Hemagglutinin protein of Influenza A virus (H1N1) (HA (H1N1))

The hemagglutinin protein of Influenza A virus (H1N1) is a trimeric glycoprotein located on the viral surface and plays an essential role in the virus’s life cycle. It is responsible for the initial attachment of the virus to host cells by binding to sialic acid-containing receptors, facilitating subsequent endocytosis. Upon exposure to the acidic environment of the endosome, hemagglutinin undergoes a conformational change that triggers fusion between the viral envelope and the host cell membrane, enabling viral RNA entry. It is the major antigenic protein of the influenza virus, targeted by neutralizing antibodies and forming the basis for vaccine-induced immunity. HA is classified as a class I fusion protein and is highly variable, necessitating ongoing surveillance for vaccine design due to antigenic drift and shift[1][2][3][4][5][7].

Other names

influenza hemagglutininHA proteinH1 hemagglutininhemagglutinin (H1)H1N1 HA

Neutralizing antibodies block receptor binding Neutralizing antibodies block conformational changes needed for fusion Inhibitors or antibodies disrupting HA function impede viral entry and infection