黑龙江地区鲤疱疹病毒3型的流行病学调查及其主要囊膜蛋白的抗原表位预测

摘要

2015-2016年对来自黑龙江地区46个养殖场送检的鲤鱼进行锦鲤疱疹病毒(Koi herpes virus,KHV)的分离鉴定,并应用DNAStar等软件对检出的阳性样本的主要囊膜蛋白(Major envelop protein,MEP)基因进行生物信息学分析.结果显示,KHV的检出率约为6.5%,3株阳性样本具有相同的MEP基因序列,称之为KHV-HLJ1516.MEP基因开放阅读框为771 bp,编码256个氨基酸,相对分子质量为28 280.58,等电点为8.40.对KHV-HLJ1516的MEP基因序列同源性分析表明,其与KHV-GZ11分离株仅有1个碱基不同,但并未导致氨基酸发生改变,碱基相似性为99%;而与HZ419分离株相比,KHV-HLJ1516的MEP基因有3个碱基发生突变,相应的氨基酸由Asn变为IIe.聚类分析结果显示,KHV-HLJ1516与KHV-GZ11处于同一分支,而HZ419位于另一分支.B细胞抗原表位预测结果显示,KHV-HLJ1516的MEP的抗原表位主要位于4~11,24~40,42~63,82~110,209~218,238~249氨基酸区段.%Carps from 46 fish farms of Heilongjiang province were subjected to isolation of Koi herpes virus (KHV) during 2015~2016.The major envelope protein (MEP) gene of the KHV was subjected to bioinformatics analyses by using the DNAStar and other software.The results showed that the detection rate of KHV in Heilongjiang province during 2015~2016 was about 6.5%.The 3 isolated KHV had the same MEP gene sequence,and which were called KHV-HLJ1516.The open reading frame (ORF) of the MEP was 771 bp,encoding 256 amino acids.The predicted relative molecular mass of the MEP was 28280.58 and isoelectric point was 8.40.The homology analysis showed that compared with KHV-GZ11,the MEP gene of the KHV-HLJ1516 had a single site nucleotide mutation which did not cause the change of amino acid.The MEP of KHV-HLJ1516 was 99% identical to KHV-GZ11 at the nucleotide level.Compared with HZ419,KHV-HLJ1516 had 3 nucleotide mutations which caused a mutation from Asn to IIe.The results of cluster analysis showed that KHV-HLJ1516 was clustered in the same branch with KHV-GZ11,while another isolate of HZ419 was clustered in another branch.B cell epitopes of the MEP showed that the likely B cell epitopes of KHV-HLJ1516 MEP were mainly located at 4~11,24~40,42~63,82~110,209~218,238~249 amino acids.