梅毒螺旋体TP17蛋白B细胞表位研究

目的:采用生物信息学方法预测梅毒螺旋体TP17蛋白B细胞表位，并验证TP17表位多肽与梅毒阳性临床血清的反应性。方法:用SOPMA、DNASTAR、SWISS-MODEL及IEDB数据库BepiPred-2.0等软件预测脂蛋白TP17的结构及B细胞表位。采用间接ELISA方法检测10份梅毒螺旋体阳性患者血清样本，与脂蛋白TP17及6段重叠多肽的反应性。结果:TP17蛋白6个线性B细胞表位为Thr27~Glu38、Leu53~Asp62、Thr66~Gln74、Lys75~Pro88、Leu107~Lys119以及Tyr132~Met145，预测的构象表位涉及的氨基酸为:Lys34-Ala35、Ala55、Pro88、Glu99、Pro136~Pro147、Thr154，这些抗原表位分散于TP17蛋白分段表达的6段重叠多肽（Tp17-1 Tp17-6）中的不同区域，ELISA结果显示这6段多肽均与梅毒患者阳性血清样本发生特异反应，OD450值在0.59~1.45之间，S/N＞2.1。结论:鉴定了TP17蛋白6个线性B细胞表位，该表位均与梅毒患者阳性血清发生特异反应。

The study on B cell epitope of Treponema pallidum TP17 protein

Objective:To predict the B cell epitope of TP17 protein of Treponema pallidumby bioinformatics method，and verify the reactivity of TP17 epitope polypeptide with syphilis positiveclinical serum. Methods: The structure and B cell epitope of lipoprotein TP17 were predicted by SOPMA，DNASTAR，SWISS-MODEL and IEDB database BepiPred-2.0. Ten Treponema pallidum positive serum samples were used to detect the reactivity of recombinant protein TP17 and 6-segment overlapping polypeptide of TP17 by indirect ELISA. Results: The predicted six linear B cell epitopes of TP17 protein were Thr27-Glu38，Leu53-Asp62，Thr66-Gln74，Lys75- Pro88，Leu107-Lys119 and Tyr132-Met145. The predicted conformational epitopes involved amino acidswere Lys34-Ala35，Ala55，Pro88，Glu99，Pro136-Pro147 and Thr154. These cell epitopes were dispersed in the 6-segment overlapping polypeptide（Tp17-1 to Tp17-6）.The results of ELISA showed that the six polypeptides had specific reaction with the positive serum samples of syphilis patients，and OD450 value was 0.59~1.45，S/N>2.1. Conclusion: 6 linear B cell epitopes of TP17 protein are identified，and all of which are specific to the positive serum of syphilis patients.