Neuraminidase (Influenza A virus H5N1) (NA)

Influenza A virus neuraminidase (NA) is a tetrameric type II transmembrane glycoprotein that serves as a critical enzyme on the viral surface [1]. Its primary biological function is the cleavage of terminal sialic acid residues from host cell receptors and viral glycoproteins, a process essential for the release of progeny virions from infected cells and the prevention of viral aggregation [1, 2]. In the H5N1 subtype, which is associated with highly pathogenic avian influenza, NA plays a pivotal role in viral dissemination and the crossing of the mucus barrier in the respiratory tract [2, 4]. This enzyme is the primary target for neuraminidase inhibitors (NAIs) such as oseltamivir, zanamivir, and peramivir, which are designed to occupy the highly conserved active site [3]. By inhibiting NA, these drugs trap newly formed viruses at the host cell surface, thereby limiting the spread of infection [2, 3]. However, the therapeutic utility of NAIs is threatened by the emergence of resistance-conferring mutations, most notably the H274Y substitution in the N1 subtype [1, 3]. Consequently, NA remains a focal point for both clinical treatment strategies and global surveillance of emerging influenza pandemic threats [4].

Other names

SialidaseExo-alpha-sialidaseN1 neuraminidaseNeuraminidase N1NA

Neuraminidase inhibitors act as transition-state analogues that bind to the conserved active site of the neuraminidase enzyme. This binding prevents the cleavage of terminal sialic acid residues on host cell receptors and viral glycoproteins, which is necessary for the release of newly synthesized virions from the host cell surface and their subsequent spread to uninfected cells [2, 3].