细粒棘球绦虫肌动蛋白抗原表位预测

Prediction of the distribution of epitopes of Actin from Echinococcus granulosus

目的对细粒棘球绦虫肌动蛋白(Echinococcus granulosus actin EgACT)的结构和抗原表位进行分析,为筛选疫苗候选抗原提供依据.方法采用生物信息学技术分析EgACT的理化性质和亲/疏水性、柔性区域、抗原指数、表面可及性、可能的信号肽序列、跨膜结构区域、二级结构及优势抗原表位.结果细粒棘球绦虫肌动蛋白由376个氨基酸组成,相对分子质量为41.95 kDa,等电点理论值为5.38,不稳定系数为39.28(稳定蛋白);亲水区域明显;柔性区域呈散在分布,较明显的分布区域位于12-30、37-42、57-63、79-85、107-118、195-208、232-240、282-293、312-319、360-368氨基酸区段;表面可及性得分较高的区域主要位于58-63、78-86、109-119、231-244、286-294、312-318、359-365氨基酸区段;抗原性指数得分较高区域与柔性区域的分布一致;无信号肽序列;无跨膜区;二级结构中的β转角占6.65%、α螺旋占37.5%、延伸链占21.28%、无规则卷曲占34.57%,优势B细胞表位位于14-29、52-61、77-82、233-242、285-290氨基酸区段,优势T细胞表位位于75-78、85-88、185-193、208-211、274-277、309-312氨基酸区段.结论成功预测出细粒棘球绦虫的肌动蛋白抗原表位,可为筛选疫苗候选抗原提供依据.

Objective To predict the main characteristics and epitopes of the protein of Echinococcus granulosus(EgACT)by molecular bioinformatics,to provide a theoretical basis for screening vaccine candidate antigens.Methods A series of bioinformatics softwares to provide physical and chemical properties,hydrophilic/hydrophobic properties,flexible region,antigen index,surface accessibility possible,signal peptide sequences,transmembrane structure regions,secondary structures and dominant antigen epitopes of EgACT.Results the protein was composed of 376 amino acids,the relative molecular weight of it was 41.95 kDa and the theoretical value of isoelectric point was 5.38,it was a stable protein.The hydrophilic region was obvious.The flexible regions were located in the amino acid regions of 12-30,37-42,57-63,79-85,107-118,195-208,232-240,282-293,312-319 and 360-368.The regions with high surface accessibility scores were mainly located in the amino acid sections of 58-63,78-86,109-119,231-244,286-294,312-318,359-365.The distribution of the regions with higher antigenicity index scores was consistent with that of the flexibleregions,there was no signal peptide sequence and transmembrane region.In the secondary structure,the beta angle accounted for 6.65%,the alpha helix accounted for 37.5%,the extended strand accounted for 21.28%and the random coil accounted for 34.57%.The dominant B cell epitopes were located in the amino acid sections of 14-29,52-61,77-82,233-242,285-290.The dominant T cell epitopes were located in the amino acid regions of 75-78,85-88,185-193,208-211,274-277 and 309-312.Conclusion The actin epitopes of Echinococcus ranulosus were predicted successfully,which provided a basis for screening vaccine candidate antigens.