大熊猫犬瘟热病毒附着或血凝蛋白基因的序列分析

Nucleotide sequecnce Analysis of the Haemagglutinin Protein Gene of Giant Panda Strain of Canine Distemper Virus

首次对犬瘟热病毒 (CDV)大熊猫 (GP)毒株附着或血凝蛋白 (H)基因进行了序列测定并与疫苗株Onderstepoort进行了比较。我们设计合成了 4对引物 ,对GP株进行了RT PCR扩增与测序。H蛋白基因全长为 194 6bp ,开放阅读框架 (ORF)始于 2 1 2 3位的ATG ,终止于 184 2 - 184 4位的TGA ,编码 6 0 7个氨基酸 ,该基因序列已被GenBank收录。将GP毒株与GenBank中疫苗弱毒株Onderstepoort进行比较 ,二者核苷酸序列的同源性为 91.4 % ,推导的氨基酸序列的同源性为 90 .2 % ,GP和Onderstepoort株H蛋白的半胱氨酸残基数目均为 12个且相对位置不变 ;疏水性有一定的变化 ,但推测的穿膜区位置 (约 35 55位氨基酸 )是一致的 ;Onderstepoort株的H蛋白潜在的N 联糖基化位点为 4个 ,GP株H蛋白为 9个 ,糖基化位点的不同可能对GP株H蛋白的抗原性产生影响。

The sequence analysis of the haemagglutinin (H) protein gene of giant panda strain of canine distemper virus (CDV) from giant panda in China was conducted and compared with Onderstepoort vaccine strain. Four pairs of primers were designed and synthesized. The PCR products amplified from GP strain were directly sequenced after they were purified. There are 1?946 nt of the complete H gene. The H gene of the GP strain showed that the largest open reading frame (ORF) encoding a protein of 607 amino acid residues started at the ATG at position 21 23 and extended to a termination codon (TGA at position 1?842 1?844). The deduced amino acid sequence of the H protein of the GP strains was compared with the CDV vaccine Onderstepoort strain extracted from the GenBank database. The sequence of the H gene and deduced H protein of the GP strain showed an identity of 91.4% and 90.2% with Onderstepoort strain, respectively. All the 12 cysteine residues found in the GP strain H protein were conserved in Onderstepoort strain. Although predicted hydrophilicity of the GP strain differed from that of the Onderstepoort strain, the predicted transmembrane position at 35 55 amino acid residues was conserved in both strains. Out of the 4 potential N linked glycosylation sites of Onderstepoort H protein, two were located in the N terminal 2/3 of the protein (one located in the putative cytoplasmic part and is probably not used), while the remaining 2 sites were located in the C terminal 1/3 of the protein. Four of the 9 potential N linked glycosylation sites of GP H protein were conserved in the Onderstepoort, but the other five sites are unique to GP, the extra glycosylation sites may influence antigenicity of the GP.