Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.21 (beta-glucosidase)
 3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The P4 variant of Dictyostelium discoideum is characterized by the production of fruiting structures in which the overall proportion of stalk to spore material is increased, relative to the wild type. The altered morphology of the mutant is due to increased sensitivity to cyclic AMP which promotes stalk cell differentiation. In the presence of 10-4 M-cyclic AMP the entire population of P4 amoebae forms clumps of stalk cells on the surface of the dialysis membrane support. Measurement of changes in activity of a range of developmentally-regulated enzymes during the development of P4 in the presence and absence of cyclic AMP has allowed us to identify three classes of enzyme: (i) Those, such as beta-glucosidase II, trehalose-6-phosphate synthetase and uridine diphosphogalactose-4-epimerase, which are required for the production of spores. (ii) Enzymes, primarily but perhaps not exclusively, required during stalk cell formation. Typical of these are N-acetylglucosaminidase and alkaline phosphatase. (iii) General enzymes, such as threonine dehydrase, alpha-mannosidase and uridine diphosphoglucose pyrophyosphorylase, which are present inboth pre-stalk and pre-spore cells and appear to be necessary for the development of both cell types.
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PMID:Enzyme activity changes during cyclic AMP-induced stalk cell differentiation in P4, a variant of Dictyostelium discoideum. 17 91

Metabolism of pantothenic acid (PaA) in beagle dogs was investigated. The dogs excreted 12.3% of the dose in the urine within 24 hr after a single oral administration of [3H]PaA (3 mg/kg). High performance liquid chromatographic analysis of the urine showed the presence of unchanged vitamin and a major metabolite, which accounted for 60.2 and 39.8% of the urinary radioactivity respectively. Although the metabolite was hydrolyzed by treatment with beta-glucuronidase or acid phosphatase, it was found that this hydrolysis resulted from the actions of beta-glucosidase contained as a contaminant in these enzyme preparations. beta-Glucosidase completely hydrolyzed the metabolite to generate PaA and glucose. The metabolite was isolated and subjected to GC/MS and NMR analyses. It was identical to synthetic PaA beta-glucoside, 4'-O-(beta-D-glucopyranosyl)-D-pantothenic acid. It was shown by the use of dog liver microsomes that PaA underwent beta-glucosidation in the presence of uridine diphosphate glucose (UDPG). It is proposed that beta-glucosidation by UDP-glucosyltransferase is a novel metabolic pathway of PaA in the dog.
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PMID:Glucoside formation as a novel metabolic pathway of pantothenic acid in the dog. 309 35

Incubation of labeled uridine diphosphate glucose with an enzyme preparation from Rhizobium meliloti or Agrobacterium tumefaciens leads to the formation of a glucan which appears to be identical to the beta 1-2 cyclic glucan described by several workers. This conclusion is based on the molecular size, the formation of sophorose and higher homologs by partial acid hydrolysis, the liberation of only glucose by total acid hydrolysis, and the release of only 3,4,6-tri-O-methylglucose after methylation and hydrolysis. A snail intestinal juice enzyme was found to break down the glucan and its partial hydrolysis products. A beta-glucosidase from sweet almonds degraded sophorose but not the intact glucan.
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PMID:The enzymatic synthesis of beta 1-2 glucans. 399 79

The biosynthesis of cholesteryl glucoside by Mycoplasma gallinarum strain J proceeds by the transfer of glucose from uridine-5'-diphosphoglucose to membrane-bound sterol. Galactose also can be coupled to cholesterol via uridine-5'-diphosphogalactose. The reaction is specific for the uridine-5'-diphospho sugars. Enzymatic activity is associated with the membrane. Treatment of the membrane to remove endogenous sterol inactivates the enzyme. Only sterol which has been bound to the membrane participates in the reaction. The optimum pH is about 8.0, and Mg(2+) is required. The reaction is unaffected by nucleotide triphosphate, uridine-5'-monophosphate, and uridine-5'-diphosphate. Reduction of pH to the optimum for beta-glucosidase in the membrane results in loss of synthesized glucoside. The enzyme is saturated at 0.5 mm uridine-5'-diphosphoglucose. The apparent K(m) of 2.05 x 10(-7) indicates a high affinity of the enzyme for the nucleotide sugar.
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PMID:Biosynthesis of cholesteryl glucoside by Mycoplasma gallinarum. 513 38

The tissue distributions of dhurrin [p-hydroxy-(S)-mandelonitrile-beta-d-glucoside] and of enzymes involved in its metabolism have been investigated in leaf blades of light-grown Sorghum bicolor seedlings. Enzymic digestion of these leaves using cellulase has enabled preparations of epidermal and mesophyll protoplasts and bundle sheath strands to be isolated with only minor cross-contamination. Dhurrin was located entirely in the epidermal layers of the leaf blade, whereas the two enzymes responsible for its catabolism, namely dhurrin beta-glucosidase and hydroxynitrile lyase, resided almost exclusively in the mesophyll tissue. The final enzyme of dhurrin biosynthesis, uridine diphosphate glucose:p-hydroxymandelonitrile glucosyltransferase, was found in both mesophyll (32% of the total activity of the leaf blade) and epidermal (68%) tissues. The bundle sheath strands did not contain significant amounts of dhurrin or of these enzymes. It was concluded that the separation of dhurrin and its catabolic enzymes in different tissues prevents its large scale hydrolysis under normal physiological conditions. The well documented production of HCN (cyanogenesis), which occurs rapidly on crushing Sorghum leaves, would be expected to proceed when the contents of the ruptured epidermal and mesophyll cells are allowed to mix.
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PMID:Tissue Distributions of Dhurrin and of Enzymes Involved in Its Metabolism in Leaves of Sorghum bicolor. 1666 Aug 50

The distribution of the glucosides of trans- and cis-2-hydroxy cinnamic acid and of the beta-glucosidase which hydrolyzes the latter glucoside was examined in preparations of epidermal and mesophyll tissue obtained from leaves of sweet clover (Melilotus alba Desr.). The concentrations of glucosides in the two tissues were about equal when compared on the basis of fresh or dry weight. Inasmuch as the epidermal layers account for no more than 10% of the leaf volume, the mesophyll tissue contains 90% or more of the glucosides. Vacuoles isolated from mesophyll protoplasts contained all of the glucosides present initially in the protoplasts.The specific activities of the beta-glucosidase in the two tissues were also similar; thus, most of the enzyme is contained in mesophyll tissue. However, the amount of enzyme in mesophyll protoplast extracts amounts to only 1 to 2% of the activity present in leaf homogenates when chlorophyll was the basis for comparison. (This small amount of coumarin-beta-glucosidase present in protoplasts is not associated with chlorophyll-containing fractions.) In contrast, 90% of the uridine diphosphate glucose-o-coumaric acid glucosyl transferase activity present in leaf homogenate was recoverable in protoplasts prepared from intact leaves. Such results indicate that most of the coumarin-beta-glucosidase in M. alba leaves is located in the extracytoplasmic space. Only a small fraction (7%) of this extra cytoplasmic beta-glucosidase was associated with individual cells or cell clusters isolated from clover leaves.
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PMID:Subcellular Localization of 2-(beta-d-Glucosyloxy)-Cinnamic Acids and the Related beta-glucosidase in Leaves of Melilotus alba Desr. 1666 8