Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Previous studies have shown that chronic administration of D-galactosamine (GalNH2) in rats produces alpha 1-antiprotease (AAP) deficiency and causes accumulation of aberrantly glycosylated AAP in hepatic granules. In order to examine the disordered mechanism which produces this altered glycosylation, the activities of 6 glycosidases in liver homogenates of control and AAP-deficient rats were determined. GalNH2 treatment increases acid pH glycosidase activity, while it decreases intermediate pH alpha-mannosidase and alpha-glucosidase activities. beta-D-Glucosidase, beta-D-mannosidase and beta-D-N-acetylglucosaminidase activities, measured at acid pH, increase more than 2-fold in the GalNH2-treated rats compared to controls. alpha-D-Glucosidase activity measured at intermediate pH decreases 2.5-fold in the experimental rats. alpha-L-Fucosidase and acid phosphatase activities are not significantly changed by GalNH2 treatment. alpha-D-Mannosidase activity can be separated into 2 fractions by ion exchange chromatography. Acid pH alpha-D-mannosidase is increased nearly 2-fold in the GalNH2-treated rats. Intermediate pH alpha-D-mannosidase optimum is decreased alpha-D-mannosidase activities have been observed in humans with AAP deficiency. alpha-Glucosidases and alpha-mannosidases play a crucial role in glycoprotein synthesis. The altered synthesis and structure of AAP in GalNH2-induced AAP deficiency may be a reflection of altered enzyme activities.
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PMID:Altered glycosidase activity in the liver of rats with galactosamine-induced alpha 1-antiprotease deficiency. 383 42

In the newborn lamb, activities of lysosomal enzymes are lower in the duodenum and jejunum than in the ileum. In contrast, there are only minor differences, if any, in activities of lysosomal enzymes between the regions of the small intestine of 5-day-old lambs. In the duodenum, jejunum and ileum, activities of hexosaminidase, alpha-mannosidase, beta-mannosidase, alpha-L-fucosidase and phosphodiesterase are greater in newborn than in 5-day-old lambs. Only in the distal part of the small intestine are activities of beta-glucuronidase, alpha-glucosidase, alpha-galactosidase, beta-galactosidase, acid phosphatase and cathepsin B higher in the newborn than in 5-day-old lambs. Cathepsin B activity is lower in the duodenum and jejunum of the newborn than in 5-day-old lambs.
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PMID:Lysosomal enzymes in the intestine of the newborn lamb. 609 93

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

beta-Fructofuranosidase, alpha-glucosidase, beta-glucosidase, alpha-mannosidase, beta-mannosidase, sucrose phosphorylase, glucosyltransferase and fructosyltransferase were separated by isoelectric focusing and sensitively detected to be slightly diffuse and insoluble spots in thin-layer gels, supported by a glass plate, by release of monosugars or a sugar phosphate, followed by conversion to glucose-6-phosphate (G6P) and then by reduction of NADP+ to NADPH, terminated by the formation of reduced Nitroblue Tetrazolium (NBT). Approximately 1-10 mU of enzyme was focused and the gel, after washing with a buffer, was partially dried and directly stained by uniformly spreading on the gel surface a staining medium containing sucrose or nitrophenyl glycosides as substrates, intermediary enzymes such as hexokinase, mutase and/or isomerase, NADP+, ATP, Mg+, phenazine methosulfate (PMS) and NBT. Specific staining procedures for each of these activities, on sucrose or on the glycosides as substrates, and staining procedures for multiple activities are described, with the conditions necessary for optimal development.
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PMID:Glucose, fructose, mannose and/or glucose-1-phosphate-releasing activity stains for glycosidases and glycosyltransferases in gels after isoelectric focusing. 751 61

Glycosidases and glycosyltransferases were electrophoresed in the presence of sodium dodecyl sulfate (SDS) in a thin-layer gel supported by a glass plate, treated with the nonionic detergent Triton X-100, and specifically stained for the sugar-releasing activity of these enzymes. Staining is based on conversion of monosugars or a sugar phosphate to glucose-6-phosphate by the appropriate intermediary enzymes, reduction of NADP+ to NADPH, and accumulation of reduced Nitroblue Tetrazolium in the gel. Among the enzymes tested, alpha-glucosidase, beta-glucosidase and beta-mannosidase could not be renatured, whereas beta-fructofuranosidase and alpha-mannosidase could be renatured unless heated before electrophoresis. Sucrose phosphorylase, glucosyltransferase and fructosyltransferase, which are single-peptide proteins with no cystine bond, could be renatured even after pretreatment with SDS and/or mercaptoethanol at 100 degrees C for 10 min. However, exclusive heating remarkably decreased the activities of these enzymes. Two-dimensional separation of the five renaturable enzymes was done in a single thin-layer gel, using SDS-electrophoresis in the first dimension and isoelectric focusing in the second dimension.
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PMID:Renaturation and activity staining of glycosidases and glycosyltransferases in gels after sodium dodecyl sulfate-electrophoresis. 752 70

The antimetastatic activity of ten compounds structurally related to nojirimycin A was examined using a pulmonary metastatic model of mouse B16 melanoma. Nojirimycin B, deoxynojirimycin, D-gluco-delta-lactam, CP3068 and CP3069 are structural analogues of nojirimycin A, and showed potent or moderate antimetastatic activities. Nojirimycin A, nojirimycin B, deoxynojirimycin and D-gluco-delta-lactam showed potent or moderate inhibitory activities against alpha-glucosidase, beta-glucosidase and beta-mannosidase, but CP3068 and CP3069 in which the structures were related to D-gluco-delta-lactam showed no inhibitory activities. CP3041, CP3042, CP3043, CP3045 and CP3048 are analogues of sodium D-glucaro-delta-lactam (ND2001), a carboxy derivative of nojirimycin A, and showed potent or moderate antimetastatic activities. But no analogue was superior to ND2001 concerning with antimetastatic and anti-beta-glucuronidase activities. CP3041 and CP3042 showed potent and moderate inhibitory activities against beta-glucuronidase, respectively, but CP3043, CP3045 and CP3048 showed little or no activities.
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PMID:Inhibition of mouse tumor metastasis with nojirimycin-related compounds. 862 56

Six new pyrrolidine alkaloids called broussonetine A, B, E, F, and broussonetinine A and B were isolated from the branches of Broussonetia kazinoki Sieb. (Moraceae). Broussonetine A, B, E and F were formulated as 2 beta-hydroxymethyl-3 beta-hydroxy-5-alpha- (10-oxo-13-hydroxytridecyl)-pyrrolidine-4-O-beta-D-glucopyranoside (1), 2 beta-hydroxymethyl-3 beta-hydroxy-5 alpha-(9-oxo-13-hydroxytridecyl)-pyrrolidine-4-O-beta-D-glucopy ran oside (2), 2 beta-hydroxymethyl-3 alpha,4 beta-dihydroxy-5 alpha-(1,13-dihydroxy-10-oxo-tridecyl)-pyrrolidine (3), and 2 beta-hydroxymethyl-3 alpha,4 beta-dihydroxy-5 alpha-(1,13-dihydroxy-9-oxo-tridecyl)-pyrrolidine (4), respectively. Broussonetinine A and B (5 and 6) were also isolated and identified as the aglycones of 1 and 2. 3 and 4 exhibited a strong inhibition of alpha-glucosidase, beta-glucosidase, beta-galactosidase and beta-mannosidase, while 5 and 6 showed a strong inhibition of beta-galactosidase and alpha-mannosidase.
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PMID:Studies on the constituents of Broussonetia species. II. Six new pyrrolidine alkaloids, broussonetine A, B, E, F and broussonetinine A and B, as inhibitors of glycosidases from Broussonetia kazinoki Sieb. 914 6

Most newly synthesized lysosomal enzymes contain a transient carbohydrate modification, mannose 6-phosphate (Man-6-P), which signals their vesicular transport from the Golgi to the lysosome via Man-6-P receptors (MPRs). We have examined Man-6-P glycoproteins in human urine by using a purified soluble fragment of the soluble cation-independent MPR (sCI-MPR) as a preparative and analytical affinity reagent. In a survey of urine samples from seven healthy subjects, the pattern of Man-6-P glycoproteins detected with iodinated sCI-MPR as a probe in a blotting assay was essentially identical in each, regardless of sex or age. Two bands of approx. 100 and 110 kDa were particularly prominent. Man-6-P glycoproteins in human urine were purified by affinity chromatography on immobilized sCI-MPR. Seven distinct bands revealed by SDS/PAGE and Coomassie Blue staining were subjected to N-terminal sequence analysis. The prominent 100 and 110 kDa Man-6-P glycoproteins were identified as N-acetylglucosamine-6-sulphatase and alpha-glucosidase respectively. This identification was confirmed by molecular mass determinations on the two major bands after deglycosylation. Sequence analysis revealed arylsulphatase A and several previously unidentified proteins as minor species. Man-6-P glycoproteins were also purified on an analytical scale to determine the proportion of a number of lysosomal enzyme activities represented by the mannose-6-phosphorylated forms. The lysosomal enzymes in urine containing the highest proportion of mannose-6-phosphorylated form were beta-mannosidase (82%), hexosaminidase (27%) and alpha-glucosidase (24%). The profiles of Man-6-P glycoproteins detected by blotting in urine and plasma were not similar, suggesting that the urinary species are not derived from the bloodstream.
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PMID:alpha-Glucosidase and N-acetylglucosamine-6-sulphatase are the major mannose-6-phosphate glycoproteins in human urine. 916 38

[reaction: see text] (1S,2S,3S,4R,5R)-4-amino-5-(hydroxymethyl)cyclopentane-1,2,3-triol 1 is prepared stereoselectively from D-lyxose and displays anomer-selective inhibition for beta-galactosidase (Ki = 3.0 x 10(-6) M) and beta-glucosidase (Ki = 1.5 x 10(-7) M), over alpha-galactosidase (Ki = 2.3 x 10(-5) M) and alpha-glucosidase (IC50 = 1.0 x 10(-4) M). There is no observable cross-reactivity with alpha-mannosidase, beta-mannosidase, or alpha-L-fucosidase.
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PMID:Anomer-selective inhibition of glycosidases using aminocyclopentanols. 1082 3

The polysaccharide hydrolase activity of a group of selected strains of the genus Aureobasidium pullulans was investigated using a new gel testing assay. A total of 31 strains were tested for alpha-amylase, alpha-glucosidase and glucoamylase, beta-glucosidase, lichenase, cellulase, xylanase and xylosidase, mannanase and mannosidase production during growth of microorganisms on respective meshed polysaccharide gels. Attempts were made to increase the polysaccharide hydrolase activity through selection of some A. pullulans strains by passaging them on the respective modified xylanase- and cellulase-containing gels. The individual saccharide degradation cleavage products were investigated by chromatography.
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PMID:Polysaccharide hydrolases of Aureobasidium pullulans. 1127 22


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