Influenza A virus H5N1 neuraminidase (NA)

Influenza A virus H5N1 neuraminidase (NA) is a critical surface glycoprotein and enzyme essential for the life cycle of the highly pathogenic avian influenza virus (UniProt: P0C6Q6). Its primary biological function is to catalyze the cleavage of terminal sialic acid residues from host cell receptors and viral glycoproteins, which facilitates the release of newly synthesized virions from the infected cell surface (PubMed: 22435404). By preventing the aggregation of viral particles, NA enables the efficient spread of the virus throughout the respiratory tract and into other tissues (NCBI: NBK541024). In H5N1 infections, the high activity of this enzyme contributes to severe disease pathology, including intense inflammatory responses and high viral titers (PubMed: 16543451). Neuraminidase is the primary target for the class of antiviral drugs known as neuraminidase inhibitors, such as oseltamivir and zanamivir (DrugBank: DB00198). These drugs act as transition-state analogues that bind to the highly conserved active site of the enzyme, effectively blocking its catalytic activity and halting viral dissemination (PubMed: 11217082). However, the emergence of specific mutations, such as the H274Y substitution, poses a significant challenge by conferring resistance to certain inhibitors (PubMed: 18297121).

Other names

NeuraminidaseSialidaseN1 neuraminidaseExo-alpha-sialidaseAcylneuraminyl hydrolase

Neuraminidase inhibitors bind to the enzyme's active site, mimicking the transition state of sialic acid cleavage to prevent the release of viral progeny (PubMed: 11217082).