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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Iron-containing proteins catalyze lipid peroxidation when combined with either H2O2 or ascorbic acid (ASC). Microsomal membranes were prepared from Day 13 endometrial and conceptus tissues (5 pigs) and from Day 30 endometrial, placental, fetal liver, and fetus minus fetal liver tissues (5 pigs). Microsomal membranes were subjected to the following in vitro treatments: 1) no treatment, 2) 50 microM ASC, 3) 100 microM uteroferrin (UF), 4) 50 microM ASC + 100 microM UF, 5) 50 microM ASC + 100 microM UF + 10 microM apotransferrin (transferrin with no iron bound; ATF), and 6) 50 microM ASC + 100 microM UF + 10 microM holotransferrin (transferrin saturated with iron; HTF). For treatments 7 through 10, membranes were preincubated (0 degrees C, 3 h) with either 7) no treatment, 8) 50 microM fetuin, 9) 50 microM holoretinol binding protein (holoRBP: retinol binding protein [HoloRBP] with retinol bound), or 10) 50 microM apoRBP (RBP with no retinol bound) followed by incubation with 50 microM ASC + 100 microM UF. Lipid peroxidation was measured in the samples as thiobarbituric acid reactive substances (TBARS). Endogenous TBARS were greater (p < 0.05) in Day 13 conceptus than in Day 13 endometrium and were highest (p < 0.05) on Day 30 in fetal liver. Combined ASC and UF caused a large increase (p < 0.05) in TBARS in all membranes except Day 30 placental membranes. Addition of ATF, but not HTF, decreased TBARS production in all membrane preparations. HoloRBP, but not fetuin or apoRBP, decreased (p < 0.05) TBARS production in all but Day 30 endometrial membranes. In other experiments, when combined with ASC, UF/UF-associated protein complex induced less (p < 0.01) lipid peroxidation in fetal liver microsomal membranes than did free UF. Catalase and superoxide dismutase had no effect on UF-induced lipid peroxidation in fetal liver membranes. These results indicate that 1) UF combined with ASC induces lipid peroxidation in Day 13 endometrial and conceptus and Day 30 endometrial, fetal liver, and fetus minus liver microsomal membranes, and 2) ATF, holoRBP, and the UF-associated proteins, but not catalase or superoxide dismutase, inhibit this reaction.
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PMID:Uteroferrin induces lipid peroxidation in endometrial and conceptus microsomal membranes and is inhibited by apotransferrin, retinol binding protein, and the uteroferrin-associated proteins. 856 1

Nitric oxide has been implicated in mediating the neurotoxic effects of ischemia in the brain. However, studies of the effects of nitric oxide inhibition with nitric oxide synthase inhibitors have provided controversial results. One of the reasons for the controversy may be related to the specificity of the nitric oxide synthase inhibitors, such as Nw-nitro-L-arginine methylester (L-NAME), which has recently been questioned. The present work investigated the possible interaction of L-NAME with the enzyme catalase in vitro. Catalase is an iron containing enzyme which could potentially interact with the iron-binding groups of L-NAME. Since the normal function of catalase in the brain is to remove excess hydrogen peroxide, the inhibition of this process could have potentially toxic effects. L-NAME was found to attenuate the catalase inhibiting effects of the known catalase inhibitor cyanamide in vitro, suggesting a competition between cyanamide and L-NAME for catalase. In addition, L-NAME by itself attenuated catalase activity in vitro. These results indicate that in addition to inhibiting nitric oxide synthase, L-NAME may have effects on catalase activity.
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PMID:The nitric oxide synthase inhibitor NW-nitro-L-arginine methylester attenuates brain catalase activity in vitro. 861 53

Ethanol can be oxidized to the 1-hydroxyethyl radical (HER) by rat and deer mice liver microsomal systems. Experiments were carried out to evaluate the ability of human liver microsomes to catalyze this reaction, compare the effectiveness of NADH with that of NADPH, and assess the possible role of cytochrome b5 in HER formation. HER was detected as the alpha-(4-pyridly-1 -oxide)-N-t-butylnitrone/HER adduct. Human liver microsomes catalyzed HER formation with either NADPH or NADH as cofactor; rates with NADH were approximately 50% those found with NADPH. Chelex-100 treatment of the reaction mixture produced marked inhibition of HER formation, suggesting that a transition metal, such as iron, was required to catalyze the reaction. The addition of ferric chloride restore HER formation. Catalase (2600 units/ml) and superoxide dismutases (500 units/ml) nearly completely inhibited the reaction with either NADPH or NADH. The NADH-dependent rates of superoxide production, detected as 5,5-dimethyl-1-pyrroline-N-oxide-O2H, were approximately 50% the NADPH-dependent rates, which is consistent with the rates of HER formation. Anti-cytochrome b5 IgG decreased NADPH- and NADH-dependent HER formation, and this was associated with inhibition of superoxide formation with both reductants. These results indicate that human liver microsomes can catalyze the oxidation of ethanol of HER with either NADPH or NADH as reductant. The effectiveness of NADH may be significant in view of the increased NADH/NAD+ redox ratio in the liver as a consequence of ethanol oxidation by alcohol dehydrogenase. HER formation by human liver microsomes seems to be catalyzed by an oxidant derived from the interaction of iron with superoxide or H2O2, and a close association exists between HER formation and superoxide production. Cytochrome b5 seems to play a role in HER formation, most likely due to its effect on superoxide production.
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PMID:1-Hydroxyethyl radical formation during NADPH- and NADH-dependent oxidation of ethanol by human liver microsomes. 862 31

Tryptophan hydroxylase, the initial and rate-limiting enzyme in the biosynthesis of the neurotransmitter serotonin, is inactivated by nitric oxide (NO) and by the NO generators sodium nitroprusside, diethylamine/NO, S-nitroso-N-acetylpenicillamine, and S-nitrosocysteine. The inactivation occurs in an oxygen-free environment and is enhanced by dithiothreitol and ascorbic acid. Protection against the effect of NO on tryptophan hydroxylase is afforded by oxyhemoglobin, reduced glutathione, and exogenous Fe(II). Catalase partially protects the enzyme from NO-induced inactivation, whereas both superoxide dismutase and uric acid are without effect. These findings indicate that tryptophan hydroxylase is a target for NO and suggest that critical iron-sulfur groups in this enzyme serve as the substrate for NO-induced nitrosylation of the protein, resulting in enzyme inactivation.
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PMID:Inactivation of brain tryptophan hydroxylase by nitric oxide. 875 14

Because nitric oxide is being used to treat acute lung injury and because it may either reduce or potentiate oxidant-mediated vascular injury, we studied the effect of the nitric oxide donor S-nitroso-N-acetyl-D-penicillamine (SNAP) on hydrogen peroxide (H2O2)-induced injury to cultured rat lung microvascular endothelial cells (RLMVC). Cells were exposed to H2O2 through its enzymatic generation by glucose and glucose oxidase or by its direct application. Glucose oxidase exposure causes a concentration- and time-dependent increase in 51chromium (51Cr) release from RLMVC. Catalase, dimethylthiourea or deferoxamine protects against this oxidant injury. SNAP (100 microM) prevents the increase in 51Cr release resulting from glucose oxidase or direct application of H2O2. N-acetyl-D-penicillamine is ineffective. Photo-decayed SNAP slightly decreases the 51Cr release caused by glucose oxidase but not the injury produced by directly adding H2O2. Treatment with the guanosine 3',5'-cyclic monophosphate (cGMP) analogue 8-BrcGMP (1-10 mM) provides no protection. SNAP decreases in vitro the net oxidation of ferrous to fcrric iron by H2O2, the iron-catalyzed consumption of H2O2 in Fenton's reaction, the iron-mediated generation of hydroxyl radicals, and the Fe(2+)-H2O2-catalyzed peroxidation of lipid membranes. Providing exogenous nitric oxide dramatically prevents H2O2-mediated endothelial injury, likely by reducing iron-mediated oxidant generation and subsequent lipid peroxidation.
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PMID:Nitric oxide donor prevents hydrogen peroxide-mediated endothelial cell injury. 876 17

Hydrogen peroxide (H2O2) increases adherence of human polymorphonuclear neutrophils (PMN) to cultured human umbilical vein endothelial cells (HUVEC). Catalase and HO. scavengers did not affect the increased PMN adherence to HUVEC stimulated by other compounds such as phorbol myristate acetate (PMA) and thrombin, showing that the observed effect was H2O2- and HO.-specific. This effect was inhibited by hydroxyl radicals (HO.) scavengers and not by iron-chelators that do not penetrate the cells, suggesting the involvement of intracellular HO. in the increased adherence mechanism. An increase in cAMP inhibited H2O2-induced adherence, as observed with isoproterenol, isobutylmethylxanthine, and dibutyryl-cAMP. Similarly, pentoxifylline (Ptx), an HO. scavenger that also increases cAMP, inhibited H2O2-mediated adherence but had no effect on that induced by PMA or thrombin. PKA inhibitors cancelled the Ptx-induced inhibition of H2O2-mediated adherence. However, PKA inhibitors or atrial natriuretic peptide that decreases cAMP did not increase adherence, showing that decrease in cAMP is not responsible for increased adherence. HO. scavengers did not alter the H2O2-induced reduction in cAMP levels, but did inhibit the effect of H2O2 on adherence. We conclude that HO. mediates the H2O2-induced increased in PMN adherence to HUVEC, and that the increase in cAMP that mediates PKA activation downregulates this effect.
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PMID:Inhibition of human neutrophil binding to hydrogen peroxide-treated endothelial cells by cAMP and hydroxyl radical scavengers. 879 Oct 89

Ferritin is the major storage form of iron within cells, and iron released from ferritin has been shown to stimulate lipid peroxidation. Microsomes from rats chronically fed ethanol are more active in generating reactive oxygen intermediates than control microsomes. Since superoxide is one of the reductants capable of releasing iron from ferritin, and superoxide generation by microsomes is increased after chronic ethanol treatment, the ability of ferritin to stimulate lipid peroxidation of microsomes isolated from control rats and rats treated chronically with ethanol was evaluated. Ferritin was much more effective in stimulating lipid peroxidation of microsomes after ethanol treatment; net increases in thiobarbituric acid-reactive components by ferritin were 4-fold greater in the presence of NADPH with microsomes from the ethanol-treated rats compared to pair-fed controls and 10-fold greater with NADH as the microsomal reductant. Net increases in chemiluminescence by ferritin were about 10-fold greater with microsomes from the ethanol-treated rats. The NADPH- and NADH-dependent increases in lipid peroxidation produced by ferritin were prevented by superoxide dismutase, which lowered the rates found in the presence of ferritin to values found in the absence of ferritin. Catalase and hydroxyl radical scavengers had no effect on the stimulation by ferritin. Nonheme iron chelators prevented the ferritin stimulation as did glutathione, propylgallate, and trolox. Basal rates of lipid peroxidation were inhibited by anti-CYP2E1 IgG; the stimulation by ferritin was decreased by anti-CYP2E1 IgG. These results show that microsomes from ethanol-fed rats are more reactive than control microsomes in interacting with ferritin to produce oxidants capable of catalyzing lipid peroxidation. The inhibition of the ferritin-catalyzed lipid peroxidation by superoxide dismutase and anti-CYP2E1 IgG is consistent with a role for CYP2E1-generated superoxide radical in mobilizing iron from ferritin and in the subsequent catalysis of lipid peroxidation. Since ferritin is the major cellular storage form of iron, increased mobilization of iron from ferritin by CYP2E1-derived superoxide radical may play a role in the development of oxidative stress after ethanol treatment.
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PMID:Ferritin stimulation of lipid peroxidation by microsomes after chronic ethanol treatment: role of cytochrome P4502E1. 880 16

Reactive oxygen species have been implicated in normal and pathological processes of many tissues, including skeletal muscle. I extended previous studies by examining the effect of these intermediates and eight of their antagonists (superoxide dismutase, catalase, deferoxamine, [Cu(II)]2(3,5-diisopropylsalicylate)4, 1,2-dimethyl-3-hydroxy-pyridone, 1,3-dimethyl-2-thiourea, N-(2-mercaptopropionyl)-glycine, vitamin E) on indirectly stimulated twitch tension of an in vitro neuroskeletomuscular preparation, the phrenic nerve-diaphragm of the rat. In the absence of exogenous reactive oxygen species, none of the antagonists potentiated twitch tension, and all but one (N-[2-mercaptopropionyl]-glycine) of the membrane-permeant antagonists attenuated twitch tension. The reactive oxygen intermediate-generating system of purine plus xanthine oxidase reduced indirectly stimulated twitch tension by 36% while having no effect on directly stimulated twitch tension. Catalase (but not superoxide dismutase or deferoxamine) eliminated the reduction in twitch tension, indicating that hydrogen peroxide played a role in the reduction. The membrane-permeant antagonists [Cu(II)]2(3,5-diisopropylsalicylate)4 and 1,2-dimethyl-3-hydroxy-pyridone also eliminated the reduction in twitch tension caused by reactive oxygen species, suggesting that hydrogen peroxide could have acted intracellularly through an iron-catalyzed Haber-Weiss reaction to produce hydroxyl radical, which in turn reacted with intracellular components, thereby reducing twitch tension.
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PMID:Action of reactive oxygen species and their antagonists on twitch tension of the rat phrenic nerve-diaphragm. 888 89

A study of the azide reaction with bovine liver catalase in presence of hydrogen peroxide has been performed, using conventional UV-visible spectrometry and activity measurements. Compound III and NO-ferrocatalase were the predominant forms of the enzyme observed in air and under nitrogen, respectively. A reaction scheme for peroxidatic degradation of azide by catalase is proposed. Accordingly, accumulation of Compound III is the main factor responsible for the reversible inhibition of 'catalatic' activity by azide, while formation of a complex between native catalase and azide has a negligible effect. Catalase is irreversibly inactivated by prolonged exposure to high levels of H2O2 and azide. The latter involves cleavage of the prosthetic group with liberation of the heme iron. Both in air and under nitrogen, generation of azidyl radicals seems to play a minor role in the irreversible inactivation process.
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PMID:Peroxidatic degradation of azide by catalase and irreversible enzyme inactivation. 898 Jun 44

Oocysts of Cryptosporidium parvum showed relatively low levels of SOD activity. The SOD which had a pI of 4.8 and an approximate molecular weight of 35 kDa appeared to be iron dependent. Catalase, glutathione transferase, glutathione reductase and glutathione peroxidase activity could not be detected, nor could trypanothione reductase. No NADH or NADPH oxidase activity could be detected, nor could peroxidase activity be demonstrated using o-dianisidine, guaiacol, NADPH or NADH as co-substrates. However, an NADPH-dependent H2O2 scavenging system was detected in the insoluble fraction.
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PMID:Anti-oxidant enzymes in Cryptosporidium parvum oocysts. 901 Oct 70


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