Molecular dynamics investigation of the ph-dependent influenza hemagglutinin conformational change

Hemagglutinin (HA) is a homotrimeric glycoprotein located on the surface of influenza virus that mediates fusion between viral and endosomal membranes of the host cell. The HA is synthesized as inactive HA0 that is cleaved into HA1 and HA2 glycopolypeptides by host proteases. When the pH within the endosome drops, the HA2 protein undergoes a large irreversible conformational change in HA, while HA1 moves away from the HA2 domains, allowing the refolding of the HA2 loop and releasing the fusion peptide.