Influenza A virus hemagglutinin protein (H1 subtype) (None)

The hemagglutinin (HA) protein is a major surface glycoprotein of the influenza A virus, essential for viral entry into host cells. The H1 subtype refers to one of at least 18 known HA subtypes found in influenza A viruses. The HA protein is responsible for binding the virus to sialic acid-containing receptors on host cells and mediating fusion between the viral envelope and host cell membrane. It exists as a homotrimer, and its antigenic sites are targets for neutralizing antibodies. Mutations affecting receptor binding specificity or cleavability can enable cross-species transmission or increase virulence. H1 subtype has caused two major pandemics, underscoring its pandemic potential when new variants emerge.

Virus entry inhibition via hemagglutinin binding