沙眼衣原体热休克蛋白60的B细胞表位预测及分析

目的：分析沙眼衣原体（Chlamydia trachomatis,CT）热休克蛋白60（heat shock protein 60,HSP60）的二级结构并预测其B细胞优势表位,进一步分析其在沙眼衣原体相关自身免疫性疾病发病中的意义。方法：以CT标准株（E/UW-5/Cx）HSP60的完整氨基酸序列为基础,分别采用SOPMA、GOR、nnPredict和HNN四种方法预测CHSP60的二级结构,并结合其跨膜区域、亲水性、表面可及性、抗原性、极性和柔韧性等参数进行综合分析,预测CHSP60可能的B细胞优势表位,并将B细胞优势表位与人HSP60的氨基酸序列进行比对,分析两者之间的同源性,寻找可能与自身免疫性疾病相关的B细胞表位。结果：四种方法对CHSP60二级结构的预测表明,其二级结构中柔性区域以无规卷曲为主,少见转角。其B细胞优势表位可能位于氨基酸79～85、135～140、433～440和526～532区域,而上述序列与人HSP60氨基酸序列比对后,发现其135～140、433～440和526～532区域与人HSP60氨基酸159～164,457～464、549～556区域有较高的同源性。结论：CHSP60可能的B细胞优势表位中,135～140、433～440和526～532区域可能与CT感染相关自身免疫性疾病的发病有关。

Prediction and analysis of B-cell epitopes of HSP60 of Chlamydia trachomatis

Objective：To predict the secondary structure and B-cell epitopes of heat shock protein 60 of Chlamydia trachomatis,and further analyse the pathogenic significance in the human autoimmune disease associated with Chlamydia trachomatis.Methods：The amino acid sequence of HSP60 from CT standard strain（E/UW-5/Cx） was selected,and the secondary structure was predicted with SOPMA,GOR,nnPredict and HNN.Combining comprehensive analysis of transmembrane domain,hydrophilicity profile,surface probability,antigenicity index,polarity and average flexibility,B-cell predominant epitopes of CHSP60 was further predicted.Predominant HSP60 epitopes with the amino acid sequence was compared with the homo HSP60 amino acid sequence.Results：Using the four methods mentioned-above,prediction of the secondary structure of CHSP60 indicated that random coils were the main structural type of the flexible region in secondary structure.The B-cell predominant epitopes were probably in the regions of 79～85,135～140,433～440,526～532 and the regions 135～140,433～440 and 526～532 have high homology with the regions 159～164,457～464 and 549～556 of homo HSP60.Conclusion：Within the possible advantages of B cell epitopes of CHSP60,the regions of 135～ 140,433～440 and 526～532 may be associated with human autoimmune diseases.