Influenza viral neuraminidase (NA)

Influenza viral neuraminidase (NA) is a major surface glycoprotein found on influenza A and B viruses that functions as a sialidase enzyme [7, 11]. Its primary biological role is to cleave terminal sialic acid residues from host cell receptors and viral glycoproteins, which is essential for the release of newly formed virions from infected cells and the prevention of viral self-aggregation [1, 3, 10]. Beyond viral budding, NA facilitates the movement of the virus through the respiratory mucus layer by degrading sialic acid-containing mucins, thereby promoting infection of the underlying epithelium [10, 14]. In the context of disease, NA is a critical virulence factor that enables the rapid spread of influenza within the respiratory tract [3, 8]. It is the primary target for the neuraminidase inhibitor (NAI) class of antiviral drugs, including oseltamivir and zanamivir, which act as transition-state analogs of sialic acid to block the enzyme's active site [2, 5, 12]. While highly effective when administered early, the therapeutic utility of targeting NA is constantly challenged by the emergence of drug-resistant strains, often characterized by specific amino acid substitutions like the H275Y mutation [6, 7].

Other names

NeuraminidaseSialidaseExo-alpha-sialidaseSialidase NAcetylneuraminyl hydrolase

Neuraminidase inhibition (prevents the cleavage of terminal sialic acid residues, thereby trapping progeny virions on the host cell surface and preventing their spread to uninfected cells).