Research Network of Immunity and Health, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China.
Science. 2013 Oct 11;342(6155):243-7. doi: 10.1126/science.1242917. Epub 2013 Sep 5.
An avian-origin human-infecting influenza (H7N9) virus was recently identified in China. We have evaluated the viral hemagglutinin (HA) receptor-binding properties of two human H7N9 isolates, A/Shanghai/1/2013 (SH-H7N9) (containing the avian-signature residue Gln(226)) and A/Anhui/1/2013 (AH-H7N9) (containing the mammalian-signature residue Leu(226)). We found that SH-H7N9 HA preferentially binds the avian receptor analog, whereas AH-H7N9 HA binds both avian and human receptor analogs. Furthermore, an AH-H7N9 mutant HA (Leu(226) → Gln) was found to exhibit dual receptor-binding property, indicating that other amino acid substitutions contribute to the receptor-binding switch. The structures of SH-H7N9 HA, AH-H7N9 HA, and its mutant in complex with either avian or human receptor analogs show how AH-H7N9 can bind human receptors while still retaining the avian receptor-binding property.
一种源自禽类可感染人类的流感（H7N9）病毒最近在中国被发现。我们评估了两种人感染 H7N9 病毒分离株 A/上海/1/2013（SH-H7N9）（含有禽类受体结合特征性的残基 Gln（226））和 A/安徽/1/2013（AH-H7N9）（含有哺乳动物受体结合特征性的残基 Leu（226））的病毒血凝素（HA）的受体结合特性。我们发现 SH-H7N9 HA 优先结合禽类受体类似物，而 AH-H7N9 HA 可结合禽类和人类受体类似物。此外，还发现 AH-H7N9 突变 HA（Leu（226）→Gln）具有双重受体结合特性，表明其他氨基酸取代有助于受体结合转换。SH-H7N9 HA、AH-H7N9 HA 及其与禽类或人类受体类似物复合物的结构显示了 AH-H7N9 如何能够结合人类受体，同时仍保留禽类受体结合特性。
