g(m2)-ganglioside and globotriaosylceramide

Topics: alpha-Galactosidase; beta-Galactosidase; Ceramides; Cerebroside-Sulfatase; Enzyme Activators; G(M1) Ganglioside; G(M2) Activator Protein; G(M2) Ganglioside; Galactosylgalactosylglucosylceramidase; Glucosylceramidase; Glucosylceramides; Glycoproteins; Glycosphingolipids; Hydrolases; Lysosomes; Protein Precursors; Proteins; Saposins; Sphingolipid Activator Proteins; Sulfoglycosphingolipids; Trihexosylceramides

Earlier studies have shown that Burkitt's lymphoma (BL) cell lines can be divided into 2 major groups: group I, which retain the original BL biopsy phenotype with expression of CD10 and CD77 antigens and lack of B-cell activation markers, and group III, which, after several in vitro passages, progress toward an "LCL-Like" phenotype with loss of CD10 and C77 expression and up-regulation of B-cell activation antigens. In previous studies we have shown that several glycolipid molecules constitute stage-specific antigens for B cells and that sequential shifts in the 3 major glycolipid series are observed during B-cell differentiation, these changes being mostly due to sequential activations of the corresponding glycosyltransferases. In the present work, 10 BL cell lines with group I or group III phenotype have been examined for cell surface expression of 5 glycolipid antigens (LacCer, GM3, Gb3/CD77, Gb4 and GM2), total glycolipid content and enzymatic activities of 4 glycosyltransferases (GM3, Gb3, Gb4 and GM2 synthetases). We now report that group I and group III BL cells differ in their glycolipid metabolism and express either mostly globoseries or ganglioseries compounds. Indeed, Gb3 is the major glycolipid of group I cells, whereas GM3 and GM2 are the 2 major components of group III cells, and these phenotypic differences are mainly due to differential activities of the corresponding glycosyltransferases: group I cells have high Gb3 synthetase activities and low or no GM3 and GM2 synthetase activities, whereas group III cells have high GM3 and GM2 synthetase activities and low Gb3 synthetase activities. Finally, we also show that, unlike LCL, group III BL cells do not synthesize Gb4.

Topics: Burkitt Lymphoma; G(M2) Ganglioside; G(M3) Ganglioside; Galactosyltransferases; Glycosphingolipids; Glycosyltransferases; Humans; N-Acetylgalactosaminyltransferases; Phenotype; Polypeptide N-acetylgalactosaminyltransferase; Sialyltransferases; Trihexosylceramides; Tumor Cells, Cultured

The lipids accumulated in organs of patients with Gaucher's, Tay-Sachs, and Fabry's disease were identified by means of the combination of thin-layer chromatography and matrix-assisted secondary ion mass spectrometry. The total lipid extract of each lipidosis tissue was chromatographed on a TLC plate and then analyzed directly by mass spectrometry without elution of the sample from the TLC plate. The amount of material needed to obtain an adequate spectrum is in the order of a few micrograms of lipids per band for both positive and negative ion detection. By scanning the plates, mass spectral and chromatographic information can be obtained simultaneously, which was shown to be useful for the qualitative identification of the components on the plates.

Topics: Chromatography, Thin Layer; Fabry Disease; G(M2) Ganglioside; Gaucher Disease; Globosides; Glucosylceramides; Glycolipids; Humans; Mass Spectrometry; Sphingolipidoses; Tay-Sachs Disease; Trihexosylceramides

Urine specimens from two sibs affected with cerebroside sulfatase activator deficiency were examined to ascertain whether the deficiency of the supplementary activator protein required for the enzymatic hydrolysis of cerebroside sulfate was also evident in urine. Material from chromatographic fractionations was examined for the activator activity to avoid ambiguities resulting from protein inhibition. There were substantial deficits in all chromatographic fractions corresponding to activator-containing fractions of control urines. Since patient urines contained elevated amounts of lactosylceramide, digalactosylceramide, and globotriaosylceramide and since similarities between activators for cerebroside sulfate and GM1 ganglioside hydrolyses had been noted previously, the chromatographic fractions were also examined for activators in other glycosphingolipid hydrolase systems. There was coincidence of activators for the GM1 ganglioside/beta-galactosidase and the globotriaosylceramide/alpha-galactosidase A reactions with the cerebroside sulfatase activator in control urine fractions, and the patients' urines were deficient in activator activities for the three reactions. Identity of the three activators was suggested and antiserum to purified GM1 ganglioside activator was used to test this possibility. There were depressed levels of cross-reacting material in fractions of patient urines by Ouchterlony double diffusion and in unfractionated urine by enzyme-linked immunosorbent assay. Purified activators for the cerebroside sulfate and GM1 ganglioside systems showed lines of identity with no spurring on Ouchterlony double diffusion, identical mobility on immunoelectrophoresis, and similar stimulatory activities toward hydrolysis of the three glycosphingolipid species by their respective enzymes. Finally, the three activator activities were retained by anti-GM1-activator IgG coupled to Sepharose 4B. The results suggest strongly that the same protein entity serves as activator for the enzymatic hydrolysis of cerebroside sulfate, GM1 ganglioside, and globotriaosylceramide.

Topics: alpha-Galactosidase; Animals; beta-Galactosidase; beta-N-Acetylhexosaminidases; Enzyme Activation; G(M1) Ganglioside; G(M2) Ganglioside; Gangliosides; Globosides; Glycosphingolipids; Hexosaminidases; Humans; Hydrolysis; Immunodiffusion; Immunosorbent Techniques; Protein Deficiency; Proteins; Proteinuria; Rats; Saposins; Trihexosylceramides