Purity ~90% (SDS-PAGE). H5N1/HA (hemaggulutinin1) belongs to the influenza viruses hemagglutinin family. Influenza hemagglutinin (HA) or haemagglutinin is a type of hemagglutinin found on the surface of the influenza viruses. It is an antigenic glycoprotein. It is responsible for binding the virus to the cell that is being infected. HA protein has two functions. Firstly, it allows the recognition of target vertebrate cells, accomplished through the binding of these cells' sialic acid-containing receptors. Secondly, once bound it facilitates the entry of the viral genome into the target cells by causing the fusion of host endosomal membrane with the viral membrane. Source: Recombinant protein corresponding to aa17-338 from Influenza A virus (A/Viet Nam/HN31242/2007(H5N1)) HA1, fused to His-tag at C-terminal expressed in Hi-5 cell using baculovirus. Molecular Weight: ~37.4kD (332aa) AA