Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
J Neurochem 1996 Sep
PMID:Inactivation of brain tryptophan hydroxylase by nitric oxide. 875 14

Bleaching of chlorophyllin, a water soluble copper containing porphyrin molecule, was investigated with regard to the potential role of active oxygen intermediate involvement. It was found that the bleaching was highly aerobic and also biphasic in nature. The aerobic photobleaching and the dark bleaching were effectively prevented by the addition of reductants such as ascorbate and cysteine. In addition, the reductant and peroxyl radical scavenger, Trolox, was highly effective in preventing bleaching. Catalase was moderately effective in preventing photobleaching whereas peroxidase and superoxide dismutase hastened the photobleaching process. It is concluded that the bleaching of chlorophyllin is a peroxidative process which does not involve singlet oxygen, superoxide, nor the .OH radical.
Biochem Biophys Res Commun 1996 Sep 04
PMID:Active oxygen intermediates and chlorophyllin bleaching. 880 3

Pyrroloquinoline quinone (PQQ) plays a role as a vitamin or growth factor. Low concentrations of PQQ induced DNA cleavage sites frequently at thymine and cytosine residues in the presence of NADH and Cu(II). Catalase and bathocuproine inhibited DNA damage, whereas free hydroxyl radical scavengers did not. Electron spin resonance and UV-visible spectrometries showed generation of semiquinone radical and superoxide during the reaction of PQQ with NADH. These results suggest that NADH-dependent PQQ redox cycle generated superoxide and hydrogen peroxide to mediate copper-dependent DNA damage. The present study has proposed a requirement to investigate the potentiality of PQQ carcinogenicity.
FEBS Lett 1996 Sep 16
PMID:NADH-mediated DNA damage induced by a new coenzyme, pyrroloquinoline quinone, in the presence of copper(II) ion. 881 12

The mechanism of inactivation of cholinesterase (EC 3.1.1.8) by the Cu2+ -ascorbic acid (AsA) system was investigated. Incubation of the enzyme with the Cu2+ -AsA system under aerobic conditions resulted in an irreversible loss of enzyme activity. At low concentrations of Cu2+, the extent of inactivation showed the same dependence in accordance with the extent of oxidation of AsA. Saturation kinetics were observed with respect to the concentration of AsA. No change in the dissociation constant of the enzyme-AsA complex was observed at various concentrations of Cu2+. Catalase at a low concentration partially protected the enzyme from the inactivation, but did not affect the oxidation of AsA. In addition, catalase at a high concentration completely protected both the enzyme from inactivation and the AsA from oxidation. Both thiourea and thiocyanate completely protected the enzyme from the inactivation, while AsA was partially oxidized only in the initial phase. Our proposed mechanism for the inactivation of an enzyme by the Cu2+ -AsA system is as follows. A ternary complex involving the enzyme, Cu2+ and AsA is formed. This is followed by a redox reaction within the complex which generates a superoxide (.O2-) and hydrogen peroxide (H2O2). The H2O2 then reacts with .O2- in a Haber-Weiss reaction producing the hydroxyl radical (.OH). Another role of H2O2 is the conversion of the reduced Cu+ within the complex to Cu2+. Thus, repeated cycles of the redox reaction between the Cu2+ and AsA take place at the same locus, producing multiple .OH, which causes its complete inactivation.
Biol Pharm Bull 1995 Sep
PMID:Inactivation of cholinesterase by ascorbic acid in the presence of cupric ions: a possible mechanism for the inactivation of an enzyme by the metal-catalyzed oxidation system. 884

The role of oxidative stress in mercuric chloride (HgCl2)-induced nephrotoxicity is uncertain and controversial. We demonstrate that I.L.C-PK1 cells, exposed to HgCl2, generate massive amounts of hydrogen peroxide, the latter completely quenched by the hydrogen peroxide scavenger, pyruvate. HgCl2 exerts a dose-dependent cytotoxicity which is attenuated by pyruvate and catalase. Cellular generation of hydrogen peroxide arises, at least in part, from mitochondria since mitochondrial rates of generation of hydrogen peroxide increase in response to HgCl2; HgCl2 also provokes a shift in absorbance spectra in rhodamine 123 loaded-mitochondria and stimulates mitochondrial state 4 respiration. HgCl2, applied for one hour, impairs cellular vitality as demonstrated by the MTT assay, an assay dependent in part on mitochondrial function. HgCl2 impairs function in other organelles such as lysosomes that maintain a transmembrane proton gradient; these latter effects are partially attenuated by pyruvate. We complement these in vitro findings with in vivo evidence demonstrating that HgCl2 stimulates renal generation of hydrogen peroxide. The functional significance of such generation of hydrogen peroxide was evaluated in rats deficient in selenium and vitamin E, a nutrient deficiency that impairs the scavenging of hydrogen peroxide and promotes the toxicity of this oxidant. In these rats serum creatinine values were significantly higher on sequential days following the administration of HgCl2. To probe the renal response to oxidative stress induced by HgCl2, we examined hydrogen peroxide-scavenging enzymes and redox-sensitive genes. Catalase activity was unaltered whereas glutathione peroxidase activity was decreased, effects that may contribute to the net renal generation of hydrogen peroxide. The redox sensitive enzyme, heme oxygenase, was markedly up-regulated in the kidney in response to HgCl2. HgCl2 also induced members of the bcl family, bcl2 and bclx, genes that protect against apoptosis and oxidant injury. In another model of oxidant-induced renal injury, the glycerol model, bcl2 mRNA was not induced at 6 and 24 hours after the administration of glycerol. In summary, we demonstrate that HgCl2 potently stimulates renal generation of hydrogen peroxide in vitro and in vivo and such generation of peroxide contributes to renal dysfunction in vitro and in vivo. We also demonstrate that in response to HgCl2, redox sensitive genes are expressed including heme oxygenase and members of the bcl family.
Kidney Int 1996 Sep
PMID:Renal oxidant injury and oxidant response induced by mercury. 887 81

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.
Pharmacol Toxicol 1995 Sep
PMID:Action of reactive oxygen species and their antagonists on twitch tension of the rat phrenic nerve-diaphragm. 888 89

To evaluate the possible role of catalase in gastric ethanol metabolism in rats, we studied acetaldehyde formation from ethanol by gastric mucosal homogenate under various in vitro conditions. Homogenized rat gastric mucosa produced significant amounts of acetaldehyde in a time and ethanol concentration-dependent manner, even in the absence of added NAD. Both acetaldehyde formation and catalase activity peaked around the physiological pH, whereas alcohol dehydrogenase (ADH) activity was in that pH range low and reached peak values only at a higher pH of 9 to 10. Catalase inhibitors sodium azide (SA) and 3-amino-1,2,4-triazole (3-AT) had little effect on ADH activity but markedly decreased catalase activity and acetaldehyde formation (1 mM of SA to 56 +/- 13% of control, 5 mM of 3-AT to 67 +/- 3% of control; mean +/- SE). 4-Methylpyrazole decreased ADH activity significantly, but did not affect acetaldehyde formation. Heating of the homogenate at 60 degrees C for 5 min decreased ADH activity only slightly, but totally abolished catalase activity and reduced acetaldehyde formation to 39 +/- 3% of control. Addition of a H2O2 generating system (beta-D(+)-glucose + glucose oxidase] increased acetaldehyde formation in a concentration-dependent manner up to 8-fold of the control value. Our results strongly suggest that, in addition to ADH, catalase may play a significant role in gastric ethanol metabolism in rats.
Alcohol Clin Exp Res 1996 Sep
PMID:Role of catalase in rat gastric mucosal ethanol metabolism in vitro. 889 20

The rate constants of H2O2 decomposition, interaction of catalase complex I with H2O2, and the effective rate constants of catalase inactivation during enzymatic catalysis (k(in)) were determined by transformation of complete kinetic curves of H2O2 decomposition by catalase in reversed micelles of Aerosol OT (AOT) in octane and aqueous solution. Effects of hydration of micelles and AOT, H2O2, and catalase concentrations in the micellar systems on each of three kinetic constants were investigated. Optimal conditions were found which provide for high operational stability and catalytic activity of catalase in micellar systems versus aqueous solutions. Stability of catalase enhances (decreased k(in)) in the presence of reduced glutathione and ethanol in AOT micelles. In reversed AOT micelles, catalase partially dissociates to subunits because their peroxidase activity was demonstrable in cumene hydroperoxide-dependent oxidation of tetramethylbenzidine. Catalase dissociation to monomers is significantly decreased in mixed micelles composed of AOT, Triton X-45, Triton X-100, or Tween-85 and octanol.
Biokhimiia 1996 Sep
PMID:[Catalytic properties of catalase in microemulsions of surface-active agents in octane]. 899 90

Catalase I from Bacillus stearothermophilus has the interesting property of increasing its enzyme activity on heating. It was confirmed that after heating at 70 degrees C for 10 min or 65 degrees C for 20 min, almost all the enzyme molecules were converted irreversibly to the activated form. The increase in kcat from 1400 to 3930 s-1 and the decrease in Km for H2O2 from 4.4 to 2.7 mM by heat activation indicate changes in the kinetic property of the enzyme molecule. Therefore, it follows that catalase I has two active forms, a high-activity form and a low-activity form. The heat activation process followed the first-order kinetics with an activation enthalpy (DeltaH*) of 191 kJ/mol while the heat denaturation process had a DeltaH* of 545 kJ/mol. The CD spectra of the two enzyme forms had small but marked differences. The conversion of the low-activity form to the high-activity form was an endothermic process with a Tm of 56 degrees C, which is much lower than that of the heat denaturation (Tm = 76 degrees C), and the enthalpy change for the transition was only 5% of that for the denaturation. It has to be noted that the high-activity form of the enzyme was converted back to a low-activity form through the process of denaturation, refolding, and reconstitution with heme. In addition, the newly obtained low-activity form was brought to a high-activity form by heating. These results suggest that the native state of catalase I has two active conformations that are roughly the same but not identical and are separated by a high energy barrier.
J Biol Chem 1997 Sep 12
PMID:Thermal conversion from low- to high-activity forms of catalase I from Bacillus stearothermophilus. 928 97

Myocardial ischemia-reperfusion injury is at least partially mediated by oxygen-derived free radicals. Catalase is a major enzyme involved in the detoxification of hydrogen peroxide. The activity of catalase in the heart is very low, which may be a factor responsible for the high sensitivity of the heart to ischemia-reperfusion injury. The present study was undertaken to determine whether elevation of catalase specifically in the heart of transgenic mice can provide protection against ischemia-reperfusion injury. Hearts isolated from transgenic mice in which catalase in the heart was elevated approximately 60-fold higher than that in nontransgenic heart and from the non-transgenic littermates were subjected to 50 min of warm (37 degrees C) zero-flow ischemia followed by 90 min reflow. Compared with nontransgenic controls, transgenic hearts showed significantly improved recovery of contractile force (75 vs. 25% at the end of 90 min reperfusion, P < 0.01). Efflux of creatine kinase was reduced by approximately 50%, and the zone of myocardial infarction as demarcated by triphenyltetrazolium at the end of reperfusion was reduced by approximately 40% in transgenic hearts compared with nontransgenic controls. These findings support the view that hydrogen peroxide is an important cause of ischemia-reperfusion damage and suggest that protection may be provided by elevation of catalase activity.
Am J Physiol 1997 Sep
PMID:Catalase-overexpressing transgenic mouse heart is resistant to ischemia-reperfusion injury. 932 93


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