311-391aa; Partial. MW: 36.4kD. Purity >90% as determined by SDS-PAGE. Saposin-A and saposin-C stimulate the hydrolysis of glucosylceramide by beta-glucosylceramidase (EC 3. 2. 1. 45) and galactosylceramide by beta-galactosylceramidase (EC 3. 2. 1. 46). Saposin-C apparently acts by combining with the enzyme and acidic lipid to form an activated complex, rather than by solubilizing the substrate. Saposin-B stimulates the hydrolysis of galacto-cerebroside sulfate by arylsulfatase A (EC 3. 1. 6. 8)
Molecular cloning of a human co-beta-glucosidase cDNAevidence that four sphingolipid hydrolase activator proteins are encoded by single genes in humans and rats.Rorman E.G., Grabowski G.A.Genomics 5:486-492(1989)