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)

beta-Glucosidase [beta-D-glucoside glucohydrolase EC 3.2.1.21] and beta-galactosidase [beta-D-galactoside galactohydrolase, EC 3.2.1.23] of Takadiastase were purified by acetone fractionation, DEAE-cellulose, and hydroxylapatite chromatography. Purity was confirmed by disc electrophoresis, ultracentrifugation and measurement of other glycosidase activities which coexisted in Takadiastase. Molecular weight of the beta-glucosidase was 218,000 by sedimentation equilibrium and 110,000-116,000 by SDS-disc electrophoresis. Molecular weight of the beta-galactosidase was 112,000 by sedimentation and 56,000-59,000 by SDS-disc electrophoresis. These values showed that both enzymes consisted of two subunits. Taka-beta-N-acetylglucosaminidase also consisted of two subunits. Both enzymes were glycoproteins containing glucosamine and neutral sugar. Stability, pH optima, isoelectric points, and some specificities were observed.
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PMID:Comparative studies of three exo-beta-glycosidases of Aspergillus oryzae. 3 73

A fucolipid that carried human blood group Lea activity was isolated from human small intestine. It contianed fucose, galactose, N-acetyl glucosamine, glucose, and ceramide in a molar ratio of 1:2:1:1:1. After periodate oxidation only 1 molecule of galactose and the N-acetylglucosamine remained. Permethylation of the lipid gave derivatives of a terminal fucose and galactose residue together with 2,4,6-tri-O-methylgalactose and 2,3,6-tri-O-methylglucose. After removal of fucose the lipid could be converted to a ceramide trihexoside with beta-galactosidase, and this, in turn, to ceramide lactoside by the action of beta-N-acetylhexosaminidase. Both enzymes converted the defucosylated derivative to a ceramide monohexoside. The methylated and the methylated and reduced derivatives of the intact lipid gave ions in mass spectrometry for a terminal hexose and deoxyhexose, a terminal trisaccharide of hexose, deoxyhexose and N-acetylhexosamine, and terminal tetra-and pentasaccharides. Ceramide fragments characteristic of hydroxy fatty acids with 16, 22, 23, and 24 carbons were found together with those of phytospingosine as the major long chain base. On the basis of these results and the immunologic activity of the fucolipid, the following structure is proposed: betaGal (1 leads to 3)betaGlcNAc (1 leads to 3)betaGal (1 leads to 4)Glc-ceramide alphaFuc (1 leads to 4).
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PMID:Characterization of a human intestinal fucolipid with blood group Lea activity. 16 7

3H-fucose and 14C-glucosamine labelled glycopeptides of the individual membrane proteins E1, E2 and E3 of Semliki Forest virus could be sequentially digested with alpha-neuraminidase, beta-galactosidase, N-acetyl-beta-glucosaminidase, alpha- and beta-mannosidase, N-acetyl-beta-hexosaminidase and finally with alpha-fucosidase. The degradations of the virus glycopeptides proceeded in the same way as stepwise digestions of reference glycopeptides of the lactosamine type obtained from IgG and alpha 1-acid glycoprotein. This suggests that all three membrane glycoproteins of Semliki Forest virus contained glycans with a monosaccharide sequence characteristic for lactosamine type oligosaccharides. The number of both distal and proximal N-acetyl-glucosamine residues was estimated to be usually two. According to exo- and endo-glycosidase digestions, fucose seemed to be attached to the innermost N-acetyl-glucosamine unit.
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PMID:Sequence analysis of lactosamine type glycans of individual membrane proteins of Semliki Forest virus. 54 66

Treatment of influenza virus and its purified hemagglutining with glycosidases from Diplococcus pneumoniae, which included beta-galactosidase, beta-N-acetylglucosminidase, and endoglycosidase D, released amino and neutral sugars from the virus and these as well as large oligosaccharides from the purified hemagglutinin. The released glucosamine-containing oligosaccharides were of one discrete size. Large oligosaccharides not removed by the glycosidases were found on the virus as well as the hemagglutinin. Some oligosaccharides on the virus were inaccessible to the enzymes, since they could be removed only from the purified hemagglutinin. Approximately 50% of the hemagglutinin carbohydrates could be removed without effect on hemagglutinating activity. Similarly, removal of 20 to 25% of the carbohydrates from intact virus particles did not alter infectivity.
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PMID:Removal of carbohydrate from influenza A virus and its hemagglutinin and the effect on biological activities. 69 Nov 10

Purified bovine prothrombin has been treated with different mixtures of glycosidases. Upon incubation of the prothrombin for 30 h with a combination of neuraminidase, alpha- and beta-galactosidase and beta-N-acetylglucosaminidase in 4 mM diisopropylfluorophosphate at pH 5.3 and 30 degrees C, about 70% of the carbohydrates were removed without affecting the coagulation activity. All the sialic acid and about half of the mannose, galactose and glucosamine residues were removed by this treatment.
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PMID:On the significance of the carbohydrate moieties of bovine prothrombin for clotting activity. 94 83

A mutant of Escherichia coli is described whose cells show a spherical or irregular morphology, associated with leakage of beta-galactosidase and other intracellular proteins. The expression of the morphologic abnormality is most marked when the mutant is grown in rich media and is suppressed by D-alamine, D-serine, D-glutamate, or glycine supplementation. D-Alanine is the most effective amino acid supplement, half maximally supressing this anomalous property at a concentration of 75 mug/ml, as measured by the reduction in beta-galactosidase released from the cells. The mutant is more sensitive to penicillin G, D-methionine, and D-valine and it is relatively resistant to lysozyme. These phenotypic abnormalities are likewise corrected by the above supplementations. The relative rates of peptidoglycan synthesis in mutant and parent, grown under restrictive conditions, were measured both in vivo and in vitro by rates of incorporation of L-[14-D]alanine and uridine-5'-diphosphate-N-acetyl-D-[1-15C-A1-glucosamine, respectively. There is not metabolic block in the biosynthesis of uridine-5'-diphosphate-N-acetyl-muramyl-pentapeptide as shown by enzymic analysis and the lack of accumulation of uridine-5'-diphosphate-N-acetylmuramyl-peptide precursors. These preliminary studies suggest that the mutant possesses a defect in the biosynthesis of peptidoglycan although the exact lesion has not yet been established.
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PMID:D-Alanine-requiring cell wall mutant of Escherichia coli. 109 98

Two major glycoasparagines (2-acetamido-N-(4'-L-aspartyl)-2-deoxy-beta-D-glycosylamines) were isolated from the urine of patients with aspartylglycosylaminuria (AGU). They were composed of equimolar amounts of sialic acid, galactose, glucosamine, and aspartic acid. They were isomeric with respect to the position of sialic acid attachment, since they produced the same glycoasparagine on incubation with the neuraminidase from Clostridium perfringens. The structure of the resulting sialic acid-free glycoasparagine was determined as beta-Gal-(1 leads to 4)-beta-GlcNAc-Asn based on the following findings. It produced galactose on incubation with beta-galactosidase, and N-acetyllactosamine and aspartic acid on incubation with 4-L-aspartylglycosylamine amindo hydrolase.
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PMID:Characterization of two glycoasparagines isolated from the urine of patients with aspartylglycosylaminuria (AGU). 121 85

Expression of apical cell surface proteins and glycoproteins was examined in polarized primary cultures of mouse uterine epithelial cells (UEC). Lectin-gold cytochemistry revealed that wheat germ agglutinin (WGA) bound specifically to the components of the apical glycocalyx as well as intracellular vesicles. Double labeling with the pH sensitive dye 3-(2,4-dinitroanilino)-3'amino-N-methyldipropylamine (DAMP) demonstrated the acidic nature of the WGA-staining intracellular vesicles. The enzymatic and chemical sensitivities of the WGA binding sites on the apical cell surface were monitored both by WGA-gold staining as well as by 125I-WGA binding assays. In thin sections, a large fraction of these sites were removed by pronase; however, application of a wide variety of proteases, glycosidases, or chemical treatments to the apical surface of intact UEC failed to reduce WGA binding. In no case did treatments designed to remove sialic acids reduce 125I-WGA binding more than 12%. In contrast, endo-beta-galactosidase as well as a combination of beta-galactosidase with beta-hexosaminidase succeeded in removing 28% and 77% of these sites, respectively. These studies suggested that the majority of the apically disposed WGA binding sites involved N-acetylglucosamine residues rather than sialic acids and included lactosaminoglycans. Many of the proteins detected at the apical cell surface by lactoperoxidase-catalyzed radioiodination were WGA-binding glycoproteins. A major class of these glycoproteins displayed Mr > 200 kDa by SDS-PAGE and was heavily labeled metabolically by 3H-glucosamine or by vectorial labeling at the apical cell surface with galactosyl transferase and UDP-3H-galactose. Analyses of the 3H-labeled oligosaccharides labeled by either procedure indicated that a large fraction of the apically disposed WGA-binding oligosaccharides consisted of neutral, O-linked mucin-type structures with median MW of approximately 1,500. Oligosaccharides in this fraction were partially (15%) sensitive to endo-beta-galactosidase digestion and bound to Datura stramonium agglutinin (68%), demonstrating the presence of lactosaminoglycan sequences. UEC were an extremely effective barrier to attachment or invasion by either a highly invasive melanoma cell line, B16-BL6, or implantation-competent mouse blastocysts. In contrast, neither uterine stromal cells nor a non-polarizing UEC cell line, RL95, prevented B16-BL6 attachment.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:WGA-binding, mucin glycoproteins protect the apical cell surface of mouse uterine epithelial cells. 129 97

Swarm rat chondrosarcoma cell cultures were metabolically labeled with [35S]sulfate, [3H]glucose, or [3H]glucosamine. Chondroitin sulfate chains were isolated from purified aggrecan using alkaline borohydride treatment and Superose 6 chromatography. Various linkage region oligosaccharide alditols were derived from these chains using sequential chondroitinase digestions (ABC lyase followed by ACII lyase). They were then further processed by mercuric acetate treatment, which removed the 4,5-unsaturated uronosyl residue from the nonreducing end of the linkage, and then beta-galactosidase digestion which liberated the 2 galactose residues from the xylitol reducing terminus. Alkaline phosphatase digestions were performed to verify the presence of phosphate esters. All linkage region structures were isolated and identified using a combination of Progel-TSK G2500 and CarboPac PA1 chromatography steps in conjunction with monosaccharide analyses. This study revealed that chondroitin sulfate chains from aggrecan synthesized by rat chondrosarcoma cells in vitro have the following properties: 1) three out of every four of their linkage regions carry a phosphate ester on xylose, 2) nearly three out of every five chains begin the repeating disaccharide region with an unsulfated first disaccharide unit, 3) nearly twice as many nonphosphorylated chains have a sulfated first disaccharide than their phosphorylated counterparts, and 4) the vast majority of these chains do not contain sulfated galactose in their linkage regions. This report also describes a borohydride reduction procedure to confer alkali stability to the 3-substituted, unsaturated disaccharides derived from chondroitinase digests of chondroitin sulfate. Furthermore, a CarboPac PA1 method is demonstrated that separates these reduced disaccharides with exceptional resolution.
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PMID:Structural analysis of the linkage region oligosaccharides and unsaturated disaccharides from chondroitin sulfate using CarboPac PA1. 155 66

Insulin action is thought to be mediated by an inositol-, glucosamine- and galactose-containing oligosaccharide liberated by phosphodiesterase hydrolysis of a glycosyl-phosphatidylinositol. This oligosaccharide inhibits insulin biosynthesis and secretion in pancreatic islets. In the present study, two main glycolipids (peak I and II) were resolved by sequential TLC of lipids extracted from islet cells labelled with tritiated glucosamine, galactose or myristate. The two glycolipids displayed comparable sensitivity to beta-galactosidase but differed from one another by their sensitivity to phosphatidylinositol-specific phospholipase C. Moreover, structural heterogeneity within each peak was suggested by their partial resistance to nitrous acid deamination. These findings support the presence in islet cells of glycolipids similar to those currently considered as a possible postreceptor target for insulin in other cell types.
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PMID:Metabolic labelling and partial characterization of glycophospholipids in pancreatic islet cells. 165 34


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