Neuraminidase (NA) (Influenza B virus) (NA)

Neuraminidase (NA) is a critical surface glycoprotein and enzyme found on the Influenza B virus (UniProt: P03474). Its primary biological function is to catalyze the cleavage of terminal sialic acid residues from glycoproteins and glycolipids on the surface of infected host cells and progeny virions (PubMed: PMID: 22226677). This enzymatic activity is essential for the release of newly formed viral progeny from the host cell, preventing viral aggregation and allowing the infection to spread to uninfected cells. Additionally, NA helps the virus navigate through the respiratory tract by degrading sialic acid-containing mucins in the mucus layer (NCBI: TaxID 11520). In the context of disease, Influenza B is a major cause of seasonal epidemics, and NA serves as a key virulence factor. Because of its indispensable role in the viral life cycle, NA is the primary target for the neuraminidase inhibitor (NAI) class of antiviral drugs, such as oseltamivir and zanamivir (PubChem: CID 65028). These drugs bind to the highly conserved active site of the enzyme, blocking its function and effectively trapping the virus on the cell surface. Monitoring for mutations in the NA gene is vital, as specific amino acid substitutions can lead to reduced drug susceptibility and clinical resistance.

Other names

SialidaseExo-alpha-sialidaseNeuraminidase proteinNA proteinInfluenza B virus NA

Neuraminidase inhibitors act as transition-state analogues that bind to the highly conserved active site of the enzyme, preventing the cleavage of terminal sialic acid residues from host cell receptors and progeny virions.