Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

Rat clonal pheochromocytoma PC12h cells were found to bind beta-galactosidase modified with specific glycosides. The enzyme modified with p-aminophenyl beta-D-glucoside was most effectively bound to the cells, followed by alpha-D-mannoside and alpha-D-glucoside. The binding was dependent on the number of PC12h cells, the incubation interval, and the pH; the maximal binding at 4 degrees C was obtained by incubation with 75 micrograms of cell protein for 15 min at pH 4.0. The binding proved to be a saturable and receptor-mediated process, and the apparent Km value and the maximal binding capacity of the cells with beta-D-glucosylated beta-galactosidase were 1.03 +/- 0.06 microM and 333 +/- 24 pmol/min/mg of protein, respectively. When the cells were cultured in the presence of nerve growth factor (NGF), GM1, GM2, and a ganglioside mixture, marked morphological differentiation was observed in the presence of NGF, and the specificity of the binding was also affected. By supplementation of NGF in the culture medium, the cells lost the selectivity of the glycoside binding, whereas cells cultured with GM1 supplement showed increased binding of the specific glycosides.
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PMID:Specific binding of glycosylated beta-galactosidase to rat clonal pheochromocytoma PC12h cells: effects of nerve growth factor and gangliosides. 312 66

We have studied the substrate specificities of a non-specific activator protein on the enzymatic hydrolyses of the following compounds: GM1 and GM2, as well as several of their derivatives including oligosaccharides, GgOse3Cer-II3-sulfate and LacCer-II3-sulfate, Gb-Ose3Cer and GbOse4Cer, three neolacto-series glycosphingolipids, and two non-ceramide glycolipids. Our results show that this activator protein has a broad spectrum of activity and exhibits the properties of a nonspecific natural detergent. The evidence of non-specificity was the ability of this activator protein to stimulate the hydrolyses of glycolipids, regardless of glycosphingolipids or non-ceramide glycolipids, carried out by glycosidases from animals, plants, and microorganisms. Its activity was, however, limited to substrates that had a lipid moiety. The oligosaccharide of GM1 and deacetyl-fatty acid free GM1 (II3-NeuGg-Ose4-sphingosine) were hydrolyzed by beta-galactosidase in the absence of this activator protein.
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PMID:Characterization of a nonspecific activator protein for the enzymatic hydrolysis of glycolipids. 336 Jul 93

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

A procedure is described for the preparation of Tay-Sachs ganglioside specifically labeled in the sialic acid portion of the molecule. Rat brain gangliosides were labeled biosynthetically by the intracranial injection of N-acetyl-(3)H-D-mannosamine. Radioactive gangliosides were isolated and selectively degraded with bacterial neuraminidase and rat liver beta-galactosidase to Tay-Sachs ganglioside-(3)H. Radioactivity in the labeled product was confined to the N-acetyl-neuraminic acid portion of the molecule.
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PMID:Preparation of radioactive Tay-Sachs ganglioside labeled in the sialic acid moiety. 541 76

GM1 and GM2 gangliosidoses are progressive neurodegenerative diseases which accumulate intralysosomal gangliosides--and to a lesser extent oligosaccharides--chiefly in the central and peripheral nervous system owing to deficiencies of beta-galactosidase and hexosaminidases A or/and B, respectively. This intralysosomal "storage" in neuronal pericarya and their processes, and subsequent loss of such nerve cells provide the background for clinical symptoms of the central nervous system and the retina, while involvement of the peripheral nervous system and the visceral organs largely remains free of clinical findings. The morphological involvement of the latter organs is widespread though varying, thus allowing morphological investigations of lymphocytes, skin, or rectum for morphological diagnosis and as a screening procedure.
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PMID:Morphology of the gangliosidoses. 610 Aug

Cerebroside sulfatase (CSase) activator was isolated from human liver by acetone precipitation, anion-exchange chromatography, gel filtration and polyacrylamide gel electrophoresis. The CSase activator was a heat-stable protein with an isoelectric point of 4.54. Molecular weight (Mr) of the activator was estimated as 22,000 with the gel permeation and about 8,000 by gel electrophoresis in the presence of sodium dodecyl sulfate, suggesting that the native activator is a trimer of a subunit with Mr 8,000. The CSase activator formed a complex with an equimolar amount of cerebroside sulfate (CS), when examined by gel permeation experiments. The activator also bound to galactosylceramide and GM2 ganglioside but scarcely to GM1 ganglioside, and activated to some extent beta-N-acetyl-hexosaminidase A and beta-galactosidase, although the CSase activator could be clearly distinguished from the GM1 beta-galactosidase activator so far known. Though the affinity chromatography using glycolipid ligands, the CSase activator did not recognize sulfate group of CS, but appeared to have a relatively broad specificity for lipid-linked hexose.
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PMID:[Purification and characterization of cerebroside sulfatase activator]. 614 Nov 30

In order to understand the mechanism of action of the activator proteins for the enzymic hydrolysis of GM1 (GM1-activator; Li, S.-C. and Li, Y.-T. (1976) J. Biol. Chem. 251, 1159-1163; for ganglioside designations, see Svennerholm, L. (1963) J. Neurochem. 10, 613) and GM2 (GM2-activator; Li, S.-C., Hirabayashi, Y., and Li, Y.-T. (1981) J. Biol. Chem. 256, 6234-6240), we have studied the effect of chemical modifications of GM1 and GM2 on their susceptibility to the activator-assisted enzymic hydrolysis. Chemically modified GM1 and GM2 were prepared by methyl esterification (Me-GM1 or Me-GM2) and reduction (HO-GM1 or HO-GM2) of the -COO- group of the sialic acid. Me-GM1 and HO-GM1 could be hydrolyzed by human hepatic beta-galactosidase in the presence of GM1-activator at rates comparable to that of the native GM1. However, in contrast to native GM2, Me-GM2 and HO-GM2 were resistant to the hydrolysis by human hepatic beta-hexosaminidase A in the presence of GM2-activator. When GM2-activator was replaced by sodium taurodeoxycholate, the native GM2 and both modified GM2 could be hydrolyzed by beta-hexosaminidase A. These results suggest that the carboxyl function of sialic acid in GM1 is not vital for beta-galactosidase or GM1-activator to carry out the cleavage of the terminal Gal. In the case of GM2 hydrolysis, the carboxyl function of sialic acid is involved in the interaction with GM2-activator. Our results also indicate that the mode of action of GM1-activator is different from that of GM2-activator and that the action of GM2-activator is different from that of sodium taurodeoxycholate.
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PMID:Effect of modification of sialic acid on enzymic hydrolysis of gangliosides GM1 and GM2. 623 75

Three to nine days after administration of suramin, 500 mg/kg intravenously in rats, a small amount of the drug (about 0.25 micromoles/g tissue) was retained by the liver and spleen, and a larger amount (about 1.2 micromoles/g tissue) was retained by the kidneys. The activities of the sphingolipid hydrolases beta-hexosaminidase and GM3-sialidase were strongly inhibited by suramin in vitro. The activity of beta-hexosaminidase was inhibited 70% by 10(-5M) and 85% by 10(-4M) suramin, and the activity of GM3-sialidase was inhibited 80% by 10(-4M) suramin. The activities of sphingomyelinase and beta-galactosidase were also inhibited by suramin but at higher concentrations of the drug. Suramin, in vitro is a weak inhibitor of glucocerebrosidase, galactocerebrosidase, alpha-galactosidase and arylsulfatase A (less than 50% inhibition at 10(-3M) concentration of the drug). The inhibition of beta-hexosaminidase by suramin was non-competitive. Inhibition of beta-hexosaminidase and GM3-sialidase may explain the accumulation of GM2 and GM3 gangliosides in the brains of rats treated intracerebrally with suramin (Constantopoulos et al, 1980).
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PMID:Effect of suramin on the activities of degradative enzymes of sphingolipids in rats. 729 29

A fluorescent derivative of GM1-ganglioside was synthesized by linking sulforhodamine 101 to the sphingosine moiety through amino dodecanoyl residue. The product (SR-12GM1) was quantitatively converted to SR-12GM2 by treatment with bovine testes beta-galactosidase and in intact cultured human skin fibroblasts was catabolized to sulforhodamine GM2, GM3 and ceramide; the latter product was further converted to sphingomyelin. In aqueous medium SR-12GM1 formed micelles. When transfer from micelles to vesicles and between vesicles was compared with that of pyrene-GM1, the transfer of SR-12GM1 occurred at higher rates, following in both cases a biexponential curve.
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PMID:Sulforhodamine GM1-ganglioside: synthesis and physicochemical properties. 795 76


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