HBsAg空间结构与分子进化分析

目的:获得乙型肝炎表面抗原HBsAg的生物信息学资料。方法:从Genbank中获得HBsAg的核酸序列,用ExPaSy、EBI和NCBI网站的在线软件推导其编码氨基酸序列、理化性质、空间结构,并在Blastn比对后选择不同地理株进行分子进化进行分析。结果:HBsAg由226个氨基酸组成,分子量25777．6Da,等电点8．74,为亲水性蛋白质;信号肽位于1-29aa处,二级结构由-螺旋(18．14%)、延伸(25．66%)、随机线圈(56．19%)组成。中国与日本、冈比亚、德国、西班牙、墨西哥、荷兰、瑞典、泰国的HBsAg相似率依次为99%、94%、94%、94%、91%、89%、98%、98%、98%．。用不同地理株HBsAg核酸序列构建出的分子进化树中,中国和日本的聚成一簇。结论:通过对HBsAg的生物信息学分析获得该抗原特征,为进一步研究乙型肝炎的感染与发病机制、研制基因工程疫苗以及研究HBsAg新的功能域等提供依据。

Spatial Structure and Polygenetic Analysis of HBsAg

Objective:To obtain bioinformatics data of HBsAg.Methods:From Genbank,nudeotide sequence of HBsAg was obtained;subsequent amino acid sequence,physico-chemical property,spatial structure and molecular evolution were analyzed by online software in ExPasy,EBI and NCBI web sites.Results:HBsAg was made up of 226 amino acids with molecular weight 25777.6 Da and pI 8.74,and through bioinformatics analyses,the hydrophilia protein was demonstrated with a cleavage site between positions 29 and 30.Secondary structure analysis revealed that HBsAg from China contained an alpha helix(18.14%),an extended strand(25.66%)and a random coil(56.19%).The similarity between China,Japan,Gambia,Germany,Spain,Mexico, Netherlands,Sweden,and Thailand were 99%,94%,94%,94%,91%,89%,98%,98%,98% respectively.According to polygenetic analysis,HBsAg from china was clustered with that from Japan.Conclusion:In this study,characteristics of HBsAg can be obtained by bioinformatics software,which provides scientific proof for the researches on its pathogenesy and genetically engineering vaccine.