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)

ESR spin trapping was utilized to study the singlet oxygen (1O2) generation in the reaction of superoxide (O2) with H2O2. The spin trap used was 2,2,6,6-tetramethyl-4-piperdone. Incubation of xanthine, xanthine oxidase and H2O2 generated 1O2 spin adduct signal. Omission of xanthine, xanthine oxidase or H2O2 caused a sharp decrease in 1O2 generation. 1O2 scavenger, sodium azide, inhibited 1O2 generation while .OH scavenger, ethanol, only slightly decreased the signal intensity. Potassium superoxide (KO2) decomposition generated 1O2. Catalase and sodium azide inhibited 1O2 generation and H2O2 enhanced it. The results demonstrate that O2 is capable of generating 1O2 upon reaction with H2O2.
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PMID:Singlet oxygen generation in the superoxide reaction. 766 19

3-Morpholinosydnonimine (SIN-1) is widely used to generate nitric oxide (NO(x).) and superoxide radical (O2-.). The effect of SOD on the toxicity of SIN-1 is complex, depending on what is the ultimate species responsible for toxicity. SIN-1 (< 1 mM) was only slightly toxic to HepG2 cells. Copper, zinc superoxide dismutase (Cu,Zn-SOD) or manganese superoxide dismutase (Mn-SOD) increased the toxicity of SIN-1. Catalase abolished, while sodium azide potentiated, this toxicity, suggesting a key role for H2O2 in the overall mechanism. Depletion of GSH from the HepG2 cells also potentiated the toxicity of SIN-1 plus SOD. Although Me2SO, sodium formate, and mannitol had no protective effect, iron chelators, thiourea and urate protected the cells against the SIN-1 plus Cu,Zn-SOD-mediated cytotoxicity. The cytotoxic effect of Cu,Zn-SOD but not Mn-SOD, showed a biphasic dose response being most pronounced at lower concentrations (10-100 units/ml). In the presence of SIN-1, Mn-SOD increased accumulation of H2O2 in a concentration-dependent manner. In contrast, Cu,Zn-SOD increased H2O2 accumulation from SIN-1 at low but not high concentrations of the enzyme, suggesting that high concentrations of the Cu,Zn-SOD interacted with the H2O2. EPR spin trapping studies demonstrated the formation of hydroxyl radical from the decomposition of H2O2 by high concentrations of the Cu,Zn-SOD. The cytotoxic effect of the NO donors SNAP and DEA/NO was only slightly enhanced by SOD; catalase had no effect. Thus, the oxidants responsible for the toxicity of SIN-1 and SNAP or DEA/NO to HepG2 cells under these conditions are different, with H2O2 derived from O2-. dismutation playing a major role with SIN-1. These results suggest that the potentiation of SIN-1 toxicity by SOD is due to enhanced production of H2O2, followed by site-specific damage of critical cellular sites by a transition metal-catalyzed reaction. These results also emphasize that the role of SOD as a protectant against oxidant damage is complex and dependent, in part, on the subsequent fate and reactivity of the generated H2O2.
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PMID:Increased cytotoxicity of 3-morpholinosydnonimine to HepG2 cells in the presence of superoxide dismutase. Role of hydrogen peroxide and iron. 767 15

Effects of hypoxia-reoxygenation (H-R) on myocytes isolated from 10 week hypertrophied and sham control rat hearts were studied. Myocyte hypertrophy was indicated by an increase in cell size. Superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) enzyme activities were significantly higher and lipid peroxidation (TBARS) was lower in hypertrophied myocytes prior to any H-R. Hypertrophied myocyte population showed significantly less damage to cell morphology due to H-R. In sham as well as hypertrophied myocytes, Na+ and Ca2+ contents were increased by H-R, but Ca2+ accumulation was significantly less in the hypertrophied myocytes. Both SOD and GSHPx activities were depressed by the oxidative stress in the sham myocytes whereas these activities were not significantly changed in the hypertrophied myocytes. Catalase activity in the prehypoxic sham and hypertrophied myocytes was comparable and this activity did not change during H-R. There was a significant increase in lipid peroxidation due to H-R but this change was less in hypertrophied myocytes. This study shows less vulnerability of hypertrophied myocytes to oxidative stress and an increase in endogenous antioxidant reserve may have an important role in mediating this protection.
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PMID:Endogenous antioxidants in isolated hypertrophied cardiac myocytes and hypoxia-reoxygenation injury. 776 Mar 50

Catalase-peroxidase was purified to near homogeneity from Streptomyces sp. The enzyme was composed of two subunits with a molecular mass of 78 kDa and contained 1.05 mol of protoporphyrin IX/mol of dimeric protein. The absorption and resonance Raman spectra of the native and its cyano-enzyme were closely similar to those of other heme proteins with a histidine as the fifth ligand. However, the peak from tyrosine ring at approximately 1612 cm-1, which is unique in catalases, was not found in resonance Raman spectra of catalase-peroxidase. The electron paramagnetic resonance spectrum of the native enzyme revealed uniquely two sets of rhombic signals, which were converted to a single high spin, hexacoordinate species after the addition of sodium formate. Cyanide bound to the sixth coordination position of the heme iron, thereby converting the enzyme to a low spin, hexacoordinate species. The time-dependent inactivation of the enzyme with diethyl pyrocarbonate and its kinetic analysis strongly suggested the occurrence of histidine residue. From the above-mentioned spectroscopic results and chemical modification, it was deduced that the native enzyme is predominantly in the high spin, ferric form and has a histidine as the fifth ligand.
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PMID:Spectral characterization and chemical modification of catalase-peroxidase from Streptomyces sp. 777 29

Streptomyces coelicolor ATCC 10147 produced catalases whose electrophoretic mobility varied depending on the growth phase in liquid culture. Polyacrylamide gel electrophoresis of cell extracts resulted in six catalase activity bands, which were designated Cat1 to Ca6. Of these, Cat4 appeared during all growth phases, whereas Cat1 appeared only during the stationary phase. Catalase-deficient mutants were screened by the H2O2 bubbling test following NTG mutagenesis. In all the non-bubbling mutants tested, the Cat4 activity band significantly decreased or disappeared, suggesting that Cat4 is the major catalase. Cat4 was purified to electrophoretic homogeneity and some of its properties analysed. The enzyme has a native molecular mass of 225 kDa, as determined by gel permeation column chromatography, and consists of four identical subunits of 57 kDa, as determined by SDS-PAGE. The enzyme contains 2.6 molecules of protohaem IX per tetramer, as indicated by the absorption spectrum. It was not reducible by sodium dithionite and exhibited no peroxidase activity with o-dianisidine as the substrate. All these characteristics, as well as inhibitor studies, indicate that the major vegetative catalase in S. coelicolor, unlike E. coli vegetative catalase, is a member of the typical monofunctional catalases found in eukaryotes and some bacteria.
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PMID:Characterization of the major catalase from Streptomyces coelicolor ATCC 10147. 788 56

The colourimetric assay of monoamine oxidase activity, as hydrogen peroxide production, normally requires the use of sodium azide to inhibit breakdown of hydrogen peroxide by catalase. Sodium azide was shown to act as an uncompetitive inhibitor of benzylamine deamination with an inhibitor constant of 1.5 mM. Catalase activity of isolated rat liver mitochondria could be eliminated with the irreversible inhibitor of catalase, 3-amino-1,2,4-triazole. The treatment did not affect benzylamine deaminating activity. The catalase-free preparation could be used to assay monoamine oxidase activity colourimetrically, as hydrogen peroxide production, in the absence of sodium azide.
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PMID:Some problems associated with measuring monoamine oxidase activity in the presence of sodium azide. 793 Dec 50

The extent of DNA damage and lipid peroxidation induced by kaempferol, a polyphenolic flavonoid with a molecular structure similar to quercetin, was studied under aerobic conditions in isolated rat-liver nuclei. Kaempferol induced significant (P < 0.05) concentration-dependent nuclear DNA degradation concurrent with lipid peroxidation; these effects were enhanced by iron(III) or copper(II). Catalase, superoxide dismutase (SOD), mannitol, and sodium azide did not show any inhibitory effect on the kaempferol-induced nuclear DNA damage in the presence of iron(III) or copper(II). On the other hand, all stimulated the kaempferol-induced DNA damage in the presence of iron(III); in the presence of copper(II) only SOD and mannitol showed statistically significant stimulatory effects. The kaempferol induced lipid peroxidation was significantly stimulated by catalase and sodium azide in the presence of iron(III). These results demonstrate the pro-oxidant properties of polyphenolic flavonoids, which are generally considered as antioxidants and anticarcinogens, suggesting their possible dual role in mutagenesis and carcinogenesis.
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PMID:Kaempferol-induced nuclear DNA damage and lipid peroxidation. 795 31

Incubation of papain (EC 3.4.22.2) with ascorbic acid (AsA) and Cu2+ in acetate buffer (pH 5.6) results in an irreversible loss of enzyme activity by site-specific generation of free radicals [H. Kanazawa, S. Fujimoto, A. Ohara, Biol. Pharm.Bull., 16, 11 (1993)]. In this study, the effect of some compounds, known free radical scavengers, on the relationship between the inactivation of papain by the Cu(2+)-AsA system and the oxidation of AsA was investigated. Catalase completely protected the enzyme from inactivation by the Cu(2+)-AsA system, although hydrogen peroxide (H2O2) by itself, known to be generated during the autoxidation of AsA, did not inactivate the enzyme. The oxidation of AsA was unaffected by catalase. Both thiourea and sodium thiocyanate completely protected the enzyme from inactivation, while AsA was partially oxidized only in the initial stage. In the presence of potassium iodide, both the inactivation of the enzyme and the oxidation of AsA were characterized by a rapid initial phase followed by a stable phase where no reaction took place and, subsequently, a slower phase. Histidine partially prevented the inactivation of the enzyme and the oxidation of AsA. The present results suggest that H2O2 serves as a source of secondary, highly reactive species, probably hydroxyl radicals, which are responsible for the inactivation, and that the protection from inactivation by some radical scavengers, such as thiourea, sodium thiocyanate, potassium iodide, and histidine, is based on the removal of metal ions (Cu2+ or Cu+) at the specific site of inactivation.
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PMID:Effect of radical scavengers on the inactivation of papain by ascorbic acid in the presence of cupric ions. 806 51

Iron, presumably by participating in generation of hydroxyl radical or other oxidant species or initiation of lipid peroxidation, has been shown to play an important role in several models of tissue injury, including acute renal failure induced by the antibiotic gentamicin. However, the sources of iron remain unknown. Rat renal mitochondria incubated at 37 degrees C with gentamicin resulted in a time- (15-60 min) and a dose-dependent (0.01-5 mM) iron release as measured by formation of iron-bathophenanthroline sulfonate complex FeII-(BPS)3 [at 60 min, control: 1.2 +/- 0.1 nmol/mg protein, n = 7; gentamicin (5 mM): 5.1 +/- 0.4 nmol/mg protein, n = 7]. No formation of FeII(BPS)3 complex was detected in the absence of mitochondria or when incubations were carried out at 0 degrees C. Similar results were obtained when 2,2'-dipyridyl, another iron chelator, was used for measurement of iron release. On the basis on our previous study that gentamicin enhances generation of hydrogen peroxide by renal cortical mitochondria, we examined whether effect of gentamicin on iron release is mediated by hydrogen peroxide. Catalase (which decomposes hydrogen peroxide), but not heat-inactivated catalase, as well as pyruvate, a potent scavenger of hydrogen peroxide, prevented gentamicin-induced iron mobilization. Superoxide dismutase, a scavenger of superoxide anion, or hydroxyl radical scavengers (dimethylthiourea or sodium benzoate) had no effect. Taken together, the data with scavengers indicate that gentamicin-induced iron mobilization from mitochondria is mediated by hydrogen peroxide.
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PMID:Gentamicin-induced mobilization of iron from renal cortical mitochondria. 821 3

Catalase plays a major role in the protection of tissues from toxic effects of H2O2 and partially reduced oxygen species. In the present study catalase was extracted and purified 330-fold from goat lung by acetone fractionation and successive chromatographies on DEAE-cellulose, Sephadex G-200, Blue Sepharose CL-6B and Ultrogel AcA-34. The purified enzyme was almost homogeneous as judged by polyacrylamide gel electrophoresis and FPLC. The molecular weight and Stokes' radius of the purified enzyme were 339 kDa and 127 +/- 2 A. The enzyme had 11 sulfhydryl groups and 15 tryptophan groups per mol of the enzyme. A broad pH optimum in the range 5.2 to 7.8 was obtained. Sulfhydryl group binding agents, thiol reagents and N-Bromosuccinimide inhibited the enzyme activity. The kinetic data show no cooperativity between the substrate binding sites. Tryptophan, indole acetic acid, cysteine, formaldehyde and sodium azide inhibited the enzyme non-competitively with Ki values of 1.5, 1.6, 6.7, 0.55 and 0.0017 mM, respectively.
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PMID:Purification and characterization of catalase from goat (Capra capra) lung. 830 90


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