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:3.2.1.31 (beta-glucuronidase)
7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have separated for enzyme analysis the following layers that surround the conceptus at midgestation: decidua, trophoblast, parietal endoderm (including Reichert's membrane), visceral endoderm, yolk-sac mesoderm and amnion. Measurement of several catabolic enzyme activities (N-acetyl-beta, D-hexosaminidase, beta-glucuronidase, alkaline and acid phosphatases and non-specific esterases) in these tissues indicates that they are biochemically distinct, perhaps reflecting the different functions that they perform in providing the embryo proper with a desirable environment for differentiation and development. Our studies also provide an example of how visceral endoderm cells can effectively block passage of maternal macromolecules (in this case a serum esterase) in the fetal circulation. Finally, since there is often difficulty in distinguishing among early embryonic and extra-embryonic cell types produced in teratocarcinoma cultures, we have considered how our observations might be of use in the respect, particularly in discriminating between visceral and parietal endoderm.
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PMID:Enzyme analysis of mouse extra-embryonic tissues. 52 44

The activities of the lysosomal acid hydrolases-cathespin D, acid phosphatase, beta-N-acetylglucosaminidase, and beta-glucuronidase-were measured in rat myometrium under the following hormonal conditions: during the estrus stage of the estrous cycle (NE); at 1,2, and 3 wk after ovariectomy; and in 3-wk postovariectomized females after hormone replacement therapy with 17 beta-estradiol (E2), progesterone (P), or E2 + P. Activities per milligram protein and per milligram DNA of the enzymes were significantly decreased after ovariectomy and were restored to the NE level or above after injecting E2 or E2 + P. Lysosomal enzyme activities did not change with hormonal state in hypophysectomized rats, suggesting that other hormones are required for mediation of enzyme activity. Acid hydrolase activities in other tissues and nonlysosomal enzyme activites in the myometrium did not fluctuate with hormonal state. Studies of lysosomal membrane integrity suggested that one population of lysosomes richer in cathepsin D and acid phosphatase and another rich in beta-N-acetylglucosaminidase and beta-glucuronidase may be present in rat myometrium. Estrogen seemed to labilize the lysosomal membrane of at least the latter of the two proposed populations of myometrial lysosomes.
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PMID:Effect of ovarian hormones on lysosomal acid hydrolase activities in rat myometrium. 55 4

A pool of acid hydrolases exists within the acellular lining material of the alveoli and distal airways of the lungs. These extracellular hydrolases, obtained using pulmonary lavage procedures, appear to be of a selected variety insofar as some hydrolases (beta-N-acetylglucosaminidase and alpha-mannosidase) are highly active while others (beta-glucuronidase and arylsulfatase) are barely detectable. The origins of these hydrolases were investigated. Neither leakage of serum nor cell damage can account for the presence of the extracellular hydrolases in lavage effluents. Electrophoretic mobilities on acrylamide gels indicate that the extracellular hydrolases generally differ from those found in serum. Cytoplasmic soluble enzymes such as lactate dehydrogenase were used to monitor cell damage and show that the extracellular hydrolases did not originate from cell leakage during the lavage procedure. Hydrolases similar to those found extracellularly are associated with highly purified lysosome-free lamellar bodies isolated from homogenates of lung. The extracellular hydrolases are probably selected by the type 2 cells of the pulmonary alveolar epithelium during their selection of lamellar bodies.
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PMID:Extracellular hydrolases of the lung. 62 5

Fibroblasts were incubated in the presence of the anti-microtubular drugs colchicine, vinblastine and vincristine. In concentrations between 10nm and 1 mM these drugs stimulated the secretion of beta-N-acetylglucosaminidase, alpha-N-acetylglucosaminidase and beta-glucuronidase, but not of beta-galactosidase. The endocytosis of beta-N-acetylhexosaminidase and alpha-N-acetylglucosaminidase, but not of beta-glucuronidase, was inhibited at drug concentrations higher than 0.1 micrometer. Formation, secretion and association with the cell membrane of sulphated proteoglycans were not affected by anti-microtubular drugs. Endocytosis of sulphated proteoglycans and their subsequent degradation was inhibited by drug concentrations above 0.1 micrometer. The inhibition of intracellular glycosaminoglycan degradation led to a moderate storage of these compounds. These results suggest that microtubules participate in the control of secretion and endocytosis of lysosomal enzymes, and in the endocytosis and degradation of lysosomal substrates such as sulphated proteoglycans.
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PMID:Studies on secretion and endocytosis of macromolecules by cultivated skin fibroblasts. Effects of anti-microtubular agents on secretion and endocytosis of lysosomal hydrolases and of sulphated glycosaminoglycans. 63 45

The effect of administration of low and high doses of pyridoxine on the metabolism of lipids and glycosaminoglycans has been studied in rats fed normal and high fat, high cholesterol diets. Low doses of pyridoxine (0.005 mg/100 g body weight) caused increased concentrations, of cholesterol and triglycerides in the serum and aorta in animals fed normal and high fat, high cholesterol diets. Administration of high doses of pyridoxine (5.0 mg/100 g body weight) caused decrease in the concentration of these lipids in these tissues except in the case of the aorta in the animals fed a normal diet. Low doses of pyridoxine generally caused a decrease in the concentration of many glycosaminoglycan fractions in the aorta in rats fed normal and high fat, high cholesterol diets, whilst high doses caused an increase. The activity of glucosaminephosphate isomerase (glutamine-forming) and UDPglucose dehydrogenase, both key enzymes in the biosynthetic pathway of glycosaminoglycans, decreased in rats given low doses of pyridoxine and increased in rats given high doses. The activity of many enzymes concerned with degradation of glycosaminoglycans--hyaluronoglucosidase, beta-glucuronidase, beta-N-acetylglucosaminidase, aryl sulphatase, and cathepsin D--generally increased in rats fed low doses of the pyridoxine and decreased in those given high doses. The concentration of hepatic 3'-phosphoadenosine-5'-phosphosulphate, and the activity of the sulphate-activating system and of aryl sulphotransferase decreased when the dose of pyridoxine was low and increased when the dose was high.
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PMID:Pyridoxine and atherosclerosis: role of pyridoxine in the metabolism of lipids and glycosaminoglycans in rats fed normal and high fat, high cholesterol diets containing 16% casein. 67 16

Properties of two hydrolases: beta-glucuronidase and N-acetyl-beta-hexosaminidase were studied in lysosomal fractions of media-intima from arterial wall. These enzymatic activities change significantly with aging. In the arterial wall, the decrease in activities of beta-glucuronidase and N-acetyl-beta-hexosaminidase between young and old rats was highly significant while there no notable change in the activities of acid phosphatase. These data are in agreement with the metabolic slow-down and the modifications of the glycosaminoglycan distribution in the media-intima of arterial wall with aging.
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PMID:Lysosomal N-acetyl-beta-hexosaminidase and beta-glucuronidase activities from arterial wall. Variations with aging. 68 75

The pH optima and apparent Km and Vmax values were determined for nine glycosidases of the retinal pigment epithelium (RPE) of the calf. In terms of micromoles of substrate cleaved per milligram protein per hour, the following relative order of enzymatic activities was observed: beta-N-acetylglucosaminidase greater than alpha-glucosidase = beta-N-acetylgalactosaminidase greater than alpha-mannosidase greater than beta-galactosidase greater than beta-glucosidase greater than alpha-fucosidase greater than alpha-galactosidase greater than beta-glucuronidase. The pH optimum of each of these enzymes was in the acidic range (below pH 6). All these findings refer to enzymatic activities of bovine RPE preparations obtained by the brushing procedure of Glocklin and Potts and washing as described by Berman and Feeney. Thus they may relate to those activities associated with particulate components of the RPE cell and not to the more soluble glycosidases. The distribution of the glycosidases between the washes of the cells and the final pellet of bovine RPE cells was examined. The activities of 10 glycosidases in the RPE of the embryonic chick were also examined. Neither beta-mannosidase nor beta-fucosidase activities could be detected in washed bovine RPE cells, although beta-mannosidase was detected in RPE of the embryonic chick. The presence of isoenzymes of beta-glucuronidase in bovine RPE was indicated. Specificity by beta-glucuronidase of bovine RPE for synthetic substrates was observed.
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PMID:Glycosidases of the retinal pigment epithelium. 70 Sep 67

Alveolar macrophages from the rabbit were exposed in the culture medium to zirconium and aluminum salts. The specific activities of the lysosomal hydrolases, that is acid phosphatase, beta-N-acetylglucosaminidase and beta-glucuronidase, were measured in the medium, whole cell homogenate, mitochondrial fraction, and in the supernatant fraction. A highly significant increase of these hydrolases was observed in the mitochondrial fraction from cells exposed to zirconium and aluminum salts as compared with those from control cell cultures. However, release of these enzymes into the medium was not much. The phenomenon of macrophage phagocytosis was observed morphologically in the cell cultures exposed in vitro to these metal compounds.
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PMID:Effects of zirconium and aluminum salts on the alveolar macrophages. 71 72

Activities of three lysosomal glycosidases, beta-galactosidase, beta-glucuronidase, and N-acetyl-beta-hexosaminidase, have been shown to differ in bf/bf and bf/+ mice. Thus bf/bf mice usually have much higher activities of these enzymes in their kidney cells than bf/+ animals. There seem, however, to be some exceptions to this general pattern, especially for galactosidase of females from the C57BL/6J strain. A likely interpretation of the difference is that the bf locus has pleiotropic effects. An alternative explanation, less likely, is that a gene closely linked to bf is involved. There is also a differential response to dihydrotestosterone in different groups of mice reflected in activity changes of the three enzymes.
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PMID:Effect of a coat color locus on kidney lysosomal glycosidases in the house mouse. 84 54

We recently presented data showing that mannose-6-phosphate was a potent competitive inhibitor of pinocytosis of human platelet beta-glucuronidase, and that treatment of "high-uptake" forms of the enzyme with alkaline phosphatase destroyed the high-uptake property of the enzyme without diminishing its catalytic activity. These data indicate that phosphate is a necessary component of the recognition marker on the enzyme for pinocytosis by human fibroblasts, and suggest that the phosphate on high-uptake forms of the enzyme is present as a phosphohexosyl moiety. Results presented here show that mannose-6-phosphate is also a potent inhibitor of pinocytosis of the following enzyme preparations: (a) beta-glucuronidase from human spleen, liver, placenta, and urine; (b) beta-hexosaminidase and beta-galactosidase from human platelets; (c) beta-hexosaminidase from human fibroblast secretions. Alkaline phosphatase treatment of all these enzymes except beta-galactosidase, which was unstable to the incubation conditions and could not be tested, greatly diminished the uptake activity of the enzymes without diminishing their catalytic activity. These results suggest that phosphohexosyl recognition is a general characteristic of pinocytosis of lysosomal glycosidases.
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PMID:Phosphohexosyl recognition is a general characteristic of pinocytosis of lysosomal glycosidases by human fibroblasts. 90 52


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