Specificity of Human Glucosylceramide ß-Glucosidase Towards Structurally Modified Glucosylceramides in a Liposomal Assay-System
Glycosphingolipids are the most abundant glycolipids in the plasma membrane of animal tissues. Their degradation occurs in lysosomes, where specific hydrolytic enzymes cut off the sugar moieties sequentially from the non-reducing end. All higher glycosphingolipids are finally hydrolyzed to glucosylceramide, which can be further degraded, via ceramide, to sphingosine. The degradation of glucosylceramide is accomplished by a membrane-associated enzyme, the glucosylceramide ß-glucosidase (EC 18.104.22.168), which hydrolyzes the membrane-bound sphingolipid to ceramide and glucose. This enzyme is defective in various forms of Gaucher’s disease (1,2) with consequent storage of glucosylceramide, primarily in the lysosomes of the reticuloendothelial system.
KeywordsEnzyme Replacement Therapy Phosphatidic Acid Sodium Taurocholate Tocopherol Acetate Amphiphilic Cation
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- 2.A.D. Patrick, A deficiency of glucocerebrosidase in Gaucher’s diesease, Biochem. J. 95: 17 c (1965).Google Scholar
- 8.F.Sarmientos, G. Schwarzmann and K. Sandhoff, Specificity of human glucosylceramide B-glucosidase towards structurally modified glucosylceramides in a detergent-free assay-system, submitted.Google Scholar
- 13.K.Sandhoff, Function and relevance of activator proteins for glycolipid degradation, in: “Molecular basis of lysosomal storage disorders”, J.A. Barranger and R.O. Brady, eds., Academic Press, Washington (1984).Google Scholar
- 14.H.-J. Kytzia and K. Sandhoff, Evidence for two different active sites on human hexosaminidase A. Interaction of GM2 activator protein with hexosaminidase A, J. Biol. Chem. 260: 7588 (1985).Google Scholar