Type III, buffered aqueous solution, 0.2 μm filtered, 1-5 units/mg protein (Lowry, using NAN-lactose), Synonym: Acyl-neuraminyl Hydrolase, Receptor-destroying enzyme, Sialidase; Neuraminidase enzymes are glycoside hydrolase enzymes that catalyze hydrolysis of terminal sialic acid residues. The most well-known are the viral nearamidases, which promote influenza virus release.