Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.17.3.2 (xanthine oxidase)
 8,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Rate sedimentation and isopycnic centrifugation were used to analyse the subcellular sites of enzymes in homogenates of goldfish intestinal mucosa. 2. The results allowed the following allocations to be made: carnitine acetyl transferase-mitochondrial and peroxisomal, xanthine dehydrogenase and NAD: alpha-glycerophosphate dehydrogenase soluble phase, NADP: isocitrate dehydrogenase soluble phase and mitochondrial, and 2-naphthyl laurate hydrolase microsomal and/or brush border. 3. Histochemistry confirmed the use of alkaline phosphatase and 1-naphthyl acetate esterase as brush border and microsome markers respectively. 4. Urate oxidase, allantoinase, allantoicase, xanthine oxidase and glycollate/lactate oxidase, activities were undetectable, and 1-naphthyl palmitate hydrolase was present only as a contaminant from pancreas.
 ...
PMID:Intestinal peroxisomes of goldfish (Carassius auratus)--examination for hydrolase, dehydrogenase and carnitine acetyltransferase activities. 31 95

Acetylcholinesterase (AchE) is reported to have a narrowly restricted distribution among human tissues. Three strains of human fibroblasts which are trisomic for chromosome 2 had an average level of AchE activity over 28 times higher than the average level in 19 control strains of human fibroblasts. In contrast, the mean pseudocholinesterase activity of the trisomy-2 strains did not differ appreciably, or significantly, from the mean for the control strains. The 19 control strains included 10 strains trisomic for autosomes other than 2, and 9 euploid strains. Our estimate of the mean AchE activity in the control strains did not differ significantly from zero and might, in any case, have originated from a minute amount of activity contributed to the cells by an esterase in our culture medium. Despite the striking elevation of AchE activity in fibroblasts trisomic for chromosome 2, extracts of these cells had only about 1.5% of the specific AchE activity (per microgram DNA) present in extracts of human cerebral cortex. None of the 22 strains studied had detectable activity for two other enzymes which, like AchE, have a restricted distribution among human tissues: xanthine oxidase and choline acetyltransferase.
 ...
PMID:Evidence for a striking increase in acetylcholinesterase activity in cultured human fibroblasts which are trisomic for chromosome two. 69 21

Procarbazine, a 1,2-disubstituted hydrazine, is employed therapeutically in the treatment of Hodgkin's disease and a limited number of other neoplasias. The isomeric azoxy metabolites of procarbazine have recently been identified as the precursors of species responsible for both the anti-cancer efficacy and toxic effects mediated by this drug. This study demonstrates that cytosolic enzymes are involved in the metabolism of the azoxy metabolites of procarbazine. Two azoxy procarbazine oxidase activities were resolved by diethylaminoethyl (DEAE)-cellulose chromatography. The activity which did not bind to this column was purified to homogeneity and was identified as a phenobarbital-inducible form of cytosolic aldehyde dehydrogenase. This protein fraction was shown to metabolize only the azoxy 2 procarbazine isomer to yield N-isopropy-p-formylbenzamide (ALD) in a reaction which did not require NAD+ as cofactor. The ALD product formed was also a substrate for a subsequent NAD(+)-dependent reduction reaction catalyzed by that purified protein. The azoxy 2 procarbazine isomer and ALD were shown to be potent inhibitors of both the dehydrogenase and esterase activities of aldehyde dehydrogenase. The second azoxy procarbazine oxidase activity which was retained by the DEAE-cellulose column co-eluted with xanthine oxidase activity. Both the xanthine dehydrogenase/oxidase and azoxy procarbazine oxidase activities of this protein fraction were inhibited by allopurinol, a specific inhibitor of xanthine dehydrogenase. Xanthine dehydrogenase/oxidase was partially purified by an alternative procedure and was shown to metabolize both the azoxy 2 procarbazine isomer and ALD, ultimately producing N-isopropylterephthalamic acid. The ability of xanthine oxidase to metabolize azoxy 2 procarbazine and ALD was confirmed using commercial, purified milk xanthine oxidase.
 ...
PMID:Metabolism of azoxy derivatives of procarbazine by aldehyde dehydrogenase and xanthine oxidase. 168 Jun 57

Glossina morsitans centralis Machado was collected from the main fly belt west of Mumbwa Zambia and from the apparently isolated 'Keembe pocket' and 11 gene-enzyme systems were examined by polyacrylamide gel electrophoresis. There were no significant differences in allele frequencies among flies collected entering a vehicle, from fly-rounds, or from F3 traps in the main fly belt. Mean heterozygosity per locus is slightly higher in flies from the main fly belt than it is in flies from the 'Keembe pocket'. Allele frequencies at loci for xanthine oxidase (Xo), aldehyde oxidase (Ao) and a thoracic esterase (Est-2) were significantly different in the two populations and it is concluded that there is little gene flow between them.
 ...
PMID:Genetics of two populations of Glossina morsitans centralis (Diptera: Glossinidae) from Zambia. 256 57

We investigated the role of reactive oxygen metabolites (ROMs) as potential mediators of tumor necrosis factor-alpha (TNF-alpha)-stimulated neutrophil adhesion to rat mesenteric venules in vivo, using intravital microscopy and fixed whole mount preparations of mesentery. Intraperitoneal injection of TNF-alpha significantly increased leukocyte rolling, adhesion, and emigration in a dose- and time-dependent manner. Leukocyte adhesion and emigration, but not rolling, were significantly attenuated by prior intravenous administration of monoclonal anti-intercellular adhesion molecule-1 (ICAM-1). Rolling leukocyte flux was significantly attenuated by intravenous preadministration of superoxide dismutase (SOD), catalase, or both. Only catalase or SOD plus catalase significantly inhibited leukocyte adhesion. Catalase alone inhibited emigration. Moreover, postadhesive treatment with catalase but not SOD, 4 h after TNF-alpha administration reduced the flux of rolling (but not adherent) leukocytes that had previously increased in response to TNF-alpha. Intragastric allopurinol (50 mg/kg at 3 and 18 h before TNF-alpha administration) or 3 wk of a tungsten-enriched diet substantially inhibited xanthine oxidase activity but had no significant effects on the above parameters of neutrophil dynamics. In parallel experiments using fixed whole mount preparations of the mesoappendix stained specifically for neutrophil esterase, neutrophil adhesion 2 h after TNF-alpha administration was also inhibited by continuous intravenous administration of catalase but not by SOD, intragastric allopurinol, or tungsten diet. These findings suggest that ROMs, apparently not from xanthine oxidase, are important mediators of TNF-alpha-induced upregulation of neutrophil adhesion in rat mesenteric venules.
 ...
PMID:Reactive oxidants mediate TNF-alpha-induced leukocyte adhesion to rat mesenteric venular endothelium. 859 90

Post-ischemic hepatic injury is characterized by zonal heterogeneity of injury (central lobular necrosis), sinusoidal neutrophil accumulation, and injury generated by reactive oxygen metabolites. We evaluated the role of the heterogeneous distribution of hepatic xanthine oxidase in the generation of neutrophil accumulation and consequent hepatocellular injury in rats subjected to shock [controlled hemorrhagic hypotension (mean arterial pressure = 37.5 + or - 2.5 mmHg for 120 min)], with or without subsequent resuscitation and hemodynamic stabilization, compared with sham-operated rats. Shock/resuscitation produced striking neutrophil accumulation (assayed by esterase histochemistry) in the pericentral sinusoids, associated with centrolobular necrosis. This paralleled the pericentral distribution of xanthine oxidase (determined by histochemical assay of frozen sections) and its release from the liver into the circulation at resuscitation. Pretreatment with allopurinol inhibited hepatic xanthine oxidase activity, neutrophil accumulation, and pericentral hepatocyte necrosis in shock/resuscitation in rats. These findings suggest that reactive oxygen metabolites generated by heterogeneously distributed xanthine oxidase may contribute to the heterogeneity of hepatocellular injury in "ischemic hepatitis."
 ...
PMID:Zonal heterogeneity of hepatic injury following shock/resuscitation: relationship of xanthine oxidase activity to localization of neutrophil accumulation and central lobular necrosis. 915 87

Among progeny of a hybrid (Rana shqiperica x R. lessonae) x R. lessonae, 14 of 22 loci form four linkage groups (LGs): (1) mitochondrial aspartate aminotransferase, carbonate dehydratase-2, esterase 4, peptidase D; (2) mannosephosphate isomerase, lactate dehydrogenase-B, sex, hexokinase-1, peptidase B; (3) albumin, fructose-biphosphatase-1, guanine deaminase; (4) mitochondrial superoxide dismutase, cytosolic malic enzyme, xanthine oxidase. Fructose-biphosphate aldolase-2 and cytosolic aspartate aminotransferase possibly form a fifth LG. Mitochondrial aconitate hydratase, alpha-glucosidase, glyceraldehyde-3-phosphate dehydrogenase, phosphogluconate dehydrogenase, and phosphoglucomutase-2 are unlinked to other loci. All testable linkages (among eight loci of LGs 1, 2, 3, and 4) are shared with eastern palearctic water frogs. Including published data, 44 protein loci can be assigned to 10 of the 13 chromosomes in Holarctic Rana. Of testable pairs among 18 protein loci, agreement between Palearctic and Nearctic Rana is complete (125 unlinked, 14 linked pairs among 14 loci of five syntenies), and Holarctic Rana and Xenopus laevis are highly concordant (125 shared nonlinkages, 13 shared linkages, three differences). Several Rana syntenies occur in mammals and fish. Many syntenies apparently have persisted for 60-140 x 10(6) years (frogs), some even for 350-400 x 10(6) years (mammals and teleosts).
 ...
PMID:Linkage groups of protein-coding genes in western palearctic water frogs reveal extensive evolutionary conservation. 928 85

It has been shown that erythrocyte membrane proteins become susceptible to degradation by membrane-bound serine protease activity after oxidative modification of the membranes (M. Beppu, M. Inoue, T. Ishikawa, K. Kikugawa, Biochim. Biophys. Acta 1196 (1994) 81-87). The aim of the present study was to clarify the presence of the serine protease in oxidized erythrocyte membranes and to characterize the selectivity of the enzyme to oxidized proteins. Human erythrocytes were oxidized in vitro with xanthine/xanthine oxidase/Fe(III) and oxidized membranes isolated. Proteolytic activity of the membranes toward spectrin obtained from oxidized membranes and bovine serum albumin oxidized with H2O2/horseradish peroxidase was increased by membrane oxidation, and the degradability of the substrates was increased by substrate oxidation. The proteolytic activity was inhibited by the serine protease inhibitor diisopropyl fluorophosphate (DFP). The 72 kDa and 80 kDa proteins in the membranes were labeled by [3H]DFP when detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions and subsequent fluorography. The 72 kDa protein was found to be a serine enzyme, acetylcholine esterase. The 80 kDa protein appeared to be responsible for the degradation of oxidatively damaged proteins. The 80 kDa protein was loosely bound to membranes and readily solubilized into a 0.1% NP-40 detergent solution. The presence of the same 80 kDa protease in intact erythrocyte cytosol was suggested. The increased serine protease activity in oxidized membranes can result from the increased adherence of the cytosolic 80 kDa serine protease to the membranes due to oxidation.
 ...
PMID:Characterization of membrane-bound serine protease related to degradation of oxidatively damaged erythrocyte membrane proteins. 981 51

Biodegradation of poly(urethane)s (PU)s using single enzymes in vitro was assessed by measuring radiolabel release from model poly(ester-urea-urethane) (PESU) and poly(ether-urea-urethane) (PETU) materials synthesized with 14C-labelled monomers. Cholesterol esterase (CE), an enzyme found in monocyte-derived macrophages (MDM), has been reported to cause a significant level of radiolabel release from both of these PUs. Previous work has shown that CE activity could be inhibited by the serine protease/esterase inhibitor, phenylmethylsulfonyl fluoride. Since many serine proteases are present in circulating blood and can be released by cells other than MDM, this study investigated the ability of serine proteases relative to that of CE to cause the degradation of PUs. In addition, the possible role of several oxidative enzymes in the breakdown of PUs was investigated. Proteinase K, chymotrypsin and thrombin, when incubated with PESU, coated on glass slips, caused significant radiolabel release, with proteinase K giving the highest values. However, the highest radiolabel release which proteinase K could elicit was ten times less than CE. Thrombin and then chymotrypsin were progressively worse in their biodegradative activity. Only CE, and not the serine proteases, could elicit a detectable radiolabel release from PETU. Although the release of reactive oxygen species and molecular oxygen occur around an implanted biomaterial, several oxidative systems (peroxidase, xanthine oxidase, catalase), known to produce one or more of these molecular species, were unable to induce radiolabel release from these PUs. The process of biodegradation as assessed by radiolabel release appears to be a specific hydrolytic process, while the role of oxidative enzymes remains less clear.
 ...
PMID:The biodegradation of poly(urethane)s by the esterolytic activity of serine proteases and oxidative enzyme systems. 1042 27

Epidemiological data indicate a beneficial effect of Mediterranean diets on human health, especially on the prevalence of cardiovascular disease. These observations are supported by recent intervention studies. However, very little is known about the current role of local Mediterranean food products, which are consumed on a less regular basis and their contribution to a healthy diet. The European consortium "Local Food-Nutraceuticals" collected 127 locally consumed wild or semi-wild plants in three Mediterranean countries, i.e. Greece, Italy, and Spain, in order to assess their ethnobotanical features as well as their biological activities. The project also includes a second line of research, the study of local conceptions about these food resources. All pharmacological assays were conducted with ethanolic extracts prepared from the dried plant material. The biological activities of the extracts were assessed with the following 12 different assays covering a broad range of mechanisms considered crucial in the pathology of chronic, aging-related diseases. Four antioxidant tests: DPPH scavenging, prevention of oxyhaemoglobin bleaching, prevention of lipid peroxidation (malondialdehyde formation), and protection from DNA damage (Comet assay); three enzyme inhibition tests: inhibition of xanthine oxidase, inhibition of myeloperoxidase-catalysed guaiacol oxidation as well as the inhibition of acetylcholine esterase; one test investigating the inhibition of cytokine-induced cell activation (including the extracts' potential cytotoxicity); one assay measuring the anti-proliferation potential; one test assessing the anti-diabetic activity (PPARgamma) as well as one assay investigating the extracts' effect on mood disorder-related biochemical parameters (hSERT). Furthermore, the polyphenol content of all extracts was determined using the Folin-Ciocalteaus method. The assays revealed diverse biological effects for the tested extracts ranging from no activity to almost complete inhibition/activation. Moreover, the experimental matrix led to the identification of a sub-set of extracts, i.e. Berberis vulgaris, Reichardia picroides, Scandix australis, Satureja montana, Thymus piperella, Lythrum salicaria and Vitis vinifera, showing high activity in a broad range of assays. In summary, the in vitro observed modulations and effects exerted by extracts derived from local food plants suggest that these plants may contribute to the observed better aging of rural Mediterranean populations.
 ...
PMID:Understanding local Mediterranean diets: a multidisciplinary pharmacological and ethnobotanical approach. 1605 96


1 2 Next >>