Hemagglutinin H5N1 (HA H5N1)

Hemagglutinin (HA) is a homotrimeric glycoprotein on the surface of influenza A viruses, particularly the H5N1 strain. It mediates viral entry into host cells by binding to sialic acid receptors and facilitating membrane fusion. HA is a major target for neutralizing antibodies and antiviral drug development. The HA1 subunit binds to the receptor, while HA2 mediates membrane fusion. The cleavage site between HA1 and HA2 is a determinant of pathogenicity. Mutations, such as residue 226 changing from glutamine to leucine, can alter receptor specificity and facilitate cross-species transmission.

Other names

H5N1 HemagglutininHAH5 HemagglutininInfluenza A H5N1 Hemagglutinin

Neutralizing antibodies block virus attachment or inhibit post-binding steps such as membrane fusion. Antiviral drugs (developing) target hemagglutinin to prevent viral entry.