i(3)so3-galactosylceramide and Gaucher-Disease

Topics: Adult; Animals; Bone Marrow; Cell Line; Ceramides; Child; Fabry Disease; Fucose; Galactose; Gangliosides; Gaucher Disease; Genetic Variation; Glycolipids; Glycoside Hydrolases; Humans; Leukemia, Myeloid; Leukodystrophy, Globoid Cell; Leukodystrophy, Metachromatic; Lipid Metabolism, Inborn Errors; Lipidoses; Mice; Niemann-Pick Diseases; Sulfoglycosphingolipids

Topics: Ceramides; Diffuse Cerebral Sclerosis of Schilder; Female; Galactosidases; Gangliosides; Gaucher Disease; Glucosidases; Glycolipids; Humans; Lipid Metabolism, Inborn Errors; Lipidoses; Male; Niemann-Pick Diseases; Pregnancy; Pregnancy Complications; Sphingolipids; Sphingomyelins; Sphingosine; Sulfoglycosphingolipids

Fluorescent glycolipids were utilized for detection of the intracellular, activator-dependent, activities of beta-glucocerebrosidase and arylsulphatase A. Activities were measured in primary skin fibroblasts from normal individuals, from patients with Gaucher disease who had mutations within the beta-glucocerebrosidase gene, and from a prosaposin-deficient patient. Fluorescent microscopy demonstrated that glucosylceramide or sulphatide labelled with a fluorescent probe (lissamine-rhodamine) were endocytosed and reached the lysosomes. There, in the presence of active enzyme and the corresponding saposin, they were hydrolysed to fluorescent ceramide, which changed its intracellular localization. When these substrates were labelled with pH-sensitive lissamine-rhodamine, which loses its fluorescence at neutral or alkaline pH, the transport of the product, i.e. fluorescent ceramide, from the lysosomes resulted in disappearance of the cellular fluorescence. In cells of patients having mutations within the genes encoding the glucocerebrosidase or the prosaposin, there was a considerable reduction in the intracellular rate of substrate hydrolysis that could be followed by fluorescence microscopy or measured quantitatively in cell extracts.

Topics: Cerebroside-Sulfatase; Enzyme Activation; Fluorescent Dyes; Gaucher Disease; Glucosylceramidase; Glucosylceramides; Glycoproteins; Humans; Intracellular Fluid; Lysosomes; Mutation; Rhodamines; Saposins; Sphingolipid Activator Proteins; Sulfoglycosphingolipids

We report the presence of antisulfatide antibodies in a patient with type I Gaucher's disease and peripheral neuropathy. The association of Gaucher's disease with hypergammaglobulinemia and monoclonal gammopathy is well documented whereas its association with peripheral neuropathy is rare. We discuss whether antibodies directed against the sulfatide antigen are related to Gaucher's disease or are a coincidental association.

Topics: Antibodies; Female; Gaucher Disease; Humans; Middle Aged; Peripheral Nervous System Diseases; Sulfoglycosphingolipids

Saposin B is involved in the hydrolysis of sulfatides, GM1 ganglioside, globotriaosylceramide, and several other sphingolipids and glycerolipids by lysosomal hydrolases. Saposin B is one of four small glycoproteins (saposins) derived from prosaposin. The carbohydrate chain of saposin B was removed and deglycosylated saposin B was characterized and compared with native saposin B. Deglycosylated saposin B stimulated the enzymatic hydrolysis of ganglioside GM1 by acid beta-galactosidase and sulfatide by arylsulfatase A to the same extent as native saposin B. In addition deglycosylated saposin B bound sulfatide and GM1 ganglioside identical to native saposin B. The stability of native saposin B to proteolytic digestion was unchanged by deglycosylation. Neither native saposin B nor deglycosylated saposin B were hydrolyzed by trypsin, endoproteinase Glu-C (V-8), chymotrypsin, or a mixture of acid proteases isolated from human testis. Unlike its effect on metabolic stability, the carbohydrate chain appears to affect folding of saposin B. When native and deglycosylated saposin B were reduced under denaturing conditions and refolded under identical conditions examination of the refolded products indicated that each protein was refolded in a qualitatively different way. A human mutation in saposin B-deficient metachromatic leukodystrophy, in which its glycosylation site is eliminated, has been reported. Our observations suggest that instability of the mutated saposin B is not due to the absence of a protective effect of the carbohydrate chain on proteolysis, but is likely due to aberrant folding resulting from the absence of a carbohydrate chain.

Topics: beta-Galactosidase; Carbohydrates; Cerebroside-Sulfatase; Chromatography, High Pressure Liquid; Drug Stability; Electrophoresis, Polyacrylamide Gel; G(M1) Ganglioside; Gaucher Disease; Glycoproteins; Glycosylation; Humans; Hydrolysis; Saposins; Sphingolipid Activator Proteins; Spleen; Structure-Activity Relationship; Sulfoglycosphingolipids

Extraction of control human spleen glucocerebrosidase with sodium cholate and butan-l-ol reversibly inactivates the enzyme in terms of its ability to hydrolyse the water-soluble substrate 4-methylumbelliferyl beta-D-glucopyranoside (MUGlc). The acidic brain lipid galactocerebroside 3-sulphate (sulphatide) reconstitutes beta-glucosidase activity in a strongly concentration-dependent manner. In this study we show that sulphatide exhibits three critical micellar concentrations (CMCs): CMC1, 3.72 microM; CMC2, 22.6 microM; CMC3, 60.7 microM. We designate the aggregates formed at these CMCs as primary, secondary and tertiary micelles respectively. From the results of kinetic studies performed at various sulphatide concentrations (0.012-248 microM), we found that sulphatide monomers (less than 3 microM) decreased the Km (for MUGlc) of control glucocerebrosidase from 11 to 4.6 mM, and lowered the Vmax. 2-fold. However, secondary and tertiary micelles were required for expression of high control glucocerebrosidase activities. Glucocerebrosidase prepared from the spleen of a patient with non-neuronopathic type 1 Gaucher's disease exhibited a very low Km (2.8 mM) even in the absence of exogenous lipid, and sulphatide monomers had no effect on the mutant enzyme's Km or Vmax. However, secondary or tertiary micelles markedly increased the Vmax. of the type 1 glucocerebrosidase to 60% of the corresponding control enzyme value. In contrast, for the glucocerebrosidase of the neuronopathic type 2 case, although sulphatide decreased the Km from 9.2 to 1.7 mM, the Vmax. never reached more than 5% that of the control enzyme, even at high concentrations of sulphatide. In addition, we found that secondary and tertiary sulphatide micelles enhanced the rate of inactivation of all three glucocerebrosidase preparations by chymotrypsin. Collectively, these results indicate the presence of two sulphatide-binding sites on glucocerebrosidase: one that enhances substrate binding, and another that enhances catalysis.

Topics: Binding Sites; Cerebrosides; Chymotrypsin; Enzyme Activation; Galactosylceramides; Gaucher Disease; Glucosidases; Glucosylceramidase; Glycoproteins; Humans; Kinetics; Micelles; Proteins; Saposins; Spleen; Sulfoglycosphingolipids

Topics: Acute Disease; Brain; Brain Chemistry; Brain Stem; Cerebellum; Cerebrosides; Cholesterol; Chromatography, Thin Layer; Female; Frontal Lobe; Galactose; Gangliosides; Gaucher Disease; Glucose; Humans; Infant; Infant, Newborn; Lipid Metabolism; Lipoproteins; Male; Phosphatidylcholines; Phosphatidylethanolamines; Phospholipids; Sphingomyelins; Sulfoglycosphingolipids; Temporal Lobe

Topics: Ceramides; Cerebrosides; Fabry Disease; Fucose; Galactosidases; Gaucher Disease; Glycolipids; Glycoside Hydrolases; Hexosaminidases; Humans; Leukodystrophy, Globoid Cell; Leukodystrophy, Metachromatic; Lipid Metabolism, Inborn Errors; Lipidoses; Neuraminic Acids; Niemann-Pick Diseases; Organ Specificity; Sphingomyelins; Sulfoglycosphingolipids

Topics: Brain; Ceramides; Cerebrosides; Diffuse Cerebral Sclerosis of Schilder; Female; Fibroblasts; Galactose; Galactosidases; Gaucher Disease; Glucose; Glycolipids; Glycoside Hydrolases; Hexosaminidases; Humans; Intestines; Kidney; Leukocytes; Lipid Metabolism, Inborn Errors; Lipidoses; Liver; Male; Muscles; Niemann-Pick Diseases; Phosphoric Diester Hydrolases; Sphingomyelins; Spleen; Sulfoglycosphingolipids; Syndrome

Topics: Diffuse Cerebral Sclerosis of Schilder; Galactosidases; Gaucher Disease; Glycolipids; Humans; Lipid Metabolism, Inborn Errors; Lipidoses; Lipoprotein Lipase; Niemann-Pick Diseases; Refsum Disease; Sulfoglycosphingolipids; Triglycerides

Topics: Adrenal Medulla; Autopsy; Brain Chemistry; Cholesterol; Diffuse Cerebral Sclerosis of Schilder; Fatty Acids; Gallbladder; Gaucher Disease; Histocytochemistry; Humans; Kidney; Lipidoses; Lipids; Liver; Microscopy, Electron; Mucopolysaccharidoses; Niemann-Pick Diseases; Pancreas; Phospholipids; Sulfoglycosphingolipids