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 studied the effect of adenosine nucleotides on several aspects of the functional activation of human peripheral blood polymorphonuclear leukocytes (PMN). Radiolabeled ATP bound to PMN in a manner suggesting the existence of specific binding sites because: 1) binding was reversed (92 +/- 6%) by 100-fold excess concentrations of unlabeled ATP but minimally by either ADP (43 +/- 12%) or GTP (37 +/- 8%); and 2) binding saturation was achieved (i.e., specific binding did not increase) above 250 microM ATP. Binding studies revealed that significant ATP hydrolysis occurred, even at low temperatures and in the presence of phosphatase inhibitors. Adenosine nucleotides activated signal transduction mechanisms in PMN because: 1) 1 to 100 microM ATP and 5'-adenylylimidodiphosphate (AMP-PNP) stimulated increased production of 1,2-diacylglycerols; 2) ATP (0.5 to 500 microM) and ADP (0.1 to 10 mM) induced increased insoluble protein kinase (PKC) activity in a dose-dependent manner when used at concentrations greater than 50 microM; 3) ATP (greater than or equal to 50 microM) induced a shift in the solubility of phorbol receptors from mostly soluble (89% in untreated cells) to mostly insoluble (68%), whereas ADP, GTP, and GDP were effective at higher concentrations; and 4) greater than or equal to 50 microM ATP stimulated increased phosphorylation of endogenous PMN proteins. AMP-PNP induced PKC activity and phosphoprotein changes that were qualitatively similar to those observed when PMN were treated with ATP, suggesting that extracellular ATP hydrolysis is not required for signal transduction to activate PKC. Functionally, ATP stimulated the secretion of specific (but not azurophil) granules because vitamin B12-binding protein and low levels of lysozyme, but not beta-glucuronidase, were released; qualitatively similar results were obtained by using AMP-PNP. These results suggest that certain adenosine nucleotides employed at physiologically relevant concentrations stimulate increased 1,2-diacylglycerol production, PKC activity, granule secretion, and endogenous phosphoprotein formation in a manner that is independent of extracellular ATP hydrolysis.
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PMID:Extracellular adenosine nucleotides stimulate protein kinase C activity and human neutrophil activation. 215 72

Levels of fasting blood glucose, serum beta-glucuronidase and beta-N-acetylglucosaminidase in 47 Libyan diabetic patients were determined. The respective mean values were 254.5 +/- 11 mg/dl, 74 +/- 5.7 Sigma units/ml and 171.8 +/- 25.5 microM PNP/dl. The mean body mass index and duration of diabetes of the patients were 30.5 +/- 0.91 kg/m2 and 7.5 +/- 1.16 years, respectively. Statistically significant correlations were found between fasting blood glucose and serum beta-glucuronidase levels (r = 0.65; p less than 0.001) and also between fasting blood glucose and beta-N-acetylglucosaminidase levels (r = 0.58; p less than 0.001). The activities of these two enzymes increase in serum with increasing fasting blood glucose levels. Patients with positive family history of diabetes have higher activities of these two enzymes than those without positive history of diabetes in the family. Patients with secondary complications have both enzymes elevated as compared with patients without secondary complications. Female patients have higher beta-N-acetylglucosaminidase activity and lower beta-glucuronidase activity than males. Age and duration of diabetes do not appear to have any effect on the activities of these enzymes.
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PMID:Serum beta-glycosidases in diabetes mellitus. 280 66

A beta-glucuronidase from Pectinex Ultra SP-L, a commercial pectolytic enzyme preparation from Aspergillus niger, was purified 170-fold by ion-exchange chromatography and gel filtration. Apparent M(r) of the purified enzyme, estimated by denaturing gel electrophoresis and size-exclusion chromatography, were 68,000 and 71,000, respectively, indicating that the enzyme is a monomeric protein. It released uronic acids not only from p-nitrophenyl beta-glucosiduronic acid (PNP-GlcA) but also from acidic galactooligosaccharides carrying either beta-D-glucosyluronic or 4-O-methyl-beta-D-glucosyluronic residues at the nonreducing termini through beta-(1-->6)-glycosidic linkages. The enzyme exhibited a maximal activity toward these substrates at pH 3.0. A regioisomer, 3-O-beta-glucosyluronic acid-galactose, was unsusceptible to the enzyme. The enzyme did act on a polymer substrate, releasing uronic acid from the carbohydrate portion of a radish arabinogalactan-protein modified by treatment with fungal alpha-L-arabinofuranosidase. The enzyme produced acidic oligosaccharides by transglycosylation, catalyzing the transfer of uronic acid residues of PNP-GlcA and 6-O-beta-glucosyluronic acid-galactose to certain exogenous acceptor sugars such as Gal, N-acetylgalactosamine, Glc, and xylose.
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PMID:Purification and characterization of a beta-glucuronidase from Aspergillus niger. 1142 8

The carbohydrate moieties of arabinogalactan-proteins (AGPs), which are mainly composed of Gal, L-Ara, GlcA, and 4-Me-GlcA residues, are essential for the physiological functions of these proteoglycans in higher plants. For this study, we have identified two genes encoding family 79 beta-glucuronidases, designated AnGlcAase and NcGlcAase, in Aspergillus niger and Neurospora crassa, respectively, based on the amino acid sequence of a native beta-glucuronidase purified from a commercial pectolytic enzyme preparation from A. niger. Although the deduced protein sequences of AnGlcAase and NcGlcAase were highly similar, the recombinant enzymes expressed in Pichia pastoris exhibited distinct substrate specificity toward 4-Me-GlcA residues of AGPs: recombinant AnGlcAase (rAnGlcAase) substantially liberated both GlcA and 4-Me-GlcA residues from radish AGPs, whereas recombinant NcGlcAase (rNcGlcAase) activity on the 4-Me-GlcA residues of AGPs was very low. Maximum activity of rAnGlcAase hydrolyzing PNP beta-GlcA occurred at pH 3.0-4.0, whereas the maximum rNcGlcAase activity was at pH 6.0. The apparent Km values of rAnGlcAase were 30.4 microM for PNP beta-GlcA and 422 microM for beta-GlcA-(1-->6)-Gal, and those of rNcGlcAase were 38.3 microM and 378 microM, respectively. Similar to the native enzyme, rAnGlcAase was able to catalyze the transglycosylation of GlcA residues from PNP beta-GlcA to various monosaccharide acceptors such as Glc, Gal, and Xyl. We propose that both AnGlcAase and NcGlcAase are instances of a novel type of beta-glucuronidase with the capacity to hydrolyze beta-GlcA and 4-Me-beta-GlcA residues of AGPs, although they differ significantly in their preferences.
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PMID:Properties of family 79 beta-glucuronidases that hydrolyze beta-glucuronosyl and 4-O-methyl-beta-glucuronosyl residues of arabinogalactan-protein. 1837 82