Neuraminidase is an antigenic glycoprotein enzyme (EC 188.8.131.52) found on the surface of the Influenza virus.
Nine neuraminidase subtypes are known; many occur only in various species of duck and chicken. Subtypes N1 and N2 have been positively linked to epidemics in man.
Neuraminidase has functions that aid in the efficiency of virus release from cells. Neuraminidase cleaves terminal sialic acid residues from carbohydrate moieties on the surfaces of infected cells. This promotes the release of progeny viruses from infected cells. Neuraminidase also cleaves sialic acid residues from viral proteins, preventing aggregation of viruses. Administration of chemical inhibitors of neuraminidase is a treatment that limits the severity and spread of viral infections.