H_3N_2亚型人流行性感冒病毒HA_1的蛋白序列同源性比较、变异规律及结构与功能的分析

Analysis and Studies on the Amino Acid Sequence Homology,Mutant Regularity,Structural and Functional Relationship of HA_1 of Human Influenza Virus(H_3N_2)

应用生物信息学数据库和工具,结合自身的实验结果,对现有的H3N2亚型人流行性感冒(流感)病毒全球分离株的HA1氨基酸序列和蛋白分子结构进行了分析研究。初步的进化分析结果表明,历史上的分离株大致分为以年代划分为特征的两大谱系,即1968～1984/1985年的谱系,时间跨度为18年;1984/1985～1997/2000年的谱系,时间跨度为13～17年。它们分别起源于两类毒株,并在各自的谱系内发展演化,基本上不存在大规模相互交叉渗透的现象。在1984/1985年,两大谱系发生交替转换和过渡,说明流感病毒的起源、发展和演化是有一定规律性的,这可能对流感的监测预报有一定的指导意义。绝大多数毒株的二硫键组成位点和糖基化位点是极其保守的。受体结合位点(RBS)的一部分构成成份保守;其他构成成份发生变异甚至高变,并与某些抗原决定簇位点重合,可能参与了抗原抗体相互作用。5个抗原决定簇位点的变异各有其特点。A和B位点的变异表现最活跃,抗原性最强,但B位点稍弱于A位点。C和D位点的抗原性一般,且D位点的变异性低于C位点。E位点抗原性一般。在各位置的变异中,大多常是相同相近性质或相同种类的氨基酸相互替换。HA1蛋白全序列的熵(entropy)峰值作图的分析表明,HA1蛋白上121～126位等区域或位点可能独立,或参与构成了某些已知或未知?

HA1 gene of human influenza virus(H3N2)from 27 Chinese strains during 1960's～1990's seasons have been sequenced in our laboratory Retrieved and combined this sequence results with all HA1 genes and protein sequences of historic human H3N2 virus strains all over the world registered in bioinformatics database and then aligned and analyzed all these HA1 sequences with bioinformatics toolsFrom the relationship of HA1,primary phylogenetic analyzing results showed that the historic human H3N2 influenza virus strains were divided into two major lineagesOne lineage contained virus strains from 1968 to 1984/1985,whose lifespan were about 18 yearsAnother lineage contained virus strains from 1984/1985 to 1997/2000,which lasted about 13～17years,In 1984～1985,these two major lineages undertook their transition and intercrossingIf the lifespan of these two major lineages is determined to be a periodicity of about 18 years,today or in recent future,there must be a brewing of new or renewed lineage of influenza virus which may cause a next great prevalence of influenzaIn most strains,the bisulfide bond and the glycosylation sites in HA1 protein were conservative and near by the antigen determination clusters,which implicted they played a important role in maintanting normal dimensional structure and antigen activityAnd there may be larger antigenic domain than known antigen sites A,B,C,D and even E by bisulfide bond shapingSome mutant sites in receptor banding site(RBS)may take part in the antigenantibody interaction,meanwhile another conservative sites may play a role in maintanting normal structureIn 5 known antigenic sites,the antigen activity of site A and B is the most strong with the highest frequency of mutationSite C and D are the dimensional antigen structure determination domainsIn mutant sites,substitution of amino acid residues usually was of same biochemical character and same kind amino acid residues such as those with same electric charge,same hydrophobicity or same small amino acid residues,that may play an important roles in antigenantibody recognition and interactionThese substitution of amino acid residues in antigen sites may cause antigen drift or viral physical functionsWith entropy plot of HA1 proteins and activity of the mutant,it is found that some new antigen site or unidentified antigen sites are sites or region in HA1 proteins including 121～126 aa,242～248 aa,213～219 aa,163～164 aa and 226 aaThe above analysis and the consequent conclusions are reported firstly in China and the whole world