吉林省2009年麻疹病毒血凝素蛋白基因特征

Analysis of Hemagglutinin Gene and Amino Acid Characteristics of Measles Viruses in Jilin Province in 2009

目的研究吉林省2009年麻疹病毒分离株的血凝素(Hemagglutinin,H)蛋白基因特征。方法 从吉林省2009年流行的麻疹野病毒中选取4株,用逆转录-聚合酶链反应扩增H蛋白全基因片段,对扩增阳性产物进行核苷酸序列测定,并利用Mega4.0和Bioedit软件进行基因亲缘关系、同源性以及糖基化位点变异分析。结果吉林省2009年4株麻疹病毒分离株均属于H1基因型H1a基因亚型,并在基因树H1a基因亚型分支中处于相对独立的小分支。2009年4株麻疹病毒分离株之间的核苷酸具有较高的同源性,为99.7%～99.8%;而且,无论与H1a基因亚型代表株China(中国)93-4相比,还是与疫苗株S(Shanghai,上海)191相比,2009年麻疹病毒分离株核苷酸同源性均延续了历年的逐年递减趋势。吉林省2009年4株麻疹病毒分离株的H蛋白均保留了4个糖基化位点,第5个糖基化位点在氨基酸第240位由丝氨酸(Serine,S)突变成天冬酰胺(Asparagine,N),导致一个潜在糖基化位点NL(亮氨酸Leucine,L)S238-240的缺失。结论吉林省2009年的麻疹病毒分离株H蛋白基因的核苷酸变异,与历年相比呈增加趋势。吉林省2009年麻疹病毒分离株第240位糖基化位点的丢失,与中国目前监测到的情况一致。

Objective To study the genetic characteristics of hemagglutinin （H） protein of measles viruses which circulated in Jilin province in 2009. Methods 4 measles virus strains which circulated in 2009 in Jilin province were chosen to do the reverse transcription-polymerase chain reaction （RT-PCR） for amplifying H gene and to do sequence analysis of the PCR products, and then to analyse the phylogenetic, nucleotide homology and glycosylated domains variation. Results 4 strains of measles virus were Hi genotype, Hia sub- genotype, and located in a small independent branch. There are higher nucleotides homology （99.7 %-99.8 % ） among the 4 strains of Jilin province in 2009. The nucleotides homology of measles virus strains in 2009 kept decreasing trend compared with both Hla representative China93-4 and China vaccine S （Shanghai） 191 year by year. The H protein of 4 measles virus strains of Jilin province in 2009 all keep 4 glycosylation sites and the fifth glycosylation site NLS （Asparagine,N; Leucine,L;Serine,S）23s-a40 was losen because of the mutation from Ser to Asn. in 240th amino acids. Conclusions The nucleotides variation of H gene of measles virus strains of Jilin province in 2009 continually kept yearly increasing trend. The variation of the 240th amino acids of glycosylation site NLS238-240 among measles virus strains in Jilin province in 2009 is the same with that of measles virus strains detected in China.