The adaptability of H9N2 avian influenza A virus to humans: A comparative docking simulation study

• Published in: Biochemical and biophysical research communications 2020-09, Vol.529 (4), p.963-969
• Main Authors: Xu, Hengyue, Qian, Jiaqiang, Song, Yifan, Ming, Dengming
• Format: Article
• Language: English
• Subjects: Animals; Binding Sites; Chickens - virology; China - epidemiology; Crystallography, X-Ray; Ducks - virology; H9N2; Hemagglutinin A; Hemagglutinin Glycoproteins, Influenza Virus - chemistry; Hemagglutinin Glycoproteins, Influenza Virus - metabolism; Host-Pathogen Interactions - genetics; Humans; Influenza A Virus, H5N1 Subtype - chemistry; Influenza A Virus, H5N1 Subtype - classification; Influenza A Virus, H5N1 Subtype - metabolism; Influenza A Virus, H7N9 Subtype - chemistry; Influenza A Virus, H7N9 Subtype - classification; Influenza A Virus, H7N9 Subtype - metabolism; Influenza A Virus, H9N2 Subtype - chemistry; Influenza A Virus, H9N2 Subtype - classification; Influenza A Virus, H9N2 Subtype - metabolism; Influenza in Birds - epidemiology; Influenza in Birds - transmission; Influenza in Birds - virology; Influenza, Human - epidemiology; Influenza, Human - transmission; Influenza, Human - virology; LSTc; Marginal contact equilibrium; Molecular Dynamics Simulation; Phylogeny; Polysaccharides - chemistry; Polysaccharides - metabolism; Protein Binding; Protein Conformation, alpha-Helical; Protein Conformation, beta-Strand; Protein Interaction Domains and Motifs; Receptors, Virus - chemistry; Receptors, Virus - metabolism; Sialylated penta-saccharide; Structural Homology, Protein; Vina docking
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2020.06.065

Influenza A virus, the H9N2 subtype, is an avian influenza virus that has long been circulating in the worldwide poultry industry and is occasionally found to be transmissible to humans. Evidence from genomic analysis suggests that H9N2 provides the genes for the H5N1 and H7N9 subtypes, which have been found to infect mammals and pose a threat to human health. However, due to the lack of a structural model of the interaction between H9N2 and host cells, the mechanism of the extensive adaptability and strong transformation capacity of H9N2 is not fully understood. In this paper, we collected 40 representative H9N2 virus samples reported recently, mainly in China and neighboring countries, and investigated the interactions between H9N2 hemagglutinin and the mammalian receptor, the polysaccharide α-2,6-linked lactoseries tetrasaccharide c, at the atomic level using docking simulation tools. We categorized the mutations of studied H9N2 hemagglutinin according to their effects on ligand-binding interactions and the phylogenetic analysis. The calculations indicated that all the studied H9N2 viruses can establish a tight binding with LSTc although the mutations caused a variety of perturbations to the local conformation of the binding pocket. Our calculations suggested that a marginal equilibrium is established between the conservative ligand-receptor interaction and the conformational dynamics of the binding pocket, and it might be this equilibrium that allows the virus to accommodate mutations to adapt to a variety of environments. Our results provided a way to understand the adaptive mechanisms of H9N2 viruses, which may help predict its propensity to spread in mammals. •40 HA mutant structures of H9N2 avian influenza virus circulating mostly in China were investigated.•Mutations in 9 of 100 amino acids of the HA protein were found critical to virus adaptability.•Compared with Q226-HA, the binding orientation of L226-HA to mammalian receptors was more stable and concentrated.