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)

The subcellular distribution of cytochrome b and ubiquinone in resting human neutrophils was investigated by rate zonal sedimentation of postnuclear supernatants on continuous sucrose gradients. Both cytochrome b and ubiquinone were mainly localized in small organelles, tertiary granules, that were resolved from the specific and azurophilic granules as well as from the cell membrane fraction. This cytochrome b- and ubiquinone-rich granule was shown to contain dicyclohexylcarbodiimide (DCCD)-sensitive, Mg2+-dependent ATPase as well as low amounts, less than a third, of the acid hydrolases beta-glucuronidase and N-acetyl-beta-glucosaminidase. Cytochrome b was also found in smaller proportions in plasma membranes and specific granules. A significant proportion of the ubiquinone was located in the region of the gradients where specific granules and mitochondria sedimented. However, quantitative measurements of oligomycin-sensitive ATPase indicated that this second localization of ubiquinone could not be entirely attributed to mitochondrial contamination. Plasma membrane contained small amounts of ubiquinone. In addition, the existence and location of a putative proton pump ATPase were also investigated. The ATPase was mainly located in the plasma membrane and in the upper half of the gradients (tertiary and specific granules), with the highest specific activity occurring in the tertiary granules. This activity was inhibited by 100 microM DCCD. Furthermore, ATP-dependent uptake of [14C]methylamine by tertiary and specific granules was observed. These results suggest that the DCCD-sensitive ATPase may function as a proton pump. DCCD inhibited the release of enzymes from specific granules that occurred when human neutrophils were activated by phorbol myristate acetate. However, higher concentrations of DCCD were required to achieve the same degree of inhibition of O2 uptake (I50 of 0.4 mM for secretion versus 1 mM for O2 uptake). These results suggest that specific granules do not play a crucial role in oxygen metabolism.
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PMID:Subcellular localization of cytochrome b and ubiquinone in a tertiary granule of resting human neutrophils and evidence for a proton pump ATPase. 614 82

Dissociated sponge cell system has proved to be a useful model to study the process of cell aggregation both on cellular and subcellular level. The purpose of this review is to discuss recent results obtained from experiments with the marine sponge Geodia cydonium. Dissociated cells form functional aggregates during a process which can be sub-divided into three phases: first, formation of small primary aggregates in the presence of Ca2+; second, formation of secondary aggregates in the presence of an aggregation factor and third, reconstitution of a functional system of water-containing channels by rearrangement in the secondary aggregates. On subcellular level a series of macromolecules are known which are involved in the control of aggregation and separation of sponge cells: Aggregation factor, aggregation receptor, anti-aggregation receptor, beta-glucuronidase, beta-glucuronosyltransferase, beta-galactosyltransferase, beta-galactosidase and a lectin. These components might be linked in the following sequence: (a) Activation of the aggregation receptor by its enzymic glucuronylation; (b) Adhesive recognition of the cells, mediated by the aggregation factor and the glucuronylated aggregation receptor; (c) Inactivation of the aggregation receptor by its deglucuronylation with the membrane-associated beta-glucuronidase; (d) Cell separation due to either the loss of the recognition site (glucuronic acid) of the aggregation receptor for the aggregation factor or to an inactivation of the aggregation factor by the anti-aggregation receptor. The activity of the anti-aggregation receptor is most likely controlled by the Geodia lectin. The events leading to cell-cell recognition cause a change in the following metabolic events: Increase of oxygen uptake, decrease of cyclic AMP level, increase of cyclic GMP level and stimulation of programmed syntheses.
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PMID:Sponge cell aggregation. 624 12

Studies were performed to elucidate further the phenomenon of secretagogue-mediated enhancement in the binding of the chemoattractant f-met-leu-[3H]phe to human neutrophils (PMN). Specific f-met-leu-[3H]phe binding to unstimulated PMN reached maximum levels after 10 to 15 min of incubation at 0 degrees C with a saturating concentration of peptide, and consisted of a readily displaceable and a nondisplaceable component. PMN, preexposed to A23187 (2.5 X 10(-8) M) or PMA (0.5 ng/ml) for 30 min at 37 degrees C to stimulate limited and preferential release of specific (secondary) granules (10 to 20% of total lysozyme, no beta-glucuronidase), demonstrated an approximate doubling in the displaceable component of f-met-leu-["3H]phe binding, accompanied by an increasing nondisplaceable component that could not be explained by bulk pinocytosis of extracellular fluid (assessed by [3H]sucrose uptake). The increase in f-met-leu-[3H]phe binding was not affected by inhibitors of protein synthesis, could not be attributed to the secreted products lysosyme or lactoferrin acting on the cell, and, on the basis of studies with PMN from patients with chronic granulomatous disease, could not be attributed to the effects of reactive oxygen species generated in low concentration during stimulation. Functional studies on PMN indicated that preexposure to secretagogues at concentrations demonstrated to increase receptor availability also enhanced subsequent f-met-leu-phe-mediated superoxide and hydrogen peroxide generation. The present data demonstrate that secretagogues may activate PMN to enhance their subsequent responses in f-met-leu-phe-mediated processes, and, combined with previous reports, support the concept that specific granules provide a source of preformed membrane and receptor material that is translocated to the cell surface during the secretion associated with directed locomotion.
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PMID:Correlation of human neutrophil secretion, chemoattractant receptor mobilization, and enhanced functional capacity. 627 63

We have demonstrated that degranulation from normal human neutrophils in whole blood was stimulated by low concentrations of lithium salts and was produced by noncytolytic means. Significant amounts of beta-glucuronidase could be released from the primary granules, in addition to vitamin B12- binding protein from the secondary granules, by 10 mM lithium. Release was almost totally inhibited by 1 mM fluoride, under the same conditions. There was no release of lactate dehydrogenase and no loss of viability of cells incubated in either lithium or fluoride at the concentrations used. Lithium was also observed to have no effect on reactive oxygen production by phagocytic stimulation of isolated neutrophils. In addition, lithium and fluoride were shown to manipulate the intracellular levels of cAMP. The results demonstrated a direct effect of lithium on release of inflammatory mediators from neutrophils in vitro. The methods used also provide a simple and effective test to study an important function of neutrophil activity and can be used to evaluate degranulation in a number of clinical conditions.
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PMID:Influence of lithium and fluoride on degranulation from human neutrophils in vitro. 629 Mar 86

Incubation of premitochondrial liver homogenate supernatants of phenobarbital-induced rats with sodium vanadate led to a time- and concentration-dependent formation of malondialdehyde and a parallel release of beta-glucuronidase from lysosomes. Both were inhibited in the presence of glutathione, (+)-catechin or dithiocarb, and took place after a lag phase of 30 min. In contrast, the glutathione content dropped immediately after addition of vanadate. Scavengers of reactive oxygen species had no effect on vanadate-induced lipid peroxidation. In liver homogenates of non-induced rats vanadate-promoted lipid peroxidation was 7.3 times lower than in those of phenobarbital-induced animals, suggesting the involvement of the microsomal mixed-function oxidase system. Thus, vanadate seems to act as a pro-oxidant of the enzymatically-promoted lipid peroxidation.
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PMID:Lipid peroxidation and lysosomal enzyme release induced by vanadate in vitro. 656 83

Neutrophils from the synovial fluid (SFN) of 10 patients with active rheumatoid arthritis (RA) were investigated to determine the generation of oxygen intermediates (OI) (O2-, H2O2, OH .), chemiluminescence, and lysosomal enzymes (lysozyme and beta-glucuronidase). Lymphocytes from healthy individuals were cocultured at 37 degrees C for 17 hr with SFN from the patients and the number of OKT4+, OKT8+, and OKT3+ cells and the response to mitogens were determined. A markedly increased OI and slightly elevated lysosomal enzyme levels were observed in SFN from patients. Coculture of lymphocytes with SFN resulted in a decreased number of OKT4+ and OKT8+ cells and a greatly reduced response to Con A and mildly diminished response to PHA, while OKT3+ cells were not affected. The simultaneous addition of superoxide dismutase and catalase restored the impairment of monoclonal antibody reaction and lymphocyte responsiveness almost to control levels. It is suggested that the disturbed immunoreactivity of synovial fluid lymphocytes from RA patients may be due to increased OI generated by stimulated neutrophils.
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PMID:Effect of stimulated neutrophils from the synovial fluid of patients with rheumatoid arthritis on lymphocytes--a possible role of increased oxygen radicals generated by the neutrophils. 660 65

It has been shown that gold accumulates in macrophages. In vitro studies have also shown that long-term anti-inflammatory and immuno-regulatory effects on these cells may be responsible for the effectiveness of gold in the treatment of rheumatoid arthritis. However, the relevance of this information to the in vivo circumstance is largely untested. In this study, the effect of gold sodium thiomalate (AuTM) on rat alveolar macrophage (AM) lysosomal enzymes, bacterial killing, and metabolic activities associated with phagocytosis were assessed after in vivo administration. The activities of beta-glucuronidase, acid phosphatase, and lysozyme were inhibited 1 day following a single AuTM injection (50 mg/kg, subcutaneous). However, lysozyme returned to normal, while the activities of beta-glucuronidase and acid phosphatase were elevated from 4 to 12 days thereafter. When AuTM was administered weekly for 8 weeks, the activities of acid phosphatase and beta-glucuronidase were elevated throughout, while lysozyme was largely unaffected. The increased lysosomal enzyme activities were not due to contamination of polymorphonuclear leukocytes. These long-term effects of AuTm on enzyme activity were in marked contrast to its in vitro effect which inhibited the activities of beta-glucuronidase and acid phosphatase. No effect of AuTM administration on the release of beta-glucuronidase upon phagocytosis of opsonized zymosan was observed. At 1 day following a single AuTM injection or 3 days after a second weekly injection, in vivo bactericidal activity of AM toward S. aureus was diminished. This bacterial killing defect was not due to decrease phagocytosis; the in vivo binding and ingestion of bacteria were normal. The defect correlated with imparied metabolic activities associated with phagocytosis, namely a significant decrease in the reduction of nitroblue tetrazolium and the stimulation of the hexose monophosphate shunt. This may be an attractive anti-inflammatory effect in light of the destructive potential of the reactive oxygen species produced by macrophages in an arthritic circumstance.
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PMID:Effect of in vivo administration of gold sodium thiomalate on rat macrophage function. 681 20

In vitro experiments were carried put to test the effect of beta-glucuronidase, ensaprost-phi, and carbocholin-proserin on a total of 725 samples of deeply-frozen bull semen in 8 nutrient media. Studied were the motility, thermal resistance, and oxygen consumption of spermatozoa. The first two indices showed highest values with the use of medium No 2 consisting of 2.8 per cent solution of sodium citrate and 4 gamma ensaprost-phi, and the consumption of oxygen was highest in medium No 1, consisting of 2.8 per cent solution of sodium citrate and 50 U beta-glucuronidase. Biologic experiments with 2106 cows were also carried out. The conception rate was 9.03 per cent higher that that of the control animals at first insemination.
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PMID:[Effect of various drugs and enzymes on the quality of deeply frozen bull sperm]. 695 72

The development of bacterial infections is a common complication during treatment with high concentrations of oxygen. To study the effect of hyperoxia on phagocytes, the adherence, chemotaxis, ingestion rates, degranulation as well as the bactericidal activity were measured in alveolar macrophages (AMs) and polymorphonuclear leukocytes (PMNs) obtained from guinea pigs exposed to 85% oxygen. The animal exposure to a Fi O2 of 85% impaired the adherence to nylon-wool, the chemotactic activity and the phagocytic rate of paraffinoil-droplets of AMs and PMNs. In AMs the secretion of beta-glucuronidase upon stimulation with opsonized zymosan was also diminished. In addition, the bacterial activity of AMs and PMNs demonstrated a reduction of 50%. These phagocytic defects may be caused by cytoskeleton alteration, induced by the increase of oxygen derived metabolites, representing an additional sepsis promoting factor during hyperoxia.
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PMID:Effects of hyperoxia on phagocytosis. 711 85

During phagocytosis, neutrophils generate reactive oxygen metabolites and release lysosomal enzymes into the extracellular medium. We have investigated the possibility that these enzyme are inactivated by the oxygen compounds. Phagocytosing neutrophils from 12 patients with chronic granulomatous disease, which do not generate these oxygen metabolites, released two to three times more activity of lysozyme and beta-glucuronidase than did normal neutrophils. This difference proved to be due to a decrease of approximately 20% of the total activity of these enzymes in normal neutrophils, but not in neutrophils of patients with chronic granulomatous disease. This inactivation of enzymes took place during phagocytosis of opsonized zymosan particles as well as during stimulation of normal cells with phorbol myristate acetate. The inactivation was not due to formation of inhibitors. The lysosomal enzymes were not activated when the neutrophils were stimulated under anaerobic conditions. Addition of catalase, superoxide dismutase, or albumin gave no protection against the oxidative damage; reduced glutathione gave partial protection. The oxidative inactivation was more pronounced in the presence of azide. Measurement of the activity and the amount of protein of acid alpha-glucosidase in the cells showed that the specific activity of this enzyme decreased by approximately 50% during 30 min of phagocytosis. This indicates that the inactivation of the lysosomal enzymes takes place in the phagolysosomes, before the enzymes have leaked into the extracellular medium.
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PMID:Phagocytosing human neutrophils inactivate their own granular enzymes. 722 38


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