sialidase, an enzyme of the hydrolase class that catalyzes the cleavage of glucosidic linkages between a sialic acid residue and a hexose or hexosamine residue at the nonreducing terminal of oligosaccharides in glycoproteins, glycolipids, and proteoglycans. Deficiency of it is an autosomal-recessive trait and is seen in sialidosis and galactosialidosis. See also neuraminidase.
