中蜂囊状幼虫病毒LN-QY株VP3蛋白空间结构及其B细胞抗原表位的预测

目的预测中蜂囊状幼虫病毒(Chinese sacbrood virus,CSBV)LN-QY株VP3蛋白的空间结构及其B细胞抗原表位。方法采用RT-PCR法从感染CSBV的蜜蜂幼虫总RNA中扩增结构蛋白VP3基因,与pMD18-T载体连接后,转化感受态大肠杆菌DH5α,提取质粒,双酶切鉴定并测序,通过与SBV-KOR、CSBV-UK株VP3基因序列的比对,获得LN-QY株VP3基因的核苷酸序列及推导的氨基酸序列,建立VP3蛋白的3D结构。在此基础上,应用DNAStar软件中的Protean模块综合分析结构蛋白的柔性区域、亲水性、表面可能性以及抗原指数等参数。结果 VP3结构蛋白的空间构象较规则,其可能的B细胞抗原表位区域位于4个区域:25-50,101-109,112-120,250-268氨基酸区段,其中,可能出现抗原表位的2个区域在100-150和250-300氨基酸区段,应作为抗原表位研究的重点区域。结论预测了CSBV LN-QY株VP3蛋白的空间结构及其B细胞抗原表位,为CSBVVP3蛋白单克隆抗体的制备以及表位疫苗的设计奠定了理论基础。

Predication of spatial structure and B cell antigenic epitope of VP3 protein of Chinese sacbrood virus LN-QY strain

Objective To predict the spatial structure and B cell antigenic epitope of VP3 protein of Chinese sacbrood virus(CSBV) LN-QY strain.Methods VP3 gene was cloned from the total RNA of larva of bees infected with CDBV by RT-PCR and inserted into vector pMD18-T.The constructed recombinant plasmid was transformed to E.coli DH5α,from which recombinant plasmid was extracted and identified by restriction analysis and sequencing.The nucleotide and deduced amino acid sequences of VP3 gene of LN-QY strain were compared with those of SBV-KOR and CSBV-UK strains,based on which a 3D model of VP3 protein was established and analyzed for flexible region,hydrophilicity,surface probability and antigenic index by the Protean module in DNAStar software.Results The spatial confirmation of VP3 protein was relatively regular,in which the potential B cell antigenic epitope regions were located in 25-50,101-109,112-120 and 250-268 aa.Antigenic epitopes might appear in two regions in 100-150 and 250-300 aa which should be served as the focus of study.Conclusion The spatial structure and B cell antigenic epitope of VP3 protein of CSBV LN-QY strain was predicted,which provided a theoretical basis for preparation of monoclonal antibody against VP3 protein of CSBV and design of epitope vaccine.