土耳其斯坦裂体吸虫23kDa蛋白基因的序列分析及抗原表位预测

Bioinformatics Prediction on Antigen Epitopes and Sequence Analysis of 23 kDa Genes of Schistosoma turkestanicum

为研究土耳其斯坦裂体吸虫23 kDa蛋白的生物学特性,以土耳其斯坦裂体吸虫cDNA为模版,利用PCR对23 kDa基因进行扩增,并将其克隆到T-easy载体后进行序列测定。利用生物信息学对其结构、抗原指数进行分析,并对其抗原表位进行预测。序列分析结果表明,该虫体的23 kDa基因长度为657 bp,A+T含量为57.38%,与曼氏血吸虫、埃及血吸虫和日本血吸虫的23 kDa基因的相似性分别为85.24%、83.71%和81.89%。蛋白二级结构分析表明,23 kDa蛋白经过4次跨膜,主要由6个α-螺旋、3个β-折叠、7个β转角和若干个无规则卷曲构成。抗原表位预测结果表明,该蛋白有3个B细胞抗原表位。综合分析土耳其斯坦裂体吸虫23 kDa蛋白是一种较好的抗原分子,是土耳其斯坦裂体吸虫疫苗的重要候选分子。

The 23 kDa gene was amplified from individual Schistosoma turkestanicum worm eDNA by polymerase chain reaction （PCR）,and the positive PCR products were cloned into the T-easy vector and sequenced,which would help to examine the biological characteristics of 23 kDa protein. The structure and antigen index of the 23 kDa protein were analyzed by bioinformatics method,and the antigen epitopes were predicted. The sequence analysis showed that the complete 23 kDa gene sequence of S. turkestanicum was 657 bp in length ,and the content of A＋T was 57.38%. Compared with the corresponding nucleic acid sequence of S. mar^oni,S, haematobium and S. japonicum,the 23 kDa gene of S.turkestanicum＇s mutation probability were 85.24%,83.71% and 81.89%,respectively. The secondary structure analysis showed that the 23 kDa protein was tetraspanin,the mainly composed of six alpha helix,three Beta sheet, seven β-bend, and several random coil,and prediction on antigen epitopes indicated that 23 kDa protein had 3 B cell antigen epitope. In conclusion,the present study revealed that 23 kDa protein of S.turkestanicum＇s was a good antigen and the potential candidate for vaccines development against S.turkestanicum.