein via lattice Monte Carlo simulation, in which residues exhibit different hydropathical energies. Reversed HP model has also been introduced to deal with protein under a lipid environment. The simulation approach seems very efficient. Preliminary computer experiment has been performed to study E-protein which is believed in the envelope of SARS(Severe Acute Respiratory Syndrome) associated coronavirus. Coil-globule transition has been reproduced in E-protein under a completely aqueous or lipid environment. Heterogeneity of this 76-residue polypeptide is verified to be important. Aqueous environment results in a hydrophobic core and hydrophilic loops. In contrast, lipid environment makes central segment as bridge or loop linking two relatively hydrophilic marginal segments.