A New Glucosylceramidase Activator in Human Placenta
Natural substrates of many lysosomal hydrolases are highly hydrophobic. While the reactions can proceed in vitro when appropriate detergents are included in the assay mixture, these enzymes must function in vivo without artificial detergents of high concentrations often required for in vitro reactions. Since the first report of an endogenous activator protein for hydrolysis of sulfatide by arylsulfatase A by Mehl and Jatzkewitz (1), so-called natural activator proteins have been described for glucosylceramidase (2–4), GM1-ganglioside β-galactosidase (5,6), GM2-ganglioside N-acetyl-β-galactosaminidase (7,8), sulfatide sulfatase (1,9), and ceramide trihexoside α-galactosidase (10). The physiological significance of at least some of these natural activators has been convincingly indicated by the existence of genetic disorders in which activators are defective, such as GM2-gangliosidosis AB variant (7) or metachromatic leukodystrophy due to activator deficiency (l1).
KeywordsCrude Enzyme Gauche Disease Sodium Taurocholate Crude Enzyme Preparation Crude Preparation
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