The HA/Hemagglutinin Protein attaches to cell surface receptors, allowing virus attachment.It determines host range and virulence.As a class I viral fusion protein, it mediates fusion of virus and endosomal membranes for cell penetration.In acidic endosomes, HA2 undergoes irreversible conformational change, releasing fusion peptide.Multiple HA trimers are needed for fusion pore formation.HA/Hemagglutinin Protein, H3N2 (P03438, sf9, His) is the recombinant Virus-derived HA/Hemagglutinin protein, expressed by Sf9 insect cells , with C-His labeled tag.
