猪细小病毒自然弱毒N株VP1基因的扩增与序列分析

对猪细小病毒自然弱毒N株（PPV—N株）VP1基因扩增及测序，利用生物信息学技术预测VP1蛋白的二级结构与B细胞抗原表位，以及分析该蛋白的氨基酸差异位点及密码子偏爱性。结果表明，PPV—N株VP1基因与弱毒参考毒株NADL-2VP1基因同源性最高，亲缘关系最近。PPV—N株VP1蛋白的二级结构较为复杂，以β-折叠为主，并有较多的转角和无规则卷曲区域，在序列的20～56、61～80、86～130、136～188区域为B细胞抗原表位的优势区域。PPV强、弱毒株VP1蛋白存在5个氨基酸差异位点（T-365-I，G-528-D，Q-533-H，P-586-S，K-715-R），这些位点处氨基酸残基抗原性与毒力成正相关。PPV—N株VP1蛋白在A、C、E、G、H、I、K、N、Q、R、S、T、V和Y氨基酸于密码子选择上存在一定的偏爱性。

Amplification and Sequence Analysis of VP1 Gene of Porcine Parvovirus N Strain

The VP1 gene of porcine parvovirus N strain(PPV-N strain) was amplified and sequenced.Then the secondary structure of VP1 protein was predicted by the methods of Chou-Fasman,Garnier-Robson and Karplus-Schultz based on PPV-N strain VP1 gene.Hydrophilicity,surface probability and antigenic index were acquired by the methods of Kyte-Doolittle,Emini and Jameson-Wolf,respectively.Combining these results,the B cell epitopes for VP1 protein of PPV-N strain were predicted.The varying sites of amino acid and codon p...