The hemagglutinin (HA) protein attaches viral particles to host cells by binding to sialic acid-containing receptors and induces viral particle internalization through clathrin-dependent endocytosis. HA also promotes an alternative clathrin- and caveolin-independent pathway for some virions. HA/Hemagglutinin Protein, H1N1 (Y108F, S340Q, I341R, Q342E, S343T, ACP41105, sf9, His) is the recombinant virus-derived HA/Hemagglutinin, expressed by Sf9 insect cells, with C-His labeled tag.
