Influenza neuraminidase (NA) (NA)

Influenza neuraminidase (NA) is a tetrameric type II transmembrane glycoprotein and a major surface antigen of influenza A and B viruses (Source: PubMed PMC6517459). It functions as a sialidase, an enzyme that cleaves terminal sialic acid residues from host cell receptors and viral glycoproteins, which is a critical step for the release of newly formed virions from the surface of infected cells (Source: UniProt P03468). By preventing the aggregation of viral particles and facilitating their movement through the respiratory mucus, NA plays a vital role in the spread of infection within the host (Source: CDC). In the context of disease, NA is the primary target for the most common class of anti-influenza drugs, known as neuraminidase inhibitors (NAIs), including oseltamivir and zanamivir, which competitively bind to the enzyme's conserved active site (Source: StatPearls NBK539909). While hemagglutinin is the dominant target of current vaccines, vaccine-elicited polyclonal antibodies against NA are increasingly recognized for their ability to provide broad, cross-reactive protection and reduce the severity of illness by inhibiting viral egress (Source: Nature Communications 10, 4338). Monitoring NA activity and antibody titers via assays like the enzyme-linked lectin assay (ELLA) is essential for evaluating vaccine efficacy and tracking the emergence of drug-resistant viral strains (Source: WHO).

Other names

SialidaseNAExo-alpha-sialidaseAcetylneuraminyl hydrolaseNeuraminidase

Neuraminidase inhibitors competitively bind to the active site of the enzyme, preventing the cleavage of sialic acid and thereby trapping progeny virions on the host cell surface to inhibit viral spread.