山羊口疮病毒四川分离株F1L基因分子特征分析及抗原表位预测

Molecular Characteristics Analysis and Antigen Epitope Prediction of F1L Gene of Orf Virus Isolate from Sichuan

为明确山羊口疮病毒(ORFV)四川分离株F1L基因分子特征并预测抗原表位,本试验利用生物信息学软件分析四川分离株ORFVF1L基因,并预测其编码蛋白的二、三级结构和B细胞表位。将F1L基因克隆转化后测序,用Mega 7.0软件比对分析该基因与其他地区来源的ORFV F1L基因的变异情况,利用SOPMA服务器预测F1L蛋白的二级结构,以DNAStar软件预测其亲水性、表面可及性、柔韧性及抗原性,以ABCpred方案作为验证并输出B细胞表位,在SWISS-MODEL服务器预测三级结构后,进一步在建模区域再验证抗原表位,最终回归蛋白质序列比对。结果显示,四川分离株ORFVF1L基因大小为1 029bp,编码342个氨基酸,基因及其编码蛋白较其他地区来源毒株有一定变异;F1L蛋白预测分析存在9个可能B细胞表位,综合三级结构预测,其122—137肽段为最优表位;所预测的四川分离株ORFV F1L蛋白优势抗原表位较其他地区具有一定特异性,较多地区在124、131、137位氨基酸出现不同。本研究结果为四川地区ORFV基因工程疫苗及特异性检测方法的研究提供了理论依据。

To determine the molecular characteristics of F1L gene of orf virus（ORFV）isolate from Sichuan,and predict the antigenic epitopes,this experiment used bioinformatics software to analyze ORFVF1L gene of Sichuan isolate and predict the secondary and tertiary structure and B cell epitopes of the encoded protein.The F1L gene was cloned,transformed and sequenced.The mutation of ORFVF1L gene from other regions was analyzed by Mega 7.0 software.The secondary structure of F1L protein was predicted by SOPMA server,and the hydrophilicity was predicted by DNAStar software.Surface accessibility,flexibility,and antigenicity were validated using ABCpred protocol,and the B-cell epitopes were exported.After using SWISS-MODEL server to predict the tertiary structure,re-validated the epitopes in the modeling area,final returned to the protein sequence alignment.The results showed that the ORFV F1L gene of Sichuan isolate was1 029 bp in size and encoded 342 amino acids.F1L gene and its encoded protein had a certain variation compared with other regions.F1Lprotein predicted 9 potential B cell epitopes.Its 122 to 137 peptide was the optimal epitope after comparison of tertiary structure;The predicted ORFV F1Lprotein antigen of Sichuan isolates had certain specificity compared with other regions,the 124,131 and 137 amino acids were different in many strains of other regions.The results of this study provided theoretical basis for the research of ORFV genetic engineering vaccines and specific detection methods in Sichuan.