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 studied the phospholipase A2 activity in fractionated human neutrophils, employing labeled phosphatidylinositol, phosphatidylcholine, and phosphatidylethanolamine as exogenous substrates. We used these phospholipid substrates labeled in the sn-1 position and measured the resulting labeled lysophospholipid forms in order to ascertain the phospholipase A2 specificity. In postnuclear supernatants from resting and A23187-activated cells, the phospholipase A2 activity showed a similar pH dependence curve with two pH optima at 5.5 and 7.5. Extracts from activated cells showed a 3-6-fold increase in enzyme activity. The subcellular distribution of phospholipase A2 activity in resting and A23187-treated human neutrophils was investigated by fractionation of postnuclear supernatants on continuous sucrose gradients. The neutral phospholipase A2 behaved as a membrane-bound enzyme and was mainly localized in the plasma membrane, the azurophilic granule, and in an ill-defined region of the gradient between the specific granules and mitochondria. The phospholipase A2 located in this undefined region showed a higher degree of activation than that located in other subcellular particulates in A23187-treated cells. This specific activation of an intracellular phospholipase A2 activity during cell stimulation indicates that cell compartmentalization may play a role in the formation of cell-activating and/or signal-transducing agents through the generation of arachidonate metabolites. Phosphatidylinositol was a better substrate for the plasma membrane enzyme, whereas phosphatidylcholine and phosphatidylethanolamine behaved as better substrates for intracellular organelle phospholipase A2 activities. The phospholipase A2 with maximal activity at pH 5.5 behaved as a soluble enzyme, and was almost completely localized in the azurophilic granules. Upon cell activation this acid enzyme activity was released in a similar way to beta-glucuronidase, a marker of azurophilic granules. These results demonstrate the different molecular properties of the phospholipase A2 activity, on the basis of its cellular location.
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PMID:Phospholipase A2 activity in resting and activated human neutrophils. Substrate specificity, pH dependence, and subcellular localization. 312 82

Using serum-coated zymosan, the generation of reactive oxidants by measurement of chemiluminescence was shown to be significantly enhanced in isolated peripheral psoriatic neutrophils compared to normal controls. This response was observed irrespective of whether zymosan was opsonized with fresh autologous or normal AB serum. However, this increased activity was reduced with zymosan was opsonized with serum that was preheated at 56 degrees C for 30 min. There was no statistical correlation of chemiluminescence activity with degranulation of beta-glucuronidase in either normal or psoriatic subjects. In addition, chemiluminescence produced by normal cells was significantly increased when zymosan was opsonized with psoriatic serum. The plasma membrane-bound enzyme, NAD(P)H oxidase, which produces superoxide in response to phagocytic stimulation, was significantly increased in psoriatic neutrophils compared to normal controls. These data add further evidence for activated neutrophils in psoriasis.
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PMID:Enhanced chemiluminescence production by phagocytosing neutrophils in psoriasis. 339 84

The isolation of plasma membrane from human peripheral blood monocytes is described. Monocytes were isolated by centrifugal elutriation, to eliminate an adherence step, thus minimizing functional and surface antigenic alterations to the cells. Monocytes were surface-labelled with a radiolabelled monoclonal antibody, 125I-WVH-1, and then disrupted by nitrogen cavitation. Membranes were separated according to equilibrium buoyant density by isopycnic centrifugation on a sucrose gradient. The subcellular membranes were localized using marker enzymes for the plasma membrane, 5'-nucleotidase and leucine 2-naphthylamidase (leucine aminopeptidase), and for intracellular membranes: galactosyltransferase (Golgi), arylsulfatase C (endoplasmic reticulum), monoamine oxidase (mitochondria), catalase (peroxisomes), beta-hexosaminidase and beta-glucuronidase (lysosomal vesicles) and lactate dehydrogenase (cytosol). The monoclonal antibody 125I-WVH-1 was shown to label the plasma membrane, as judged by known markers, and represents a highly specific trace label, applicable to the use of plasma membrane as an immunogen for monoclonal antibody production. The NAD-splitting enzyme, NAD+ nucleosidase, was detected and its presence on the plasma membrane was demonstrated. The subcellular localization of non-specific esterase in human mononuclear phagocytes is controversial. No evidence was found for alpha-naphthyl acetate esterase activity on the plasma membrane or in lysosomal vesicles. However, a membrane-bound esterase in fractions with properties similar to the smooth endoplasmic reticulum was detected.
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PMID:Isolation of plasma membrane from human blood monocytes. Subcellular fractionation and marker distribution. 397 89

Rat liver microsomal fractions have been equilibrated in various types of linear density gradients. 15 fractions were collected and assayed for 27 constituents. As a result of this analysis microsomal constituents have been classified, in the order of increasing median density, into four groups labeled a, b, c, and d. Group a includes: monoamine oxidase, galactosyltransferase, 5'-nucleotidase, alkaline phosphodiesterase I, alkaline phosphatase, and cholesterol; group b: NADH cytochrome c reductase, NADPH cytochrome c reductase, aminopyrine demethylase, cytochrome b(5), and cytochrome P 450; group c: glucose 6-phosphatase, nucleoside diphosphatase, esterase, beta-glucuronidase, and glucuronyltransferase; group d: RNA, membrane-bound ribosomes, and some enzymes probably adsorbed on ribosomes: fumarase, aldolase, and glutamine synthetase. Analysis of the microsomal fraction by differential centrifugation in density gradient has further dissociated group a into constituents which sediment more slowly (monoamine oxidase and galactosyltransferase) than those of groups b and c, and 5'-nucleotidase, alkaline phosphodiesterase I, alkaline phosphatase, and the bulk of cholesterol which sediment more rapidly (group a2). The microsomal monoamine oxidase is attributed, at least partially, to detached fragments of external mitochondrial membrane. Galactosyltransferase belongs to the Golgi complex. Group a2 constituents are related to plasma membranes. Constituents of groups b and c and RNA belong to microsomal vesicles derived from the endoplasmic reticulum. These latter exhibit a noticeable biochemical heterogeneity and represent at the most 80% of microsomal protein, the rest being accounted for by particles bearing the constituents of groups a and some contaminating mitochondria, lysosomes, and peroxisomes. Attention is called to the operational meaning of microsomal subfractions and to their cytological complexity.
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PMID:Analytical study of microsomes and isolated subcellular membranes from rat liver. 3. Subfractionation of the microsomal fraction by isopycnic and differential centrifugation in density gradients. 415 Apr 90

The 100000g supernatants from 13-day-old suckling-rat intestinal homogenates contained 43.5% of the total intestinal maltase activity, compared with 7.1% in weaned adult rats aged 40 days. The soluble maltase activity was separated on Sepharose 4B into two quantitatively equal fractions at pH6.0, one containing a maltase with a neutral pH optimum and the other a maltase with an acid pH optimum. The neutral maltase was shown to be a maltase-glucoamylase identical with membrane-bound maltase-glucoamylase in molecular weight, heat-sensitivity, substrate specificity, K(m) for maltose and K(i) for Tris. The soluble enzyme was induced by cortisol, but the ratio of the soluble to bound enzyme fell during induction. Solubility of the neutral maltase was not accounted for by the action of endogenous proteinases under the preparative conditions used. It is postulated that the soluble neutral maltase is a membrane-dissociated form of the bound enzyme and that the relationship between these two forms is modulated by cortisol. The acid maltase generally resembled acid maltase of liver, muscle and kidney. It was shown to be a maltase-glucoamylase with optimal activity at pH3.0, and molecular weight of 136000 by density-gradient centrifugation. At pH3.0 its K(m) for maltose was 1.5mm. It was inhibited by turanose (K(i)=7.5mm) and Tris (K(i)=5.5mm) but not by p-chloromercuribenzoate or EDTA. Some 55% of its activity was destroyed by heating at 50 degrees C for 10min. The acid maltase closely resembled beta-glucuronidase and acid beta-galactosidase in its distribution in the intestine, response to tissue homogenization in various media, and decrease in activity with cortisol treatment and weaning, indicating that it was a typical lysosomal enzyme concentrated in the ileum.
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PMID:Soluble neutral and acid maltases in the suckling-rat intestine. The effect of cortisol and development. 421 59

1. The response of renal beta-glucuronidase with time to the injection of gonadotrophin was investigated in each submicrosomal fraction of rough and smooth microsomal fractions of mouse kidney homogenate. 2. The increase in beta-glucuronidase activity appeared initially in membranes of the rough microsomal fraction, 24h after injection. 3. Afterwards the newly synthesized enzyme appeared in the contents of the rough microsomal fraction and was subsequently found in the smooth microsomal fraction, reaching a maximum concentration in this fraction at 72h. 4. At this juncture, a decrease in the enzyme activity was observed in rough microsomal contents whereas the lysosomal fraction had reached its maximum value. 5. The time-course of the appearance of beta-glucuronidase in the submicrosomal fractions after the gonadotrophin stimulation suggests that the newly synthesized enzyme at the site of membrane-bound ribosomes is transferred across the membrane into cisternae of the rough endoplasmic reticulum, and then is transported into lysosomes via the smooth endoplasmic reticulum. 6. The properties of microsomal and lysosomal beta-glucuronidases were compared.
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PMID:Intracellular transport of mouse kidney -glucuronidase induced by gonadotrophin. 507 72

In order to evaluate quantitative changes in kidney proteins, computer-assisted histophotometry of tissues was performed. Kidney marker enzyme concentrations were considered to be involved in inductive and alterative developments in the proximal tubule. These effects were caused by the administration of aminoglycosides. Indicator enzymes of the proximal tubule such as membrane-bound alkaline phosphatase (AP) and alanine-aminopeptidase (AAP) as well as lysosomal beta-glucuronidase (beta-Gl) were stained in kidney tissues. Graphic monitoring and digital display of kidney cortex sections were registered by electronic image analysis using the 'Micro-Videomat' 2 system. As an experimental design, 160 kidneys of Wistar rats were studied. Their kidneys were analyzed after one, two and three intravenous applications of gentamicin, 25 mg/kg/day, or tobramycin, 25 mg/kg/day, or amikacin, 50 mg/kg/day, on consecutive days. In a fourth test group, the kidneys were examined after the third application and a 5-day recovery period. Concentrations of tubular marker enzymes were significantly increased (2p less than 0.01, Wilcoxon test) after two applications of gentamicin: AP 37.6%, AAP 6.3% and beta-Gl 11.8%. Contrary to these findings, after two injections of tobramycin or amikacin only slight alterations were documented: tobramycin, AP 14.5%, AAP -0.1% and beta-Gl 0.4%; amikacin, AP 6.0% and AAP 4.2%. The studies indicate that tobramycin induces less severe nephrotoxic and inductive reaction than gentamicin and partly than amikacin in doses administered during our experiments. In all cases, enzyme activities studied were nearly normalized after three applications of aminoglycosides and a recovery period of 5 days. Quantitative computer-assisted evaluation of the proteins located in the tubule appears to be a tool for monitoring the degree of alterations caused by enzyme induction, enzyme release and excretion of kidney proteins.
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PMID:Quantitative histophotometry analysing significant inductive and alterative effects of aminoglycoside application (gentamicin, tobramycin, amikacin) upon tubular kidney proteins. 618 68

Three lysosomal-type acid hydrolases were examined in subcellular fractions of the developing epidermis of fetal rats to assess the relationship of degradative enzymes to cornification. As the granular layer developed and cornified between 18 and 20 days (D) of gestation, epidermal acid phosphatase increased, acid phospholipase A remained constant, and beta-glucuronidase activity declined. The enzymes were present in 3,000, 17,000, and 100,000 g particulate fractions and soluble cytoplasm. However distribution differed: acid phosphatase and phospholipase A were more preferentially localized than was glucuronidase in the 17,000 g fraction which excluded mitochondria and ribosomes and was enriched in lamellar granules. The findings suggested that acid phosphatase and phospholipase were present in membrane-bound organelles (e.g., lamellar granules) in the granular layer. Particulate acid phosphatase increased with granular layers on days 19 and 20 while a 7-fold increase in soluble enzyme coincided with cornification on day 20. As shown by isoelectric focusing, the enzyme became more heterogeneous at day 20 than at day 18, suggesting increased glycosylation. The particulate fraction displayed lysosomal characteristics with respect to release of acid phosphatase, which was inhibited by hydrocortisone and enhanced by retinol. When fetal epidermis was allowed to cornify in organ cultures, similar increases in acid phosphatase occurred. The presence of hydrocortisone did not affect increase in total enzyme but a greater proportion remained in the particulate fraction. The findings suggest that particulate acid phosphatase and phospholipase are compartmentalized in organelles with lysosomal characteristics during development of granular cells and that release of phosphatase is coincident with cornification. This may reflect not only exocytosis of lamellar granules but also intracellular release of the hydrolytic enzyme.
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PMID:Acid hydrolases of the epidermis: subcellular localization and relationship to cornification. 618 89

Alveolar hydatid cysts (LCM) grow progressively and contribute significantly to the morbidity of hydatid-hosts. To examine whether modifications in immune effector parameters correlate with the pattern of LCM growth, in vivo experiments were carried out in C57BL/6J mice infected intraperitoneally with LCM. Immigrant peritoneal and intra-LCM leukocytes were tested for the loss of cell surface receptors, membrane-bound and internalized immune complexes (ICs) and lysosomal enzyme contents during the restrictive and progressive growth phases of the LCM. The proportion of Fc and C3b receptor-bearing intra-LCM leukocytes decreased 2-fold and 31 to 72% of the leukocytes contained ICs during the progressive phase of the LCM. Acid phosphatase and beta-glucuronidase activities of macrophages declined sharply during the restrictive phase but they gradually increased as the infection progressed. IC-mediated dysfunction of effector leukocytes and modulation of antibody dependent cell cystolysis mechanism are discussed in murine hydatidosis.
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PMID:Characterization of the inflammatory cells in progressing tumor-like alveolar hydatid cyst. 2. Cell surface receptors, endocytosed immune complexes and lysosomal enzyme content. 624 Aug 19

In vitro protein synthesis, lysosomal hydrolases activity and peroxidase activity in the anterior pituitary were estimated in adult male rats treated with 50 micrograms of estradiol benzoate (EB) for 1 day or 7 days. Pituitary protein synthesis, protein and RNA content increased after 7 days. A significant increase in total and membrane-bound acid phosphatase was noted after 1 day or 7 days of EB treatment whereas total beta-glucuronidase activity decreased in both 1 and 7 day group. Cathepsin activity increased after 7 days and pituitary peroxidase system did not change by EB treatment. These findings suggest that immediate change in the enzyme milieu may be one of the first reactions by which EB expresses its feedback control.
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PMID:Estradiol benzoate induced changes in protein synthesis and lysosomal hydrolases in the pituitary of male rats. 631 2


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