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)

In human pancreas, soybean agglutinin (SBA) conjugated to horseradish peroxidase reacted with the acinar cells secreting blood group A and/or H antigen, but not with those secreting only B antigen. For detailed histochemical characterization of SBA staining, the effects of treatment with unlabeled lectins and of digestion of certain enzymes on SBA staining were investigated in formalin-fixed, paraffin-embedded pancreatic tissue from individuals of different blood groups. Pre-incubation of sections with unlabeled Dolichos biflorus agglutinin to block A antigen eliminated subsequent SBA staining in the cells secreting A antigen, although failing to induce any effects in those secreting H antigen. In contrast, pre-incubation with unlabeled Ulex europaeus agglutinin-I (UEA-I) to block H antigen abolished SBA staining in cells secreting H antigen but not in those secreting A antigen. Treatment with galactose oxidase yielded the same results as those with unlabeled UEA-I, i.e., SBA reactivity was significantly diminished in cells secreting H antigen but not in those secreting A antigen. Digestion with beta-galactosidase resulted in a slight decrease of SBA staining in the cells secreting H antigen. Accompanying the decrease of SBA staining, reactivity with Griffonia simplicifolia agglutinin-II (GSA-II) appeared for the first time in the enzyme-susceptible, SBA-reactive cells secreting H antigen. Pre-treatment with galactose oxidase abolished this effect of beta-galactosidase. The GSA-II reactivity disclosed by treatment with galactosidase was completely eliminated by digestion with beta-N-acetylhexosaminidase, indicating that GSA-II staining after digestion with galactosidase is due to exposed penultimate beta-N-acetyl-D-glucosamine residues. These results demonstrate that at least two substances react with SBA in acinar cells of human pancreas, one being terminal beta-N-acetyl-D-galactosamine residues of A antigen, and the other being terminal beta-D-galactose-(1----3 or 1----4)-beta-N-acetyl-D-glucosamine dimers in the precursor of blood group H antigen. Such dimers may exist in close proximity to L-fucose residues of H antigen, since unlabeled UEA-I blocked SBA staining.
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PMID:Histochemical reactivity of soybean agglutinin with blood group antigens and their precursor substances in acinar cells of human pancreas. 295 34

Depletion of macrophages from human peripheral blood mononuclear cells (PBMC) caused a marked decrease in galactose oxidase and sodium periodate, but not a calcium ionophore, stimulated Interferon-gamma (IFN-gamma) production. Reconstitution of such depleted cultures with galactose oxidase treated macrophages, but not lymphocytes, restored IFN-gamma levels to those of control nonfractionated PBMC. Thus, galactose oxidase seemed to act on macrophages which in turn stimulated lymphocyte production of IFN-gamma. Unlike human cells which have terminal galactose residues on glycoproteins, murine cell glycoproteins terminate their oligosaccharide component in the order N-acetyl-neuraminic acid followed by D-galactose, N-acetyl-glucosamine, and glycoprotein. Galactose oxidase or sodium periodate only activated murine macrophages to stimulate lymphocyte IFN-gamma production after exposing D-galactose residues by the removal of the terminal N-acetyl-neuraminic acid residues with neuraminidase. Removal of such exposed terminal galactose residues with beta-galactosidase inhibited the effect of galactose oxidase on murine macrophages. Taken together, these results strongly suggest that oxidation of terminal galactose residues on macrophages is the initial site of action of galactose oxidase and sodium periodate. Studies with Boyden chambers have shown that galactose oxidase-treated macrophages released a soluble factor which stimulates lymphocyte production of IFN-gamma. Based on these findings, it appears that the oxidation of terminal galactose residues on the surface of macrophages leads to the induction and transmission of a soluble signal for lymphocyte production of IFN-gamma.
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PMID:Generation of a soluble IFN-gamma inducer by oxidation of galactose residues on macrophages. 299 10

Diplococcal beta-galactosidase, which is known to be useful for the structural studies of glycoprotein-linked oligosaccharides, was found to show the same substrate specificity in cleaving Gal beta 1-4 linkages of glycolipids as that of the oligosaccharides. The optimum conditions of beta-galactosidase in the 80% ammonium sulfate precipitates of the culture medium of Streptococcus (Diplococcus) pneumoniae were determined with nLcOse4Cer radiolabeled by the galactose oxidase-NaB3H4 procedure. Detergent was required for the highest activity, and different combinations of several buffers and detergents showed different properties in stimulating beta-galactosidase, and in enhancing or suppressing N-acetyl-beta-hexosaminidase which was contaminated in the enzyme preparation. The optimum pH was found to be at 6.5, and specific activity and Km were 8.1 nmol/mg protein/h and 1 nmol, respectively. While more than 70% of beta-galactose was liberated from LacCer and nLcOse4Cer within 1 h under the optimum conditions to form GlcCer and nLcOse3Cer, respectively, none was liberated from LcOse4Cer, GalCer, GgOse4Cer, GbOse3Cer, IV3 alpha GalnLcOse4Cer, and Il3NeuAcGgOse4Cer, showing the substrate specificity solely to Gal beta 1-4 linkage.
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PMID:Diplococcal beta-galactosidase with a specificity reacting to beta 1-4 linkage but not to beta 1-3 linkage as a useful exoglycosidase for the structural elucidation of glycolipids. 312 98

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

The chemical nature of one determinant (CFA 10) of a chicken onco-developmental antigen system was investigated using both chemical modification of cell surfaces and hapten inhibition. The presence of CFA 10 on pigeon RBC's is restricted both by the developmental status of the bird and by genetic segregation within the species. The involvement of a galactose-like structure with this determinant was suggested by the ability of alpha-galactosidase, sodium-m-periodate, and galactose oxidase to destroy CFA-10 activity. Other glycosidases including beta-galactosidase and proteolytic digestion failed to alter the antigenic determinant. Sugar inhibition assays using monospecific antisera against CFA 10 verified both the galactose-like specificity of the determinant and the possible significance of an alpha- vs. beta-internal linkage. It was possible to unmask cryptic CFA-10 sites on pigeon (10-) RBC's with use of specific glycosidases. While these cryptic sites also were susceptible to alpha-galactosidase, they may not be identical to the naturally exposed CFA 10 sites on pigeon (10+) RBC's. When pigeon (10-) RBC's were incubated in vitro with serum from 10+ pigeons, CFA 10 was detectable on the RBC surface. It is suggested that one mechanism of controlling the presence of CFA 10 on pigeon RBC's may be developmental changes in gene expression mediated through the serum environment.
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PMID:Identification of a galactose-like component of a chicken onco-developmental antigen. 616 57

Inhibition by low-molecular-weight sugars of precipitin line formation between a polysaccharide (EF) excreted by Leishmania tropica subsp. major, Leishmania enriettii, and rabbit antileishmanial antibodies on double gel diffusion plates revealed that galactose residues, possibly as components of lactosyl groups, were the critical immunodominant sugars mediating antibody recognition of EF. The galactose residues of the EF of L. tropica subsp. major were specifically labeled with tritium via galactose oxidase and sodium boro[3H]hydride. The radioactive EF had an apparent molecular weight of about 85,000 on sodium dodecyl sulfate-polyacrylamide gels and was precipitated by antileishmanial antibodies as well as Ricinus communis lectins I and II (galactose specific). Lectins specific for glucose-mannose residues, fucose, N-acetylglucosamine, and N-acetylgalactosamine did not precipitate the labeled EF. Treatment of [3H]EF with proteolytic (trypsin, papain, protease) or glycosidic (alpha-amylase, beta-galactosidase) enzymes had no effect on either the electrophoretic pattern of the material or on its recognition by antileishmanial antibodies or R. communis lectin. This resistance to enzyme activity suggests that EF may be a useful marker for the presence of the parasite in vivo if it can be detected in minute quantities.
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PMID:Identification of galactose as the immunodominant sugar of leishmanial excreted factor and subsequent labeling with galactose oxidase and sodium boro[3H]hydride. 617 74

The carbohydrate moiety of the factor VIII/von Willebrand (vW) factor protein is important in the expression of vW factor activity and the intravascular survival of the protein. Studies of normal human factor VIII/vW factor protein indicate that there is a requirement of a full complement of penultimate galactose for the maintenance of a normal multimeric structure. Release of penultimate galactose by beta-galactosidase or modification by galactose oxidase results in loss of the largest molecular weight multimers and increased numbers of intermediate and smaller multimers. In contrast, terminal galactose on the factor VIII/vW factor protein does not appear to play a significant role in the maintenance of the multimer organization. The abnormalities in multimeric structure and molecular size were demonstrated by NaDodSO4/polyacrylamide/agarose gel electrophoresis, NaDodSO4/glyoxyl-agarose electrophoresis, and sucrose density ultracentrifugation. These studies indicate that the penultimate galactose plays a role in the maintenance of the largest multimers of the factor VIII/vW factor protein. This may explain why, in some patients with variant forms of vW disease, a carbohydrate abnormality also may affect the multimeric structure of the plasma factor VIII/vW factor protein.
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PMID:Role of carbohydrate in multimeric structure of factor VIII/von Willebrand factor protein. 660 5

A glycopeptide (called "senescence-factor glycopeptide", SF-G) has been isolated from a tryptic digest of human erythrocytes by specific adsorption and elution from immobilized peanut lectin. SF-G was detectable in old but not in young erythrocytes isolated from the same unit of blood. It is present in small quantities, less than 1% of the D-galactose oxidase-borotritide-labeled D-galactosyl residues of erythrocytes. SF-G is free of sialic acid but is quite distinct from a similar glycopeptide isolated from completely desialylated erythrocytes. SF-G binds to spleen monocytes, and this property is abolished upon treatment of SF-G with beta-galactosidase. Some, but not all, of the oligosaccharide chains of the SF-G are of the O-glycosyl type, being released by an endo-N-acetyl-alpha-D-galactosaminidase.
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PMID:Isolation and characterization of a glycopeptide from human senescent erythrocytes. 662 53

The glycoproteinic nature of the insulin receptor was indicated using two different approaches: 1. [125I] insulin binding to soluble receptors from mouse liver was inhibited by digestion with beta-galactosidase or pretreatment with Ricinus communis I or concanavalin A. An other enzyme (neuraminidase) and lectins (wheat germ agglutinin, Dolichos biflorus) did not affect the binding reaction. These data confirmed that insulin directly interacts with the galactoglycoproteins of liver membranes. 2. The galactose oxidase-sodium boro[3H] hydride technique, previously used for labeling accessible membrane galactoglycoproteins, was again utilized to discern the components that interact with insulin. When liver membranes were equilibrated with 10-7 M insulin prior to labeling, the SDS gel radioactive profiles were specifically modified with two galactoglycoprotein of apparent molecular sizes 195 000 and 145 000, compatible with their participation in the insulin binding interaction. Membrane pretreatment with beta-galactosidase or Sophora japonica lectin reduced the labeling in most peaks, thus supporting the argument for labeling sensitivity. Preincubation of membranes with 10-7 M proinsulin slightly hindered labeling, while pretreatment with 10-7 M glucagon was ineffective, suggesting a specificity of the insulin effect. These data indicate that glycoprotein nature of the insulin receptor for two reasons: alteration of insulin binding after modification of the galactoglycoproteins, and alteration of galactoglycoprotein labeling after insulin binding. Two galactoglycoproteins, with apparent molecular weights 145 000 and 195 000, respectively, were identified and they are suggested to have insulin binding properties.
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PMID:Identification of liver cell membrane galactoglycoproteins involved in the process of insulin binding. 703 Mar 99

Stigmatella aurantiaca is a gram-negative bacterium which forms, under conditions of starvation in a multicellular process, characteristic three-dimensional structures: the fruiting bodies. For studying this complex process, mutants impaired in fruiting body formation have been induced by transposon insertion with a Tn5-derived transposon. The gene affected (fbfB) in one of the mutants (AP182) was studied further. Inactivation of fbfB results in mutants which form only clumps during starvation instead of wild-type fruiting bodies. This mutant phenotype can be partially rescued, if cells of mutants impaired in fbfB function are mixed with those of some independent mutants defective in fruiting before starvation. The fbfB gene is expressed about 14 h after induction of fruiting body formation as determined by measuring beta-galactosidase activity in a merodiploid strain harboring the wild-type gene and an fbfB-delta trp-lacZ fusion gene or by Northern (RNA) analysis with the Rhodobacter capsulatus pufBA fragment fused to fbfB as an indicator. The predicted polypeptide FbfB has a molecular mass of 57.8 kDa and shows a significant homology to the galactose oxidase (GaoA) of the fungus Dactylium dendroides. Galactose oxidase catalyzes the oxidation of galactose and primary alcohols to the corresponding aldehydes.
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PMID:fbfB, a gene encoding a putative galactose oxidase, is involved in Stigmatella aurantiaca fruiting body formation. 949 64


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