Mutation of the Second Sialic Acid-Binding Site, Resulting in Reduced Neuraminidase Activity, Preceded the Emergence of H7N9 Influenza A Virus.

ABSTRACT: The emergence of the novel influenza A virus (IAV) H7N9 since 2013 has caused concerns about the ability of the virus to spread between humans. Analysis of the receptor-binding properties of the H7 protein of a human isolate revealed modestly increased binding to α2,6 sialosides and reduced, but still dominant, binding to α2,3-linked sialic acids (SIAs) compared to a closely related avian H7N9 virus from 2008. Here, we show that the corresponding N9 neuraminidases (NAs) display equal enzymatic activities on a soluble monovalent substrate and similar substrate specificities on a glycan array. In contrast, solid-phase activity and binding assays demonstrated reduced specific activity and decreased binding of the novel N9 protein. Mutational analysis showed that these differences resulted fro

SUBMITTER: Dai M 

PROVIDER: S-EPMC5391454 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature