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)

Lamotrigine (LTG) is a novel triazine anticonvulsant currently undergoing clinical trials. LTG N-glucuronide, the major human metabolite of LTG, was isolated from human urine by means of XAD-2 column chromatography and semi-preparative HPLC. The structure of the suspected lamotrigine 2-N-glucuronide was proven by mass spectroscopy and NMR spectroscopy, along with chemical and enzymatic hydrolysis studies. High resolution fast atom bombardment mass spectrometry and Electrospray tandem mass spectrometry of the glucuronide gave an M+ ion at 432.0 amu and a fragment ion at 256.0 (M - 176)+ amu. The proton NMR of the glucuronide indicated the presence of a glucuronic acid moiety. A downfield anomeric proton (5.35-5.60 ppm) implied direct attachment to the aromatic triazine ring. Carbon-13 NMR of the glucuronide revealed an upfield shift (delta = -7.0 ppm) of the C-3 carbon of the triazine ring compared to LTG, indicating attachment of the glucuronide to the N-2 position. Chemical degradation or rearrangement of the glucuronide occurs at neutral pH to produce an unknown product (RP-1), while at basic pH a different unknown product (RP-2) is formed. The glucuronide is unusually stable at acidic pH. Treatment of the glucuronide with beta-glucuronidase resulted in hydrolysis to LTG, and enzymatic hydrolysis was inhibited by saccharo-1,4-lactone.
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PMID:Isolation and characterization of a novel quaternary ammonium-linked glucuronide of lamotrigine. 167 89

The gene ccpA encoding the catabolite control protein CcpA of Staphylococcus xylosus has been cloned and characterized. The CcpA protein belongs to the Lacl/GaiR family of bacterial regulators and is comprised of 329 amino acids, with a molecular mass of 36.3 kDa. It shows 56% identity with the CcpA proteins of Bacillus subtills and Bacillus megaterium. Inactivation of the ccpA gene in the genome of S. xylosus relieved the activities of three enzymes, alpha-glucosidase, beta-glucuronidase, and beta-galactosidase, from cataboilte repression by several carbohydrates. Concomitantly, transcription initiation of the maltose-utilization operon malRA, including the alpha-glucosidase gene malA, was no longer subject to glucose-specific control. Carbon source-dependent malRA regulation was also lost upon deletion of a palindromic sequence in the malRA promoter region resembling the catabolite-responsive elements essential for CcpA-dependent catabolite repression in Bacillus. These results strongly suggest that S. xylosus CcpA controls transcription of catabolite-repressible genes and operons by binding to catabolite-responsive operators when rapidly metabolizable carbohydrates are available. Accordingly, the cloned S. xylosus ccpA gene could complement the ccpA mutation in B. subtilis. The ccpA gene of S. xylosus is transcribed from two promoters, one of which is subject to autogenous repression by CcpA. Autoregulation results in a slight reduction of CcpA protein in glucose-grown cells. The characterization of the role of CcpA in carbon catabolite repression in S. xylosus demonstrates that a regulatory mechanism originally detected in Bacillus applies to another Gram-positive bacterium with low GC content.
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PMID:Catabolite repression mediated by the catabolite control protein CcpA in Staphylococcus xylosus. 887 37

A new, highly inducible fungal promoter derived from the Aspergillus awamori 1,4-beta-endoxylanase A (exlA) gene is described. Induction analysis, carried out with the wild-type strain in shake flasks, showed that exlA expression in regulated at the transcriptional level. Using a beta-glucuronidase (uidA) reporter strategy, D-xylose was shown to be an efficient inducer of the exlA promoter, whereas sucrose or maltodextrin were not. Upon D-xylose induction, the exlA promoter was threefold more efficient than the frequently used A. niger glucoamylase (glaA) promoter under maltodextrin induction. Detailed induction analyses demonstrated that induction was dependent on the presence of D-xylose in the medium. Carbon-source-limited chemostat cultures with the uidA reporter strain showed that D-xylose was also a very good inducer in a fermenter, even in the presence of sucrose.
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PMID:An expression system based on the promoter region of the Aspergillus awamori 1,4-beta-endoxylanase A gene. 898 32

The biochemical and immunological effects of Listeria monocytogenes hemolysin in CD-1 mice were studied. Intraperitoneal injection of 256 complete hemolytic units (CHU) caused a twofold increase in plasma beta-glucuronidase levels but was not lethal. In contrast, 256 or more CHU caused 100% lethality in 4 to 5 min when administered intravenously. Intravenous administration of 50 CHU caused a 10- to 11-fold increase in plasma beta-glucuronidase levels and was lethal for a variable percentage of the animals. Carbon clearance experiments showed the phagocytic index to be depressed by relatively small amounts of intravenously administered hemolysin and suggested that hemolysin may function as a leucocidal agressin during listeric infection. Increased plasma levels of ornithine carbamyltransferase after intravenous injection of hemolysin indicated hepatocellular damage. Liver carbohydrate and blood glucose determinations on fasted mice showed a reduced gluconeogenic capability in hemolysin-treated animals. Mice immunized with purified hemolysin or live vaccine were more resistant to several of the toxic parameters studied. The data indicate that hemolysin is produced during listeric infection and is antigenic, but not necessarily a protective immunogen.
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PMID:Biochemical and Immunological Effects of Listeria monocytogenes Hemolysin. 1655 43