Neuraminidase (NA) of H9N2 influenza A virus (NA)

The Neuraminidase (NA) of the H9N2 influenza A virus is a critical surface glycoprotein and enzyme (EC 3.2.1.18) essential for the viral life cycle [8, 10]. Its primary biological function is to act as a sialidase, cleaving terminal sialic acid residues from host cell receptors and viral glycoproteins to facilitate the release of newly formed virions from the cell surface [5, 8]. This enzymatic activity prevents the self-aggregation of progeny viruses and enables their spread through the respiratory tract by degrading mucus components [5, 8]. H9N2 viruses are endemic in poultry and pose a significant zoonotic threat, as they can sporadically infect humans and serve as genetic donors for highly pathogenic strains like H5N1 and H7N9 [6, 11]. As a primary therapeutic target, NA is inhibited by antiviral drugs known as neuraminidase inhibitors (NAIs), such as oseltamivir and zanamivir, which competitively bind to the enzyme's active site to block viral egress [2, 12]. However, the clinical utility of these treatments and vaccines is frequently undermined by antigenic drift and the emergence of mutations that confer drug resistance or alter host specificity [3, 9, 12].

Other names

SialidaseN2 neuraminidaseNA proteinReceptor-destroying enzyme

Neuraminidase inhibition