结核分枝杆菌pepA蛋白的生物信息学分析  

Bioinformatic analysis of the pepA protein of Mycobacterium tuberculosis

作　　者：包嘉佳 徐蕾[1] BAO Jia-jia;XU Lei(Department of Microbiology and Parasitology,Chongqing Medical University,Chongqing 400016)

机构地区：[1]重庆医科大学病原生物学教研室,重庆400016

出　　处：《中国病原生物学杂志》2020年第6期642-648,共7页Journal of Pathogen Biology

基　　金：重庆市科委自然科学基金项目(No.cstc2017jcyjAX0409)。

摘　　要：目的通过生物信息学方法分析结核分枝杆菌(Mycobacterium tuberculosis,Mtb)pepA蛋白的结构和功能。方法采用Protparam、ProtScaleon Expasy、TMHMM、SingalP5.0、PSORT、NetPHOS3.1、BLAST、SOPMA、SWISS-MODEL、ABCpred、SYFPEITHI等生物信息学软件分析Mtb H37Rv菌株pepA蛋白的生物学特性。结果pepA蛋白的编码基因Rv0125全长1068 bp,该蛋白由355个氨基酸组成,等电点5.04,为疏水性蛋白,有1个的信号肽和1个丝氨酸蛋白酶结构域,含有19个磷酸丝氨酸位点;蛋白二级结构中无规则卷曲占44.79%,为稳定蛋白;该蛋白预测含多个B细胞和T细胞表位,其中MHC-I型和MHC-II型表位集中在蛋白N端的前60个氨基酸区域。结论该蛋白预测含多个B细胞和T细胞表位,其中MHC-I型和MHC-II型表位集中在蛋白N端的前60个氨基酸区域,该区域可激活Mtb特异性CTL和Th免疫应答,可作为抗结核肽疫苗的候选。Objective To bioinformatically analyze the structure and function of the pepA protein of Mycobacterium tuberculosis.Methods The NCBI database was used to retrieve the amino acid sequence of the pepA protein of M.tuberculosis and the gene sequence that codes for it.The online analysis software NCBI ORF Finder was used to analyze the open reading frames of the gene sequence coding for the pepA protein.Online software such as PortParam and ProtScale on Expasy were used to analyze the pepA protein to determine its physicochemical properties such as its molecular mass,isoelectric point,and hydrophilicity.Secretion of the pepA protein was analyzed using TMHMM,SignalP5.0,PSORT,and other pieces of software.The phosphorylation sites of the protein were analyzed using the software NetPhos 3.1 Servera.A BLAST online tool predicted that the protein would have a conserved domain,and the similarity of the amino acid sequences was compared between pepA(NP214639.1)and pepB(NP21531.1),pepC(NP21531.1),pepD(NP215498.1),pepE(NP216605.1),and pepN(NP177885.1).SOPMA and SWISS-MODEL were used to predict the structure of the pepA protein.ABCpred and SYFPEITHI were used to predict B-cell and T-cell epitopes.Results The gene Rv0125 encoding the pepA protein(ID:886924)is 1,068 bp in length.The protein consists of 355 amino acids and has an isoelectric point of 5.04.It is a hydrophobic protein with 1 signal peptide and 1 serine protease domain.It has 27 phosphorylation sites,including 19 phosphoserine sites.Random coils accounted for 44.79%of the secondary structure of the protein.The protein has an instability index of 29.97,indicating that it is stable protein.In the pep gene family of M.tuberculosis strain H37 Rv,the amino acid sequence of pepA is most similar to the related member pepD(65%)but is less similar to PepB,pepC,pepE,and pepN(7-33%).The protein was predicted to contain multiple B-cell and T-cell epitopes.Amino acids at positions 10-26,41-60,136-156,159-175 and 309-324 were highly likely to be the B-cell epitopes of Mtb32 a.The

关 键 词：PEPA 结核分枝杆菌 MHC-I 肽疫苗 

分 类 号：R378.91[医药卫生—病原生物学]