摘要
１６株１９７９～１９９２年Ｈ３Ｎ２亚型流感病毒株ＨＡ１基因核苷酸序列分析表明，ＨＡ１基因长度均为９８４个核苷酸，共编码３２８个氨基酸。随病毒株出现时间的推移，ＨＡ１基因间核苷酸替换数增加。在１４年内，不同病毒株间共发生了８３个核苷酸位点的改变，其中６８．７％发生在嘧啶碱与嘧啶碱和嘌呤碱与嘌呤碱间各自互换。８３个核苷酸位点的改变仅导致毒粒ＨＡ１蛋白分子上３０个氨基酸位点的改变，说明流感病毒毒粒ＨＡ１基因与其他基因节段一样，其核苷酸序列的改变，多数也是由于毒粒ＲＮＡ复制中缺乏在ＤＮＡ复制酶中所发现的核对活性。在３０个氨基酸位点改革中，三分之二以上是发生在毒粒ＨＡ１蛋白分子的抗原决定簇（Ａ、Ｂ、Ｄ和Ｅ）上，这清楚表明了，毒粒ＨＡ１基因上编码子的改变，主要是人群免疫压力所造成。然而，无一个发生在半胱氨酸位点上，表明１６株病毒ＨＡ１蛋白分子上二硫键位点均相同。同时发现了，１９８７年后出现的Ｈ３病毒株的ＨＡ１蛋白分子上比Ａ／曼谷／１／７９（Ｈ３Ｎ２）病毒株多一个糖基化点，而且氨基酸替换速度比１９６８～１９７９年Ｈ３病毒株慢，分别为０．５％和０．７％氨基酸改变／ＨＡ１区／年。证实了相似时间、不同地区可分离出ＨＡ１蛋白结构?
The nucleotide sequence analyses of HA1 genes of 16 strains of influenza A (H3N2) virus isolated from 1979 to 1992showed that the lengths of HA1 genes of viruses all the tested were 984 nucleotides coding for 328 amino acids. The increaseof subtituting number of nucleotides of virus HA1 gene was parallel with the lapse of time of viral appearance. There were 83nucleotides changed in different H3N2 strains isolated within 14 years.68.7% of substitutions were or changes.The 83 nucleotides changed only led to 30 amino acids changes. These indicated that the nucleotide substitution of HA1 gene of influenza virus, like other viral genes, caused mainly by the lack of proofreading activity found among DNA polymerases in DNA replication. Of 30 amino acid changes two-third were in antigenic determinants (A, B, D and E) on the virus HA1 protein molecule. This pointed out that the coding changes of virus HA1 gene were mainly caused by herd immunity pressure. However, the change of cysteine had not been occurred by nucleotide change. This indicated that the all disulphide bonds were the same with in 16 H3N2 viruses. It was found that the number of glycosylation in HA1 protein molecule of H3 viruses isolated after 1987 was one more than that of A / Bangkok/1/79(H3N2) virus and that the rate of ent structures of HA1 protein could also be isolated in the same time at a single place.mainstream, but there were two main branches in evolution of viruses isolated from 1989-1990.
出处
《中华实验和临床病毒学杂志》
CAS
CSCD
1994年第4期291-296,共6页
Chinese Journal of Experimental and Clinical Virology
