Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q8NEX9 (reductase)
 26,410 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bioluminescent bacteria require myristic acid (C14:0) to produce the myristaldehyde substrate of the light-emitting luciferase reaction. Since both endogenous and exogenous C14:0 can be used for this purpose, the metabolism of exogenous fatty acids by luminescent bacteria has been investigated. Both Vibrio harveyi and Vibrio fischeri incorporated label from [1-14C]myristic acid (C14:0) into phospholipid acyl chains as well as into CO2. In contrast, Photobacterium phosphoreum did not exhibit phospholipid acylation or beta-oxidation using exogenous fatty acids. Unlike Escherichia coli, the two Vibrio species can directly elongate fatty acids such as octanoic (C8:0), lauric (C12:0), and myristic acid, as demonstrated by radio-gas liquid chromatography. The induction of bioluminescence in late exponential growth had little effect on the ability of V. harveyi to elongate fatty acids, but it did increase the amount of C14:0 relative to C16:0 labeled from [14C]C8:0. This was not observed in a dark mutant of V. harveyi that is incapable of supplying endogenous C14:0 for luminescence. Cerulenin preferentially decreased the labeling of C16:0 and of unsaturated fatty acids from all 14C-labeled fatty acid precursors as well as from [14C]acetate, suggesting that common mechanisms may be involved in elongation of fatty acids from endogenous and exogenous sources. Fatty acylation of the luminescence-related synthetase and reductase enzymes responsible for aldehyde synthesis exhibited a chain-length preference for C14:0, which also was indicated by reverse-phase thin-layer chromatography of the acyl groups attached to these enzymes. The ability of V. harveyi to activate and elongate exogenous fatty acids may be related to an adaptive requirement to metabolize intracellular C14:0 generated by the luciferase reaction during luminescence development.
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PMID:Elongation of exogenous fatty acids by the bioluminescent bacterium Vibrio harveyi. 249 4

Tolrestat, and aldose-reductase inhibitor, was shown to be a rapid and potent inhibitor of chloride exchange on the band 3 protein of human erythrocytes. Tolrestat binds to a site distinct from the chloride transport site and binds to one half of the transporters at 5 x 10(-7) mol/L in the absence of chloride and at 3.6 x 10(-5) mol/L in physiologic chloride concentrations. Although these concentrations are 20- to 1,000-fold greater than the IC50 for aldose-reductase inhibition by tolrestat, they are achieved during routine pharmacologic therapy in humans. Consequently, Cl/HCO3 exchange rates may be reduced and there may be decreased CO2 clearance from coronary and respiratory center capillary beds and inappropriate hyperpnea. There also may be transitory intracellular alkalinization in cells with a Cl/HCO3 exchanger in their plasma membrane.
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PMID:Inhibition of erythrocyte anion exchange by tolrestat, an inhibitor of aldose reductase. 250 83

To evaluate the effect of anticancer chemotherapeutic antigens on rat prostate, ten kinds of anticancer agents corresponding to the dose generally used for humans were intraperitoneally injected to 63-day-old Wistar rats. The anticancer agents were administered as follows: Cyclophosphamide (CPM) was used at the dose of 8 mg/kg for 7 days. Methotrexate (MTX), actinomycin-D (ACD) and cis-platinum (CDDP), 163 micrograms/kg, 8 micrograms/kg and 833 micrograms/kg for 5 days, respectively. Nitrogen mustard (NM), bleomycin (BLM), peplomycin (PLM), adriamycin (ADM), vincristine (VCR), and vinblastine (VBL), 500 micrograms/kg, 250 micrograms/kg, 170 micrograms/kg, 2.5 mg/kg, 33 micrograms/kg and 83 micrograms/kg, twice in a week, respectively. The rats were killed on the fifth day after completion of the schedule. Then, the weight of the body, the prostate, the epididymis and the adrenal gland were measured. In addition, 5 alpha-reductase activities and histological findings in the prostate were examined. For determination of 5 alpha-reductase activities, cell-free homogenate obtained from the rat ventral prostate was incubated with C14-testosterone at 37 degrees C for 30 minutes in an atmosphere of 95% of O2 and 5% of CO2. Subsequently, the metabolites from testosterone were separated and purified with thin layer chromatography using the solvent system with benzene acetone, 4:1 (v/v). 5 alpha-Reductase activity was determined with the sum of dihydrotestosterone (DHT) and androstanediol converted from testosterone and indicated as pmol product/mg protein. The 5 alpha-reductase activity was employed as a biological marker for the degree of androgenic dependency in the prostate. The results were summarized as follows. CDDP significantly reduced the weight of the body (p less than 0.001, n = 7), but not the activity of 5 alpha-reductase. NM and VBL had a specific action to reduce the weight of the prostate (p less than 0.01, n = 8) without causing loss of body weight. NM and VBL showed no influence on 5 alpha-reductase activities. The activity of 5 alpha-reductase was markedly damaged by BLM (p less than 0.05, n = 6) and PLM (p less than 0.05, n = 5). However no significant reduction was recognized in the weight of the body and the prostate. CPM, MTX, ACD, ADM and VCR were ineffectual on the body and the prostate weight and 5 alpha-reductase activities. In the histological examination, atrophy and degeneration of the glandular epithelium were revealed in the prostate treated with NM, VBL and CDDP.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Effect of anticancer agents on rat prostate. Evaluation of organ weight, histological finding and 5 alpha-reductase activities]. 258 30

Biochemical studies of testosterone 5 alpha-reductase and 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD) in rat submandibular gland (SMG) were performed. 14C-labeled testosterone or dihydrotestosterone (DHT) was incubated with subcellular fractions from rat SMG in the presence of 0.2 mM NADPH at 37 degrees C for 20 min in an atmosphere of 95% O2 and 5% CO2. Among the subcellular fractions, the high 5 alpha-reductase activity was detected in the nuclear fraction and 3 alpha-HSD in cytosol. Nuclear 5 alpha-reductase was efficiently solubilized in 2 mg digitonin per mg protein and 0.3 M KCl solution at 4 degrees C for 30 min. The maximum velocities (Vmax) of nuclear and solubilized 5 alpha-reductase activity for testosterone were 71.4 pmol/mg protein per min and 25.4 pmol/mg protein per min. Apparent Michaelis constant (Km) of nuclear and solubilized enzymes for testosterone were calculated as 11.1 microM and 16.7 microM by the Lineweaver Burk plot, respectively. The activity of solubilized 5 alpha-reductase from nuclei was stable by NADPH and KCl, and the molecular weight of the enzyme was estimated as 158 K.D approximately 200 K.D by Bio-Gel A-1.5 m column chromatography. The column chromatography also showed a peak of 3 alpha-HSD activity in cytosol, revealing the molecular weight of approximately 50 K.D. However, the elution peak of the 3 alpha-HSD was effectively decreased by KCl in Tris-HCl buffer. The molecular weight of 5 alpha-reductase and 3 alpha-HSD in SMG were similar to those in prostate. A stable and extractable 5 alpha-reductase was demonstrated in nuclei of rat SMG with possessing a considerable affinity for testosterone and also high 3 alpha-HSD activity for DHT was revealed in cytosol of the tissue.
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PMID:[Biochemical characteristics of nuclear 5 alpha-reductase and cytosol 3 alpha-hydroxysteroid dehydrogenase in rat submandibular gland]. 272 79

3-Hydroxy-3-methylglutaryl-CoA reductase, mevalonate kinase, mevalonate-5-phosphate kinase and mevalonate-5-pyrophosphate decarboxylase activities have been determined in brain, liver, intestine and kidneys from 19-day-old chick embryo. Levels of brain reductase and decarboxylase were clearly higher than those found in the other tissues assayed. However, only small differences were observed in the activity of both kinases among the different tissues. Mevalonate metabolism by sterol and nonsterol pathways has been investigated in chick embryo at the same developmental stage. Mevalonate incorporation into total nonsaponifiable lipids was maximal in liver, followed by intestine, brain and kidneys. The shunt pathway of mevalonate not leading to sterols was negligible in both brain and liver, while a clear CO2 production was observed in intestine and kidneys. Sterols running in TLC as lanosterol and cholesterol were the major sterols formed from mevalonate by brain and kidney slices, while squalene and squalene oxide(s) were found to be mainly synthesized by liver slices. Minor differences in the percentage of different sterols were observed in chick embryo intestine. The importance of free and esterified cholesterol accumulation in the different tissues on the inhibition of cholesterogenic activity is discussed.
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PMID:Quantitative role of different embryonic tissues in mevalonate metabolism by sterol and nonsterol pathways. Relationship with enzyme activities of cholesterogenesis. 301 12

Formate dehydrogenase from Pseudomonas aeruginosa contains molybdenum, a [4Fe-4S] cluster and cytochrome b. This paper reports the detection of molybdenum as Mo(V) by e.p.r. spectroscopy. In order to generate Mo(V) signals, addition of amounts of excess formate varying between 10- and 50-fold over enzyme, followed by 200-fold excess of sodium dithionite, were used. Two Mo(V) species were observed. One, the major component, has g1 = 2.012, g2 = 1.985 and g3 = 1.968, appeared at low concentrations of formate and increased linearly in intensity with increasing concentrations of formate up to 25-fold excess over the enzyme. At higher formate concentration this signal disappeared. The appearance and disappearance of this Mo(V) signal seems to parallel the state of reduction of the [4Fe-4S] clusters. A second, minor, Mo(V) species with g-values g1 = 1.996, g2 = 1.981 and g3 = 1.941 appears at a constant level during the formate-dithionite titration. No evidence has been obtained for nuclear hyperfine coupling to protons. The major Mo(V) species has unusual e.p.r. signals compared with other molybdenum-containing enzymes, except for that observed in the formate dehydrogenase from Methanobacterium formicicum [Barber, Siegel, Schauer, May & Ferry (1983) J. Biol. Chem. 258, 10839-10845]. The present work suggests that the enzyme is acting as a CO2 reductase, with dithionite as an electron donor to a [4Fe-4S] cluster, which in turn donates electrons to molybdenum, producing a Mo(V) species with CO2 bound to the metal.
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PMID:Purification and properties of formate dehydrogenase from Pseudomonas aeruginosa. Electron-paramagnetic-resonance studies on the molybdenum centre. 303 82

An enzyme from Clostridium thermoaceticum has been isolated which reduces disulfides of carbon monoxide dehydrogenase and it has been named CO dehydrogenase disulfide reductase. The enzyme is a tetramer of molecular weight 225,000 made up of four apparently identical monomers. It does not contain methionine or tryptophan and contains 2 calcium and 1 zinc/monomer. NADP or ferredoxin serves as an electron carrier. This enzyme is part of the system that permits certain bacteria to grow with CO or CO2 and H2 as the source of carbon and energy. The portion of the pathway which is being investigated is the conversion of methyltetrahydrofolate, CO, and CoASH to acetyl-CoA. All the enzymes required for this synthesis have now been purified. In combination with CO dehydrogenase, CO dehydrogenase disulfide reductase with NADP or ferredoxin catalyzes a reversible exchange of [3H]CoASH with acetyl-CoA. The disulfide reductase apparently is involved in the portion of the pathway in which CoASH is introduced into the acetyl-CoA. In addition, the reductase activates CO dehydrogenase in the overall synthesis of acetyl-CoA from methyltetrahydrofolate, CO, and CoASH by reducing about one disulfide group/monomer of the alpha 3 beta 3 CO dehydrogenase. The above exchange reaction in combination with the observation that [14C]acetate is formed from CO and the 14CH3-[Co]corrinoid enzyme in the absence of CoASH have permitted ordering of the sequence of reactions by which CO dehydrogenase plays a central role in the autotrophic synthesis of acetyl-CoA.
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PMID:The autotrophic pathway of acetogenic bacteria. Role of CO dehydrogenase disulfide reductase. 308 Apr 30

The enzymes involved in antioxidative activity and the cellular content of the antioxidants glutathione and ascorbate in the cyanobacteria Nostoc muscorum 7119 and Synechococcus 6311 have been examined for their roles in hydroperoxide removal. High activities of ascorbate peroxidase and catalase were found in vegetative cells of both species and in the heterocysts of N. muscorum. The affinity of ascorbate peroxidase for H2O2 was 15- to 25-fold higher than that of catalase. Increased activity of ascorbate peroxidase was observed in N. muscorum when H2O2 production was enhanced by photorespiration. Catalase activity was decreased in dilute cultures whereas ascorbate peroxidase activity increased. Ascorbate peroxidase activity also increased when the CO2 concentration was reduced. Ascorbate peroxidase appears to be a key enzyme in a cascade of reactions regenerating antioxidants. Dehydroascorbate reductase was found to regenerate ascorbate, and glutathione reductase recycled glutathione. In vegetative cells glutathione was present in high amounts (2-4 mM) whereas the ascorbate content was almost 100-fold lower (20-100 microM). Glutathione peroxidase was not detected in either cyanobacterium. It is concluded from the high activity of ascorbate peroxidase activity and the levels of antioxidants found that this enzyme can effectively remove low concentrations of peroxides. Catalase may remove H2O2 produced under photooxidative conditions where the peroxide concentration is higher.
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PMID:Hydroperoxide metabolism in cyanobacteria. 308 78

The purpose of this study was to determine if the metabolic response to obesity and to pair feeding of obese Zucker rats to lean Zucker rats was similar across skeletal muscles. Oxidation of glucose, palmitate and isoleucine was studied in muscle strips in vitro using appropriate 14- carbon substrates as tracers. The plantaris muscle was subjected to histochemical analyses using an alkaline actomyosin ATPase, NADH-tetrazolium reductase and an oil red 0 stain. Soleus muscles from both ad libitum and pair fed obese rats oxidized less glucose to CO2, but released similar amounts of lactate when compared to the soleus muscles of lean rats. Oxidation of glucose was similar in the extensor digitorum longus (EDL) muscle of ad libitum fed obese rats, but lower when pair fed to the intake of lean rats. No differences were apparent in palmitate oxidation to CO2 or in incorporation into lipid (both soleus and EDL muscles), except in the EDL muscle of pair-fed obese rats which exhibited a higher rate for palmitate metabolism when compared with lean rats. Isoleucine oxidation to CO2 was higher in the EDL and plantaris muscles, but similar in the soleus muscle of ad libitum-fed obese rats when compared with lean rats. The magnitude of the difference in isoleucine oxidation was similar when the obese rats were pair fed. No differences in the percentage of plantaris muscle fibers sensitive to alkaline ATPase staining were observed. The plantaris muscle of obese rats, contained a higher proportion of oxidative fibers. These results indicate the great risk in generalizing about metabolic activity of the whole skeletal muscle mass based on observations made on one, or even two, distinct muscles in this animal model. Also, pair feeding of obese to lean Zucker rats did not result in uniform changes in metabolism between muscles of the obese rats.
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PMID:Metabolic characteristics of skeletal muscle from lean and obese Zucker rats. 345 May 49

The cause of the hypercholesterolemia that characterizes the nephrotic syndrome has never been adequately explained. The present study examines the possibility that enhanced availability of the cholesterol precursor, mevalonic acid, to the liver in the nephrotic state may result in increased hepatic cholesterogenesis. In normal animals, the kidneys are known to be the major site of the metabolism of circulating mevalonate to both cholesterol and CO2. Previous studies, using perfusion of isolated, intact kidneys, have shown that the excretion and metabolism of mevalonate are both impaired in nephrosis. The present investigation has demonstrated in vivo that puromycin aminonucleoside nephrosis results in a 25% reduction in the oxidation of mevalonate to CO2. In the same nephrotic animals, cholesterogenesis from circulating mevalonate was significantly increased in both liver and carcass. In addition, liver slices from nephrotic animals incorporated increased amounts of [5-14C]mevalonate into cholesterol when calculated per whole liver, but not per gram of liver. Oxidation of mevalonic acid by kidney slices was significantly reduced, whether expressed as per gram of tissue or per whole organ. HMG-CoA (3-hydroxy-3-methylglutaryl) reductase activity in liver of nephrotic animals was significantly increased. We conclude that, in the nephrotic state, impaired mevalonate metabolism by the kidney may contribute to enhanced cholesterogenesis by increasing delivery of mevalonate to liver and carcass; in addition, nephrosis appears to provide an undefined stimulus for HMG-CoA reductase activity in the liver, thereby providing an additional enhancement of hepatic cholesterogenesis.
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PMID:The role of circulating mevalonate in nephrotic hypercholesterolemia in the rat. 379 48


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