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)

This study determined in a blind fashion the activity levels and thermostability properties of two lysosomal hydrolytic enzymes, acid phosphatase and alpha-mannosidase, in plasma samples from 25 cystic fibrosis (CF) patients and 25 age- and sex-matched normal controls. Mean alpha-mannosidase activity (3.2 +/- 1.0 mU/ml) and acid phosphatase activities (6.5 +/- 2.9 mU/ml) in CF patients were not significantly different from those found in normal individuals (2.8 +/- 0.7 and 7.6 +/- 3.4 mU/ml, respectively). Using stringent conditions no differences in thermostability properties of these enzymes were found between plasma from CF patients as compared to that of normal controls. When activity levels of these enzymes and of four additional hydrolytic enzymes, alpha-L-fucosidase, alpha-galactosidase, alpha-glucosidase and beta-galactosidase, were determined in submandibular saliva, no significant differences in enzyme levels between CF and age- and sex-matched controls were noted nor were thermostability differences found. Our data do not support the concept that altered properties of these enzymes are useful as markers for detection of CF homozygotes and heterozygotes, nor the hypothesis that the defect underlying this disease is a deficiency of post-translational modification of glycoproteins leading to their mis-compartmentalization and qualitative alteration.
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PMID:Plasma and submandibular saliva lysosomal enzymes in cystic fibrosis. 639 40

Castanospermine (1,6,7,8-tetrahydroxyoctahydroindolizine) was tested against a variety of commercially available glycosidases and found to be a potent inhibitor of almond emulsin beta-glucosidase, and also to inhibit fungal beta-xylosidase. This alkaloid was inactive on yeast alpha-glucosidase, alpha- or beta-galactosidase, alpha-mannosidase, beta-N-acetylhexosaminidase, beta-glucuronidase, alpha-L-fucosidase. Fifty-percent inhibition of beta-glucosidase required about 10 micrograms/ml of castanospermine. The amount of inhibition was uniform throughout the time course, and the inhibition with regard to substrate concentration (p-nitrophenyl-beta-D-glucopyranoside) appeared to be of the mixed type. Castanospermine was also a potent inhibitor of beta-glucocerebrosidase when assayed with fibroblast extracts using either a fluorimetric or a radioactive assay. Interestingly enough, castanospermine also inhibited the lysosomal alpha-glucosidase, and this inhibition required comparable levels of alkaloid to that required for inhibition of beta-glucocerebrosidase. However, a number of other lysosomal glycosidases were not sensitive to castanospermine (i.e., alpha- or beta-galactosidase, alpha- or beta-mannosidase, alpha- or beta-L-fucosidase, beta-N-acetylhexosaminidase, beta-glucuronidase).
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PMID:Castanospermine, a tetrahydroxylated alkaloid that inhibits beta-glucosidase and beta-glucocerebrosidase. 640 22

A 17-year-old Japanese boy was found to have ataxia, generalized angiokeratomas, skeletal deformities, visual impairment, and macular cherry-red spots, without hepatomegaly, splenomegaly, or renal failure. Laboratory examination disclosed a deficiency of beta-galactosidase as well as of neuraminidase activity in the leukocytes and fibroblasts, while alpha-galactosidase and alpha-L-fucosidase activities were normal. On electron microscopic examination, numerous cytoplasmic vacuoles containing flocculated material were found in the vascular endothelial cells, histiocytes, perineurial cells, and Schwann's cells.
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PMID:beta-Galactosidase and neuraminidase deficiency associated with angiokeratoma corporis diffusum. 643 42

The isoprotein pattern of semi-purified R binder (an acidic glycoprotein which binds cobalamin) from saliva and sera of 8 cystic fibrosis patients was compared to that of R binder from samples of 5 healthy children. In cases of cystic fibrosis, the mean isoelectric point of salivary R binder was increased from 3.78 up to 4.34 and its microheterogeneity was reduced. These significant physicochemical modifications were not observed with R binder from cystic fibrosis sera and they did not correlate with the beta-galactosidase, alpha-mannosidase, alpha-L-fucosidase nor neuraminidase activity of saliva. We propose the R binder as a model molecule to study the glycoprotein metabolism in cystic fibrosis since it contains 30-40% carbohydrate, is easily complexed with cyano[57Co]cobalamin and is present in most tissues and fluids of the human organism.
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PMID:Cobalamin R binder as a possible model molecule for glycoprotein study in cystic fibrosis. 643 1

Activities of glycosidases neuromanidase, alpha-L-fucosidase, beta-galactosidase and beta-N-acetylglucosaminidase were studied in rat small intestine and liver tissue under conditions of hyper- and hypovitaminosis A. Both excessive and insufficient administrations of vitamin A were accompanied by distinct alterations in activity of the enzymes studied in small intestine and (although less distinct) in liver tissue. The most significant dependence on the presence of vitamin A exhibited beta-galactosidase and especially alpha-L-fucosidase, activity of which was decreased in hypervitaminosis and increased in hypovitaminosis A. Activity of neuraminidase was usually slightly altered but its marked activation was noted in liver tissue under conditions of hypervitaminosis A. Vitamin A appears to participate in allosteric control of the glycosidase activity in small intestine and in catabolism of glycoproteins. The alterations of the enzymatic activity found in hyper- and hypovitaminosis A might be responsible for changes in composition of membrane glycoproteins and, hence, for the typical for vitamin A disbalance impairments in cellular growth and differentiation.
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PMID:[Enzymatic activity of glycoprotein catabolism in the organs of rats with hyper- and hypovitaminosis A]. 677 13

Simultaneous or sequential treatment of rat adipocytes with neuraminidase plus beta-galactosidase decreased insulin binding by 43%. No modification was observed with either enzyme individually. alpha-Mannosidase enhanced insulin binding (38%), whereas beta-N-acetylglucosaminidase and alpha-L-fucosidase were ineffective. Lectins that interact with galactose (Ricinus communis I, RCAI), mannose, Lens culinaris agglutinin (LCA), Concanavalin A (Con A) or N-acetylglucosamine (wheat-germ agglutinin, WGA) decreased insulin binding by 43, 57, 59 and 85% respectively. Lectin inhibition was dose-dependent, saturable and prevented by specific monosaccharides. RCAI, LCA, Con A and WGA decreased the insulin dissociation process by 45, 90, 78 and 84% respectively. Lectins specific for sialic acid, terminal galactose, N-acetylgalactosamine or fucose (Limulus polyphemus, peanut, soybean and Ulex I agglutinins) did not modify either insulin binding or dissociation. These results indicate involvement of penultimate D-galactose, internal N-acetyl-D-glucosamine and D-mannose residues in both processes. They suggest that, in rat adipocytes, a glycosidic moiety participates in the insulin-receptor interaction through N-linked oligosaccharides of the 'complex type'.
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PMID:Further characterization of the insulin receptor glycosidic moiety in rat adipocytes. 679 21

Band-3 glycoprotein was purified from human blood-group-A erythrocyte membranes by selective solubilization and gel chromatography on Sepharose 6B in the presence of sodium dodecyl sulphate. The purified glycoprotein was subjected to hydrazinolysis in order to release the carbohydrate moiety. The released oligosaccharides were N-acetylated and applied to a column of DEAE-cellulose. Most of the band-3 oligosaccharides obtained were found to be free of sialic acids. When this neutral fraction was subjected to gel chromatography on a column of Sephadex G-50, two broad peaks were observed indicating that the band-3 glycoprotein was heterogeneous in the size of the oligosaccharide moieties. All fractions from gel chromatography were found to contain galactose, mannose, N-acetylglucosamine and fucose. The higher-molecular-weight (mol.wt. 3000-8000) peak consisted of fucose, mannose, galactose, N-acetylglucosamine and N-acetylgalactosamine in a molar proportion of 1.6:3.0:8.4:10.5:0.2. Most of these oligosaccharides were digested with a mixture of beta-galactosidase and beta-N-acetylhexosaminidase after alpha-L-fucosidase treatment to give a small oligosaccharide with the structure alpha Man2-beta Man-beta GlcNAc-GlcNAc. Methylation studies and limited degradation by nitrous acid deamination showed that the oligosaccharides contained the repeating disaccharide Gal beta 1----4GlcNAc beta 1----3, with branching points at C-6 of some of the galactose residues. These results indicate that a major portion of the band-3 oligosaccharide has a common core structure, with heterogeneity in the numbers of the repeating disaccharides, and contains fucose residues both in the peripheral portion and in the core portion. Haemagglutination tests were also carried out to determine the blood-group specificities of the glycoprotein and the results demonstrated the presence of both blood-group-H and I antigenic activities.
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PMID:The carbohydrate moiety of band-3 glycoprotein of human erythrocyte membranes. 718 22

Binding of the mouse IgM antibody 6C4 is lost after treatment of human free secretory component with peptide N-glycosidase F (Bakos et al. (1991) J. Immunol. 146, 162-168) or periodate, suggesting that asparagine-linked oligosaccharides contain the epitope recognized by this antibody. Inhibition of antibody binding to free secretory component by milk oligosaccharides established that lacto-N-tetraose is the minimum structure recognized by the antibody, but larger oligosaccharides with terminal Gal beta 1-3GlcNAc sequences bind with much higher affinity. Antibody binding is enhanced by substitution with the Lewis Fuc alpha 1-4 and is inhibited by Fuc alpha 1-2Gal substitution. Free secretory component, however, does not bind other antibodies that recognize Le(a) or Leb oligosaccharides, and binding is lost after digestion with a beta-galactosidase that cleaves Gal beta 1-3 linkages but not after digestion with alpha-L-fucosidase. Therefore, the major epitope recognized by 6C4 on free secretory component is probably not an asparagine-linked Le(a) oligosaccharide. The antibody also binds to human milk lactoferrin, some human mucins, and lacto-series glycolipids including III4 alpha Fuc-lactotetraosyl ceramide and lactotetraosyl ceramide. Based on affinity chromatography of oligosaccharides released from free secretory component, the epitope recognized by antibody 6C4 is present on approximately 3.5% of the asparagine-linked oligosaccharides.
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PMID:Recognition of type 1 chain oligosaccharides and lacto-series glycolipids by an antibody to human secretory component. 757

Human gastric surface epithelial cells display the ABH blood group antigens with the core structure of N-acetyllactosamine (NAcLc). Their expression is under the control of the secretor gene Se. The Thomsen-Friedenreich (T)-antigen (Gal beta 1-3GalNAc) is another core structure of the ABH antigens. We examined the gastric surface epithelial expression of T- and alpha 1-2 fucosylated T (FucT) histochemically with peanut agglutinin (PNA) and monoclonal antibody (MAb) MBr1, respectively. Eight of 24 individuals exhibited the PNA-reactive antigen (i.e., T-expressers) and others the MBr1-reactive antigen (i.e., FucT-expressers). alpha-L-fucosidase digestion of the FucT-positive tissues and beta-galactosidase digestion of the T-positive tissues, respectively, made them reactive with PNA and the antibody specific for GalNAc alpha-O-Ser/Thr. There was a remarkable correlation among reactivities with MBr1, Ulex europaeus lectin 1 (UEA1), and anti-Leb MAb CO-431. ABH blood group status had no correlation with this expression. We conclude that human gastric surface epithelial cells constitutionally synthesize T in alpha configuration (i.e., Gal beta 1-3GalNAc alpha-O-Ser/Thr) and that it was alpha 1-2 fucosylated only in the FucT-expressers. alpha 1-2 fucosylation of T is suggested to be regulated by the Se gene.
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PMID:Fucosylated Thomsen-Friedenreich antigen in alpha-anomeric configuration in human gastric surface epithelia: an allogeneic carbohydrate antigen possibly controlled by the Se gene. 830 54

The purpose of the present paper was to study the effects of a dietary undigestible carbohydrate and intestinal microflora on mucin distribution (neutral, acid, sulphonated), glycolytic activities: beta-D-galactosidase (EC 3.2.1.23), N-acetyl-beta-D-galactosaminidase (EC 3.2.1.43), N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30), alpha-L-fucosidase (EC 3.2.1.51) and bacterial metabolism (gas production, short-chain fatty acids (SCFA) and lactic acid caecal concentration) in germ-free (GF), conventional (CV) and heteroxenic (HE) rats (GF rats associated with a human flora). Rats were fed on either a control diet or a diet containing 40 g trans-galactosylated oligosaccharide (TOS)/kg. In GF rats fed on the control diet caecal pH was almost neutral and glycolytic activities negligible. The number of mucus-containing cells increased from the caecum to the colon for the three types of mucin. TOS had no effect in the caecum but it modified mucin cell repartition in the colon. In CV and HE rats fed on the control diet caecal pH was similar (6.8), but caecal SCFA and lactic acid concentrations (mumol/g) and gas production (ml/24 h) were higher in CV (70, 5.9 and 2.3 respectively) than in HE rats (32, 4.6 and 0.4 respectively). In CV, as in HE rats, acid-mucin-containing cells increased from the caecum to the colon and glycolytic activities were similar. TOS reduced acid-mucin-containing cells in the caecum of CV rats by twofold but had no effect in either the caecum or the colon of HE rats. TOS strongly increased beta-galactosidase activity and slightly modified the other glycolytic activities. Its effect on bacterial metabolites depended on bacterial status. However, comparison between CV and HE rats showed no evident relationship between the number of mucus-containing cells and measured bacterial metabolites. Differences between CV and HE rats might be due to bacterial microflora specificity. TOS had an intrinsic effect on mucus cell distribution in the colon of GF rats. In CV and HE rats the presence of the flora abolished this effect.
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PMID:Effects of galacto-oligosaccharide and bacterial status on mucin distribution in mucosa and on large intestine fermentation in rats. 832 64


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