细粒棘球绦虫转酮醇酶生物信息学分析  

A bioinformatic analysis of the transketolase of Echinococcus granulosus

作　　者：张耀刚[1] 曹得萍[1,2] 李超群[1] 樊海宁[2] 

机构地区：[1]青海大学医学院病原生物学教研室,青海西宁810001 [2]青海大学包虫病重点实验室

出　　处：《中国病原生物学杂志》2017年第3期233-237,共5页Journal of Pathogen Biology

基　　金：国家自然科学基金项目(No.81360255)

摘　　要：目的利用生物信息学技术对EgTK基因编码蛋白的结构和功能进行预测和分析。方法利用ExPASy系统的ProtParam、ProtScale、SignalP、SOMPA程序与SubLoc v1.0、DNAStar、IEDB、SYPEITHI、Phyre2等生物信息学软件分析EgTK的理化性质、抗原表位、跨膜区、二、三级结构等。结果 EgTK基因由7个外显子,6个内含子构成,CDS长度为1 878bp,编码625个氨基酸,分子式为C_(3015)H_(4791)N_(829)O_(900)S_(22),分子质量为67.76ku;为跨膜蛋白,位于细胞质,二级结构主要以α螺旋、无规则卷曲为主。EgTK有16个潜在的B细胞线性表位,11个CTL细胞表位,13个Th细胞表位;EgTK三级结构与人类转酮醇酶相似性为97%;经多重比对,除去两端多余序列,共有473个氨基酸残基参与比对,发现195个变异位点、123简约性信息位点、72单态突变位点。结论生物信息学技术分析EgTK蛋白存在多个B、T细胞表位,具有良好的免疫原性,可为该蛋白的基因克隆、表达等提供理论依据。Objectives To use bioinformatics to predict and analyze the structures and functions of the transketolase protein encoded by the transketolase gene of Echinococcus granulosus （EgTK）. Methods The ExPASy tools Prot- Param, ProtScale, SignalP, and SOMPA and the software SubLocv1. 0, DNAStar, IEDB, SYPEITHI, and Phyre2 were used to analyze physicochemical properties, epitopes, transmembrane domains, and the secondary and tertiary structure of EgTK. Results The EgTK gene consisted of 7 exons and 6 introns, its coding sequence was 1 878 bp in length, and it encoded 625 amino acids. The molecular formula of the EgTK protein was C3015 H4791 N829 O900 S22, its relative molecular weight was 67.76 ku, and its isoelectric point was 6.33. Results indicated that EgTK may be a three transmembrane pro tein that is located in the cytoplasm. Alpha helices （38.88 %） and random curls （31.84 %） accounted for a high percentage of the secondary structure of EgTK. Nine amino acids were located in hydrophilic regions of the EgTK protein, 14 were located in flexible regions, 17 were located in regions with a high antigenic index, and 11 were located in regions with a high level of surface accessibility. EgTK has 16 B-cell linear epitopes, 11 eytotoxic T-lymphocyte epitopes, and 13 helper T-cell epitopes. The tertiary structure of E. granulosus transketolase has a 97% similarity to human transketo- lase. After removal of superfluous sequences at both ends, multiple blast analyses revealed 195 variable sites, 123 parsimony-informative sites, and 72 singleton variable sites in 473 amino acid residues. Conclusion Bioinformatics indicated that the EgTK protein has several B- and T cell epitopes and good immunogenicity, and these findings will provide a theoretical basis for subsequent gene cloning and expression.

关 键 词：细粒棘球绦虫 转酮醇酶 生物信息学 抗原表位 

分 类 号：R383.33[医药卫生—医学寄生虫学]