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

---

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

Two monoclonal antibodies, HH8 and HH9, have been established after immunization of mice with galactosyl-A glycolipid antigen having the terminal structure, Gal beta 1----3GalNAc alpha 1----3[Fuc alpha 1----2]Gal beta 1----R, which is the precursor for type 3 chain A (repetitive A) and type 3 chain H (A-associated H). Both antibodies react strongly and specifically with galactosyl-A, but HH8 (IgM) showed strong hemagglutination of blood group A1, A2, O and B erythrocytes after sialidase treatment, while HH9 (IgG1) did not react with human erythrocytes even after sialidase treatment. HH8 and anti-T antibody, but not HH9, reacted with glycophorin A after sialidase treatment. The reactivity of HH8 with glycophorin A was abolished by beta-galactosidase and was inhibited by liposomes containing galactosyl-A, but not other glycolipids. In addition, anti-T antibody and peanut lectin reacted specifically with galactosyl-A glycolipids. These findings indicate that HH8 recognizes the terminal disaccharide Gal beta 1----3GalNAc alpha 1----R, which is the same sequence as the classically known Thomsen-Friedenreich antigen (T-antigen), whereas HH9 does not cross-react with T-antigen but recognizes the entire galactosyl-A structure. The T-antigen was also demonstrated by immunohistology with HH8 after neuraminidase treatment in a subset of cells in stratified epithelium.
...
PMID:Monoclonal antibodies directed to the blood group A associated structure, galactosyl-A: specificity and relation to the Thomsen-Friedenreich antigen. 328 40

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.
...
PMID:N-Acetylneuraminic acid and N-glycolylneuraminic acid in the O-linked oligosaccharides of a tumor cell glycoprotein. Incorporation and distribution. 391 40

We describe the structures of two positional isomers of sialylheptasaccharide isolated from the urine of a patient with sialidosis with partial deficiency of beta-galactosidase. Based on structural studies including compositional sugar analysis, exoglycosidase digestion, chemical ionization mass spectrometry, proton nuclear magnetic resonance spectrometry, and methylation analysis, their structures were deduced to be as follows: AcNeu alpha 2----6Gal beta 1----4GlcNac beta 1----2Man alpha 1----3(Man alpha 1----6)Man beta 1----4GlcNac; AcNeu alpha 2----6Gal beta 1----4GlcNac beta 1----2Man alpha 1----6(Man alpha 1----3)Man beta 1----4GlcNac. Sialyloligosaccharide 1 has previously been found in the urine and liver of patients with mucolipidosis I and II and sialidosis, but sialyloligosaccharide 2 has not been found yet in human urine. These two sialyloligosaccharides could not be completely separated by any chromatographic procedures tested. The analytical techniques, including methylation study and NMR spectroscopy, could not clearly detect the differences between them. However, alpha-mannosidase treatment gave important information for the structural analyses of these sialyloligosaccharides.
...
PMID:Two positional isomers of sialylheptasaccharides isolated from the urine of a patient with sialidosis. 393 47

The biosynthesis of galactosyl-beta 1,3-N-acetylglucosamine has been demonstrated using membrane preparations from pig trachea. Unlike the UDP-galactose:2-acetamido-2-deoxy-D-glucose 4 beta-galactosyltransferase, which is inhibited by high levels of N-acetylglucosamine, the UDP-galactose:N-acetylglucosamine 3 beta-galactosyltransferase shows no inhibition at 200 mM N-acetylglucosamine. About 80% of the total disaccharide synthesized at 200 mM N-acetylglucosamine was base-labile suggesting the 1,3-linkage, alpha-Lactalbumin inhibits galactose incorporation into galactosyl-beta 1,4-N-acetylglucosamine but has little or no effect on the activity of the 1,3-galactosyltransferase. Escherichia coli beta-galactosidase readily hydrolyzed the base-stable product, but not the base-labile component. The apparent 1,3-linked disaccharide was reduced with NaBH4 and was isolated by Bio-Gel P-2 column chromatography. Methylation analysis by gas chromatography/mass spectrometry showed tetramethyl galactose and a 3-substituted N-acetylglucosaminitol. Neither the beta 1,4 nor the beta 1,3 disaccharide was hydrolyzed by green coffee bean alpha-galactosidase. Both disaccharides were readily hydrolyzed by bovine testes beta-galactosidase. This is the first report on the galactosyltransferase which catalyzes the synthesis of the galactosyl-beta 1,3-N-acetylglucosamine linkage such as found in the Type I chain of human blood group substances. A tissue survey in rats showed only rat intestine to have readily detectable UDP-galactose: N-acetylglucosamine 3 beta-galactosyltransferase activity. The intestinal membrane fraction like the tracheal enzyme catalyzes the synthesis of two disaccharides as judged by base treatment, and these appear to be the beta 1,3 and beta 1,4 isomers of galactosyl-N-acetylglucosamine.
...
PMID:Biosynthesis of galactosyl-beta 1,3-N-acetylglucosamine. 627 54

In previous studies on glycosyltransferase activities in porcine trachea, we demonstrated the presence of two galactosyltransferases which transfer galactose from UDP-galactose to N-acetylglucosamine (Sheares, B.T. and Carlson, D.M. (1983) J. Biol. Chem. 258, 9893-9898). One enzyme, UDP-galactose:N-acetylglucosamine 3 beta-galactosyltransferase, synthesized galactosyl-beta 1,3-N-acetylglucosamine while the other, UDP-galactose:N-acetylglucosamine 4 beta-galactosyltransferase, synthesized galactosyl-beta 1,4-N-acetylglucosamine. A third galactosyltransferase has now been demonstrated utilizing a solubilized membrane preparation from pig trachea, which also synthesizes galactosyl-beta 1,4-N-acetylglucosamine as determined by gas-liquid chromatography and Diplococcus pneumoniae beta-galactosidase treatment. This new UDP-galactose:N-acetylglucosamine 4 beta-galactosyltransferase is distinct from the lactose synthetase A protein in that it does not bind to alpha-lactalbumin-agarose or to N-acetylglucosamine-agarose. The enzyme is separable from the UDP-galactose:N-acetylgalactosaminyl-mucin 3 beta-galactosyltransferase by affinity chromatography on asialo ovine submaxillary mucin adsorbed to DEAE-Sephacel. This newly discovered 4 beta-galactosyltransferase binds to UDP-hexanolamine-Sepharose and is partially separated from UDP-galactose:N-acetylglucosamine 3 beta-galactosyltransferase by Sephacryl S-200 gel filtration chromatography. Neither high concentrations of N-acetylglucosamine (200 mM) nor alpha-lactalbumin inhibits the incorporation of galactose into galactosyl-beta 1,4-N-acetylglucosamine by this enzyme.
...
PMID:Two distinct UDP-galactose: 2-acetamido-2-deoxy-D-glucose 4 beta-galactosyltransferases in porcine trachea. 642 38

In search of a beta-galactosidase which specifically hydrolyses beta 1----3 bound galactose residues in galacto-glycoconjugates, an acid beta-galactosidase from chicken liver was investigated. The isolation procedure involved ammonium sulphate precipitation followed by lectin chromatography on Con A-Sepharose 4B, ion-exchange chromatography on DEAE-cellulose, gel filtration on Sepharose 6B and affinity chromatography on p-aminophenyl-thio-beta-D-galactoside-agarose. The beta-galactosidase was purified 3000-fold with 11% recovery of enzyme activity. The purified protein showed an apparent molecular mass of above 200000 in SDS-polyacrylamide gel electrophoresis. A few minor bands were also present. The reduced and denatured beta-galactosidase migrated as a single major band with an apparent molecular mass of 67000. The enzyme released galactose from lactose and from the synthetic substrates Gal beta 1----3Gal, Gal beta 1----6Gal and Gal beta 1----3Ara. However, the enzyme did not release galactose from the snail gland galactans and the high molecular weight galacto-glycoconjugates and it did not hydrolyse the peanut agglutinin receptor of the red blood cell membrane.
...
PMID:Isolation of a beta-galactosidase from chicken liver. 644 30

The neutral oligosaccharide fraction obtained from the hydrazinolysate of the plasma membrane glycoproteins of calf thymocytes was shown to be a mixture of twelve oligosaccharides. Oligosaccharides A, B, and C, which released galactose on treatment with jack bean beta-galactosidase but not with diplococcal beta-galactosidase, were shown to have the structures Gal beta 1-3Gal beta 1-4GlcNAc beta 1-4(Gal beta 1-3Gal beta 1-4GlcNAc beta 1-2)Man alpha 1-6(3)[Gal beta 1-3Gal beta 1-4GlcNAc beta 1-6(Gal beta 1-3Gal beta 1-4GlcNAc beta 1-2)Man alpha 1-3(6)]Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-6)GlcNAc, Gal beta 1-3Gal beta 1-4GlcNAc beta 1-4(Gal beta 1-3Gal beta 1-4GlcNAc beta 1-2)Man alpha 1-6(3)[Gal beta 1-3Gal beta 1-4GlcNAc beta 1-2Man alpha 1-3(6)]Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-6)GlcNAc, and Gal beta 1-3Gal beta 1-4GlcNAc beta 1-2Man alpha 1-6(Gal beta 1-3Gal beta 1-4GlcNAc beta 1-2Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-6)GlcNAc, respectively. Oligo saccharides D and E, which released galactose on treatment with either jack bean beta-galactosidase or diplococcal beta-galactosidase, were shown to have the structures Gal beta 1-4GlcNAc beta 1-2Man alpha 1-(Gal beta 1-4GlcNAc beta 1-2Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-)GlcNAc and Gal beta 1-4GlcNAc beta 1-2Man alpha 1-(GlcNAc beta 1-2Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-)GlcNAc, respectively. Five oligosaccharides (F1, G, H1, I, and J) were shown to have typical high-mannose type structures (Man alpha 1-)n.Man beta 1-4GlcNAc beta 1-GlcNAc, with n-values of 8, 7, 6, 5, and 4, respectively. The structures of the remaining two oligosaccharides F2 and H2 were elucidated as GlcNAc beta 1-2Man alpha 1-(GlcNAc beta 1-2Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-)GlcNAc and Man alpha 1-(Man alpha 1-)Man beta 1-(GlcNAc beta 1-Man alpha 1-)Man beta 1-GlcNAc beta 1-GlcNAc, respectively.
...
PMID:The asparagine-linked sugar chains of the glycoproteins in calf thymocyte plasma membrane. Structural studies of neutral oligosaccharides. 677 78

Gangliosides were isolated from purified preparations of human peripheral blood lymphocytes and neutrophils. Structural analyses and comparisons were performed by direct probe mass spectrometry and by degradation studies with the following enzymes: Escherichia freundii endo-beta-galactosidase; Clostridium perfringens and Arthrobacter ureafaciens neuraminidase; and jack bean beta-N-acetylhexosaminidase and beta-galactosidase. This combination of techniques allowed us to obtain carbohydrate composition and sequence information without the aid of methylation or carbohydrate compositional analyses using only 1-2 mg of purified gangliosides. On the basis of these studies we propose that human lymphocytes and neutrophils have gangliosides with the following structures. NeuAc alpha 2 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Structure A NeuAc alpha 2 leads to ? GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Structure B NeuAc alpha 2 leads to ? Gal beta 1 leads to 3,4GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Structure C All three compounds were isolated from both cell types with structure A being the major lymphocyte ganglioside and structure C the major neutrophil ganglioside. Structure B is a novel ganglioside and may represent a leukocyte-specific glycosphingolipid. Neuraminidase degradation studies demonstrated that only one ganglioside species of each cell type contains an internally linked sialic acid residue, and on the basis of thin layer chromatographic analysis this component is the same as the major brain ganglioside, GM1 (II3-N-acetylneuraminosyl-gangliotetraosylceramide). In addition, large gangliosides with the general structure NeuAc alpha 2 leads to ?(Gal beta 1 leads to 3,4GlcNAc beta 1 leads to 3)n Gal beta 1 leads to 4Glc beta 1 leads to 1Cer were isolated. These results are discussed as they relate to blood group antigens and specific cell surface markers in human leukocytes.
...
PMID:Isolation and structural characterization of human lymphocyte and neutrophil gangliosides. 678 May 55

Among the seven oligosaccharide fractions obtained by Bio-Gel P-4 column chromatography of urine of GM1-gangliosidosis Type 1 patients, three fractions (peaks V, VI, and VII) were completely missing in the urine of GM1-gangliosidosis Type 2 patients. Structural study of these oligosaccharide fractions by sequential exoglycosidase digestion in combination with methylation analysis and periodate oxidation has shown that peaks V, VI, and VII are mixtures of 16, 30, and 49 isomeric oligosaccharides. All these 95 oligosaccharides contain Gal beta 1 leads to 4GlcNAc beta 1 lead to 3 repeating structures in their outer chain moieties, indicating that the tissues of GM1-gangliosidosis Type 2 patients do contain beta-galactosidase activity which releases readily galactose residue from such repeating sugar chains.
...
PMID:Urinary oligosaccharides of GM1-gangliosidosis. Structures of oligosaccharides excreted in the urine of type 1 but not in the urine of type 2 patients. 679 May 42

We have characterized the UDP-galactose: alpha-N-acetylgalactosaminide beta 3 galactosyltransferase in human tracheal epithelium using asialo ovine submaxillary mucin as the acceptor. Maximal enzyme activity was obtained at pH 6.0-7.5 and at 20-25 mM MnCl2 and at 2% Triton X-100. Cd2+ could substitute for Mn2+ as the divalent ion cofactor. Spermine, spermidine, putrecine, cadaverine, and poly-L-lysine stimulated the enzyme activity at low (2.5 mM) MnCl2 concentration. The apparent Michaelis constants for N-acetylgalactosamine, asialo ovine submaxillary mucin, and UDP-galactose were 15.5, 1.14, and 1.36 mM, respectively. The enzyme activity was not affected by alpha-lactalbumin. The alpha-N-acetygalactosaminide beta 3 galactosyltransferase was shown to be different from the N-acetylglucosamine galactosyltransferase by acceptor competition studies. The product of galactosyltransferase was identified as Gal beta 1 leads to 3GalNAc alpha Ser (Thr) by (a) isolation of [14C]Gal-GalNAc-H2 after alkaline borohydride treatment of the 14C-labeled product, (b) establishment of the beta-configuration of the newly synthesized glycosidic bond by its complete cleavage by bovine testicular beta-galactosidase, and (c) assignment of the 1 leads to 3 linkage by identification of threosaminitol obtained from the oxidation of the disaccharide with periodic acid followed by reduction with sodium borohydride, hydrolysis in 4 N HCl, and analysis on an amino acid analyzer. The 1 leads to 3 linkage was confirmed by its resistance to jack bean beta-galactosidase and by the presence of a m/e 307 ion fragment and the absence of a m/e 276 ion by gas-liquid chromatography-mass spectrometry analysis. When acid and beta-galactosidase-treated human tracheobronchial mucin was used as the acceptor, 3.3% of the product was found as [14C]Gal-GalNAc-H2. The remainder of the [14C]Gal was found in longer oligosaccharides formed by a different beta-galactosyltransferase. This galactosyltransferase is slightly inhibited by alpha-lactalbumin and stimulated by spermine.
...
PMID:Mucin biosynthesis. Characterization of UDP-galactose: alpha-N-acetylgalactosaminide beta 3 galactosyltransferase from human tracheal epithelium. 680 62


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---