Broad-spectrum anti-influenza activity of the NMPA-approved drug Pamiparib is uncovered by virtual docking to the evolutionarily conserved domain of IAV-M2 protein

Influenza viruses generate new strains or subtypes through antigenic drift and antigenic shift, leading to the failure of existing antiviral drugs and potentially causing widespread viral infection and influenza epidemics. However, during evolution, certain influenza virus proteins remain unchanged or undergo only minor mutations. Therefore, drugs targeting these evolutionarily conserved viral protein regions may exhibit broad-spectrum antiviral activity across subtypes and against mutations. The purpose of this study is to target the evolutionarily conserved domain of influenza A virus M2 protein and screen for drugs with cross-strain, mutation-resistant, and broad-spectrum antiviral activity. This study used AlphaFold3 to predict the M2 conserved domain structure and employed AutoDock to perform virtual screening of the NMPA database, identifying seven potential candidate drugs. Molecular dynamics simulations indicated that pamiparib exhibits strong affinity for the M2 conserved domain. It demonstrates excellent physiological activity in vitro in inhibiting the replication of H1N1 replication, while showing no effect on other viruses. CETSA experiments confirmed that pamiparib has the potential to bind to the M2 proteins of various influenza virus subtypes. In addition, pamiparib suppresses effectively viral infection in vivo. Ultimately, this study verifies that antiviral drugs designed to target the evolutionarily conserved regions of the influenza virus M2 protein indeed possess broad-spectrum antiviral activity across different strains.