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)

The activity of beta-N-acetylglucosaminidase (NAG), beta-galactosidase, alpha-L-fucosidase, beta-glucuronidase, beta-glucosidase and alpha-mannosidase was determined in the urine of rats at progressive ages from newborn to old animals. The age-dependence of urinary creatinine, protein and pH values was also studied. Enzyme activity, related to urinary creatinine, was significantly higher in the newborn group than other ages. The excretion of NAG increased significantly in adult rats (3-6 months old) compared to young rats (1 month old). Most of the enzyme activities were diminished in old rats (25 months old). Increased proteinuria and creatinine excretion were observed in rats since 3 months of age. Age-related differences among enzyme activities therefore should be considered when these urinary glycosidases are to be studied in rats.
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PMID:Age-related excretion of six glycosidases in rat urine. 136 39

Naturally occurring IgG autoantibody against Band 3 glycoprotein of human erythrocyte membrane (anti-Band 3) recognizes the erythrocytes modified with oxidizing or SH-blocking agents as well as senescent erythrocytes. Location of the antigenic determinants of Band 3 this autoantibody recognizes was investigated by competitive inhibition studies of the antibody binding to the modified cells. Autologous IgG binds to the modified erythrocytes, and purified Band 3 totally inhibits the binding. This inhibitory activity of Band 3 was not affected by digestion of Band 3 with various proteases. Treatment of Band 3 with endo-beta-galactosidase that destroys the poly-N-acetyllactosaminyl sugar chain of Band 3 or with neuraminidase resulted in loss of the inhibitory activity. Oligosaccharides released from Band 3 by hydrazinolysis effectively inhibited the binding of autologous IgG and 125I-labeled purified anti-Band 3 to the modified cells, whereas the oligosaccharides depleted of acidic components did not. Endo-beta-galactosidase and neuraminidase destroyed the activity of the oligosaccharides, but alpha-L-fucosidase did not. Furthermore, human lactoferrin that contains sialylated two N-acetyllactosaminyl units also exhibited potent inhibitory activity, and the activity was destroyed by endo-beta-galactosidase and neuraminidase. These results indicate that the antigenic determinants of Band 3 are located in sialylated poly-N-acetyllactosaminyl sugar chains. Based on this finding, mechanism of appearance of the antigen on senescent erythrocytes recognized by anti-Band 3 (senescent antigen) was discussed.
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PMID:Antigenic determinants of senescent antigen of human erythrocytes are located in sialylated carbohydrate chains of Band 3 glycoprotein. 137 38

A series of 6- and 8-acylamino-4-methylumbelliferyl beta-D-galactopyranosides, beta-D-glucopyranosides, and alpha-L-fucopyranosides having various fatty acid residues were synthesized; 6-(9) and 8-hexadecanoylamino-4-methylumbelliferyl beta-D-galactopyranoside (10) were shown to be substrates for human galactocerebrosidase. Analogs of 9 with shorter acyl residues (octanoyl and butanoyl) were substrates for another type of beta-D-galactosidase, i.e., GM1-ganglioside-beta-D-galactosidase. The specificity of various beta-D-galactosidases for synthetic D-galactopyranosides, differing in the length and position of their acylamide residue, tested with enzyme preparations from patients with two types of glycolipidosis, Krabbe's disease (galactocerebrosidase deficiency) and GM1-beta-galactosidase deficiency), suggested that 9 is a specific substrate for galactocerebrosidase in biochemical tests for Krabbe's disease. Fluorogenic 6-octanoyl- and 6-hexadecanoyl-amino-4-methylumbelliferyl beta-D-glucopyranoside were much less readily hydrolyzed by both human and animal glucocerebrosidase than chromogenic 2-hexadecanoylamino-4-nitrophenyl beta-D-glucopyranoside. Comparison of the hydrolysis of 4-methylumbelliferyl alpha-L-fucopyranoside with that of 6-hexadecanoylamino-4-methylumbelliferyl alpha-L-fucopyranoside by multiple forms of human alpha-L-fucosidase showed that the enzyme is capable of hydrolyzing not only hydrophilic but also synthetic, lipid-like substrates.
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PMID:The use of glycosides of 6- and 8-acylamino-4-methylumbelliferone in studies of the specificity and properties of human lysosomal glycolipid hydrolases. 159 66

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

The 18 kDa and 32 kDa lectin binding proteins of Chlamydia trachomatis were characterized as glycoproteins by treatments with glycosidases. The proteins of the serovar L2 whole cell lysate were separated by SDS-PAGE and transferred to nitrocellulose paper. After treatment with an enzyme, the proteins were reacted with a biotinylated lectin. Each of the endoglycosidases tested affected the binding of the lectin to the protein. PNGase F inhibited the binding of Dolichos biflorus agglutinin (DBA), soybean agglutinin (SBA), and Ulex europaeus agglutinin I (UEAI) to both the 18 kDa and 32 kDa proteins. Endoglycosidase F and H inhibited the binding of these lectins to the 32 kDa protein completely and to the 18 kDa protein partially. In the exoglycosidase treatments, alpha-L-fucosidase prevented binding of only UEAI to the two proteins while beta-galactosidase inhibited the binding of SBA. Mannosidase abolished the binding of all the lectins tested. Neuraminidase had no effect. The proteins isolated by electroelution from the excised gels after SDS-PAGE were digested with an endoglycosidase. PNGase F-treated proteins showed a lower molecular weight mobility in which the lectin binding ability was destroyed. Endo-alpha-N-acetylgalactosaminidase had no effect. The polysaccharide stain of isolated proteins with p-phenylenediamine showed a positive reaction. Radiolabeling with [3H]glucosamine did not reveal the 18 kDa and 32 kDa proteins in autoradiography but [3H]galactose did.
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PMID:The characterization of lectin-binding proteins of Chlamydia trachomatis as glycoproteins. 172 47

A tetrahydroxyindolizidine alkaloid, 6,7-diepicastanospermine, was isolated from the seeds of Castanospermum australe by extraction with methanol and purified to homogeneity using ion-exchange, preparative thin-layer, and radial chromatography. A very low yield of a pyrrolidine alkaloid, N-(hydroxyethyl)-2-(hydroxymethyl)-3-hydroxypyrrolidine, was also obtained by analogous methods. The purity of both alkaloids was established by gas chromatography of their trimethylsilyl (TMS) derivatives as better than 99%. The molecular weight of each alkaloid was established as 189 and 161, respectively, by mass spectrometry, and the structure of each was deduced from their 1H and 13C NMR spectra. The structure of the pyrrolidine alkaloid is suggestive of a possible biosynthetic route to the polyhydroxyindolizidine and polyhydroxypyrrolizidine alkaloids which co-occur in C. australe. 6,7-Diepicastanospermine was found to be a moderately good inhibitor of the fungal alpha-glucosidase, amyloglucosidase (Ki = 8.4 x 10(-5) M) and a relatively weak inhibitor of beta-glucosidase. It failed to inhibit alpha- or beta-galactosidase, alpha- or beta-mannosidase, or alpha-L-fucosidase. Comparison of its inhibitory activity toward amyloglucosidase with those of its isomers, castanospermine and 6-epicastanospermine, demonstrated that epimerization of a single hydroxyl group can produce significant alteration of such inhibitory properties.
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PMID:6,7-Diepicastanospermine, a tetrahydroxyindolizidine alkaloid inhibitor of amyloglucosidase. 191 89

Chromatographic methods were developed for the separation and characterization of acidic (sialylated) and neutral (asialo-complex and high-mannose) oligosaccharides released from glycoproteins with peptide N-glycosidase F. endo-beta-N-acetylglucosaminidase F and endo-beta-N-acetylglucosaminidase H using a carbohydrate analyzer (Dionex BioLC). All the carbohydrate separations were carried out on a polymeric pellicular anion-exchange column HPIC-AS6/CarboPac PA-1 (Dionex) using only two eluants namely, 0.5 M NaOH and 3% acetic acid/NaOH pH 5.5, which were mixed with water to generate various gradients. Developed conditions for quantitative detection of carbohydrates with pulsed amperometry were necessary to obtain steady baselines at 0.1-0.3 microA output with suitable sensitivity (less than 5 pmol) in separations employing a variety of acidic and alkaline sodium acetate gradients. Oligosaccharides released from heat-denatured and trypsin-treated glycoproteins were purified initially from large-scale digestion (greater than 0.1 g) by extraction of peptide material into phenol/chloroform and finally by ion-exchange chromatography of the acqueous phase. Oligosaccharides isolated from the peptide N-glycosidase digests of bovine fetuin, human transferrin and alpha 1-acid glycoprotein gave multiple peaks in each charge group in separations based on the charge content at pH 5.5. Alkaline sodium acetate gradients were developed to obtain oligosaccharide maps of the glycoproteins within 60 min, in which separated oligosaccharides eluted in the order of neutral, mono-, di-, tri- and tetra-sialylated species based on both charge, size and structure. Baseline separations were obtained with neutral oligosaccharide types but mixtures of high-mannose and complex types were poorly resolved. The high-mannose peaks were eliminated specifically from complex oligosaccharides by digesting with alpha-mannosidase. Treatment with beta-galactosidase, beta-N-acetylglucosaminidase and alpha-mannosidase resulted in a decrease of the oligosaccharide elution times corresponding to the number of sugar residues lost, the profile of changes was highly reproducible. In contrast, treatment with alpha-L-fucosidase, endo-beta-N-acetylglucosaminidase F and endo-beta-N-acetylglucosaminidase H resulted in an increase in their corresponding oligosaccharide retention times similar to the presence of an additional sugar residue. Conditions developed for separation of the reduced oligosaccharides and also a mixture of monosaccharide to oligosaccharide containing about 15 sugar residues within 30 min were useful in determining the effect of endo- and exo-glycosidases on porcine thyroglobulin oligosaccharides. Changes in elution time of the oligosaccharides following specific glycosidase digestions combined with methylation analysis provided a rapid and sensitive tool for confirmation of the carbohydrate primary structures present in thyroglobulin.
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PMID:Rapid characterization of asparagine-linked oligosaccharides isolated from glycoproteins using a carbohydrate analyzer. 199 74

The structure of the N-linked oligosaccharide of the 85-kDa surface glycoprotein (Tc-85) from the infective trypomastigote form of Trypanosoma cruzi was investigated. Tc-85 metabolically labeled with [14C]glucose was purified by affinity chromatography on wheat germ agglutinin-Sepharose. Binding to the lectin was lost on treatment of Tc-85 with neuraminidase. The N-linked asialo-oligosaccharide was released by endo-beta-N-acetylglucosaminidase F digestion of asialo-Tc-85 and was further analyzed using specific exoglycosidases. [14C]fucose was detected after alpha-L-fucosidase treatment or mild acid hydrolysis. The afucosyl oligosaccharide was 3H-labeled by the galactose oxidase-NaB3H4 method. [3H]Galactose was released by alpha-galactosidase, and only then was beta-galactosidase effective in removing another galactose. The gal(alpha 1-3)gal unit was demonstrated by periodate oxidation studies on the [3H]galactose-labeled asialo-glycoprotein. The presence of gal(alpha 1-3)gal in Tc-85 could be related to the recent finding of elevated antibody levels against this epitope in patients with Chagas' disease.
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PMID:The N-linked carbohydrate chain of the 85-kilodalton glycoprotein from Trypanosoma cruzi trypomastigotes contains sialyl, fucosyl and galactosyl (alpha 1-3)galactose units. 210 74

Cyclophellitol [1S,2R,3S,4R,5R,6R)-5-hydroxymethyl-7-oxabicyclo[4,1,0] heptane-2,3,4-triol) was tested against 9 glycosidases and found to be a specific inhibitor of almond beta-glucosidase. Cyclophellitol inhibited almond beta-glucosidase activity by 50% at 0.8 micrograms/ml and was a competitive inhibitor of almond beta-glucosidase as revealed by Lineweaver-Burk plot. Cyclophellitol was inactive against yeast alpha-glucosidase, beta-galactosidase, beta-glucuronidase, alpha-L-fucosidase, end-beta-N-acetyl glucosaminidase, alpha-mannosidase, and cellulase. It was weakly active toward fungal beta-xylosidase. Cyclophellitol-treated almond beta-glucosidase was equally suppressed after dialysis; thus cyclophellitol is likely to bind to almond beta-glucosidase irreversibly. The inhibitor was found by fluorimetric assay to be active against beta-glucosidase but inactive toward alpha-glucosidase in Molt-4 microsomal fraction. It also inhibited Molt-4 beta-glucocerebrosidase completely at 2 micrograms/ml when the enzyme was assayed with a synthetic labeled substrate, and the inhibitory activity was more than one hundred times higher than that of nojirimycin, castanospermine, or of deoxynojirimycin. Mice administered 1 mg of cyclophellitol daily for 5 days began to exhibit severe abnormalities of nervous system similar to those found in Gaucher's mouse.
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PMID:Biological activities of cyclophellitol. 214 35

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


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