转基因植物中Bt Cry2Ab蛋白的抗原表位特征预测

Prediction on Antigenic Epitope Characteristics of Bt Cry2Ab Protein in Transgenic Crops

[目的]通过生物信息学方法了解转基因作物中Bt Cry2Ab蛋白的二级结构、三级结构、B细胞抗原表位及T细胞抗原表位等结构特征,为今后的抗体设计奠定基础。[方法]以在NCBI数据库中获得Cry2Ab蛋白序列为材料,应用DNAStar中的多种方法预测其B细胞表位,并通过在线预测软件NetMHCII 2.2分析Cry2Ab蛋白与MHC-II类分子的结合能力,从而预测其T细胞抗原表位。[结果]对Cry2Ab蛋白B细胞抗原表位的预测表明,Cry2Ab蛋白的第208～215区域是潜在的B细胞抗原表位;对Cry2Ab蛋白与MHC-II类分子结合能力的分析表明,Cry2Ab蛋白的第177～185区域、299～307区域和255～263区域是潜在的T细胞抗原表位,暗示含有HLA-DRB10101和HLA-DRB10701等位基因的人群对Cry2Ab蛋白更敏感。[结论]该研究有助于深入了解Cry2Ab蛋白的生物学特征,为完善转基因食品过敏原性的评估方法提供新线索。

[Objective] This study aimed to predict the structural characteristics of Bt Cry2Ab protein in transgenic crops with bioinformatic analysis to provide the theoretical clues for design of antibody Cry2Ab.[Method] The amino acid sequence of Cry2Ab protein was searched from NCBI database.The B cell epitopes were predicted with DNAStar.The binding affinity between Cry2Ab protein and MHC-II molecules was analyzed with NetMHCII 2.2 Server to predict the T cell epitopes.[Result] Prediction result suggested the potential B cell epitope of Cry2Ab locating in the region of 208-215.Analysis of the binding affinity between Cry2Ab and MHC-II molecules suggested the regions of 177-185,299-307 and 255-263 were the potential T cell epitopes.Human with HLA-DRB10101 alleles and HLA-DRB10701 alleles were more sensitive to Cry2Ab protein.[Conclusion] This study facilitates to understand the structural characteristics of Cry2Ab protein and provides a new clue to improve the assessment method for potential allergenicity of genetically modified food.