E型肉毒神经毒素(BoNT)基因序列分析及其B细胞表位预测

Gene sequence analysis of Clostridium botulinum neurotoxin serotype E and prediction of related B cell epitopes

目的：分析不同E型肉毒梭菌的肉毒神经毒素（BoNT）基因序列的同源性，预测E型BoNT的B细胞表位。方法：用LaserGene软件中的MegAlign程序比对GenBank中5株不同E型肉毒梭菌的BoNT基因序列；分别利用BioSun和LaserGene软件分析E型BoNT的表位参数、蛋白质二级结构及氨基酸序列保守性，利用三维结构显示软件Cn3D，分析E型BoNT可能的B细胞表位的空间定位，进而预测E型BoNT的B细胞表位。结果：5个E型BoNT基因核酸序列同源性为97．2％-100％，氨基酸序列同源性为95％-100％；E型BoNT轻链中的62-78，111-127区段，重链中443-465，661-677，693～709，727-743，853-869，1093-1109，1128-1144，1163-1179区段最有可能是其B细胞优势表位。结论：我们利用不同分析软件，结合多参数综合预测出了E型BoNT的多个B细胞表位，为进一步鉴定E型BoNer的B细胞表位及其多表位疫苗的研究奠定了基础。

Objective： To analyze homology of different botulinum neurotoxin （BoNT） serotype E gene sequences and predict B cell epitopes of BoNT serotype E. Methods：Five different BoNT serotype E sequences from GenBank were analyzed by MegAlign program of Lasergene software;combined with analysis of several indexes related to B cell epitopes, the prediction of the secondary structure of BoNT serotype E and highly conserved BoNT serotype E amino acids sequence, B cell epitopes of BoNT serotype E were predicted by two different bioinformatical softwares. The three-dimensional orientation of above predicted epitopes were analyzed by Cn3D. Results：Multiple sequences aligment analysis showed that nucleic acid homology of the five different BoNT serotype E genes was 97.2% - 100% and amino acids homology was 95% - 100%. The B cell epitopes of BoNT serutype E were probably located at or adjacent to its N-terminal No. 62 -78, 111 - 127 of the light chain and N-terminal No. 443 -465,661 -677,693 -709,727 -743, 853 -869, 1 093 - 1 109, 1 128 - 1 144, 1 163 - 1 179 of the heavy chain of BoNT serotype E. Conclusion ： These data obtained by the epitope prediction using multiple parameters and the different analysis softwares are helpful for further epitope identification and lay foundation for multiepitopes-based vaccine of BoNT serotype E.