鲤春血症病毒中国分离株糖蛋白基因和氨基酸序列的初步解析

2002～2004年间从国内养殖鲤科鱼类和观赏鱼类中分离出8株鲤春血症病毒(SVCV)。根据SVCV参考株 全序列,设计引物,用逆转录聚合酶链式反应扩增出8株SVCV糖蛋白编码基因片段,并对扩增产物进行了克隆和 序列测定。用生物信息学方法对测得的序列进行分析,结果8个国内分离株的糖蛋白基因序列与参考株的基因序 列相似性均在92％以上,8个国内分离株之间基因序列相似性均在97．7％以上;8个国内分离株之间糖蛋白推导 出的氨基酸序列相似性均在94．5％以上,与参考株氨基酸序列相似性在92．9％-94．9％之间。系统发育树分析结 果表明,SVCV国内分离株与USA株、980451株、980528株和970469株的进化方向一致,与其它SVCV毒株在进 化方向上不同。8个毒株有19个共同的酶切位点,推导出的氨基酸序列中有10个亲水区、10个可能的抗原位点 和10个跨膜蛋白区域,其峰值基本一致。对SVCV国内分离株的糖蛋白6个功能位点(天冬酰胺糖基化位点、精 氨酸-甘氨酸-天冬氨酸序列、酪蛋白激酶Ⅱ磷酸化位点、蛋白激酶C磷酸化位点、酪氨酸磷酸化位点和肉豆蔻酰 基化位点)进行了初步分析。

Amino Acid Sequence of a Chinese Isolate of Spring Viraemia Virus of Carp and Preliminary Analysis of the Glycoprotein Gene

Eight Spring Viraemia Viruses (SVCV) have been isolated from cultured carp and koi in China between 2002 to 2004. Based on the complete genome of SVCV reference strain, primers were designed and the glycoprotein genes from the 8 isolates were amplified, cloned and se-quenced. These genes were compared with other SVCVs in GenBank and showed nucleotide identities of more than 92%. There was more than 97. 7% nucleotide identities within the eight isolates. The homology was more than 94. 5% among the deduced amino acid sequences of the 8 isolates and 92. 0-94. 0% with other SVCV isolates. Phylogenetic analysis showed that the isolates shared evolutionary direction with USA isolates, and were different from other SVCV isolates from European countries. Nineteen common enzyme sites were found in the 8 isolates. Ten hy-drophobic regions, 10 possible antigenic sites and 10 transmembrane domains were also searched by the software and showed almost the same patterns. The functional sites include MYRISTYL, RGD, CK2-PHOSPHO, PKC-PHOSPHO, TYR-PHOSPHO and Asn-glycosylation sites.