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)

A human neutrophil protease, initially termed neutral peptide-generating protease, has been shown to cleave angiotensin II directly from angiotensinogen and has been identified as leukocyte cathepsin G. When purified neutrophils were disrupted by nitrogen cavitation and fractionated by differential centrifugation, 44 and 24% of the angiotensin II-generating activity was in the lysosomal and undisrupted cell fractions, respectively. Cytochalasin B-treated human neutrophils stimulated with N-formyl-L-methionyl-L-leucyl-L-phenylalanine released beta-glucuronidase, lysozyme, and angiotensin II-generating protease in a dose-dependent fashion, consistent with localization of this protease to the neutrophil granule. Individually purified angiotensin II-generating protease and cathepsin G had similar proteolytic and esterolytic activity for angiotensinogen and N-benzoyl-L-tyrosine ethyl ester on a weight basis, exhibited identical mobilities by SDS-gradient polyacrylamide gel electrophoresis and pH 4.3 disc-gel electrophoresis, and gave precipitin lines of antigenic identity on Ouchterlony analysis with goat antibody to the angiotensin II-generating protease. Thus, the angiotensin II-generating protease of human neutrophils has been identified as cathepsin G on the basis of subcellular localization, substrate specificity, physicochemical characteristics, and antigenic identity.
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PMID:Identification of a human neutrophil angiotension II-generating protease as cathepsin G. 617 48

Rates of production of p-nitrophenyl glucuronide by isolated perfused livers from fed or fasted phenobarbital-treated rats were estimated by monitoring the concentration of glucuronide in the effluent perfusate. Infusion of epinephrine decreased the steady state level of p-nitrophenyl glucuronide by about 39% (half-maximal inhibition at approximately 5 microM). This result was unexpected because epinephrine activated glycogenolysis and elevated hepatic UDP-glucuronic acid contents. The effect of epinephrine can be attributed to its interaction with alpha-adrenergic receptors, since the inhibition of glucuronide production by epinephrine was reversed by an alpha-antagonist (phentolamine) but not by a beta-antagonist, propranolol. Since alpha-adrenergic agonists increase the cytosolic free calcium concentration, we investigated the possibility that the decrease in glucuronide production elicited by epinephrine was mediated by calcium. Removal of calcium from the perfusion fluid diminished the inhibition of glucuronide production by epinephrine, while increasing extracellular calcium from 0 to 150 microM restored the inhibition in a dose-dependent manner. In the presence of extracellular calcium, glucuronide production was inhibited by the addition of the calcium ionophore A23187 or angiotensin II, a hormone which increases cytosolic calcium. Concentrations of ionized calcium comparable to physiological intracellular levels (0.1-2 microM) increased microsomal beta-glucuronidase activity by 50 to 100% but had no effect on microsomal glucuronosyl-transferases . These results indicate that activation of hepatic alpha-adrenergic receptors increases cytosolic calcium which stimulates microsomal beta-glucuronidase activity. This decreases net glucuronide formation by the liver. In support of this hypothesis, rates of glucuronide production were unaffected by epinephrine in perfused livers from beta-glucuronidase-deficient C3H/HeJ mice.
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PMID:Calcium-mediated inhibition of glucuronide production by epinephrine in the perfused rat liver. 633 73

To characterize the inflammatory effect of spinorphin, an endogenous peptide purified from bovine spinal cord, its effects on chemotaxis, O2- generation, and exocytosis by N-formylmethionyl-leucyl-phenylalanine (FMLP)-stimulated human neutrophils (PMNs) in vitro were examined. At 10 microM, spinorphin significantly inhibited chemotaxis by FMLP-stimulated PMNs. Spinorphin at 100 microM also inhibited both O2- generation and exocytosis of beta-glucuronidase and collagenase by FMLP-stimulated PMNs. The mechanisms by which spinorphin inhibits these PMN functions were examined further. Spinorphin markedly suppressed the binding of FML[3H]P to its receptor on PMNs, as observed in a binding assay. However, other neuropeptides that were examined (angiotensin II and substance P) had no effect on FML[3H]P binding, suggesting the possibility that spinorphin plays a specific role in the inhibition of the binding between FMLP and its receptor. The suppression of FMLP binding also caused a decrease of the FMLP-induced intracellular calcium concentration [Ca2+]i, which acts as a second messenger leading to PMN functions. These results suggest that spinorphin may be a new endogenous inflammation-regulatory peptide that modulates the interaction of FMLP with its receptor.
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PMID:Inhibitory effects of spinorphin, a novel endogenous regulator, on chemotaxis, O2- generation, and exocytosis by N-formylmethionyl-leucyl-phenylalanine (FMLP)-stimulated neutrophils. 931 Mar 46