沙眼衣原体多形态膜蛋白D基因序列分析及其B细胞抗原表位预测

分析沙眼衣原体多形态膜蛋白D(PmpD)的基因序列并预测PmpD蛋白的B细胞抗原表位。在GenBank中检索沙眼衣原体不同血清型的PmpD基因序列,进行序列比对分析。以L2血清型PmpD基因序列为材料,采用Karplus-Schulz、Chou-Fasman和Gamier-Robson方案预测蛋白质的二级结构和柔性区;按Jamesonv-Wolf方案预测抗原指数,运用Kyte-Doolittle方案预测PmpD氨基酸的亲水性,利用Emini方案预测蛋白质的表面可及性。检索到20个沙眼衣原体不同菌株的PmpD基因序列,分析发现其核苷酸序列非常保守,一致性高达99.14%~100%;对预测结果综合分析,推测最有可能的B细胞表位位于PmpD N端的67~74、132~140、335~340、851~861、972~988及1091~1097。多参数方案综合预测PmpD蛋白的B细胞抗原表位,为进一步实验鉴定PmpD抗原表位及其多表位疫苗设计和研究奠定基础。

Sequence analyses of Chlamydia trachomatis polymorphic membrane protein D gene and prediction of related B cell epitopes

To analyze gene sequence and predict the B cell epitopesof Chlamydia trachomatis(Ct) polymorphic membrane protein D(PmpD).Search the gene sequences of the different Ctserotypes in GenBank,and then align them by LaserGene software.The secondary structure and the flexibility plot of PmpD of Ct serovar L2 were predicted by the algorithmof Karplus-Schulz,Chou-Fasman and Gamier-Robson based on PmpD sequence,and the antigenic index,the hydrophilicity plot and the surface probability plot were predicted by the methods of Jamesonv-Wolf,Kyte-Doolittle and Emini respectively.Sequence alignments indicate that the PmpDgenes of the 20 different Ctstrains share 99.14-100% identical nucleotide sequences.The B cell epitopes of PmpD by these predicted results was analyzed,which are most likely localized in or adjacent to its N-terminal No.67-74,132-140,335-340,851-861,972-988,1091-1097 of PmpD.The results obtained by epitopes prediction using multiple parameters are helpful for further epitopes identification and design of multiepitopes-based vaccine of PmpD.