Hemagglutinin/HA Proteins, Antibodies, cDNA Clones, ELISA Kits Research Reagents
The influenza viral Hemagglutinin (HA) protein is a homotrimer with a receptor binding pocket on the globular head of each monomer. HA has at least 18 different antigens. HA contains antigenic sites recognized by the host immune system, cleavage sites cleaved by host proteases, receptor binding sites attaching to sialyl receptors on the target cell, and fusion peptides mediating membrane fusion. HA allows the recognition of target vertebrate cells. Once bound it facilitates the entry of the viral genome into the target cells by causing the fusion of the host endosomal membrane with the viral membrane.