The identification of lysosomal ganglioside sialidase in human cells.

In this report we present evidence for the existence of a lysosomal ganglioside sialidase. The sialidase activity was solubilized by sonication and stimulated by cholate. The absence of ganglioside sialidase activity in sialidosis patients indicates that lysosomal sialidase is active towards gangliosides and glycoproteins. The plasma membranes were associated with two types of ganglioside sialidase activities, one was enhanced by cholate while the other was partially inhibited by this detergent.