Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Uptake of radioactivity from 14C-galactose into gangliosides by cultured skin fibroblasts was studied. GM3 was the major ganglioside in control human fibroblasts. An increase of GM1 was demonstrated in GM1-gangliosidosis fibroblasts. The degree of GM1 accumulation was correlated with the clinical types of this disease. The fibroblasts from an infantile-type patient showed a marked increase of GM1. In late-onset types the amount of total gangliosides was only slightly increased, but the distribution of individual gangliosides was definitely abnormal; a relative increase of GM1 was demonstrated in these cases. GM1 beta-galactosidase activities were not detectable in either infantile or late-onset cases.
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PMID:GM1-gangliosidosis: accumulation of ganglioside GM1 in cultured skin fibroblasts and correlation with clinical types. 9 63

To identify membrane components of CER cells interacting with vesicular stomatitis virus (VSV) during fusion at acidic pH (fusion from without, FFWO) two different approaches have been used, i.e. (i) treating the whole cells with enzymes and (ii) testing the ability of isolated membrane molecules to interfere with FFWO. Phospholipase A2 and C digestion of cells greatly reduced syncytia formation, pointing towards the involvement of lipid structures as target sites for VSV. Cell susceptibility to FFWO was also reduced after neuraminidase, beta-galactosidase or periodate treatment, suggesting that carbohydrate residues may participate in a complex receptor structure required for virus fusion. When membrane molecules were examined separately for their ability to inhibit viral FFWO, phosphatidylserine, phosphatidylinositol, sphingomyelin, cholesterol and GM3 ganglioside were found to be active, confirming the role of membrane lipid moiety in the cell surface structures involved in the early phases of VSV infection.
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PMID:Role of membrane phospholipids and glycolipids in cell-to-cell fusion by VSV. 166 Jul 97

An activator protein that stimulates the enzymic hydrolysis of sialic acid from gangliosides by ganglioside sialidase was fractionated from human liver. This fraction was distinct from those stimulating the hydrolysis of galactose from GM1 ganglioside by beta-galactosidase and the hydrolysis of N-acetylgalactosamine from GM2 ganglioside by hexosaminidase A. This fraction was highly specific for the hydrolysis of sialic acid from GM3 ganglioside, and was equally effective in fibroblasts from patients with mucolipidosis IV and in fibroblasts from controls.
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PMID:Stimulation of GM3 ganglioside sialidase activity by an activator protein in patients with mucolipidosis IV and controls. 180 63

The interaction of the sulfatide activator protein with different glycosphingolipids have been studied in detail. The following findings were made. 1. The sulfatide activator protein forms water-soluble complexes with sulfatides [Fischer, G. and Jatzkewitz, H. (1977) Hoppe-Seyler's Z. Physiol. Chem. 356, 6588-6591] and various other glycospingolipids. 2. In the absence of degrading enzymes the activator protein acts in vitro as a glycosphingolipid transfer protein, transporting glycosphingolipids from donor to acceptor liposomes. Lipids having less than three hexoses, e.g. galactosylceramide, sulfatide and ganglioside GM3 were transferred at very slow rates, whereas complex lipids such as gangliosides GM2, GM1 and GD1a were transferred much faster than the former. The transfer rate increased with increasing length of the carbohydrate chain of the lipid molecules. 3. Both the acyl residue in the ceramide moiety and the nature of the carbohydrate chain are significant for recognition of the glycosphingolipids by the sulfatide activator protein. Apparently, both residues serve as an anchor and the longer they are the better they are recognized by the protein. 4. In the absence of activator protein, degradation rates of sulfatide derivatives by arylsulfatase A, and of ganglioside GM1 derivatives by beta-galactosidase, increase with decreasing length of acyl residues in their hydrophobic ceramide moiety. Addition of activator protein stimulates the degradation of only those GM1 and sulfatide derivatives that have long-chain fatty acids in their hydrophobic ceramide anchor.
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PMID:Glycosphingolipid specificity of the human sulfatide activator protein. 188 21

The composition of whole embryo gangliosides at embryonic day E-12 was compared among the C57BL/6 (B6) DBA/2 (D2), and C3H mouse strains. N-acetylneuraminic acid was the predominant sialic acid species in the E-12 embryos. N-glycolyneuraminic acid was either undetectable or present in only trace amounts. Whole embryo ganglioside sialic concentration was significantly lower in D2 embryos than in B6 or C3H embryos. GM3 and GD3 were the most abundant ganglioside species in each strain and comprised approximately 75% of the total distribution. The D2 embryos expressed an elevation of GD1a and a reduction of GQ1b relative to B6 and C3H. Also, the level of GM1 was significantly higher in the D2 embryos than in the B6 or C3H embryos. Since a reduction of beta-galactosidase activity and an elevation of GM1 concentration in brain were previously reported in postnatal DBA mice, our results suggest that the elevated GM1 in D2 embryos may result from a reduced activity of GM1 beta-galactosidase.
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PMID:Ganglioside GM1 elevation in DBA/2 mouse embryos. 211 May 23

In an autopsy case of galactosialidosis, GM3, GM2, GM1, and GD1a were accumulated in sympathetic and spinal ganglia and grey matter of the spinal cord. Especially, the accumulations of GM3 and GM2 amounted to 41- and 86-fold increases in sympathetic ganglia, respectively, as compared to normal controls. In addition LacCer, GA2 and GA1 were accumulated in sympathetic and spinal ganglia. The accumulations of GM3 and GD1a are considered to be the result of defective lysosomal sialidase activity and the accumulation of GM1, LacCer and GA1 is also considered to be due to decreased beta-galactosidase activity in this disorder. To better understand the possible mechanism of GM2 accumulation, we determined the activity of GM2 synthesizing enzyme (GM3:UDP-GalNAc transferase), as well as hexosaminidase activity, in sympathetic ganglia, but they did not change. Abnormal ganglioside and neutral glycosphingolipid metabolism, as well as sialyloligosaccharide and sialylglycoprotein metabolism, may be involved in the pathogenesis of this disorder.
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PMID:Abnormal glycosphingolipid metabolism in the nervous system of galactosialidosis. 211 76

Sensitive staining methods with wheat germ agglutinin were developed for the detection of glycosphingolipids of neolacto series (A) and gangliosides with a terminal N-acetylneuraminyl residue (B) on thin-layer chromatograms. (A) Neolacto series glycosphingolipids were treated by beta-galactosidase on the chromatograms in the presence of taurodeoxycholate. Then the chromatograms were incubated with biotinated wheat germ agglutinin followed by incubation with a complex of avidin and biotinated horseradish peroxidase, and the reaction was detected by 4-chloro-1-naphthol. In the case of gangliosides, sialidase treatment on the chromatograms was performed before the beta-galactosidase treatment. The sensitivity of the method for Lc3Cer, nLc4Cer, sialyl-nLc4Cer, and sialyl-nLc6Cer was 4 pmol, 7.6 pmol, 2.9 pmol and 1.4 pmol, respectively. (B) The gangliosides on the chromatograms were oxidized by periodic acid and reduced by NaBH4. Then the chromatograms were stained with wheat germ agglutinin as mentioned above. As little as 0.5 pmol of GM3, NeuAc-nLc4Cer, and NeuAc-nLc6Cer was detected by this method, whereas the detected limits for these gangliosides were 10 pmol, 10 pmol and 2 pmol, respectively, when periodate oxidation was omitted. GM4, GD3 and GD1a were an order less reactive than GM3, GM2, GM1 or GD1b were not stained under the same condition. In contrast to NeuAc-containing gangliosides, any gangliosides with N-glycolylneuraminic acid were not stained by the method in (B).
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PMID:Specific staining on thin-layer chromatograms of glycosphingolipids of neolacto series and gangliosides with a terminal N-acetylneuraminyl residue by different procedures with wheat germ agglutinin. 246 40

The uptake and catabolism of [3H-ceramide]-GM1 was followed in living fibroblasts from patient with different forms of beta-galactosidase deficiency. Gangliosides are identified according to the nomenclature of Svennerholm (1963). A total inability to metabolize the ingested substrate was found in infantile GM1-gangliosidosis whereas cells from an adult GM1-gangliosidosis variant showed a slower rate of degradation, compared with controls. Morquio B fibroblasts had a comparable catabolism of GM1 as controls. Fibroblasts from different types of galactosialidosis, a recessive disease associated with a coexistent beta-galactosidase/neuraminidase deficiency all showed degradation of ingested GM1. In view of the molecular defect in this disease, this catabolism must be due to the 10-20% of monomeric beta-galactosidase molecules present in the lysosomes. Unexpectedly, in these cells an impaired metabolism of GM3 was found. The same finding was observed when cells with an isolated neuraminidase deficiency (mucolipidosis I) were loaded with GM1. A hypothesis is presented to explain these results.
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PMID:Ganglioside GM1 metabolism in living human fibroblasts with beta-galactosidase deficiency. 308 9

A sialidase [EC 3.2.1.18] has been partially purified from human placenta by means of procedures comprising Con A-Sepharose adsorption, ammonium sulfate precipitation, sucrose density gradient centrifugation, and high-pressure liquid chromatography on a Shim pack Diol 300 column. On high-pressure liquid chromatography, most of the beta-galactosidase that comigrated with the sialidase on sucrose density gradient centrifugation was removed. The sialidase was purified 3,600-fold from the preparation obtained by Con A-Sepharose adsorption. The enzyme liberated the sialic acid residues from (alpha 2-3) and (alpha 2-6) sialyllactose, colomic acid, fetuin, and transferrin, but not from bovine submaxillary mucin. The enzyme also hydrolyzed gangliosides GM3, GD1a, and GD1b in the presence of sodium cholate as a detergent, but GM1 and GM2 were less susceptible to the enzyme. The optimum pHs for 4-methylumbelliferyl-N-acetylneuraminate, sialyllactose, fetuin, and GM3 lay between 4.0 and 5.0.
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PMID:Human placental sialidase: partial purification and characterization. 365 92

Four major ganglioside species were isolated from porcine erythrocyte membranes by DEAE-Sephadex and Iatrobeads column chromatography. Treatment of the lipids with graded neuraminidase and beta-galactosidase, gas chromatographic analysis of their carbohydrates, sphingosine bases and molecular species of sialic acid revealed that the structure of these gangliosides were GM3(NeuAc), GM3(NeuGc), GD3(NeuAc) and GD3(NeuGc), each of which was 16 +/- 2 micrograms, 304 +/- 42 micrograms, 30 +/- 3 micrograms and 240 +/- 26 micrograms, respectively, per gram of the dry erythrocyte stroma. The amount of GM3 and GD3 accounted for more than 95% of total gangliosides of the erythrocytes. Porcine erythrocytes may provide a good source for large scale preparation of ganglioside GD3 which recently was identified as a human melanoma-associated antigen.
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PMID:Characterization of gangliosides of porcine erythrocyte membranes: occurrence of ganglioside GD3 as major ganglioside. 393 Sep 8


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