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)

Capillary endothelial cells can be induced to form capillary-like structures in vitro by plating on fibronectin-coated dishes (Ingber, D. E., and Folkman, J. (1989) J. Cell Biol. 109, 317-330), thereby mimicking angiogenesis. To assess the role of glycoproteins bearing asparagine-linked oligosaccharides in this process, we tested the effect of oligosaccharide processing inhibitors on the formation of capillary tubes. Deoxymannojirimycin, a compound that prevents synthesis of hybrid and complex-type oligosaccharides, inhibited the formation of capillary tubes. In contrast, swainsonine, an inhibitor that blocks synthesis of complex- but not hybrid-type oligosaccharides, did not inhibit tube formation. Lectin affinity chromatography of 2-[3H] mannose-labeled glycopeptides from endothelial cells induced to form tubes did not reveal a striking difference in the spectrum of oligosaccharides compared to uninduced cells. Since endothelial cells formed tubes normally in the presence of swainsonine, we analyzed glycopeptides from swainsonine-treated induced and uninduced cells. Cells induced to form tubes were enriched in monosialylated hybrid-type oligosaccharides sensitive to alpha-fucosidase, beta-galactosidase, and beta-N-acetylhexosaminidase, suggestive of sialyl Lewis-X determinants. We used an enzyme-linked immunoassay to measure sialyl Lewis-X epitopes on capillary endothelial cells and found that both induced and uninduced cells expressed sialyl Lewis-X epitopes. Deoxymannojirimycin and, to a lesser extent, swainsonine reduced the level of sialyl Lewis-X epitopes in cells induced to form capillary tubes, but neither compound affected the level of epitopes in cell monolayers. We conclude that synthesis of at least hybrid-type oligosaccharides is required for capillary tube formation in vitro and that an increase in monosialylated, fucosylated glycans on asparagine-linked oligosaccharides occurs during this process.
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PMID:1-Deoxymannojirimycin inhibits capillary tube formation in vitro. Analysis of N-linked oligosaccharides in bovine capillary endothelial cells. 146 26

Specific glycosidase activities were determined in samples of gingival crevicular fluid (GCF) collected from eight predetermined sites in two groups, each of 20 adult patients, with either gingivitis or periodontitis. The total activities (as units of enzyme activity per sample) of alpha-L-fucosidase, sialidase, beta-N-acetylglucosaminidase, beta-galactosidase, beta-glucosidase and alpha-glucosidase were significantly greater in the periodontitis group. In contrast, the total beta-mannosidase and hexosaminidase A activities were significantly greater in the gingivitis group, while there was no significant difference in the total alpha-mannosidase activity between the groups. Only the specific activities (as units of enzyme activity per min per microliter of GCF) of beta-mannosidase and hexosaminidase A were significantly different between the groups being greater in the gingivitis group. When used to predict the clinical status of individual periodontal sites, the total enzyme activities had specificity and sensitivity values of 91.9 and 61.3%, respectively. Measurement of glycosidase activities might thus have a role in monitoring the efficacy of periodontal treatment or in predicting future periodontal disease but this will require further investigation.
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PMID:Glycosidase activities in gingival crevicular fluid in subjects with adult periodontitis or gingivitis. 161 Mar 3

F62 LOS of Neisseria gonorrhoeae consists of two components. The higher molecular weight (MW) component is recognized by monoclonal antibody (MAb) 1-1-M and the smaller MW component by MAb 3F11. Epitope expression of the two LOS components and their partial structures were investigated by treating the F62 LOS with several glycosidases and then monitoring their antigenicity with the two mouse IgM MAbs. The 1-1-M-defined LOS component was cleaved with both beta-N-acetylhexosaminidase and endo-beta-galactosidase, and each cleavage resulted in the loss of expression of the 1-1-M-defined epitope. The N-acetylhexosamine (HexNAc) released by the hexosaminidase was found to be GalNAc, and the smaller oligosaccharide released by the endo enzyme was identified to be a dimer GalNAc beta----Gal. In contrast, the MAb 3F11-defined LOS component was not digested by the endo galactosidase, but it was cleaved with alpha and beta-galactosidase, and expression of the MAb 3F11-defined LOS epitope expression of the MAb 3F11-defined LOS was abolished by the treatment with each of two exo enzymes. MAb 3F11 bound to the 1-1-M-defined LOS component resulting from the removal of the beta-GalNAc residue, and the resulting LOS was further cleaved with beta-galactosidase, but not with alpha-galactosidase. From these results, we conclude the following: (1) MAbs 1-1-M and 3F11 both recognize the non-reducing termini of the LOS components; (2) the 1-1-M-defined LOS component has the GalNAc beta----Gal beta 1----4-Glc (or GlcNAc) structure, and the GalNAc beta----Gal residue is involved in the MAb 1-1-M-defined epitope; (3) the MAb 3F11-defined LOS component may not have a Gal beta 1----4GlcNAc beta 1----4Gal beta 1----4Glc structure within the molecule. However, it has beta-Gal residue at its non-reducing terminus, and this residue is involved in the MAb 3F11-defined epitope; (4) the two LOS components share a similar antigenic structure, and the 3F11-defined epitope structure is present in the MAb 1-1-M-defined LOS component. Expression of this epitope within the 1-1-M-defined LOS molecule is blocked by the beta-GalNAc residue; however, the beta-GalNAc residue at the non-reducing end may be not the only structural difference between the two components.
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PMID:Epitope expression and partial structural characterization of F62 lipooligosaccharide (LOS) of Neisseria gonorrhoeae: IgM monoclonal antibodies (3F11 and 1-1-M) recognize non-reducing termini of the LOS components. 172 May 5

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

Incubation of UDP-GlcNAc and radiolabeled GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4GlcNAc (1) with human serum resulted in the formation of the branched hexasaccharide GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4GlcNAc (2) in yields of up to 22.2%. The novel reaction represents midchain branching of the linear acceptor; the previously known branching reactions of oligo-(N-acetyllactosaminoglycans) involve the nonreducing end of the growing saccharide chains. The structure of 2 was established by use of appropriate isotopic isomers of it for degradative experiments. The hexasaccharide 2 was cleaved by an exhaustive treatment with jack bean beta-N-acetylhexosaminidase, liberating two GlcNAc units and the tetrasaccharide Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4GlcNAc (3). Endo-beta-galactosidase from Bacteroides fragilis cleaved 2 at one site only, yielding the disaccharide GlcNAc beta 1-3Gal (4) and the branched tetrasaccharide GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4GlcNAc (5). The structure of 5 was established by partial acid hydrolysis and subsequent identification of the disaccharide GlcNAc beta 1-6Gal (6), together with the trisaccharides GlcNAc beta 1-6Gal beta 1-4GlcNAc (7) and GlcNAc beta 1-3(GlcNAc beta 1-6)Gal (8) among the cleavage products. Galactosylation of 2 with bovine milk beta 1,4-galactosyltransferase and UDP-[6-3H]Gal gave the octasaccharide [6-3H]Gal beta 1-4GlcNAc beta 1-3 Gal beta 1-4GlcNAc beta 1-3([6-3H]-Gal beta 1-4GlcNAc beta 1-6)[U-14C] Gal beta 1-4GlcNAc (17), which could be cleaved with endo-beta-galactosidase into the trisaccharide [6-3H]Gal beta 1-4GlcNAc beta 1-3Gal (18) and the branched pentasaccharide GlcNAc beta 1-3-([6-3H]Gal beta 1-4GlcNAc beta 1-6) [U-14C]Gal beta 1-4GlcNAc (19). Partial hydrolysis of 2 with jack-bean beta-N-acetylhexosaminidase gave the linear pentasaccharide 1 and the branched pentasaccharide Gal beta 1-4GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4GlcNAc (20). The serum beta 1,6-GlcNAc transferase catalyzed also the formation of GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4Glc (11) from UDP-GlcNAc and GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc (10). The pentasaccharide Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4GlcNAc (16), too, served as an acceptor for the enzyme.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Human serum contains a novel beta 1,6-N-acetylglucosaminyltransferase activity that is involved in midchain branching of oligo (N-acetyllactosaminoglycans). 183 57

beta-N-Acetylhexosaminidase of HL-60 cells was separated into two main forms, A and S, by chromatography on DEAE-cellulose. Analysis of developmental changes in the isoenzyme pattern was complicated by the fact that the specific activity of beta-N-acetylhexosaminidase underwent a 6-fold change during the normal growth cycle. Two other lysosomal enzymes, beta-galactosidase and alpha-mannosidase, behaved similarly. Induction of differentiation of HL-60 cells with dimethyl sulphoxide at a low cell density (3 x 10(5) cells/ml) had a greater effect on the abundance of alpha-subunits of beta-N-acetylhexosaminidase, measured with 4-methylumbelliferyl-beta-N-acetylglucosaminide 6-sulphate, than of beta-subunits, measured with 4-methylumbelliferyl-beta-N-acetylglucosamine, and resulted in an isoenzyme profile in which A and B were the major forms, with the levels of form S greatly decreased.
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PMID:Treatment of HL-60 cells with dimethyl sulphoxide inhibits the formation of beta-N-acetylhexosaminidase S. 214 59

In the cell adhesion of aggregation-competent Dictyostelium cells, the requirement for the carbohydrate moiety of the glycoprotein appeared to be indirect in that it acts to protect the protein moiety from proteolytic degradation; however, the effect was limited to the tunicamycin (TM)-sensitive carbohydrate moiety (Hirano, T., et al. (1983) J. Biochem. 93, 1249-1257). In the present study, we showed that the EDTA-stable adhesion of aggregation-competent Dictyostelium cells was abolished by the treatment of intact cells with jack bean alpha-mannosidase, whereas neuraminidase, beta-galactosidase, beta-N-acetylhexosaminidase, or alpha-L-fucosidase had no effect. The EDTA-stable cohesiveness of TM-treated cells in the presence of leupeptin (TM/LP cells) was also abolished by the treatment of the cells with alpha-mannosidase. The effect of alpha-mannosidase was not prevented in the presence of LP. The N-glycoside-deficient contact site A (an adhesion-mediating glycoprotein) was obtained from TM/LP cells and was shown to have a molecular weight of 70,000. This protein (p 70) was shown to still have carbohydrates as detected by polyacrylamide gel electrophoresis (PAGE) in the presence of sodium dodecyl sulfate (SDS) and subsequent staining of the gel with periodic acid-silver stain. Moreover, p 70 reacted with anti-gp 68, which has a specificity against alpha-mannosyl residues of carbohydrate chains. However, p 70 treated with alpha-mannosidase showed decreased reactivity with anti-gp 68. The monovalent antibody fragment of anti-contact site A or anti-p 70 inhibited EDTA-stable cell adhesion of both control and TM/LP cells. These results indicated that TM-resistant mannosyl residues of contact site A are directly involved in EDTA-stable adhesion of aggregation-competent cells. This is the first report of the direct involvement of the carbohydrate moiety in cell adhesion of aggregation-competent Dictyostelium cells. A schematic model is presented of the role of the carbohydrate moiety in EDTA-stable cell adhesion, including the direct effect of carbohydrates.
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PMID:Direct implication of surface mannosyl residues in cell adhesion of Dictyostelium discoideum. 241 9

We examined the effects of alpha-L-fucosidase digestion on lectin staining in formalin-fixed, paraffin-embedded human pancreatic tissue from individuals of different blood groups. Digestion with the enzyme resulted in apparent diminished intensity of Ulex europaeus agglutinin-I (UEA-I) staining in the acinar cells. In addition to the decreased intensity of UEA-I staining, reactivity with soybean agglutinin (SBA) was increased in the enzyme-susceptible, UEA-I-reactive cells. The intensity of Griffonia simplicifolia agglutinin-II (GSA-II) staining performed after beta-galactosidase digestion in UEA-I-reactive acinar cells was markedly increased by prior treatment with fucosidase. GSA-II staining following sequential digestion with fucosidase and galactosidase was completely abolished by subsequent digestion with beta-N-acetylhexosaminidase. These results therefore substantiate the previous assumption that SBA-reactive D-galactose-(beta 1-3,4)-N-acetyl-D-glucosamine and GSA-II reactive beta-N-acetyl-D-glucosamine imparted following galactosidase digestion represent precursors of H antigen. The present study further demonstrated that intense peanut agglutinin (PNA) staining was imparted after digestion with fucosidase in UEA-I-reactive sites in secretors. In contrast, nonsecretors showed vivid PNA staining that was usually detected throughout the pancreas without prior enzyme digestion. Here, fucosidase digestion had if any little effect on PNA staining. These results suggest that in secretors a terminal trisaccharide, fucosylated D-galactose-(beta 1-3)-N-acetyl-D-galactosamine exhibiting positive PNA reaction after fucosidase digestion, exists in UEA-I-reactive acinar cells. It is assumed that the secretor gene could control the step of final fucosylation of D-galactose-(beta 1-3)-N-acetyl-D-galactosamine in human pancreas.
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PMID:Effects of alpha-L-fucosidase digestion on lectin staining in human pancreas. 245 90

Fetuin derivatives with enzymatically altered oligosaccharide units were tested for their ability to inhibit pertussis toxin-mediated agglutination of goose erythrocytes and the binding of 125I-labeled fetuin to pertussis toxin-coated polystyrene tubes. Fetuin oligosaccharides were sequentially degraded by treatment with: neuraminidase (asialofetuin) followed by beta-galactosidase (asialoagalactofetuin) and, lastly, with beta-N-acetylhexosaminidase (asialoagalacto-a[N-acetylglucosamino]fetuin). Asialofetuin retained only 19 and 53% of the inhibitory activity of native fetuin in the hemagglutination and 125I-fetuin binding assays, respectively. Asialoagalactofetuin showed no further reduction of inhibition in the hemagglutination system and, instead, resulted in partial recovery of inhibition in the 125I-fetuin-pertussis toxin binding assay. Asialoagalacto-a[N-acetylhexosamino]fetuin showed a further decrease in ability to inhibit pertussis toxin binding in both assays. The inhibitory activity of asialoagalactofetuin could be restored to that of native fetuin by adding back D-galactose with UDP-Gal:D-glucosyl-1,4-beta-galactosyltransferase, followed by the addition of terminal sialic acid residues with CMP-N-acetylneuraminic acid:beta-D-galactosyl-1,4-N-acetyl-beta-D-glucosamine-alpha-2,6-N- acetylneuraminyltransferase. The data suggested that a requirement for pertussis toxin binding to fetuin may be the presence of acetamido-containing sugar groups in the nonreducing terminal position of fetuin's oligosaccharides.
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PMID:Use of glycosyltransferases to restore pertussis toxin receptor activity to asialoagalactofetuin. 245 26

Using lectin staining methods in combination with exo- and endo-glycosidase digestion procedures, we analyzed the chemical structure of different types of blood group-related substances in serous cells of formalin-fixed, paraffin-embedded human submandibular glands. Serous cells produced only H antigen; A and B antigens were not present, and the expression of H antigen is dependent on the secretor status of the tissue donor. Although reactivity with Ulex europaeus agglutinin I (UEA-I) was not markedly reduced by alpha-L-fucosidase digestion, an affinity for peanut agglutinin (PNA) was seen after fucosidase digestion in the cells from secretors. In those from nonsecretors, no PNA reactivity appeared after enzyme digestion. On the other hand, sialidase digestion elicited PNA reactivity in serous cells irrespective of the donor's secretor status. PNA reactivity observed after fucosidase or sialidase digestion was susceptible to endo-alpha-N-acetylgalactosaminidase (endo-GalNAc-dase) digestion. SBA reactivity in UEA-I-negative cells from secretors, or in cells from fetuses and newborn infants, was markedly reduced by beta-galactosidase digestion. After galactosidase digestion, reactivity with Griffonia simplicifolia agglutinin II (GSA-II) appeared in the corresponding cells. This GSA-II reactivity was almost completely eliminated by subsequent beta-N-acetylhexosaminidase digestion. Whereas PNA reactivity in these cells was not reduced by beta-galactosidase treatment, it was significantly diminished by endo-GalNAc-dase digestion. These results suggest that at least two kinds of precursor disaccharides are produced in submandibular serous cells, i.e., SBA-reactive D-galactose-(beta 1-3,4)-N-acetyl-D-glucosamine and PNA-reactive D-galactose-(beta 1-3)-N-acetyl-D-galactosamine alpha 1-serine or threonine (O-glycosidically linked Type 3 chain or T antigen). Final fucosylation and synthesis of these two types of precursor chain appear to be under the control of the secretor gene.
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PMID:Histochemical analysis of the chemical structure of blood group-related carbohydrate chains in serous cells of human submandibular glands using lectin staining and glycosidase digestion. 249 20


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