呼吸道合胞病毒B亚型分离株的G蛋白基因分析

CLONING AND SEQUENCING OF cDNA FROM G PROTEIN GENE OF SUBGROUP B RESPIRATORY SYNCYTIAL VIRUS STRAIN ISOLATED IN CHINA

对一株长春地区Ｂ亚型分离株（ＣＣ１６９）的Ｇ蛋白基因进行了序列分析，结果表明：我国呼吸道合胞病毒（ＲＳＶ）分离株ＣＣ１６９同ＲＳＶＢ亚型原型株ＣＨ１８５３７的核苷酸同源性为９４％，核苷酸的有义突变率达６５％。由核苷酸推导出氨基酸序列的同源性为８９４％，氨基酸的变异全部发生在胞外区，并主要集中在一个高度保守区的两端，胞内区和跨膜区保守不变。氨基酸的变异导致了分离株既有糖基化位点的改变，又有蛋白长度的变异。此外还初步探讨了我国ＲＳＶＢ亚型分离株ＣＣ１６９的Ｇ蛋白基因同原型株之间的变异与疫苗研制中的意义。

The nucleotide sequence of the G protein gene of respiratory syncytial virus (RSV) CC169 strain isolated from China that has been identified as subgroup B with monoclonal antibodies, was determined from cDNA that had been amplified by RT PCR and cloned into pTZ18R plasmid vector. The homology of nucleotide was 94% as compared with G protein cDNA of a RSV prototype strain (CH18537). Deduced amino acid identity of G protein was 89.4%. The amino acid changes were only in the extracellular part of the protein where there were two extensive divergent domains with a highly conserved region in between; whereas the cytoplasmic and transmembrane domains were conserved. This study demonstrates the sequence diversity of the G protein of subgroup B RSV between a Chinese isolate and the prototype strain CH18537.