Neuraminidases, also known as sialidases, catalyze the removal of N-acetylneuraminic acid/sialic acid groups from glycoproteins and glycolipids. In addition to having diverse roles in mammalian physiology, neuraminidases are involved in infection by pathogens, including influenza virus. Specifically, viral neuraminidases are essential for viral replication. 4-Methylumbelliferyl-N-acetyl-α-D-neuraminic Acid (4-MUNANA) is a fluorogenic substrate used to assay neuraminidase activity. 4-Methylumbelliferone, released from 4-MUNANA by neuraminidase, is commonly detected using excitation at 365-380 nm and emission at 445-454 nm. Assays using 4-MUNANA sensitively measure the activity of neuraminidases from mammalian and viral sources.
