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)

beta-Galactosidases were purified to homogeneity from livers of a normal control and a patient with the adult form of GM1 gangliosidosis. The purification was achieved by chromatography on DEAE-Sepharose fast flow, Con A-Sepharose, p-aminophenyl-1-thio-beta-D-galactopyranoside-Sepharose, and QAE-Mono Q. The normal and mutant enzymes were purified about 5000-fold with a yield of 10% and 1800-fold with a yield of 34%, respectively, and could hydrolyze 4-methylumbelliferyl-beta-D-galactoside, GM1 ganglioside, and asialofetuin. The purified normal enzyme was eluted from a TSK gel G-4000SW column as three symmetrical peaks of protein which were coincident with the three peaks of enzyme activity. The enzyme in these three peaks had apparent molecular weights of 800,000 (polymer), 140,000 (dimer), and 65,000 (monomer), whereas the mutant enzyme was eluted as two symmetrical peaks of protein and enzyme activity. The apparent molecular weight of a major monomeric form of the enzyme (beta-galactosidase A) was 60,000, and no dimeric form of the enzyme existed. Normal and mutant purified enzyme preparations migrated as a single major protein band with apparent molecular weights of 65,000 or 60,000, respectively, by SDS-polyacrylamide gel electrophoresis after treatment with mercaptoethanol. On isoelectric focussing, the mutant enzyme migrated more anodally than the normal enzyme. The mutant enzyme also had altered enzyme properties, such as pH optimum, Km values, substrate specificity and heat-stability. These data on the characteristics of the purified enzyme preparations provide the first direct evidence that patients with the adult form of GM1 gangliosidosis have a structurally altered beta-galactosidase.
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PMID:Purification and characterization of human liver beta-galactosidase from a patient with the adult form of GM1 gangliosidosis and a normal control. 312 90

Human thyroglobulin glycopeptides representing the multiple asparagine-linked complex (unit B) carbohydrate units of this protein were found to contain substantial amounts of sulfate (ranging from 0.5 to 2.5 mol/mol of oligosaccharide); this substituent was shown to occur primarily in the form of terminal beta-linked Gal-3-SO4 residues which represent novel capping groups occurring alternatively to sialic acid and in comparable amounts. Upon hydrazine/nitrous acid fragmentation and radiolabeling with NaB3H4, all human unit B DEAE-resolved glycopeptide fractions yielded an acidic disaccharide which was characterized as Gal-3-SO4 beta 1----4-anhydromannitol. Studies on glycopeptides modified by desialylation, desulfation, and beta-galactosidase treatment indicated that the majority (approximately 70%) of the complex carbohydrate units contain sulfate groups and that Gal-3-SO4 and sialic acid residues can coexist in terminal positions on the same N-linked oligosaccharide. In addition to Gal-3-SO4, the most acidic unit B variants were found to contain GlcNAc-6-SO4 which was recovered as Gal beta 1----4-anhydromannitol-6-SO4 after hydrazine/nitrous acid treatment and NaB3H4 reduction. On the basis of chromatography on immobilized concanavalin A, it was determined that whereas the Gal-3-SO4 groups occur on biantennary as well as more highly branched carbohydrate units, GlcNAc-6-SO4 is exclusively present in the latter oligosaccharides. In contrast to the N-linked carbohydrate units, the previously described O-linked glycosaminoglycan chain of human thyroglobulin yielded GlcA beta 1----3-anhydrotalitol-6-SO4 upon hydrazine/nitrous acid/NaB3H4 treatment, indicating that it is a chrondroitin 6-sulfate-like polymer. The distribution of sulfate in the complex oligosaccharides of calf thyroglobulin was quite different from that in the human protein; sulfate was not detectable in most of the glycopeptides and was sequestered in a single multibranched complex-type glycopeptide fraction (1.6 mol of sulfate/mol of oligosaccharide) which contained about equal amounts of Gal-3-SO4 and GlcNAc-6-SO4. The difference in galactose sulfation between human and calf thyroglobulins may be related to the substitution in the latter protein of some of the galactose residues by alpha-D-Gal capping groups.
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PMID:Occurrence of sulfate in the asparagine-linked complex carbohydrate units of thyroglobulin. Identification and localization of galactose 3-sulfate and N-acetylglucosamine 6-sulfate residues in the human and calf proteins. 317 May 47

The MAT-B1 and MAT-C1 ascites sublines of the 13762 rat mammary adenocarcinoma, which differ in several cell surface properties, contain a major mucin-type glycoprotein, termed ASGP-1. The sialic acid content of MAT-C1 ASGP-1 is 2-3-fold greater than MAT-B1 ASGP-1 (Sherblom, A. P., Buck, R. L., and Carraway, K. L. (1980) J. Biol. Chem. 255, 783-790). Sialic acid analysis demonstrated that, whereas MAT-C1 ASGP-1 contained approximately equal amounts of N-acetylneuraminic acid (NeuAc) and N-glycolylneuraminic acid (NeuGl), MAT-B1 ASGP-1 was devoid of NeuGl. MAT-B1 microsomes also did not contain NeuGl. MAT-B1 cells incubated with [3H]N-acetylmannosamine did not synthesize either labeled CMP-NeuGl or free NeuGl, even though the CMP-sialic acid synthetase was active with the substrate NeuGl. Thus, MAT-B1 cells may be deficient in the enzyme N-acetylneuraminate monooxygenase. The O-linked oligosaccharides from both MAT-B1 and MAT-C1 ASGP-1 have been shown to contain a core tetrasaccharide Gal(beta 1-4)GlcNAc(beta 1-6)(Gal(beta 1-3]GalNAc in which both galactose residues may be linked to additional sugars (Hull, S. R., Laine, R. A., Kaizu, T., Rodriquez, I., and Carraway, K. L. (1984) J. Biol. Chem. 259, 4866-4877). The distribution of NeuAc and NeuGl between the two galactose termini of the core tetrasaccharide was examined for MAT-C1 ASGP-1. Oligosaccharides were released by alkaline-borohydride treatment of MAT-C1 ASGP-1 which had been labeled with [14C]glucosamine and galactose oxidase/B3H4. Following fractionation by Bio-Gel P-4, DEAE-Sephadex, and high-performance liquid chromatography, oligosaccharides were analyzed for NeuAc and NeuGl and for susceptibility to digestion with beta-galactosidase. Three disialylated oligosaccharides were identified containing 2 mol of NeuAc (5.5% recovery), 2 mol of NeuGl (4.5%), or 1 mol each of NeuAc and NeuGl (11.1%). For monosialylated oligosaccharides, NeuGl appeared preferentially associated with the Gal(beta 1-4)GlcNAc terminus (9.0%), whereas significant amounts of oligosaccharide containing NeuAc at both the Gal(beta 1-3)GalNAc (2.6%) and Gal(beta 1-4)GlcNAc (4.5%) termini were detected. Each of the major qualitative differences between MAT-B1 and MAT-C1 oligosaccharides, including the presence of NeuGl (MAT-C1), sulfate (MAT-B1), and alpha-linked galactose (MAT-B1), occurs at the Gal(beta 1-4)GlcNAc terminus.
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PMID:N-Acetylneuraminic acid and N-glycolylneuraminic acid in the O-linked oligosaccharides of a tumor cell glycoprotein. Incorporation and distribution. 391 40

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

gG.2 glycoprotein was purified by H966 monoclonal antibodies linked to Sepharose from herpes simplex virus type 2-infected HEp-2 cells labeled with [3H] glucosamine. The glycoprotein was subjected to Pronase digestion and the glycopeptides were fractionated by Con A-Sepharose in a major fraction (88.5% of total radioactivity) unbound to the lectin gel and in a minor species which bound to the lectin as a N-linked diantennary oligosaccharide. Mild and strong acid hydrolysis of Con A-unbound and Con A-bound fractions revealed that (i) both species were highly sialylated; (ii) the Con A-unbound fraction contained mainly labeled N-acetylgalactosamine, as is the case for O-linked oligosaccharides; and (iii) the Con A-bound fraction carried the vast majority of the labeled N-acetylglucosamine present in gG.2. Three size classes of oligosaccharides were separated from mild alkaline borohydride-treated Con A-unbound glycopeptides, which accounted for about 80% of the radioactivity present in the fraction. Galactosaminitol was recovered as the major labeled product in the strong acid hydrolyzates of the oligosaccharides generated by reductive beta-elimination, indicating that they were O-glycosidically linked to the peptide backbone. Thin-layer and DEAE-Sephacel chromatography of the three O-linked oligosaccharide species indicated that disialylated tetrasaccharides and monosialylated trisaccharides were the major components, whereas neutral disaccharide was a minor component. Digestion with neuraminidase and beta-galactosidase of the O-linked oligosaccharides supported the idea that the common disaccharide core was mainly of the structure beta-galactosyl-N-acetylgalactosamine. The large occurrence of O-linked oligosaccharides differentiates this type 2-specific herpes simplex virus glycoprotein from the type-common herpesvirus glycoproteins gB, gC, and gD.
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PMID:Oligosaccharide chains of herpes simplex virus type 2 glycoprotein gG.2. 402 10

1. A multienzyme system capable of degrading keratosulphates to yield galactose, N-acetylglucosamine and sulphate was found in the liver extract of a marine gastropod, Charonia lampas. 2. During the degradation, neither oligosaccharides nor sulphated sugars were produced. 3. It is suggested that the degradation could be attributed to the concerted action of beta-galactosidase, beta-N-acetylglucosaminidase and a sulphatase (sulphohydrolase), tentatively designated keratosulphatase. 4. Two forms of keratosulphatase (I and II) were separated by DEAE-Sephadex column chromatography. Both forms could release all the sulphate from keratosulphates and neither appeared to be identical with glycosulphatase or chondrosulphatase, both of which are also present in Charonia lampas. 5. beta-Galactosidase and beta-N-acetylglucosaminidase could degrade keratopolysulphate to a greater extent in the presence of keratosulphatase than in its absence. 6. It is suggested that keratosulphate was first desulphated by the action of keratosulphatase, and the desulphated polymer was then degraded to galactose and N-acetylglucosamine by the action of beta-galactosidase and beta-N-acetylglucosaminidase. 7. beta-Galactosidase alone released a small amount of galactose from shark cartilage keratopolysulphate, but beta-N-acetylglucosaminidase alone did not release N-acetylglucosamine. This indicates that unsulphated galactose residues occupy all the non-reducing terminal positions in keratopolysulphate chains.
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PMID:Enzymic degradation of keratosulphates. 424 91

1. Saline extract of sheep pancreas acetone-dried powder was shown to catalyse acyl ester hydrolysis of spinach leaf galactosyl diglycerides and also galactosylglucosyl diglyceride of Lactobacillus casei. 2. Sodium deoxycholate stimulated the enzyme activity. Ca(2+) had no effect on the hydrolysis of monogalactosyl diglyceride, but it enhanced that of digalactosyl diglyceride. When added together, there was considerably less activity with both the substrates. 3. Optimal hydrolysis was observed at pH7.2. 4. The initial point of hydrolysis was at position-1, leading to the formation of monogalactosyl monoglyceride and digalactosyl monoglyceride. Further hydrolysis to the corresponding galactosylglycerols and later to galactose and glycerol was also observed, indicating the presence of alpha- and beta-galactosidases in the enzyme preparation. 5. Formation of monogalactosyl diglyceride from digalactosyl diglyceride by the action of alpha-galactosidase was noted. 6. Monogalactosyl diglyceride was also hydrolysed by beta-galactosidase to a limited extent, giving rise to diacylglycerol and galactose. 7. Attempts at purification of monogalactosyl diglyceride acyl hydrolase by using protamine sulphate treatment, Sephadex G-100 filtration and DEAE-cellulose chromatography gave a partially purified enzyme which showed 9- and 81-fold higher specific activity towards monogalactosyl diglyceride and digalactosyl diglyceride respectively. This still showed acyl ester hydrolysis activity towards methyl oleate, phosphatidylcholine and triacylglycerol. 8. When sheep, rat and guinea-pig tissues were compared, guinea-pig tissues showed the highest activity towards both monogalactosyl diglyceride and digalactosyl diglyceride. In all the species pancreas showed higher activity than intestine.
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PMID:Degradation of monogalactosyl diglyceride and digalactosyl diglyceride by sheep pancreatic enzymes. 446 78

1. Chicken brain arylsulphatase A was purified 2000-fold, with overall recovery 14%, by using ammonium sulphate fractionation, ethanol precipitation, Sephadex G-200 gel filtration and DEAE-Sephadex column chromatography. 2. The purified preparation was free from beta-glucuronidase, beta-galactosidase, acid phosphatase, inorganic pyrophosphatase and adenosine 3'-phosphate 5'-sulphatophosphate sulphohydrolase activities. 3. Polyacrylamide-gel electrophoresis indicated that the purified preparation was not homogeneous. 4. Chicken brain arylsulphatase was markedly inhibited by carbonyl reagents in the presence of traces of Cu(2+) in the system. Other metal ions such as Fe(2+) and Zn(2+), were inactive. 5. Ascorbic acid alone had no effect on enzyme activity but enhances the inhibition by Cu(2+). 6. Chicken brain arylsulphatase A resembled arylsulphatase A of other animal species in its kinetic properties such as K(m) value, anomalous time-activity relationship and the inhibitory effect of phosphate, sulphite and sulphate ions. However, its electrophoretic mobility, behaviour under zinc acetate fractionation and stimulation by Ag(+) were similar to arylsulphatase B of other animal species. Thus, this enzyme did not correspond to either arylsulphatase A or arylsulphatase B but properties of both. 7. The purified enzyme preparation can degrade cerebroside 3-sulphate.
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PMID:Purification and properties of arylsulphatase A from chicken brain. 507 33

1. The presence of beta-galactosidase (EC 3.2.1.23) in an acetic acid extract of ram testis is reported. Some properties of the crude enzyme preparation were studied. 2. The purification of beta-acetylglucosaminase (EC 3.2.1.30) and of beta-galactosidase from the ram-testis extract by ammonium sulphate precipitation and chromatography on a CM-cellulose column is described. 3. The final purifications of the separated enzymes achieved were for the beta-acetylglucosaminase 35 times and for the beta-galactosidase 99 times. 4. The possibility of using DEAE-cellulose and Sephadex G-200 to purify the enzymes was investigated.
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PMID:Purification of beta-acetylglucosaminase and beta-galactosidase from ram testis. 594 69

1. The activities of beta-galactosidase, beta-glucosidase, beta-glucuronidase and N-acetyl-beta-glucosaminidase from rat kidney have been compared when 4-methylumbelliferyl glycosides are used as substrates. 2. Separation by gel electrophoresis at pH7.0 indicated slow- and fast-moving components of rat-kidney beta-galactosidase. 3. The fast-moving component is also associated with the total beta-glucosidase activity and inhibition experiments indicate that a single enzyme species is responsible for both activities. 4. DEAE-cellulose chromatography and filtration on Sephadex gels suggests that the beta-glucosidase component is a small acidic molecule, of molecular weight approx. 40000-50000, with optimum pH5.5-6.0 for beta-galactosidase and beta-glucosidase activities. 5. The major beta-galactosidase component has low electrophoretic mobility, a calculated molecular weight of 80000 and optimum pH3.7.
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PMID:Separation and properties of beta-galactosidase, beta-glucosidase, beta-glucuronidase and N-acetyl-beta-glucosaminidase from rat kidney. 602 11


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