肠道病毒71型六安地区分离株VP1基因的生物信息学分析及B细胞表位预测

Bioinformatics analysis and B-cell epitope prediction of VP1 gene of enterovirus 71 isolated in Lu′an city

目的对肠道病毒71型(EV71)VP1基因编码衣壳蛋白进行系统结构与功能预测,为制备EV71疫苗和诊断抗原的研究提供理论基础。方法基于编号为1404-Luan(CHN)-08的EV71六安地区分离株VP1基因编码蛋白的氨基酸序列,应用ProtParam、SigalP、TMPRED、Sosui、SOPMA、Phyre、Bepipred等生物信息学方法预测其信号肽、跨膜区、疏水性、二级结构、三级结构等性质和潜在的B细胞表位。结果 EV71六安地区分离株VP1基因编码蛋白没有信号肽,无跨膜区,是一个亲水性蛋白;VP1蛋白二级结构以无规则卷曲和β-片层为主,含有少量的α-螺旋,少见β-转角;VP1的三级结构中4～121氨基酸部分在蛋白表面形成一环状结构(VPl GH loop);EV71 VP1潜在的B细胞表位共有6个可能的抗原表位。其中,预测分值最高的线性表位区域位于157～177位氨基酸残基。结论成功预测了EV71六安地区分离株VP1二级结构、三级结构和B细胞表位,为制备EV71基因工程疫苗和诊断抗原的开发提供了理论基础。

Objective To predict the structure and function of enterovirus 71（EV71） major coat protein VP1 for providing a basis of the preparation of EV71 vaccines and relative diagnostics techniques.Methods EV71 Lu′an isolate of 1404-Luan（CHN）-08 was selected for VP1 analysis based on its amino acid sequence.Bioinformatics methods including ProtParam,SigalP,TMPRED,Sosui,SOPMA,Phyre,Bepipred were used to predict its signal peptides,transmembrane domains,hydrophobicity,secondary structure,tertiary structure,potential B-cell epitopes and other properties.Results The VP1 protein of this isolate was a hydrophilic protein without signal peptide and transmembrane domains.Its secondary structure was rich of random coil and β-sheet,containing a small amount of α-helix and rare β-turn.The tertiary structure prediction of this protein showed a ring structure（VP1 GH loop） formed on the protein surface at 4 to 121 amino acids position,which might play a very important role in the function of VP1.Antigenic prediction of this protein showed six potential B cell epitope,among which the highest score of linear epitope region was located at 157 to 177 amino acid positions.Conclusion The secondary structure,tertiary structure and B cell epitopes of VP1 of EV71 Lu′an isolate are successfully predicted by comprehensive variety of strategies.This study is helpful for the preparation of EV71 genetically engineered vaccines and the development of diagnostic antigens.