Department of Infectious Diseases, Hangzhou Center for Disease Control and Prevention, Hangzhou, China.
Intervirology. 2011;54(5):233-45. doi: 10.1159/000322383. Epub 2011 Feb 5.
Our aim was to reveal the molecular characteristics of human H1N1 influenza virus hemagglutinin (HA) genes from 1947 to 2009 in China.
129 HA gene sequences were downloaded from NCBI's GenBank and analyzed by DNASTAR software. Additionally, the three-dimensional structure of HA protein was predicted by the SWISS-MODEL service.
First, 2009 Chinese HA genes were 99% identical to those of Mexican and American ones; their key sites remained highly conserved. Second, 50 Chinese strains from 1947 to 2009 clustered by the year of isolation, and 2009 strains had only 70% identity to 1947-2008 ones. Third, over the past 60 years, 3 receptor-binding (RB) sites and 2 of the 8 glycosylation sites (amino acids 279 and 290) underwent considerable changes while the cleavage sites remained stable. Fourth, the human HA sequences differed completely from swine and avian isolates. Finally, the mutation of cleavage sites can change the three-dimensional structures, but single mutations cannot.
Thus, in the past 60 years, Chinese H1N1 influenza HA genes kept stable with high affinity and low pathogenicity to human except changes in 2 glycosylation and 3 RB sites which were associated with the pandemic strength, range and host specificity of viruses.
揭示中国 1947 年至 2009 年人类 H1N1 流感病毒血凝素（HA）基因的分子特征。
从 NCBI 的 GenBank 下载了 129 个 HA 基因序列，并使用 DNASTAR 软件进行分析。此外，通过 SWISS-MODEL 服务预测了 HA 蛋白的三维结构。
首先，2009 年中国的 HA 基因与墨西哥和美国的基因 99%相同；其关键位点仍然高度保守。其次，1947 年至 2009 年的 50 株中国分离株按分离年份聚类，2009 年的分离株与 1947-2008 年的分离株仅有 70%的同一性。第三，在过去的 60 年中，3 个受体结合（RB）位点和 2 个 8 个糖基化位点（氨基酸 279 和 290）发生了很大变化，而切割位点保持稳定。第四，人类 HA 序列与猪和禽分离株完全不同。最后，切割位点的突变可以改变三维结构，但单个突变不能。
因此，在过去的 60 年中，中国的 H1N1 流感 HA 基因保持稳定，对人类具有高亲和力和低致病性，除了 2 个糖基化和 3 个 RB 位点的变化外，这些变化与病毒的大流行强度、范围和宿主特异性有关。
