新疆细粒棘球绦虫EgAgB8/3蛋白的生物信息学分析及意义

Bioinformatics analysis and significance of EgAgB8/3 protein from Echinococcus granulosus in Xinjiang Uygur Autonomous Region

目的分析新疆细粒棘球蚴EgAgB8/3蛋白氨基酸序列,了解该蛋白特性,预测其抗原表位,为进一步研究和选择包虫病免疫学诊断与防治的最佳候选抗原提供理论依据。方法利用生物信息学方法推测EgAgB8/3蛋白氨基酸序列及理化性质,用不同的生物信息学软件分析EgAgB8/3蛋白的特性及二级结构,并结合多参数预测其抗原表位。结果 EgAgB8/3抗原是由75个氨基酸残基组成的多肽,相对分子质量为8.58×10~3,等电点为8.5;蛋白特性分析显示EgAgB8/3蛋白α螺旋、β折叠、β转角和无规卷曲等二级结构特点,有3个β转角较好区域可作为表位所在参考区段;3种软件多参数综合分析预测,EgAgB8/3蛋白抗原表位集中在1~7(FVVVAHA)、6~19(HADDDDDEVTKTKK)、32~38(FQSDPLG)区段。结论运用生物信息学分析方法预测到EgAgB8/3抗原3个B细胞的优势表位,对进一步研究EgAgB8/3抗原性和研发更有价值的包虫病免疫诊断与防治靶标具有重要意义。

Objective To analyze the amino acid sequencing of EgAgB8/3 protein from Echinococcus granulosus in Xinjiang Uygur Autonomous Region, understand the characteristics of this protein, predict the epitope of its antigen, so as to provide theoretical foundation for further studying and selecting the best alternative antigen of immunological diagnosis and prevention of echinococcosis. Methods The amino acid sequencing and physicochemical property of E- gAgB8/3 proteins were predicted by bioinformatics method, the characteristics and secondary structure of EgAgB8/3 proteins were analyzed by different bioinformatics software, and its antigenic epitope was predicted combined with multiple parameters. Results EgAgB8/3 antigen was polypeptide composed of 75 amino acid residues, the relative molecular mass was 8.58x103, isoelectric point was 8.5; the analysis of protein characteristics showed the secondary structure characteristics of α-helix, β-sheet, β-turn and random coil of EgAgB8/3 proteins, among which, there were 3 better areas of β-turn that could be as reference segment of epitope; comprehensive analysis of three software and multiple parameters predicted that, the epitope of EgAgB8/3 protein antigen was mainly located in 1-7 （FVVVAHA）, 6-19 （HAD- DDDDEVTKTKK） and 32-38 （FQSDPLG）. Conclusion The prediction for dominant epitope of three B cell epitopes of EgAgB8/3 protein by bioinformatics method has important significance for further studying the antigenicity of EgAgB8/3 and developing more valuable target for immunological diagnosis and prevention of eehinocoeeosis.