结核分枝杆菌Rv3203蛋白的生物信息学及免疫信息学分析

Bioinformatics and Immunoinformatics Analysis of Mycobacterium Tuberculosis Rv3203 Protein

目的运用生物信息学及免疫信息学方法分析结核分枝杆菌(Mtb)Rv3203蛋白的结构特征,为研究Rv3203蛋白在Mtb感染中的功能提供基础。方法利用信息学软件分别预测Rv3203蛋白的理化性质、溶解度、跨膜区、信号肽、亚细胞定位、糖基化位点、磷酸化位点、相互作用蛋白、免疫原性、抗原性、毒性、致敏性,以及T、B细胞抗原表位和二级结构,并对蛋白的三级结构进行建模,最后对Rv3203蛋白进行密码子优化、计算机克隆和构建进化树。结果Rv3203蛋白由224个氨基酸组成,理论等电点为4.68,为结构稳定的弱疏水性蛋白;无跨膜区和信号肽,定位于细胞质,具有1个糖基化位点和11个磷酸化位点;与lipD、lipE、lipP、lipZ、amiB2、amiC、bpoC、Rv0183、Rv1367c和Rv3204发生相互作用,参与Mtb的多种生物学过程;免疫原性为3.4211,抗原性为0.6533,无毒性,无致敏性;含5个CTL表位、1个Th表位和4个B细胞表位;二级结构和三级模型含大量的α-螺旋和无规则卷曲;经密码子优化后可在大肠杆菌中克隆并高效表达;此外,Mtb的Rv3203蛋白还与Mycobacterium canettii CIPT 140010059具有高度同源性。结论Rv3203蛋白是一个结构稳定且具有热稳定性的酸性蛋白,具有免疫原性和抗原性,无毒性和致敏性,含多个T/B细胞表位,可在体外克隆并高效表达,参与Mtb的多种生物学过程及调控宿主的免疫应答反应。

Objective To analyze the structural characteristics of Mycobacterium tuberculosis(Mtb)Rv3203 protein by bioinformatics and immunoinformatics methods,and to provide a basis for studying the function of Rv3203 protein in Mtb infection.Methods The physicochemical properties,solubility,transmembrane region,signal peptide,subcellular localization,glycosylation site,phosphorylation site,interacting protein,immunogenicity,antigenicity,toxicity,allergenicity,T and B cell epitopes and secondary structure of Rv3203 protein were predicted by bioinformatics software,and the tertiary structure of the protein was modeled.Finally,the codon optimization,computer cloning and phylogenetic tree construction of Rv3203 protein were carried out.Results Rv3203 protein was composed of 224 amino acids,and the theoretical isoelectric point was 4.68,which was a weakly hydrophobic protein with stable structure.No transmembrane region and signal peptide,located in the cytoplasm,with 1 glycosylation site and 11 phosphorylation sites;it interacted with lipD,lipE,lipP,lipZ,amiB2,amiC,bpoC,Rv0183,Rv1367c and Rv3204,and participated in various biological processes of Mtb.Immunogenicity was 3.4211,antigenicity was 0.6533,no toxicity,no sensitization;it contained 5 CTL epitopes,1 Th epitope and 4 B cell epitopes.The secondary structure and tertiary model contained a large number of α-helices and random coils;after codon optimization,it could be cloned and efficiently expressed in E.coli;in addition,Mtb Rv3203 protein had high homology with Mycobacterium canettii CIPT 140010059.Conclusion Rv3203 protein is an acidic protein with stable structure and thermal stability,with immunogenicity and antigenicity,non-toxicity and sensitization.It contains multiple T/B cell epitopes and can be cloned and efficiently expressed in vitro.It participates in various biological processes of Mtb and regulates the immune response of the host.