Influenza virus neuraminidase enzyme (NA)

Influenza virus neuraminidase is a tetrameric enzyme embedded in the viral envelope, responsible for cleaving α-ketosidic linkages of sialic acid from host cell glycoproteins and glycolipids. This enzymatic activity facilitates the release of progeny virions from infected cells and prevents aggregation on the cell surface, maximizing viral spread. Neuraminidase is encoded on the sixth segment of the influenza viral genome and is a key target for antiviral drugs (neuraminidase inhibitors). Nine subtypes (N1-N9) exist for influenza A, with a single subtype described for B and C. Mutations in the neuraminidase gene can confer drug resistance and drive antigenic diversity, contributing to pandemic potential. The structure consists of four identical subunits, each with a cytoplasmic tail, transmembrane region, stalk, and a globular catalytic head where substrate binding and cleavage occur. This enzyme operates synergistically with hemagglutinin (another major envelope protein of the influenza virus), balancing attachment to host cells (by hemagglutinin) with release (by neuraminidase).

Other names

Influenza neuraminidaseviral neuraminidasesialidase (EC 3.2.1.18)NA (for subtypes, e.g., N1, N2)

Competitive inhibition of the active site, blocking sialic acid cleavage, preventing virus release and spread