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 investigated the pregnancy-induced changes in macrophage activity which are important in the expression of host defense against infections. Several macrophage functions were examined by using Listeria monocytogenes. In pregnant mice, prolonged survival and enhanced in vivo elimination of bacteria were observed in the early phase of primary infection. Functions of peritoneal macrophages, including in vitro phagocytosis intracellular killing, glucose consumption, generation of superoxide anion, and intracellular beta-glucuronidase activity were shown to be enhanced in pregnant mice. These findings indicate that pregnancy enhances macrophage functions qualitatively. Possible mechanisms for this enhancement and the significance of macrophage activation for pregnant hosts are discussed.
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PMID:Enhanced resistance against Listeria monocytogenes at an early phase of primary infection in pregnant mice: activation of macrophages during pregnancy. 301 73

The effects of the carbonic anhydrase inhibitor acetazolamide on basal and parathyroid hormone (PTH)-induced bone metabolism were studied to evaluate the manner in which acetazolamide inhibits bone resorption. Half-calvaria from 5 to 6-day-old mice were cultured using the following treatments: control; acetazolamide (10, 33, or 100 microM); PTH (16.7 nM bovine PTH 1-34); acetazolamide + PTH. The effects of acetazolamide on PTH-induced cAMP accumulation and protein synthesis were determined. Media from bones cultured for 48 hours were analyzed for calcium to assess bone resorption, glucose to assess calvarial glucose utilization, and lactic acid to assess calvarial lactic acid release. Media were also assayed for beta-glucuronidase activity as an indicator of lysosomal enzyme release and for lactate dehydrogenase activity as an indicator of cytosolic enzyme release and cytotoxicity. Acetazolamide at 100 microM completely inhibited PTH-induced bone resorption. This inhibition did not appear to be due to cell death, as acetazolamide did not increase lactate dehydrogenase release. Acetazolamide had no effect on PTH-enhanced cAMP levels, indicating that receptor binding and adenylate cyclase activation were unaffected. Acetazolamide alone did not alter calvarial protein synthesis, but did significantly inhibit protein synthesis in the presence of PTH. PTH significantly enhanced calvarial glucose utilization, lactic acid release, and beta-glucuronidase release. Acetazolamide inhibited all of these PTH-induced parameters in a manner that roughly paralleled its inhibition of bone resorption; acetazolamide alone had no effect on the basal values. Our results indicate that acetazolamide inhibition of bone resorption in vitro may involve general alterations in hormonally stimulated bone cell metabolism secondary to carbonic anhydrase inhibition.
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PMID:Role of carbonic anhydrase in bone resorption: effect of acetazolamide on basal and parathyroid hormone-induced bone metabolism. 303 87

The intestinal first pass metabolism of amygdalin has been investigated in rat small intestine in vitro. The results show that amygdalin is hydrolyzed to prunasin, essentially in the wall of the proximal jejunum. This specific beta(1-6)hydrolytic cleavage of the terminal glucose residue is pH-dependent and can be inhibited by glucono-delta-lactone, a potent inhibitor of the lysosomal beta-glucosidase of the rat intestine. No substrate competition between phloridzin and lactose vs amygdalin was noted. None of the more common soluble beta- or alpha-enzymatic activities of mammalian intestine (alpha-glucosidase, alpha-amylase) or mammalian liver (beta-galactosidase, beta-glucuronidase) were capable of catalyzing the hydrolysis of the terminal glucose from amygdalin at pH's 5.0, 7.0 or 9.0. Furthermore, no metabolic activity of isolated rat livers toward amygdalin and prunasin was observed within two hours of recirculating perfusion. However, cecal contents of conventional rats, exhibited both amygdalin- and prunasin-hydrolyzing activities. The resulting mandelonitrile dissociates spontaneously into cyanide and benzaldehyde. Therefore, our findings indicate that metabolism of amygdalin to prunasin occurring in the proximal part of jejunum is apparently mediated by enzymatic beta(1-6)glucosidase activity of the gut wall. In contrast, the toxicity of amygdalin due to the release of cyanide obviously requires microbiological activities of the gut flora.
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PMID:Intestinal first pass metabolism of amygdalin in the rat in vitro. 308 25

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

A method was developed for the analysis of non-reducing terminal structure of radiolabelled chondroitin sulphate chains with the aid of N-acetylgalactosamine 4-sulphatase ('terminal 4-sulphatase'), N-acetylgalactosamine 6-sulphatase ('terminal 6-sulphatase'), beta-glucuronidase and beta-N-acetylhexosaminidase. Studies with this method on the non-reducing terminal structure of [35S]sulphate- and [3H]glucose-labelled chondroitin sulphate chains from rat and chick-embryo cartilages showed that the presence of a high proportion of 4-sulphated hexosamine residues is a common feature of the termini of newly synthesized chondroitin sulphate chains. Of the non-reducing terminal 4-sulphated hexosamine residues, about 14% (chick embryo) or 46% (rat) contained an additional sulphate group at position 6. The internal portion of the chondroitin sulphate chains, in contrast, contained little or no 4,6-bis-sulphated hexosamine residue, suggesting that 4,6-bis-sulphated structure may play a role in biosynthetic control at the level of chain termination.
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PMID:A distinct terminal structure in newly synthesized chondroitin sulphate chains. 315 11

It is suggested that the important drugs rifampicin and halothane and the raised glucose levels in diabetes mellitus exert injurous effects on cells through a lysosomal mechanism. Further evidence is given of by time rifampicin induction of beta-glucuronidase and beta-N acetylglucosaminidase and its possible relation to hepatitis and pancreatitis. On the basis of preliminary data halothane may cause hepatitis connected to lysosomal enzyme release in the presence of other aggravating factors common to the perioperative period. The onset of diabetic vascular complications may be related to the similar raised levels of lysosomal enzymes found in insulin, drug and diet controlled disease. Release of these enzymes into plasma may be a marker of important changes in the lysosome, whether due to enzyme induction or damage, and could be a primary mechanism of many disease processes including some thought to be mainly autoimmune in character. Routine estimation in the clinical laboratory along with existing cytoplasmic and microsomally derived enzymes in the chemical screen would be a useful way of surveying lysosomal changes in the wide spectrum of disease in a general hospital.
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PMID:Rifampicin, halothane and glucose as mediators of lysosomal enzyme release and tissue damage. 341 3

Four unconjugated metabolites, which were produced through the oxidation of the isopropyl chain of 2-isopropylnaphthalene (2-IPN), were isolated from the urine of rabbits receiving 2-IPN orally and identified: 2-(2-naphthyl)propionic acid, 2-(2-naphthyl)-2-propanol, 2-(2-naphthyl)-1,2-propanediol, and 2-(2-naphthyl)-2-hydroxypropionic acid, together with a small amount of the unchanged compound. Further, the unconjugated metabolites, which were produced through the oxidation of the naphthalene ring, were isolated and identified: 2-isopropylnaphthols and 2-isopropyl-5,6 (or 7,8)-dihydronaphthalene-5,6 (or 7,8)-diol. The identification of these metabolites was made by means of TLC, GLC, MS, IR, GC/MS, and FT-NMR. The presence of glucuronides of metabolites B, C, D, F, and H was also suggested by TLC and GLC of the extract obtained after hydrolysis by beta-glucuronidase. In addition, quantitative determination of the metabolites indicated that the total urinary excretion of the metabolites except 2-isopropylnaphthols in 24 hr after administration was about 29% of the dose.
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PMID:Identification and determination of urinary metabolites of 2-isopropylnaphthalene in rabbits. 360 68

Rabbit alveolar macrophages express a plasma-membrane receptor that recognizes glycoprotein ligands bearing terminal mannose, fucose or N-acetylglucosamine residues. Macrophage membranes were washed extensively with buffers containing high salt and mannose or EDTA to remove endogenously bound ligand, before Triton X-100 extraction. The extracts were chromatographed on mannose-Sepharose. Elution with mannose, followed by dialysis and a second mannose-Sepharose step with EDTA elution, produced a preparation that migrated as single protein band of Mr 175,000 on SDS/polyacrylamide-gel electrophoresis. The purified protein binds mannose-BSA (bovine serum albumin) with a dissociation constant of 1.9 X 10(-8) M. Ligand binding is Ca2+ and pH-dependent, with maximal binding at neutral pH and low binding below pH 6.0. The binding of 125I-mannose-BSA is inhibited by ligands bearing high-mannose oligosaccharides, such as mannan or beta-glucuronidase, as well as the monosaccharides mannose, fucose and N-acetylglucosamine. Galactose, galactosylated BSA, glucose and mannose 6-phosphate are non-inhibitory. Amino acid compositional analyses indicate that the receptor contains high concentrations of aspartate/asparagine and glutamate/glutamine, and low amounts of methionine. The carbohydrate composition was studied by lectin overlays of electrophoretically transferred receptor, and the results indicate the presence of N-linked complex and O-linked sialylated oligosaccharides. A protein of Mr 175,000 was immunoprecipitated from radio-iodinated macrophage membranes with an antibody generated against purified rabbit lung mannose receptor.
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PMID:Isolation and characterization of a mannose-specific endocytosis receptor from rabbit alveolar macrophages. 366 87

Lysosomal enzyme activities in pancreatic islets of obese hyperglycemic ob/ob mice aged 3 to 6 months were investigated and compared with those of normal lean NMRI mice of the same age. It was observed that the glycogenolytic glucose-producing hydrolase acid amyloglucosidase displayed a fivefold higher activity in the islets of obese mice than in the islets of normal NMRI mice. However, other islet lysosomal enzyme activities measured, such as N-acetyl-beta-D-glucosaminidase and beta-glucuronidase, were of the same magnitude in both obese and lean mice. A starvation period of 24 hours induced a significant depression of islet acid amyloglucosidase activity in obese as well as lean mice, whereas the activities of N-acetyl-beta-D-glucosaminidase and beta-glucuronidase were unaffected. Further, the activities of other types of islet lysosomal enzymes, such as acid phosphatase and cathepsin D, were also measured in obese mice. These activities were not found to be affected by the actual fasting period. A good correlation (r = 0.815; P less than 0.01) was observed between islet acid amyloglucosidase activity and plasma insulin concentrations in obese mice, whereas no such relationship was apparent with regard to other islet lysosomal enzyme activities recorded. Acid amyloglucosidase activity in liver tissue of the obese mouse was about 30 times lower than that of islet tissue. Further, the activity of liver amyloglucosidase was of the same order of magnitude in obese and lean mice. Similarly, other lysosomal enzyme activities in the liver of obese and lean mice were not strikingly different.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Lysosomal enzyme activities in pancreatic islets from normal and obese hyperglycemic mice. 391 27

Human urinary chondroitin sulfate isolated from the cetylpyridinium chloride-complex of the non-dialyzable fraction of the pooled urine was subjected to ethanol fractionation, successive enzymic digestion with neuraminidase and mucopolysaccharidases, and anion exchange chromatography. The gas liquid chromatographic analyses of the acetyl and butaneboronic acid ester derivatives of the reduced terminal sugar units after treatment with sodium borohydride plus hydrolysis revealed that 42% of the urinary chondroitin sulfate was bound to peptide through xylose. The reducing terminal sugar units of the peptide-free form consisted of 34.6% of xylose, 22.4% of galactose, 16.4% of glucose of unknown origin and 26.6% of glucuronic acid. These observations showed that the xyloside, galactoside and glucuronide linkages at non-terminal sites of carbohydrate chains of chondroitin sulfate were cleaved in tissues. It was thus suggested that the endo-types of beta-xylosidase, beta-galactosidase and beta-glucuronidase, which act on proteochondroitin sulfate are present in tissues.
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PMID:Reducing terminals of urinary chondroitin sulfate. 393 89


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