Cheng Cong-sheng, Lan Yu, Liu Yan, Zhang Zhi-qing, Shu Yue-long
National Key Laboratory for Infectious Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 100052, China.
Wei Sheng Wu Xue Bao. 2007 Jun;47(3):418-22.
NS1 gene was amplified from an H5N1 influenza virus, A/Anhui/01/2005 for cloning, sequence analysis and later expression in Escherichia coli. The result showed that NS1 of A/Anhui/01/2005 strain had the close phylogenetic relationship with that of H5N1 avian influenza strains recently isolated in Fujian and Hunan. Correspondingly, its amino acid sequence showed the highest homology with that of Fujian and Hunan strains. The amino acid position of 92 involved in virus virulence was Asp, contrast to Glu in A/HK/156/97. Five amino acid deletion from 80 to 84 was also found in A/Anhui/01/2005, which was considered as a contributor to virus resistance against cytokine, such as IFN, TNF, etc. A motif binding to CBSF, conveted to GFWEN, which was different from previous GLEWN found in other 19 strains. Besides, the PL motif of ESEV, binding to PDZ domain, is the same as previous high-mortality H5N1 isolates. Furthermore, this NS1 was efficiently expressed in Escherichia coli and the highly purified product demonstrated wonderful activity as confirmed by Western blot. As a result, the work paves the way for further understanding the role of NSI in human H5N1 infection and development of new antiviral drugs against influenza virus.
从一株H5N1流感病毒A/Anhui/01/2005中扩增NS1基因，用于克隆、序列分析以及随后在大肠杆菌中的表达。结果显示，A/Anhui/01/2005毒株的NS1与福建和湖南近期分离的H5N1禽流感毒株具有密切的系统发育关系。相应地，其氨基酸序列与福建和湖南毒株的氨基酸序列具有最高的同源性。参与病毒毒力的第92位氨基酸为天冬氨酸，与A/HK/156/97中的谷氨酸不同。在A/Anhui/01/2005中还发现从第80位到第84位有五个氨基酸缺失，这被认为是该病毒对细胞因子如干扰素、肿瘤坏死因子等产生抗性的一个因素。一个与CBSF结合的基序转变为GFWEN，与其他19个毒株中发现的先前的GLEWN不同。此外，与PDZ结构域结合的ESEV的PL基序与先前高致死率的H5N1分离株相同。此外，该NS1在大肠杆菌中高效表达，经蛋白质印迹法证实，高度纯化的产物具有良好的活性。因此，这项工作为进一步了解NS1在人类H5N1感染中的作用以及开发抗流感病毒的新型抗病毒药物铺平了道路。
