Neuraminidase (Influenza A virus H3N2v) (NA)

Neuraminidase (NA) is a critical surface glycoprotein of the H3N2v influenza A virus, a variant strain primarily circulating in swine that occasionally infects humans (CDC, 2023). As a glycoside hydrolase, NA functions by cleaving terminal sialic acid residues from host cell receptors and viral glycoproteins (UniProt, 2024). This enzymatic activity is essential for the release of newly synthesized virions from the surface of infected cells, preventing viral aggregation and facilitating the spread of the infection throughout the respiratory tract (PubMed, 2021). Additionally, NA helps the virus navigate through the mucus layer of the respiratory epithelium by degrading sialic acid-containing decoys (Nature, 2018). Because of its indispensable role in the viral life cycle, NA is a primary target for antiviral therapy. Drugs such as oseltamivir and zanamivir act as competitive inhibitors, binding to the highly conserved active site of the enzyme to halt viral replication (PubChem, 2024). Monitoring for mutations that confer drug resistance is a significant aspect of managing H3N2v infections, as specific amino acid substitutions can drastically reduce the efficacy of existing neuraminidase inhibitors (WHO, 2022).

Other names

SialidaseExo-alpha-sialidaseN2 neuraminidaseNANeuraminidase [Influenza A virus (A/Indiana/08/2011(H3N2v))]

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 on host cell receptors and viral glycoproteins, which results in the aggregation of progeny virions on the cell surface and halts the spread of infection (PubChem, 2024).