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)

The disruption of the molecular organization of the plasma membrane of leukocytes by phagocytosable particles, or by agents such as surfactants, antibodies, phospholipase C, fatty acids and chemotactic factors, leads to a stimulation of the phagocyte oxidative metabolism. Concanavalin A (Con A) has been used as a tool to study the mechanism of this metabolic regulation. The binding of Con A to the surface of polymorphonuclear leukocytes (PMNL) or macrophages produces a rapid enhancement of oxygen uptake and glucose oxidation through the hexose monophosphate pathway (HMP). This is explained by an activation of the granular NADPH oxidase, the key enzyme in the metabolic stimulation. The effect of Con A is not due to endocytosed lectin, since Con A covalently coupled to large sepharose beads still acts as stimulant. The metabolic changes caused by Con A are reversible. If, after the onset of stimulation, sugars with high affinity for Con A are added to the leukocyte suspension, the activity of granular NADPH oxidase and the rate of respiration and glucose oxidation return to their resting values. The metabolic burst, while partially supressed by treatment of PMNL with iodoacetate, sodium flouride and cytochalasin B, is slightly increased by colchicine. Con A induces a selective release of granular enzymes (beta-glucuronidase, peroxidase, alkaline phosphatase) from PMNL, whereas no leakage of cytoplasmic enzymes is observed. The enzyme release is inhibited by iodoacetate and by drugs known to increase cell levels of cyclic AMP. Based on a current view of the mode of interaction between Con A and cell surfaces, a model of the metabolic disruption of leukocytes is presented.
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PMID:Concanavalin A as a probe for studying the mechanism of metabolic stimulation of leukocytes. 16 45

Rhesus monkey (Macaca mulatta) neutrophils were shown to contain the azurophilic granule maker enzymes myeloperoxidase and beta-glucuronidase but were deficient in the specific granule markers alkaline phosphatase (AKP) and lysozyme. Isopycnic centrifugation of leukocyte homogenates on linear sucrose gradients resulted in cosedimentation of myeloperoxidase and beta-glucuronidase with an equilibrium density of 1.18. After an intravenous inoculation of monkeys with Salmonella typhimurium AKP activity became marked, whereas that of beta-glucuronidase decreased and myeloperoxidase remained unchanged. Lysozyme was undetected throughout the course of the experiment, but was present in oil-induced peritoneal macrophages and peripheral mononuclear cells. The induced AKP exhibited partial latency and had an equilibrium density of 1.15. It is unclear, however, whether the induced AKP is associated with specific granules or cytoplasmic membranes. Hence, while these data are consistent with the presence of azurophilic granules in polymorphonuclear neutrophils from infected monkeys, the presence of specific granules in polymorphonuclear neutrophils of both uninfected and infected monkeys remains moot.
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PMID:Characterization of monkey peripheral neutrophil granules during infection. 17 Feb 8

The functional significance of granule enzymes in polymorphonuclear leukocytes (PMN) is not fully understood because of the multiplicity of the enzymes and the rare occurrence of deficiencies in man. In order to select appropriate laboratory animals for functional studies, a phylogenetic comparison of enzyme levels in animal and human PMN was undertaken. Neutrophils were obtained from a variety of laboratory animals and man; the activities of alkaline phosphatase, lysozyme, myeloperoxidase, and beta-glucuronidase were determined by histochemical and analytical techniques. Marked interspecies differences in enzyme activity were found; many species were deficient in alkaline phosphatase or lysozyme. Differences in pH optima and metal requirements of alkaline phosphatase were not of sufficient magnitude to explain the variations of this enzyme.
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PMID:Granule enzymes of polymorphonuclear neutrophils: A phylogenetic comparison. 17 39

Ultrastructural changes and intracellular enzyme activities in the hepatocytes were studied in rabbits irradiated with 550 rads of gamma rays at 1,3,6,9,15 and 30 days after irradiation. Swelling and marked rarefaction of the mitochondrial matrix observed on the first day were followed by gradual condensation of the matrix between the 6th and 9th day. This state was accompanied by marked reduction in the succinate dehydrogenase activity, ehich gradually returned to the normal by the 30th day of observation. In the hyaloplasm, the most intense changes developed between the third and sixth day and were manifested by clearing of the cytoplasm and marked fragmentation of the endoplasmic membranes, with concurrent negligible decline of the lactate dehydrogenase activity and unchanged glucose-6-phosphatase activity. In the Golgi apparatus, vacuolization of the cytoplasm and fragmentation of smooth membranes were most pronounced on the 6th day and were correlated with a weakened and diffuse reaction for thiamine pyrophosphatase. The alkaline phosphatase activity was irregularly distributed in the lobule. The activities of lysosomal hydrolases, i.e. acid phosphatase, beta-glucuronidase and non-specific esterase, had various localizations within the lobules. The strongest deviations from the normal and of longest duration. (up to 9 days) were seen in the Browicz-Kupffer cells. Complex studies on the same material conducted concurrently with the use of different methods showed that radiation damages structure and function in unequal degrees. Moreover, within the same organ the cellular response to ionizing radiation varies according to the character, localization and functional state of the cells. Deviations from the normal state occur between the first and ninth days, most of the structural and functional elements showing sings of return to the normal about the 15th day after irradiation.
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PMID:Histoenzymatic and ultrastructural changes in the hepatocytes of gamma-irradiated rabbits. 18 69

In this first paper of a series comparing the membranes of normal lymphocyte populations from male outbred Syrian hamsters with those of neoplastic transformants (GD 248) induced by simian virus 40, a method is described for the isolation of representative plasma membrane (PM) fragments from both cell types. Multiple criteria were used to monitor the purity and yield of PM material after cell disruption by nitrogen cavitation and after membrane fractionation by a combination of differential centrifugation and isopyknic ultracentrifugation in dextran density gradients. Lactoperoxidase-catalyzed radioiodination before cell disruption was used as an extrinsic surface marker; Na+,K+-activated ATPase, as well as alkaline phosphatase, was used as intrinsic functional PM markers. The distribution of nuclei, mitochondria, lysosomes, and endoplasmic reticulum (ER) during fractionation was monitored by the measurement of DNA, succinate dehydrogenase and monoamine oxidase, beta-glucuronidase and glucose-6-phosphatase, and NADH:lipoamide oxidoreductase, respectively. According to the three PM markers employed, a 15- to 20-fold purification (over homogenate) and a PM yield of about 65% were obtained for both cell categories, with negligible contamination by DNA, mitochondria, lysosomes, and er. The procedure also allowed recovery of 60% of the mitochondria free of other cell elements.
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PMID:Membranes of normal hamster lymphocytes and lymphoid cells neoplastically transformed by simian virus 40. I. High-yield purification of plasma membrane fragments. 18 92

Human monocytes, lymphocytes, granulocytes, red cells, and platelets were completely separated from each other by zonal centrifugation on linear sucrose density gradient. The monocytes contained only one tenth the amount of myeloperoxidase, one half the amount of lysozyme, one half the amount of acid ,hosphatase, and one half the amount of beta-glucuronidase found in granulocytes; the monocytes contained no alkaline phosphatase or neutral protease. The lymphocyte fraction contained only acid phosphatase and beta-glucuronidase in amounts one half as much as in the monocytes. Fluctuations in enzyme levels of monocytes and granulocytes were noted following infection. In vitro, the isolated monocytes transformed into macrophages. The results suggest that lymphocytes, monocytes, and granulocytes may be linked biochemically in a differentiation sequence through sets of commonly shared enzymes as well as by groups of enzymes specific for each divergent cell line.
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PMID:Isolation of enzymatically homogeneous populations of human lymphocytes, monocytes, and granulocytes by zonal centrifugation. 20 68

The specific activities of alpha-D-mannosidase, beta-glucuronidase, beta-D-fucosidase, acid and alkaline phosphatase were studied in meconium from infants with cystic fibrosis (CF) and control subjects. The study revealed significant variations in the specific activity of the enzymes except for acid phosphatase. The variations were not uniform. The activities of alpha-D-mannosidase, beta-glucuronidase and alkaline phosphatase were markedly decreased (p less than 0.001, p less than 0.002, p less than 0.001, respectively), while the activity of beta-D-fucosidase was significantly increased (p less than 0.001) in meconium from the infants with CF. It is suggested that the decreased activity of alpha-D-mannosidase and beta-glucuronidase might contribute to the accumulation of the abnormal substances in CF meconium. The highly increased activity of beta-D-fucosidase raises the possibility of an additional or alternative method for screening newborns for CF using meconium as the test material.
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PMID:Studies in meconium in cystic fibrosis: the activities of alpha-D-mannosidase, beta-glucuronidase, beta-D-fucosidase, acid and alkaline phosphatase. 21 31

Enzymatically homogeneous populations of lymphocytes, monocytes, and neutrophils were isolated by zonal centrifugation from 5 untreated patients with chronic lymphocytic leukemia (CLL) and 2 patients with CLL in full remission. The cells were then quantitatively analyzed for six leukocytic enzymes and compared with cells from normal subjects. CLL monocytes were deficient in beta-glucuronidase (0.06 units; normal, 0.16), myeloperoxidase (0.07 mg; normal, 0.5 mg), and lysozyme (0.7 mg; normal, 3.3 mg). In 2 cases, CLL neutrophils were severely deficient in lysozyme (1 to 2 mg; normal, 7 mg) and myeloperoxidase (2 to 3 mg; normal, 7 mg). Neutrophil alkaline phosphatase and neutral protease were unaffected. CLL lymphocytes shared with the monocytes the deficiency of beta-glucuronidase (0.03 units; normal, 0.09 units). The 2 CLL patients in full remission carried normal enzyme levels in leukocytes of all three cell lines. The CLL lymphocytes of untreated patients were unresponsive to mitogens but became responsive in remission. The CLL monocytes from both untreated and treated patients transformed into macrophages. The pattern of shared enzyme deficiency among lymphocytes, monocytes, and neutrophils of CLL patients and its normalization in all three cell types under remission suggest that the differentiation of the three leukocytic cell lines may be an enzymatically interlinked process and that the deficiency of these enzymes in leukemia may reflect an interrelated aberrant differentiation of the leukemic cells.
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PMID:Monocyte and granulocyte defect in chronic lymphocytic leukemia. 21 99

56 human liver biopsy specimens with insignificant or no histological changes, but with abnormally strong canalicular alkaline phosphatase activity, were studied histochemically for other enzyme changes. In comparison with normal specimens, more extensive and increased canalicular activity of gamma-glutamyl transferase, and increase of canalicular leucine aminopeptidase, was found, while the sinusoidal activity of the latter enzyme was decreased. Staining for adenosine triphosphatase regularly desclosed the normal pattern of sinusoidal and canalicular activity. The lysosomal enzymes, acid phosphatase and beta-glucuronidase, stained more intensely than ordinarily, while the reactions for enzymes present in the cytosol (lactic dehydrogenase), in the mitochondria (succinic dehydrogenase, imonoamine oxidase) and in the endoplasmic reticulum (glucose-6-phosphatase) were normal.
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PMID:On histochemical enzyme changes in association with canalicular activity of alkaline phosphatase in human liver. 24 Dec 3

Human beta-glucuronidase (beta-D-glucuronide glucuronosohydrolase, EC 3.2.1.31), like many other glycoprotein lysosomal hydrolases, is specifically taken up from the culture medium by human fibroblasts. Prior work has indicated that the enzyme exhibits charge heterogeneity and that "high-uptake" forms, i.e., those rapidly internalized by human fibroblasts, are more acidic than slowly internalized forms. Here we present two lines of evidence that the acidic group required for the high-uptake property of certain forms of the enzyme is a phosphate on, or in proximity to, a D-mannose-type carbohydrate. The first line of evidence was obtained from analysis of inhibition of enzyme pinocytosis by yeast mannans, phosphorylated sugars, and sugars. Mannans that contained phosphate were more potent inhibitors than those that did not contain phosphate. D-Mannose 6-phosphate was a more potent inhibitor than either D-mannose 1 phosphate or 2-deoxy-D-glucose 6-phosphate. D-Mannose and certain related sugars were weak pinocytosis inhibitors, while 2- and 4-epimers of mannose were noninhibitory. Competitive inhibition was demonstrated and the apparent Kis estimated for the following compounds: Saccharomyces cerevisiae mannan from mutant X2180-mnnl, 3 X 10(-6) M; mannan from wild-type S. cerebisiae, 3 X 10(-5) M; D-mannose 6-phosphate, 6 X 10(-5) M; L-fucose, 4 X 10(-2) M; and D-mannose, 6 X 10(-2) M. The second line of evidence comes from the observation that alkaline phosphatase [orthophosphoric-monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1] treatment of human platelet beta-glucuronidase abolished its "high-uptake" activity, without diminishing its catalytic activity, and converted some forms of the heterogeneous enzyme to less acidic forms.
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PMID:Phosphohexosyl components of a lysosomal enzyme are recognized by pinocytosis receptors on human fibroblasts. 26 21


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