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)

Scavengers of different active oxygen species affect fibrin plate lysis, catalysed by various proteinases, only at relatively high concentrations (> 10(-2) M). Singlet oxygen scavengers change proteinase activity insignificantly except for strong inhibition of pepsin and papain by sodium azide, but pepsin-by histidine, and fibrinolytic urokinase activity-by all used O2 delta 1 scavengers. Of all used scavengers of OH-radical only ethanol caused significant changes in the proteinases under study, except for alpha-chymotrypsin. The most strong inhibitory effect on proteinase activity was demonstrated by scavengers of superoxide radical. Thus, nitrotetrazolium blue strongly inhibited the activity of plasmin, urokinase (fibrinolytic activity), papain and pepsin. Catalase changed proteinase activity insignificantly, though it leads to total inhibition of pepsin activity at final 4.5 x 10(-4) M concentration. These facts and our previous findings on generating of active oxygen species by proteinases give us grounds to suppose that minor active oxygen species, endogenous for the "proteinase-substrate" system, can participate in the catalytic function of some proteinases.
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PMID:Effect of active oxygen species scavengers on fibrinolytic activity of some proteinases. 874 26

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

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.
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PMID:Role of catalase in rat gastric mucosal ethanol metabolism in vitro. 889 20

This study was undertaken to examine if modulations of intracellular and extracellular Ca2+ affect the lethal cell injury and impairment of membrane transport function induced by oxidants in rabbit renal cortical slices. The oxidant t-butylhydroperoxide (t-BHP) and H2O2 increased lactate dehydrogenase (LDH) release and inhibited PAH uptake in a dose-dependent manner, but the potency of H2O2 was 100 times lower than that of t-BHP. Catalase prevented the effect of H2O2 but not that of t-BHP, suggesting that lower potency of H2O2 is attributed to the endogenous catalase activity. t-BHP induced lipid peroxidation and inhibited microsomal (Na+)-(K+)-ATPase activity. Omission of Ca2+ from the medium or addition of Ca2+ channel blockers (verapamil, diltiazem, and nifedipine) prevented the oxidant-induced LDH release. Similar effect was observed by addition of La3+. Buffering intracellular Ca2+ with BAPTA/AM decreased the oxidant-induced LDH release. However, the oxidant-induced impairment in PAH uptake was not altered under the same conditions. Also, the inhibition of microsomal (Na+)-(K+)-ATPase activity by t-BHP was not affected by verapamil, La3+, and BAPTA/AM. Dithiothreitol and glutathione prevented the oxidant-induced LDH release and reduction of PAH uptake and impeded the oxidant-induced inhibition of (Na+)-(K+)-ATPase activity and lipid peroxidation. Effects of t-BHP on TEA uptake were similar to those on PAH uptake. Modulations of intracellular or extracellular Ca2+ had little effect on the oxidant-induced lipid peroxidation. Glycine did not exert protective effect against the oxidant-induced cell injury. These results suggest strongly that Ca2+ plays an important role in the oxidant-induced LDH release but not in the oxidant-induced alterations of membrane transport function in rabbit renal cortical slices. The role of Ca2+ in oxidant-induced LDH release is not apparently associated with peroxidation of membrane lipid.
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PMID:Differential effect of Ca2+ on oxidant-induced lethal cell injury and alterations of membrane functional integrity in renal cortical slices. 897 86

Reaction of chromium(VI) with alpha-lipoic acid (reduced form, also called 1,2-dithiolane-3-pentanoic acid) generated Cr(V) and hydroxyl radical (*OH) as measured by electron spin resonance and ESR spin trapping. 5,5-Dimethyl-1-pyrroline was used as a spin trapping agent. Catalase inhibited the *OH generation and enhanced the Cr(V) formation. Superoxide dismutase had an opposite effect. H2O2 enhanced the *OH generation and decreased the Cr(V) formation in a dose-dependent manner. Metal chelators, EDTA, diethylenetriaminepentaacetic acid, deferoxamine, and 1, 10-phenanthroline inhibited *OH radical generation in the order of EDTA > 1,10-phenanthroline > DTPA > deferoxamine. Oxygen consumption measurements indicated that molecular oxygen was used to generate *OH radical in the mixture of Cr(VI) and alpha-lipoic acid. H2O2 and superoxide radical (O2-) were involved as reactive intermediates. The *OH radical was generated via Cr(V)-mediated Fenton-like reaction (Cr(V) + H2O2 --> Cr(VI) + OH- + *OH). HPLC measurements show that the *OH radical generated by this reaction is capable of generating 8-hydroxyl-2'-deoxyguanosine from 2-deoxyguanosine. Incubation of Cr(VI) with cultured Jurkat cells resulted in an activation of DNA binding activity of the nuclear factor (NF)-kappaB. Addition of alpha-lipoic acid enhanced the NF-kappaB activation, while the *OH radical scavenger, sodium formate, inhibited it, showing that alpha-lipoic acid enhanced Cr(VI)-induced NF-kappaB activation via free radical reactions. The results indicate that while alpha-lipoic acid is considered to be an antioxidant, it may be a cellular one-electron Cr(VI) reductant and could be involved in the mechanism of Cr(VI)-induced carcinogenesis.
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PMID:One-electron reduction of chromium(VI) by alpha-lipoic acid and related hydroxyl radical generation, dG hydroxylation and nuclear transcription factor-kappaB activation. 902 68

The active oxygen species hydrogen peroxide (H2O2) was detected cytochemically by its reaction with cerium chloride to produce electron-dense deposits of cerium perhydroxides. In uninoculated lettuce leaves, H2O2 was typically present within the secondary thickened walls of xylem vessels. Inoculation with wild-type cells of Pseudomonas syringae pv phaseolicola caused a rapid hypersensitive reaction (HR) during which highly localized accumulation of H2O2 was found in plant cell walls adjacent to attached bacteria. Quantitative analysis indicated a prolonged burst of H2O2 occurring between 5 to 8 hr after inoculation in cells undergoing the HR during this example of non-host resistance. Cell wall alterations and papilla deposition, which occurred in response to both the wild-type strain and a nonpathogenic hrpD mutant, were not associated with intense staining for H2O2, unless the responding cell was undergoing the HR. Catalase treatment to decompose H2O2 almost entirely eliminated staining, but 3-amino-1,2,4-triazole (catalase inhibitor) did not affect the pattern of distribution of H2O2 detected. H2O2 production was reduced more by the inhibition of plant peroxidases (with potassium cyanide and sodium azide) than by inhibition of neutrophil-like NADPH oxidase (with diphenylene iodonium chloride). Results suggest that CeCl3 reacts with excess H2O2 that is not rapidly metabolized during cross-linking reactions occurring in cell walls; such an excess of H2O2 in the early stages of the plant-bacterium interaction was only produced during the HR. The highly localized accumulation of H2O2 is consistent with its direct role as an antimicrobial agent and as the cause of localized membrane damage at sites of bacterial attachment.
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PMID:Localization of hydrogen peroxide accumulation during the hypersensitive reaction of lettuce cells to Pseudomonas syringae pv phaseolicola. 906 52

Hydrogen peroxide removal activities in normal and acatalasemic mouse hemolysates were examined to determine the optimal temperature of catalase. From thermal stability of the removal activities in hemolysates, the removal activities were divided into two activities. The removal activity deactivated at lower temperature was catalase, and the 50% inactivation was observed after 10 min incubation at 47.2 +/- 0.5 degrees C for normal hemolysates and 34.0 +/- 0.8 degrees C for acatalasemic ones. The removal activity deactivated at a higher temperature remained after the addition of sodium azide, and the 50% inactivation was observed at 63.5 +/- 1.4 degrees C. After separation of the removal activities by carboxymethyl-cellulose column chromatography, the removal activity deactivated at higher temperature was attributed to the activity by hemoglobin. From Lineweaver-Burk plot analysis of the removal rates by hemoglobin at 37 degrees C, the Michaelis constant for hydrogen peroxide and the maximum velocity were 201 +/- 53 microM and 5.37 +/- 1.39 micromol/s per g of Hb, respectively. Removal rates by hemoglobin in mouse hemolysates at 37 degrees C in 70 microM hydrogen peroxide were 1.32 +/- 0.12 micromol/s per g of Hb. Catalase activity (k/g Hb: rate constant related to the hemoglobin content) in normal mouse hemolysates was 104 +/- 12 at 25 degrees C and 117 +/- 10 at 37 degrees C, and that in acatalasemic hemolysates was 10.5 +/- 1.7 at 25 degrees C. These results indicate that activity of hydrogen peroxide removal by hemoglobin is substantial and the activity in acatalasemic hemolysates is predominant at low concentration of hydrogen peroxide.
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PMID:Characterization of hydrogen peroxide removal activities in mouse hemolysates: catalase activity and hydrogen peroxide removal activity by hemoglobin. 930 Jul 94

Catalase was chemically modified by sodium chondroitin sulfate using the benzoquinone binding method. Thus, 40-42% of the catalase preparation was modified. Treatment of catalase and superoxide dismutase with benzoquinone-activated chondroitin sulfate results in a bienzymic conjugate with electrophoretically heterogenous composition. The yield of the products and their residual catalytic activity indicate that the method can be used for the preparation of modified catalase and the bienzymic conjugate to study their efficiency in vivo.
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PMID:Modification of catalase by chondroitin sulfate. 946 40

Chlorins are cyclic tetrapyrrole derivatives of great interest for use in photodynamic therapy. We have found that horseradish peroxidase (EC 1.11.1.7) (HRP) can convert deuteroporphyrin IX (Deutero) into chlorins. Some characteristics of this enzymatic transformation were investigated. The formation of chlorins was determined spectrophotometrically by monitoring the change in absorbance in the Q-band region (638 nm). The reaction occurred without addition of H2O2 and had a pH optimum of 7.5. The presence of thiol-containing reductants, with a great preference for reduced glutathione, was required and could not be substituted by adding H2O2. Ascorbic acid acted as a potent inhibitor of the reaction, while other organic acids (citric and benzoic) had little to no inhibitory effect. The requirement for O2 was suggested by the inhibitory effect of sodium hydrosulfite and was confirmed by carrying the assay in nitrogen-saturated solutions. Though the reaction occurred without adding H2O2, low amounts of H2O2 (3-30 microM) were stimulatory to the assay. However, concentrations of 300 microM H2O2 or higher were inhibitory. Similarly, light was not required, but was stimulatory at low levels and inhibitory at high levels. Catalase and deferoxamine were inhibitory, but superoxide dismutase and mannitol had no effects. Kinetic analysis and respiratory studies suggest that HRP may initially react with reduced glutathione in a reaction that does not consume much oxygen. The ensuing steps, probably involving an oxygen free radical and porphyrin radical intermediates, consume a large amount of O2 to oxidize Deutero into chlorin.
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PMID:Horseradish peroxidase-dependent oxidation of deuteroporphyrin IX into chlorins. 950 Aug 44

The nitric oxide (NO) donors, sodium nitroprusside (SNP), 1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium+ ++-1,2-diolate] (DETA NONOate), and S-nitroso-N-acetyl-D,L-penicillamine (SNAP) produce a dose-dependent increase in cell death in a catecholaminergic cell line (CATH.a) derived from the central nervous system. Cell death is associated with a decrease in mitochondrial membrane potential. Dopamine also induced cell death of CATH.a cells and this was potentiated by concentrations of SNP which alone did not produce cell death. Hemoglobin, a scavenger of NO radicals, blocked SNP- and SNAP-induced cell death. Catalase and superoxide dismutase, enzymes that metabolize H2O2 and superoxide, respectively, did not inhibit SNP- or SNAP-induced cell death. These data indicate that NO donors produce cell death in CATH.a cells through a mechanism related to the production of NO and the loss of the mitochondrial membrane potential but unrelated to the production of H2O2.
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PMID:Nitric oxide induces cell death in a catecholaminergic cell line derived from the central nervous system. 950 23


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