Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:EXPT02288 (NADH)
 21,914 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glutathione reductase plays an important role in protecting hemoglobin, red cell enzymes, and biological cell membranes against oxidative damage by increasing the level of reduced glutathone (GSSGR) in the process of aerobic glycolysis. The enzyme deficiency may result in mild to moderately severe hemolytic anemia upon exposure to certain drugs or chemicals. However, hereditary deficiency of the enzyme is extremely rare. Recent studies on glutathione reductase in the red cell have shown more insight in the understanding of red cell metabolism and interactions with other enzymes, especially glucose-6-phosphate dehydrogenase (G-6-PD). Glutathione reducatase in serum may be a source of error in any clinical laboratory test in which an enzyme activity is determined indirectly by measuring the change in reduced nicotinamide-adenine dinucleotide (NADH) or reduced nicotinamide adenine dinucleotide phosphate (NADPH) absorbance. Glutathione reductase levels are reduced in banked blood when citrate-phosphate-dextrose (CPD) is used as a preservative. Reviewed is the role of glutathione reductase in the metabolism of the red cell and its clinical implication and usefulness.
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PMID:Glutathione reductase in the red blood cells. 62 27

Under aerobic conditions, 9,10-phenanthrenequinone and 5,6-chyrsenequinone undergo oxidation-reduction cycling in the presence of NADH and the NAD-linked 15-hydroxyprostaglandin dehydrogenase. This results in the formation of potentially hazardous semiquinones, the superoxide anion, and H2O2. Superoxide dismutase inhibits this cycling by destroying the free radical chain propagator, the superoxide anion. Four other polycyclic aromatic hydrocarbon quinones are not substrates of the enzyme and they cause it to undergo a time-dependent inactivation. This presumably results from alkylation of the enzyme. Glutathione fully protects the enzyme against inactivation by 1,2-naphthoquinone but is only partially effective against 7,8-benzo[a]pyrenequinone. These results suggest that in tissues which contain the NAD-linked 15-hydroxyprostaglandin dehydrogenase some polycyclic aromatic hydrocarbon quinones might produce deleterious effects by undergoing redox cycling. Others might cause such effects by irreversibly inhibiting the enzyme which catalyzes the first step in prostaglandin catabolism.
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PMID:Polycyclic aromatic hydrocarbon quinones may be either substrates for or irreversible inhibitors of the human placental NAD-linked 15-hydroxyprostaglandin dehydrogenase. 130 94

The iron storage protein, ferritin, represents a possible source of iron for oxidative reactions in biological systems. It has been shown that superoxide and several xenobiotic free radicals can release iron from ferritin by a reductive mechanism. Tetravalent vanadium (vanadyl) reacts with oxygen to generate superoxide and pentavalent vanadium (vanadate). This led to the hypothesis that vanadyl causes the release of iron from ferritin. Therefore, the ability of vanadyl and vanadate to release iron from ferritin was investigated. Iron release was measured by monitoring the generation of the Fe(2+)-ferrozine complex. It was found that vanadyl but not vanadate was able to mobilize ferritin iron in a concentration dependent fashion. Initial rates, and iron release over 30 minutes, were unaffected by the addition of superoxide dismutase. Glutathione or vanadate added in relative excess to the concentration of vanadyl, inhibited iron release up to 45%. Addition of ferritin at the concentration used for measuring iron release prevented vanadyl-induced NADH oxidation. Vanadyl promoted lipid peroxidation in phospholipid liposomes. Addition of ferritin to the system stimulated lipid peroxidation up to 50% above that with vanadyl alone. Ferritin alone did not promote significant levels of lipid peroxidation.
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PMID:Tetravalent vanadium releases ferritin iron which stimulates vanadium-dependent lipid peroxidation. 164 80

The reductive activation of N,N'-bis(2-pyridylmethylene)-1-4-butanediamine (N,N',N",N"')-Cu(II)-diperchlorate (CuPUPY), a di-Schiff base copper complex with antineoplastic properties, was investigated in vitro in the presence of glutathione, ascorbate, NADH or NADPH. Glutathione and ascorbate but not the pyridine dinucleotides were able to reduce the compound. The apparent second order rate constants of the reduction reaction (9.6 +/- 2.0 M-1 sec-1 for ascorbate and 94.7 +/- 1.9 M-1 sec-1 for glutathione) indicate that glutathione is more effective by about one order of magnitude in reducing CuPUPY than ascorbate. Reduction by glutathione triggered a CuPUPY-supported redox-cycle with oxygen yielding H2O2. Whereas reduction by ascorbate was reversible, CuPUPY reduced by glutathione reacted with excess reduced glutathione (GSH) in a ligand exchange reaction yielding a GSH-Cu(I) complex which was reoxidized by O2, forming a complex between copper(II) and oxidized glutathione. These results suggest a dual role for the reduced thiol tripeptide; promoting oxidative stress induced by CuPUPY at low concentrations and inhibiting it at high concentrations. This hypothesis was verified by showing that optimum glutathione/CuPUPY ratios are needed in order to obtain maximum oxidative damage to both DNA and albumin in vitro. Evidence was obtained for the occurrence of the same reaction pathway in human K562 erythroleukemia cells: CuPUPY was more toxic to cells in which glutathione synthesis was inhibited by buthionine sulfoximine. Moreover, ESR spectroscopy revealed alterations in the hyperfine structure of the Cu(II) spectrum, consistent with the occurrence of ligand-exchange reactions in K562 cells.
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PMID:Oxidative stress induced by a di-Schiff base copper complex is both mediated and modulated by glutathione. 165 1

The selenite-induced glutathione peroxidase in Chlamydomonas reinhardtii has been purified about 323-fold with a 10% yield, as judged by PAGE. The native enzyme had an Mr of 67,000 and was composed of four identical subunits of Mr 17,000. Glutathione was the only electron donor, giving a specific activity of 193.6 mumol/min per mg of protein. L-Ascorbate, NADH, NADPH, pyrogallol, guaiacol and o-dianisidine did not donate electrons to the enzyme. In addition to H2O2, organic hydroperoxides were reduced by the enzyme. The Km values for glutathione and H2O2 were 3.7 mM and 0.24 mM respectively. The enzyme reaction proceeded by a Ping Pong Bi Bi mechanism. Cyanide and azide had no effect on the activity. The enzyme contained approx. 3.5 atoms of selenium per mol of protein. On immunoprecipitation, Chlamydomonas glutathione peroxidase was precipitated and its activity was inhibited about 90% by the antibody raised against bovine erythrocyte glutathione peroxidase. The antibody also cross-reacted with the subunits of Chlamydomonas glutathione peroxidase in Western blotting SDS/PAGE. In terms of enzymic, physico-chemical and immunological properties, the experimental results demonstrate clearly that Chlamydomonas glutathione peroxidase resembles other well-characterized glutathione peroxidases from animal sources that contain selenium.
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PMID:Characterization and immunological properties of selenium-containing glutathione peroxidase induced by selenite in Chlamydomonas reinhardtii. 203 42

Mitomycin C (MC) activation to a reactive species was studied in nuclei isolated from rat liver and EMT6 tumor cells. Both preparations were similar in the rate of 4-(p-nitrobenzyl)pyridine (NBP) alkylation by MC and the levels of NADPH-cytochrome P-450 reductase. MC activation by both hepatic and EMT6 cell nuclei was inhibited by the presence of O2 and by heat inactivation. NADPH was preferred over NADH as the source of reducing equivalents by both types of isolated nuclei. MC activation to alkylating metabolites was not affected when EDTA or diethylenetriaminepentaacetic acid, two Fe2+ chelating agents, was present in the incubation system with either preparation of isolated nuclei. Glutathione (1 and 5 mM) and N-acetylcysteine (1 and 10 mM) both inhibited MC alkylation of NBP in nuclear preparations from rat liver and EMT6 tumor cells by 50-60%. Ethylxanthate (1 mM) effectively inhibited the MC alkylation of NBP by hepatic nuclei but was unable to inhibit MC alkylation of NBP by tumor cell nuclei. At 100 mM, ethylxanthate produced a slight stimulation in the rate of MC alkylation of NBP. These data are consistent with the hypothesis that MC activation in EMT6 tumor cells proceeds via a one electron reduction pathway which is inhibitable by glutathione but not inhibitable by ethylxanthate. Hepatic nuclei are apparently able to activate MC by either a one- or two-electron pathway.
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PMID:Effects of glutathione and ethylxanthate on mitomycin C activation by isolated rat hepatic or EMT6 mouse mammary tumor nuclei. 241 96

Estradiol and 2-hydroxyestradiol labeled with 3H at different positions in rings A or B were incubated with male rat liver microsomes, and their oxidative transformation was followed by the transfer of 3H into 3H2O. 14C-labeled estrogen or catechol estrogen was used to determine the fraction that becomes bound covalently to microsomal protein. The further metabolism of 2-hydroxyestradiol involves activation of the steroid at C-4 and, to a much lesser extent at C-1, by a cytochrome P-450 mediated reaction as indicated by the effects of NADPH, spermine, SKF-525A, and CO in the microsomal system. Glutathione promoted the loss of 3H from C-4 of either estradiol or 2-hydroxyestradiol but had less effect on this reaction at C-1 and inhibited it at C-6,7. It also abolished the irreversible binding of 14C-labeled estradiol and 2-hydroxyestradiol to microsomal protein. NADPH was needed specifically for glutathione to exert its effect both on the transfer of 3H into 3H2O and on the formation of water-soluble products from catechol estrogen by rat liver microsomes. It could not be replaced by NADP, NAD, or NADH. Ascorbic acid inhibited these enzymatic reactions but did not affect significantly the initial 2-hydroxylation of estradiol. Evidence is also provided for the further hydroxylation of 2-hydroxyestradiol at C-6 (or C-7). These results indicate that cytochrome P-450 activates catechol estrogens by an electron abstraction process.
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PMID:Activation and irreversible binding of regiospecifically labeled catechol estrogen by rat liver microsomes: evidence for differential cytochrome P-450 catalyzed oxidations. 284 84

Extracellular reduction of ferricyanide was exhibited by isolated Cuscuta protoplasts. A larger decrease in NADH than NADPH levels of the ferricyanide-treated protoplasts pointed to the major involvement of the former as an electron donor. Glutathione levels were also found to be lowered in similarly treated tissue. The time-dependent variation in intracellular ATP levels in presence of ferricyanide supported the concept of plasma membrane ATPase activation during transplasma membrane electron transport in eukaryotes.
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PMID:Changes in intracellular redox and energy status during induced transplasma membrane electron transport in Cuscuta protoplasts. 297 17

Preventing the oxidation of hemoglobin in solution is one of the major requirements for the successful production and long-term storage of hemoglobin-based blood substitutes. To this end we have studied the effects of antioxidants on the rate of methemoglobin formation and disappearance in solutions of human and bovine hemoglobin at 4 degrees C and 37 degrees C. Ascorbate and desferal (5 mM) were observed to act as prooxidants, increasing the rate of methemoglobin formation at 37 degrees C. Trehalose, mannitol, glucose, and EDTA (5 mM) had no significant effect. Glutathione and NADH (10 mM) were the most effective antioxidants tested, causing a significant decrease in the rate of methemoglobin formation at 37 degrees C for periods of up to 50 hours. The combination of these antioxidants in bovine hemoglobin at 4 degrees C resulted in the reduction of methemoglobin levels to nearly undetectable levels in approximately 150 hours. In addition, NADH and glutathione were found to reduce methemoglobin levels to 10% over a period of 100 hours in a sample of human hemoglobin that had been stored at 4 degrees C for one year and had 60% methemoglobin. These results suggest that the prevention and reversal of methemoglobin formation during the long-term storage of hemoglobin solutions and hemoglobin-based blood substitutes may now be possible.
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PMID:The reduction of methemoglobin levels by antioxidants. 317 Feb 37

14,15-Secoestra-1,3,5(10)-trien-15-yne-3,17 beta-diol (1) is a mechanism-based inactivator of human placental 17 beta,20 alpha-hydroxysteroid dehydrogenase (estradiol dehydrogenase, EC 1.1.1.62). Inactivation with alcohol 1 requires NAD-dependent enzymic oxidation and follows approximately pseudo-first-order kinetics with a limiting t1/2 of 82 min and a "Ki" of 2.0 microM at pH 9.2 and 25 degrees C. At saturating concentrations of NAD, the initial rate of inactivation is slower than in the presence of 5 microM NAD, suggesting that cofactor binding to free enzyme impedes the inactivation process. Glutathione completely protects the enzyme from inactivation at both cofactor concentrations. Inactivation with 45 microM tritiated alcohol 1 followed by dialysis and gel filtration demonstrates a covalent interaction and affords an estimated stoichiometry of 1.4 molecules of steroid per subunit (2.8 per dimer). Chemically prepared 3-hydroxy-14,15-secoestra-1,3,5(10)-trien-15-yn-17-one (2) rapidly inactivates estradiol dehydrogenase with biphasic kinetics. From the latter phase, a Ki of 2.8 microM and a limiting t1/2 of 12 min at pH 9.2 were determined. Estradiol, NADH, and NAD all retard this latter inactivation phase. We propose that enzymatically generated ketone 2 inactivates estradiol dehydrogenase after its release from and return to the active site of free enzyme.
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PMID:Mechanism-based inactivation of 17 beta,20 alpha-hydroxysteroid dehydrogenase by an acetylenic secoestradiol. 346 92


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