鼠TRAM蛋白B细胞表位预测及其免疫原性检测

Prediction of the secondary structure and the B cell epitope of TRAM protein and determination of its immunogenicity

目的预测TRAM蛋白的二级结构和B细胞表位,为抗鼠TRAM单克隆抗体制备奠定基础.方法以TRAM蛋白的氨基酸序列为基础,采用Goldkeu计算机分析软件以及网络nnpredict二级结构分析软件对TRAM蛋白二级结构及B细胞表位预测.合成针对该表位的多肽,以此多肽为免疫原免疫兔,对其免疫原性进行检测.结果用多参数预测TRAM蛋白的二级结构和B细胞表位,综合评判表明:TRAM分子的第216～229位氨基酸满足亲水性、可及性和可塑性,在二级结构上位于蛋白伸展结构或无规则卷曲结构内,最可能为其优势B细胞表位.此多肽能诱导机体产生较高的抗体滴度,多克隆抗体具有高的特异性.结论 TRAM分子的第216～229位氨基酸为其优势B细胞表位,这为制作B细胞优势短肽单克隆抗体提供了理论依据.

Objective To predict the secondary structure and the B cell epitopes of TRAM protein, and to provide research basis for developing monoclonal antibody against TRAM. Methods Based on amino acid sequence of TRAM protein, the analysis of the flexible regions of secondary structure and the B cell epitopes of TRAM protein were predicted by software of nnpredict and Goldkeu. The peptide of the epitopes was synthesized and used for immunizing rabbits. The immunogenicity of the peptide was determined. Results The computer predicted that most possible epitopes of TRAM protein were within or near its N-teminal No. 216-229, which accorded with its hydrophilicity, accessibility, flexibi- lity, and which located in extend and/or ruleless convolute frame of the protein for the secondary structure. Synthesized peptides induced high titer of antibody and the polyclonal antibody to TRAM has high specificity. Conclusion N-teminal No. 216-229 of TRAM protein may be a B cell epitope, which provides a theory basis for the production of site-directed monoclonal antibody.