Neuraminidase (Influenza B virus Victoria lineage) (NA)

Neuraminidase (NA) of the influenza B Victoria lineage is a tetrameric type II transmembrane glycoprotein essential for the life cycle of influenza B viruses belonging to this specific genetic group [1]. It functions as a sialidase, catalyzing the cleavage of terminal sialic acid residues from host cell surface receptors and viral glycoproteins [2]. This enzymatic activity is vital for the release of newly synthesized virions from the host cell membrane and prevents the aggregation of viral particles, thereby facilitating the spread of the virus within the respiratory tract [3]. As a major surface antigen, NA is a primary target for neuraminidase inhibitors (NAIs) such as oseltamivir, zanamivir, and peramivir, which are used to treat and prevent influenza infections [4]. These drugs function by binding to the highly conserved active site of the NA enzyme, acting as transition-state analogues that competitively inhibit its activity [5]. Continuous surveillance of the Victoria lineage is necessary because mutations in the NA protein can lead to reduced susceptibility to these antiviral drugs, impacting public health strategies [6]. The Victoria lineage is one of two distinct lineages of influenza B that have co-circulated globally since the 1980s, making its NA a critical component of seasonal quadrivalent vaccines [4]. Inhibition of this target effectively halts the progression of the viral infection by limiting the number of cells that can be infected by progeny virions [3].

Other names

SialidaseExo-alpha-sialidaseNAReceptor-destroying enzymeInfluenza B Victoria NA

Competitive inhibition of the neuraminidase enzyme, preventing the cleavage of terminal sialic acid residues from host cell receptors and viral glycoproteins, which traps progeny virions on the host cell surface and prevents the spread of infection [3, 5].