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

Low-potential electron acceptors of photosystem I of chloroplast lamellae produce superoxide anions (0-2) and hydrogen peroxide by autoxidation, but have no effect on ethylene formation from methionine; equimolar amounts of ferredoxin are less active in photosynthetic O-2 and H2O2 production but strongly stimulate ethylene production from methionine. 2. Ten to fifty units of superoxide dismutase inhibit fifty to two hundred units of superoxide dismutase stimulate ethylene formation from methionine by chloroplast lamellae in the presence of ferredoxin. This stimulation is stronger at pH 7.0 than at pH 7.8. Catalase inhibits ethylene formation from methionine. 3. Pulse-radiolytic production of nitrite (NO-2) from hydroxylamine, initiated by hydroxyl radicals (.OH) or O-2, shows no difference in the presence or absence of ferredoxin, nor do the decay kinetics of O2. 4. From the above observations and from model reactions (xanthine/xanthine oxidase; iron salts in the presence of H2O2), it is concluded that reduced ferredoxin in the presence of H2O2 forms a Fenton-type oxidizing species for methionine, generating ethylene in the presence of pyridoxal phosphate. 5. Inhibitory effects of both superoxide dismutase and catalase in oxygen-dependent reactions need not necessarily indicate the participation of the 'Haber-Weiss' reaction.
 ...
PMID:Oxygen activation in isolated chloroplasts. Mechanism of ferredoxin-dependent ethylene formation from methionine. 21 71

Our objective was to determine whether hydroxylamine is a possible intermediate in the oxidative conversion of L-arginine to nitric oxide. Vasorelaxation by hydroxylamine is known to be mediated by nitric oxide. The vasorelaxant properties of hydroxylamine were examined using rat aortic rings and an isolated rat lung perfusion model. Hydroxylamine and acetylcholine were equally effective in relaxing norepinephrine-contracted intact aortic rings, whereas only hydroxylamine relaxed aortic rings with endothelium removed. This endothelium-independent vasorelaxation by hydroxylamine indicated that the hydroxylamine-converting enzyme is not localized solely within endothelial cells. Catalase, an enzyme known to oxidize hydroxylamine to nitric oxide, was present in homogenates of intact and endothelium-denuded rings. Cyanamide, another catalase substrate and a known precursor of nitroxyl (HNO), was not a vasorelaxant of aortic rings or of isolated, hypoxia-constricted lungs. These results suggest that free nitroxyl is not an intermediate in the oxidation of hydroxylamine to nitric oxide. An overall pathway for the oxidative conversion of L-arginine through an hydroxylamine intermediate to nitric oxide is proposed.
 ...
PMID:Hydroxylamine is a vasorelaxant and a possible intermediate in the oxidative conversion of L-arginine to nitric oxide. 250 70

Vegetative cells of Bacillus subtilis in logarithmic growth phase produced one catalase, labeled catalase 1, with a nondenatured molecular weight of 205,000. As growth progressed, other activity bands with slower electrophoretic mobilities on polyacrylamide gels appeared, including a series of bands with a common nondenatured molecular weight of 261,000, collectively labeled catalase 2, and a minor band, with a molecular weight of 387,000, labeled catalase 3. Purified spores contained only catalase 2, and it was not produced in spo0A- or spo0F-containing mutants. Strains deficient in catalase 1 or catalase 2 or both were selected after mutagenesis. Sensitivities of the two main catalases to NaCN, NaN3, hydroxylamine, and temperature were similar, but the apparent Kms for H2O2 differed, being 36.6 and 64.4 mM, respectively, for catalase 1 and catalase 2. The levels of catalase 1 increased 15-fold during growth into stationary phase and could be increased 30-fold by the addition of H2O2 to the medium. Catalase 2, which was not affected by H2O2, appeared only after the cells had reached stationary phase, and the maximum levels were only half of the basal level of catalase 1.
 ...
PMID:Multiple catalases in Bacillus subtilis. 311 25

Catalase-peroxidase was isolated from aerobically grown Rhodopseudomonas capsulata. The enzyme resembles typical catalases in some of its physicochemical properties. It has an apparent molecular weight of 236,000 and is composed of four identical subunits. It shows a typical high spin ferric heme spectrum with absorption maxima at 403 and 635 nm and shoulders at 503 and 535 nm. Upon binding of cyanide, the enzyme is converted to the low spin state, as shown by the shift of the Soret maximum to 418 nm and the band at 532 nm. It has an isoelectric point at pH 4.5. The enzyme differs from typical catalases in also having a strong peroxidatic activity with dianisidine, pyrogallol, and diaminobenzidine as electron donors. Both the catalatic and the peroxidatic activities are similarly inactivated by treatment with 1 mM H2O2, heating to 50 degrees C, exposure to ethanol/chloroform, and photooxidative conditions. In contrast to typical catalases, but similarly to peroxidases, the enzyme is reduced by sodium dithionite. The pH optimum of the peroxidatic activity is 5-5.3 (in contrast to 6-6.5 of the catalatic activity). 50% of the apparent maximal activities are reached at 0.3 and 4.2 mM H2O2 for the peroxidatic and catalatic activities, respectively. Both enzymic activities are equally inhibited by cyanide, 50% inhibition being achieved with 2.2 X 10(-5) M KCN. Contrarily, the two activities differ in their response to hydroxylamine and azide. 50% inhibition of the catalatic activity is obtained with 1.5 X 10(-4) M azide or 2.15 X 10(-6) M hydroxylamine; 50% inhibition of the peroxidatic activity requires 7.3 X 10(-4) M azide or 7.8 X 10(-5) M hydroxylamine. The activation energies of the catalatic and the peroxidatic activities are 1.9 and 1.7 kcal/mol, respectively.
 ...
PMID:Purification and characterization of a catalase-peroxidase from the photosynthetic bacterium Rhodopseudomonas capsulata. 357 Dec 90

When challenged with reactive oxidants, the nonsulfur phototrophic bacterium Rhodobacter sphaeroides ATH 2.4.1 exhibited an oxidative stress response during both phototrophic and chemotrophic growth. Upon preincubation with 100 microM H2O2, catalase activity increased fivefold. Catalase was also induced by other forms of oxidative stress, heat-shock, ethanol treatment, and stationary-phase conditions. Only one band of catalase activity was detected after native and denaturing PAGE. The enzyme was purified 304-fold with a yield of 7%. The purified enzyme displayed a heterodimeric structure with subunits of 75 and 68 kDa, corresponding to a molecular mass of approximately 150 kDa for the native enzyme. The subunits had almost identical amino-terminal peptide sequences, sharing substantial similarity with other bacterial catalases. The enzyme exhibited an apparent Km of 40 mM and a Vmax of 285,000 U (mg protein)-1. Spectroscopic analysis indicated the presence of protoheme IX. The heme content calculated from pyridine hemochrome spectra was 0.43 mol per mol of enzyme. The enzyme had a broad pH optimum and was inhibited by cyanide, azide, hydroxylamine, 2-mercaptoethanol, and sodium dithionite. These data indicate that this catalase belongs to the class of monofunctional catalases.
 ...
PMID:Purification and characterization of a catalase from the nonsulfur phototrophic bacterium Rhodobacter sphaeroides ATH 2.4.1 and its role in the oxidative stress response. 957 36

There is considerable interest in the role of the 1-hydroxyethyl radical (HER) in the toxic effects of ethanol. The goal of this study was to evaluate the effects of HER on classical antioxidant enzymes. The interaction of acetaldehyde with hydroxylamine-o-sulfonic acid has been shown to produce 1, 1'-dihydroxyazoethane (DHAE); this compound appears to be highly unstable, and its decomposition leads to the generation of HER. Addition of DHAE into a solution of PBN led to the appearance of the typical EPR spectra of PBN/HER adduct. No PBN/HER spin adduct was detected when DHAE was incubated with 0.1 M PBN in the presence of GSH. In the absence of PBN, DHAE oxidized ascorbic acid to semidehydroascorbyl radical, presumably via an ascorbate-dependent one-electron reduction of HER back to ethanol. Catalase was progressively inactivated by exposure to DHAE-generated HER in a time and HER concentration-dependent manner. Ascorbic acid and PBN gave full protection to catalase against HER-dependent inactivation. The antioxidants 2-tert-butyl-4-methylphenol, propylgallate, and alpha-tocopherol-protected catalase against inactivation by 84, 88, and 39%, respectively. Other antioxidant enzymes were also sensitive to exposure to HER. Glutathione reductase, glutathione peroxidase, and superoxide dismutase were inactivated by 46, 36, and 39%, respectively, by HER. The results reported here plus previous results showing HER interacts with GSH, ascorbate, and alpha-tocopherol suggest that prolonged generation of HER in cells from animals chronically exposed to ethanol may lower the antioxidant defense status, thereby contributing to mechanisms by which ethanol produces a state of oxidative stress and produces toxicity.
 ...
PMID:Interaction of 1-hydroxyethyl radical with antioxidant enzymes. 1060 Jan 75

Catalase, myoglobin and NO-synthase are heme proteins. Catalase is capable of producing NO from azide and hydroxylamine (Ignarro LJ, FASEB J 1989; 3:31-36). Heme is the center of catalyzing the production of NO. Thus, we investigated the mode of vasorelaxation induced by azide and nitrite in the endothelium-denuded aorta of guinea pig or rat. Both agents elicited a rapid relaxation of the aorta in a concentration dependent manner: EC50 values for azide and nitrite were 0.1 microM and 0.1 mM, respectively. These relaxation responses were inhibited by the presence of methylene blue, but not by NO-arginine or L-NMMA. Azide rapidly raised the cGMP content of the muscle, which seemed to precede the relaxation response. The catalase activity of the aorta was inhibited by azide and hydroxylamine with the similar IC50 values to EC50 values for relaxation. Myoglobin was found in the vessel tissue by the immunohistological method. Using a NO-sensitive electrode, the NO production from aortas was detected after addition of azide and nitrite. The NO production from nitrite was shown to precede the oxidation of heme moiety of oxymyoglobin. These results suggest that catalase as well as myoglobin, heme proteins, can be the cellular target for pharmacological agents to produce NO leading to vasorelaxation.
 ...
PMID:[NO production through catalase and myoglobin, hemeproteins, in vascular smooth muscle]. 1062 51

Impairment of mitochondrial functions has been found in ethanol-induced liver injury. Ethanol can be oxidized to the 1-hydroxyethyl radical (HER) by rat liver microsomal systems. Experiments were carried out to evaluate the ability of HER to cause mitochondrial swelling as an indicator of the mitochondrial permeability transition (MPT). Electron spin resonance (ESR) spectroscopy was used to detect HER and to study its interaction with mitochondria. The ESR signal intensity of the spin adduct formed from alpha-(4-pyridyl-1-oxide) N-tert-butylnitrone (POBN) and HER generated from either a thermic decomposition of 1,1'-dihydroxyazoethane (DHAE) or a Fenton reaction system containing ethanol was markedly diminished by the addition of mitochondria, indicating an interaction between HER and mitochondria. Exposure of rat liver mitochondria to HER generated from either system caused swelling, as reflected by a decrease in absorbance at 540 nm, in a HER concentration-dependent and a cyclosporin A-sensitive manner. Mitochondrial swelling was also induced in the Fenton reaction system without ethanol. The DHAE-dependent generation of HER in mitochondrial suspension resulted in a decrease of membrane protein thiols and collapse of the membrane potential (delta psi). The swelling induced by HER was prevented by glutathione and vitamin E, but not by superoxide dismutase. Catalase did not prevent the swelling caused by the acetaldehyde/hydroxylamine O-sulfonate (HOS) system, but was inhibitory in the Fenton reaction system with or without ethanol. These results indicate that HER, as well as hydroxyl radical, can induce the MPT, and suggest the possibility that the collapse of delta psi caused by HER may, at least in part, contribute to impairment of mitochondrial function caused by ethanol and in ethanol-induced liver injury.
 ...
PMID:Mitochondrial permeability transition induced by 1-hydroxyethyl radical. 1128 Dec 95

2-Nitropropane (2-NP), a widely used industrial solvent, is carcinogenic to rats. To clarify the mechanism of carcinogenesis by 2-NP, we investigated DNA damage by 2-NP metabolites, N-isopropylhydroxylamine (IPHA) and hydroxylamine-O-sulfonic acid (HAS), using 32P-5'-end-labelled DNA fragments obtained from genes that are relevant to human cancer. In the presence of Fe(III) EDTA, both IPHA and HAS caused DNA damage at every nucleotide position without marked site preference. The damage was inhibited by free hydroxyl radical (-*OH) scavengers, catalase and deferoxamine mesilate, an iron chelating agent. These results suggest that the DNA damage was caused by -*OH generated via H(2)O(2) by both IPHA and HAS. In contrast, in the presence of Cu(II), IPHA frequently caused DNA damage at thymine. The Cu(II)-mediated DNA damage caused by IPHA was inhibited by catalase, methional and bathocuproine, a Cu(I)-specific chelator, suggesting the involvement of H(2)O(2) and Cu(I). These results suggest that the DNA damage induced by IPHA in the presence of Cu(II) was caused by a reactive oxygen species like the Cu(I)-hydroperoxo complex. On the other hand, HAS most frequently induced DNA damage at 5'-TG-3', 5'-GG-3' and 5'-GGG-3' sequences. Catalase and methional only partly inhibited the Cu(II)-mediated DNA damage caused by HAS, suggesting that the reactive oxygen species and another reactive species participate in this process. Formation of 8-oxodG by IPHA or HAS increased in the presence of metal ions. This study suggests that metal-mediated DNA damage caused by 2-NP metabolites plays an important role in the mutagenicity and the carcinogenicity of 2-NP.
 ...
PMID:Mechanism of metal-mediated DNA damage induced by metabolites of carcinogenic 2-nitropropane. 1147 Apr 85

Catalase-1 (Cat-1), one of the two monofunctional catalases of Neurospora crassa, increases during asexual spore formation to constitute 0.6% of total protein in conidia. Cat-1 was purified 170-fold with a yield of 48% from conidiating cultures. Like most monofunctional catalases, Cat-1 is a homotetramer, resistant to inactivation by solvents, fully active over a pH range of 4-12, and inactivated by 3-amino-1,2,4-triazole. Unlike most monofunctional catalases, Cat-1 consists of 88 kDa monomers that are glycosylated with alpha-glucose and/or alpha-mannose, is unusually stable, and is not inactivated or inhibited by hydrogen peroxide. Cat-1 was more resistant than other catalases to heat inactivation and to high concentrations of salt and denaturants. Cat-1 exhibited unusual kinetics: at molar concentrations of hydrogen peroxide the apparent V was 10 times higher than at millimolar concentrations. Inactivation of Cat-1 activity with azide and hydroxylamine was according to first order kinetics, while cyanide at micromolar concentrations was a reversible competitive inhibitor.
 ...
PMID:Molecular and kinetic study of catalase-1, a durable large catalase of Neurospora crassa. 1172 3


1 2 Next >>