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 role of bilirubin conjugates in the formation of pigment gallstones is not known. In this study, we completely solubilized and then analyzed by high-performance liquid chromatography specimens of black pigment gallstones from eight nb/nb mice with hereditary hemolytic anemia. Each dried gallstone specimen of about 200 micrograms was dissolved in 5 ml of dimethyl sulfoxide/0.15 M HCI/50 mM disodium-EDTA (8:1:1 by volume) at room temperature. Stone dissolution was complete by 30 min as monitored by the A456 and direct observation, and no oxidative products of bilirubin were observed in the visible spectrum, 350 to 750 nm. By high-performance liquid chromatography, the intact tetrapyrroles were separated as diconjugated and monoconjugated bilirubins; unconjugated bilirubin was resolved as XIII, IX and III alpha-isomers. The isocratic solvent system used was 0.1 M di-n-dodecylamine acetate/0.1 M di-n-octylamine acetate (4:1, v/v) in methanol, pH 7.4, at a flow of 1 ml per min. Diconjugated bilirubin accounted for 6.0 +/- 2.4 molar % (mean +/- S.E.), monoconjugated bilirubin for 37.4 +/- 8.4% and unconjugated bilirubin for 56.3 +/- 8.9% of the solubilized pigments. The IX alpha-isomer represented 96 +/- 1.9% of the unconjugated bilirubin. The presence of bilirubin conjugates in gallstones was confirmed by ethylanthranilate diazotization: the conjugated azodipyrrole in stone had the same retention time as that of conjugated azodipyrrole from rat and mouse bile. A majority of the bilirubin conjugates was sensitive to beta-glucuronidase of liver origin, indicating that the C-1 glucuronide ester was present.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Monoconjugated bilirubin is a major component of hemolysis-induced gallstones in mice. 339 22

Goats were jugularly infused with the pneumotoxin 3-methylindole (3MI; 15 mg/kg, 0.5 microCi/kg) dissolved in cremophor-EL to characterize the urinary metabolites of 3MI in a ruminant specie. Urine was collected for 36 hr after the beginning of a 2-hr infusion period, and 3MI metabolites were purified using reversed-phase HPLC. Goats excreted 3MI as at least 11 distinct metabolites. Metabolites were characterized using a combination of UV spectroscopy, 1H- and 13C-NMR spectroscopy, and negative-ion FAB/MS. Two of the metabolites (E1 and E2), representing approximately 30% of the urinary radioactivity, were unambiguously identified as diastereomeric glucuronides of 3-hydroxy-3-methyloxindole [HMOI; 3-(beta-D-glucosiduronic acid)-3-methyloxindole]. Glucuronide conjugates were investigated using enzymatic and chemical hydrolysis. These ethereal glucuronides were unique in that they were not readily hydrolyzable with bovine beta-glucuronidase, although one of the diastereomers was hydrolyzed sparingly by beta-glucuronidase from Helix pomatia. Treatment of the glucuronides with 6 M HCI for a 2-hr period liberated unconjugated HMOI. Treatment of each diastereomer with dilute acid (pH 3) or dilute alkali (pH 10) was ineffective at hydrolyzing the conjugates. Goats form HMOI from 3MI and extensively glucuronidate the metabolite before excreting it, as opposed to mice that do not conjugate HMOI before excretion. These ethereal glucuronic acid conjugates seem to be unique in that they are essentially resistant to beta-glucuronidase-catalyzed hydrolysis.
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PMID:Identification of beta-glucuronidase-resistant diastereomeric glucuronides of 3-hydroxy-3-methyloxindole formed during 3-methylindole metabolism in goats. 882 99

From the roots of the Chinese medicinal herb Pseudostellaria heterophylla a single-chained lectin with a molecular weight of 36 kDa and high hemagglutinating activity was isolated. The lectin was adsorbed on DEAE-cellulose in 10 mM Tris-HCI buffer (pH 7.4) and was eluted by the same buffer containing 50 mM NaCl. It was adsorbed on SP-Sepharose in 10mM NH4OAc (pH 4.5) and eluted by approximately 0.5 M NaCl in the same buffer. The hemagglutinating activity of the lectin could not be inhibited by a large variety of monosaccharides, but was largely abrogated by exposure to 0.05 M HCl, 0.05M NaOH or 80 degrees C. However, about 50% of the activity remained after exposure to 0.025M NaOH or 40 degrees C. Despite possession of an N-terminal sequence exhibiting some similarity to thaumatin-like proteins with antifungal activity, the lectin was devoid of antifungal activity. The lectin exerted some inhibitory effect on the glycohydrolases alpha-glucosidase, beta-glucosidase and beta-glucuronidase which are involved in HIV infection but had no suppressive action on human immunodeficiency virus-type 1 reverse transcriptase.
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PMID:A novel lectin from Pseudostellaria heterophylla roots with sequence simularity to Kunitz-type soybean trypsin inhibitor. 1144 23