Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

A significant sequence homology was found between a thermostable beta-galactosidase from Sulfolobus solfataricus and two beta-glucosidases, respectively, from Caldocellum saccharolyticum and from Agrobacterium sp. These glycosidases appear to form a new protein family, since no homology could be detected with established beta-galactosidase or beta-glucosidase families.
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PMID:Sequence homology between a beta-galactosidase and some beta-glucosidases. 192 72

Maternal protein deficiency imposed on rats a month prior to conception, and during gestation and lactation, resulted in a significant cell loss in cerebrum, cerebellum, brain stem and spinal cord of pups at weaning. The cerebellum was the most affected central nervous system (CNS) region; it contained only 25% of the normal cell number. Undernourished pups were also found to have a lower concentration of total gangliosides in cerebrum as compared to that of controls. However, the total ganglioside concentration was unaffected in the cerebellum, brain stem and spinal cord by maternal undernutrition. In all regions, undernutrition caused significant changes in the proportions of individual gangliosides; these alterations were region-specific. Sialidase, beta-galactosidase, beta-glucosidase, and beta-hexosaminidase, which are involved in the catabolism of gangliosides, showed higher activities in all the regions of undernourished pups, suggesting that these enzymes may play a role in maintaining the porportions of various ganglioside fractions.
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PMID:Maternal protein deficiency in rat: effects on central nervous system gangliosides and their catabolizing enzymes in the offspring. 194 99

This present study reports the ability of a range of derivatives of L-histidine, histamine and imidazole to act as inhibitors of sweet-almond beta-glucosidase, yeast alpha-glucosidase and Escherichia coli beta-galactosidase. The addition of a hydrophobic group to the basic imidazole nucleus greatly enhances binding to both the alpha- and beta-glucosidases. L-Histidine (beta-naphthylamide (Ki 17 microM) is a potent competitive inhibitor of sweet-almond beta-glucosidase as is omega-N-acetylhistamine (K1 35 microM), which inhibits the sweet-almond beta-glucosidase at least 700 times more strongly than either yeast alpha-glucosidase or Escherichia coli beta-galactosidase, and suggests potential for the development of selective reversible beta-glucosidase inhibitors. A range of hydrophobic omega-N-acylhistamines were synthesized and shown to be among the most potent inhibitors of sweet-almond beta-glucosidase reported to date.
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PMID:Histidines, histamines and imidazoles as glycosidase inhibitors. 201 15

The changes in the activities of certain lysosomal hydrolases, viz., beta-glucuronidase, beta-N-acetylglucosaminidase, beta-galactosidase, beta-glucosidase, alpha-glucosidase, alpha-galactosidase, alpha-mannosidase, cathepsin B, cathepsin D, and collagenolytic cathepsin, in serum and heart of rats subject to myocardial infarction with isoproterenol, were studied during the periods of peak infarction and recovery. The activities of all the enzymes assayed exhibited a significant increase both in serum and in heart at peak infarction stage and these levels returned to normal during the stage of recovery and repair. The infiltration of inflammatory cells at the infarct regions and the altered lysosomal fragility are probably responsible for the increased activity of the enzymes studied. This may also bring about the catabolism of connective tissue constituents as reported in literature.
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PMID:Influence of isoproterenol-induced myocardial infarction on certain glycohydrolases and cathepsins in rats. 201 10

Gastric intubation was adopted as a means of comparing the effect of two feeding levels, continuous nutrient supply (C) and restricted nutrient supply (R), on the digestive development of pigs weaned at 14 d of age, during the first 5 d post-weaning. The absolute weights of the stomach and the pancreas were significantly greater (P less than 0.001) in C compared with R pigs. The effect was not significant for pancreas weight when expressed per kg body-weight but was significant (P less than 0.05) for stomach weight. The weights of the small intestine (SI), SI mucosa and total mucosal protein were significantly higher (P less than 0.001) in C pigs but protein content per g mucosa was similar in the C and R groups. There was no significant effect of treatment on the activity of lactase (beta-glucosidase; EC 3.2.1.23) or sucrase (sucrose-alpha-glucosidase; EC 3.2.1.48) irrespective of the basis of comparison used. The specific activity (mumol/min per g protein) of maltase (alpha-glucosidase; EC 3.2.1.20) and of glucoamylase (glucan-1,4-alpha-glucosidase; EC 3.2.1.3) were similar in C and R groups but activities of maltase (mumol/g mucosa) (P less than 0.05), and maltase and glucoamylase (mol/d) (P less than 0.01) were significantly higher in C pigs. Villous height and crypt depth were significantly greater in C pigs (P less than 0.001 and P less than 0.05 respectively). Enteroglucagon was significantly (P less than 0.05) higher in C compared with R pigs. Xylose absorption and the digestibility of energy were not affected by treatment. Digestibility of dry matter, organic matter, crude protein (nitrogen x 6.25) and carbohydrate were significantly higher (P less than 0.001, P less than 0.01, P less than 0.05 and P less than 0.001 respectively) in R pigs compared with C pigs but the differences were small, ranging from 1.3 to 2.5%. These results demonstrate that (1) nutrient intake in the weaned pig affects the anatomy, morphology and function of the gut, (2) there is considerable 'spare capacity' for digestion of cereal-based diets even in pigs weaned at 14 d of age, (3) measurements in vitro of digestive function are of limited value unless supported by information in vivo on absorption/digestibility.
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PMID:Digestive development of the early-weaned pig. 2. Effect of level of food intake on digestive enzyme activity during the immediate post-weaning period. 204 2

Nine healthy volunteers were studied before, during, and after ingesting a fermented dairy product containing Lactobacillus acidophilus, Bifidobacterium bifidum, and mesophilic cultures (Streptococcus lactis and S cremoris) for 3 wk. Hydrogen and methane productions and fecal beta-galactosidase and beta-glucosidase activities were measured as indicators of fermentation capacity of the colonic flora. Fecal concentrations of nitroreductase, azoreductase, and beta-glucuronidase, which may be implicated in colonic carcinogenesis, were also assessed. Hydrogen and methane productions, fecal beta-galactosidase, beta-glucuronidase, and azoreductase activities did not change over three 3-wk periods whereas fecal beta-glucosidase activity increased (42 +/- 6, 91 +/- 12, and 40 +/- 6 IU/g N, P less than 0.01) and nitroreductase decreased (0.87 +/- 0.13, 0.54 +/- 0.11, and 0.57 +/- 0.08 IU/g N, P less than 0.05).
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PMID:Effect of chronic ingestion of a fermented dairy product containing Lactobacillus acidophilus and Bifidobacterium bifidum on metabolic activities of the colonic flora in humans. 211 57

The activities of alpha- and beta-glucosidase, beta-galactosidase and beta-N acetylglucosaminidase were assessed at acidic pH by fluorimetry using the appropriate 4-methylumbelliferyl substrate in four Mycoplasma species (M. pneumoniae, M. gallisepticum, M. hominis and M. capricolum) and in Acholeplasma laidlawii. The glycosidase activities were in a low range (0.1-4.2 nmole per h per mg protein) with the exception of higher activities of beta-N-acetylglucosaminidase in A. laidlawii. The enzyme levels of a virulent and a nonvirulent strain of M. pneumoniae were comparable. Despite the very sensitive assay, neuraminidase activity was not detected in M. pneumoniae and M. gallisepticum. No induction of alpha-glucosidase could be demonstrated for M. pneumoniae or A. laidlawii. At least part of the glycosidase activities was localized in the membrane fraction of all mycoplasmas studied. This may support the hypothesis that pathogenic mycoplasmas, being membrane parasites, may modify, by their glycosidases, some host cell glycoconjugates. However, our study did not distinguish the pathogenic mycoplasmas to possess a characteristic glycosidase profile.
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PMID:Glycosidase activities of mycoplasmas. 211 90

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

Previous studies have shown that bovine retinas incubated with [3H]galactose incorporated it, unmodified, into large molecules. Light and electron microscope autoradiography showed a significant proportion of the label to be in cone inner segments, and pulse-chase studies showed it was subsequently transported to the synaptic pedicles. In this report, evidence is presented to show that the galactose-labelled macromolecules are resistant to hydrolysis by proteolytic enzymes, testicular hyaluronidase, chondroitinase ABC, beta-glucosidase and beta-glucuronidase, but are readily degraded by alpha-amylase and beta-galactosidase, and to a lesser extent by beta-amylase. Treatment with alpha-amylase also leads to specific removal of radioactivity from cone inner segments and pedicles, as judged by light-microscopic autoradiography. These studies appear to indicate that the cone-specific galactose label is in glycogen or glycogen-like molecules.
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PMID:D-[3H]galactose incorporation into glycogen in retinal cone cells. 231 72


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