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

An ultrasensitive colorimetric assay for manganese is described. It is based upon the catalysis, by Mn(II), of the photochemical oxidation of o-dianisidine, sensitized by riboflavin. Catalase increases the Mn(II)-catalyzed rate of photosensitized oxidation of dianisidine to the bisazobiphenyl, while superoxide dismutase inhibits the rate. The mechanism appears to involve oxidation of Mn(II) by O2-, followed by oxidation of dianisidine by MnO2+ in equilibrium Mn(III). Cu(II) interferes, but Zn(II), Fe(II), Fe(III), Co(II), and Ni(II) do not. Chelating agents and thiol reductants also interfere. Interference by Cu(II) can be overcome by the addition of cyanide, while interference by organic compounds can be surmounted by wet ashing. This assay provides a linear response to Mn(II) over the range 10-2500 nM. The limit of detection was 5 nM Mn(II).
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PMID:An ultrasensitive colorimetric assay for manganese. 339 49

Exploratory factor analysis of reported specific activities of the antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase in normal human tissues, normal mouse tissues, vertebrate red blood cells and neoplastic human cell lines shows that the activities of copper-zinc superoxide dismutase, catalase and glutathione peroxidase in normal tissues are influenced by a single factor. Catalase activity has the highest loading and correlation with this factor, suggesting a catalase- or hydrogen peroxide-related influence. The activity of manganese superoxide dismutase is influenced by a separate factor. The activities of copper-zinc and manganese superoxide dismutases in normal tissues therefore appear to be dichotomously regulated. The activities of superoxide dismutase and glutathione peroxidase in vertebrate red blood cells are influenced by a single factor. The activity of catalase is influenced by a separate factor. The roles of glutathione peroxidase and catalase in hydrogen peroxide catabolism in red blood cells in fact differ. In neoplastic human cell lines, two bipolar factor factors appear to influence the activities of catalase and manganese superoxide dismutase, and glutathione peroxidase and copper-zinc superoxide dismutase, respectively. The factors are, however, mainly catalase and glutathione peroxidase activity factors as the loadings and correlations of manganese superoxide dismutase on the one hand and copper-zinc superoxide dismutase on the other, with the respective factors, are relatively small. Potentially low superoxide production and intrinsically low peroxidizability of tumour cell membranes underlie the peculiar variation of antioxidant enzyme activities in tumour cells. Factor analysis is proposed as a heuristic data reduction and hypothesis-creating technique for the variation of antioxidant and other functionally-linked enzyme activities in normal and pathological cells and tissues.
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PMID:Factor analysis of the activities of superoxide dismutase, catalase and glutathione peroxidase in normal tissues and neoplastic cell lines. 350 91

NADH-dependent reduction of polyvanadate was observed by using rat liver microsomes as the enzyme source. The reduced vanadate form obtained was blue in color with a broad absorption maximum in the red region around 650 nm. Microsomes and phosphate anions were found to be essential for polyvanadate reduction. The rate and the extent of formation of blue color compound was dependent on the amount of vanadate present. Cytochrome b5 was found to be involved in this SOD-insensitive reaction. The rate of disappearance of the blue-colored compound was dependent on concentration of NADH and was found to be sensitive to SOD. Catalase and Mn2+, which inhibit oxygen consumption accompanying NADH oxidation, increased both the rate and extent of the blue color compound formed. The results suggest that vanadate acts as an electron acceptor.
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PMID:NADH-dependent polyvanadate reduction by microsomes. 365 Jun 95

Microsomal membranes isolated from sugar beet (Beta vulgaris L. var. GWD-2) storage tissue were found to contain a Na3VO4-dependent system for the oxidation of NADH. The system was demonstrated to be enzymatic in nature and specific for Na3VO4. Maximal Na3VO4-dependent NADH oxidation was observed at pH 6.5, when Na3VO4 was present at 200 microM and when NADH was present at 100 microM. The oxidation activity was insensitive to rotenone and antimycin A but was inhibited by NaN3, NaCN, and quinacrine. Sodium vanadate-dependent NADH oxidation occurred with a concomitant uptake of O2 from the assay solution. Both NADH oxidation and O2 consumption were dependent upon the presence of Na3VO4, inhibited by manganese, and preferred NADH to NADPH. Catalase prevented Na3VO4-dependent O2 consumption but accelerated NADH oxidation. The effects of manganese and catalase suggest that superoxide anion and hydrogen peroxide may be involved in this process. While it is unclear as to the physiological significance of Na3VO4-dependent NADH oxidation in plant cells, the presence of this system indicates that caution must be exercised when coupled ATPase assays depending upon NADH oxidation are used with plant membranes in the presence of Na3VO4.
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PMID:Vanadate-dependent NADH oxidation in microsomal membranes of sugar beet. 384 27

1. Oxygen was taken up rapidly when pyruvate was added to mixtures of pyridoxamine and Mn(2+) ions after lag periods that were shortened by peroxidase (donor-hydrogen peroxide oxidoreductase, EC 1.11.1.7). 2. The total oxygen uptake was proportional to the pyridoxamine added and was accompanied by the disappearance of pyridoxamine; the pyruvate acted catalytically and hydrogen peroxide was not formed. 3. At pH6 more than half the pyridoxamine that disappeared was accounted for as pyridoxal and ammonia; it is suggested that the primary reaction is the oxidative deamination of the pyridoxamine. 4. Results were similar when alpha-oxobutyrate or glyoxylate were substituted for pyruvate, except that the reactions were slower and the yield of pyridoxal less. 5. The oxidative decarboxylations of alpha-oxoglutarate and phenylpyruvate are catalysed by Mn(2+) ions and these reactions are activated by peroxidase; pyridoxamine increased both the rates and total oxygen uptakes in these reactions, and ammonia was produced. 6. The lag periods in the oxidation of mixtures of pyridoxamine and alpha-oxo acids, catalysed by Mn(2+) ions, were also shortened by traces of colloidal manganese dioxide. 7. It is suggested that the activating effect of peroxidase depends on its catalysis of manganese oxidation.
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PMID:The oxidation of Schiff bases of pyridoxamine with -oxo acids by manganous ions and peroxidase. 463 37

1. Oxygen was taken up rapidly when pyridoxal or pyridoxal phosphate was added to mixtures of pea-seedling extracts and Mn(2+) ions. 2. The increases in total oxygen uptake were proportional to the pyridoxal or pyridoxal phosphate added and were accompanied by the disappearance of these compounds. 3. In addition to Mn(2+) ions, the reactions depended on two factors in the extracts, a thermolabile one in the non-diffusible material and a thermostable one in the diffusate; these factors could be replaced in the reactions by horse-radish peroxidase (donor-hydrogen peroxide oxidoreductase, EC 1.11.1.7) and amino acids respectively. 4. When pyridoxal phosphate was added to mixtures of amino acids and Mn(2+) ions oxygen uptake was rapid after a lag period of 30-90min.; the lag period was shortened to a few minutes by peroxidase, particularly in the presence of traces of p-cresol, or by light. 5. When pyridoxal replaced pyridoxal phosphate relatively high concentrations were required and peroxidase had only a small activating effect. 6. Pyridoxal or pyridoxal phosphate disappeared during the reactions and carbon dioxide and ammonia were formed. 7. With phenylalanine as the amino acid present, benzaldehyde was identified as a reaction product. 8. It is suggested that the reactions are oxidations of the Schiff bases formed between pyridoxal or pyridoxal phosphate and amino acids, mediated by a manganese oxidation-reduction cycle, and resulting in oxidative decarboxylation and deamination of the amino acids.
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PMID:The oxidation of Schiff bases of pyridoxal and pyridoxal phosphate with amino acids by manganous ions and peroxidase. 594 50

The formation of cinnabarinate in the presence of manganese ions and catalase was investigated spectrophotometrically. The absorption peak of cinnabarinate at 460 nm appeared only in a reaction system containing manganese ions and catalase. If catalase was omitted, a new absorption peak at 360 nm was observed while the absorption peak of cinnabarinate reached a plateau. Furthermore, in the presence of hydrogen peroxide, the absorption spectrum of cinnabarinate changed; catalase suppressed this absorption change. We conclude that in the course of cinnabarinate formation in the presence of manganese ions hydrogen peroxide is produced, which decomposes cinnabarinate. Catalase prevents the accumulation of hydrogen peroxide, which results in the steady increase of cinnabarinate. Cinnabarinate formation by manganese ions shows an initial lag phase. This lag phase disappeared by preincubating 3-hydroxyanthranilate under aerobic conditions. Incubation of 3-hydroxyanthranilate resulted in the generation of superoxide anions. When both manganese ions and superoxide anions were present, the lag phase of cinnabarinate formation disappeared. In the process of cinnabarinate formation, manganese ions serve to dismutate superoxide anions, as does superoxide dismutase; manganese (II) ions were oxidized to manganese (III) ions by superoxide anions. From these results we have proposed a mechanism of cinnabarinate formation catalysed by manganese ions.
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PMID:Cinnabarinate formation in malpighian tubules of the silkworm. Bombyx mori: reaction mechanism of cinnabarinate formation in the presence of catalase and manganese ions. 666

Rat kidney homogenates metabolize N6-trimethyl-lysine to N-trimethylammoniobutyrate, but not to carnitine. The first step in this conversion is the hydroxylation of trimethyl-lysine to form 3-hydroxy-N6-trimethyl-lysine. An assay system was developed in which hydroxylation of trimethyl-lysine is linear with respect to both time and homogenate protein concentration. The rate is 5 nmol of 3-hydroxy-N6-trimethyl-lysine formed/min per mg of homogenate protein. The cofactors required are ascorbate, alpha-oxoglutarate, FeSO4, and O2. Catalase and dithiothreitol give a 20% stimulation. Ca2+ produces a 2-fold increase in specific activity and cannot be replaced by Mg2+, Mn2+ or Zn2+. These last three bivalent cations lead to a decreased activity. Subcellular distribution studies demonstrate that trimethyl-lysine hydroxylase activity parallels the distribution profile of succinate dehydrogenase and citrate synthase. Thus trimethyl-lysine hydroxylase has a mitochondrial localization. Distribution of trimethyl-lysine hydroxylase activity between cortex and medulla of kidney if 67 and 33% respectively, similar to mitochondrial distribution.
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PMID:Carnitine biosynthesis. Hydroxylation of N6-trimethyl-lysine to 3-hydroxy-N6-trimethyl-lysine. 677 70

Superoxide dismutase has been identified and peroxidatic activity demonstrated in Mycobacterium leprae. The superoxide dismutase, shown indirectly to be a manganese-containing enzyme, was present at low activity in the cell-free extract. Peroxidatic activity was detected in a haemoprotein on polyacrylamide gels, but quantitative assay was not possible. Catalase, although present in a cell-free extract, appeared to be a host-derived enzyme, thus emphasizing the importance of establishing the authenticity of enzyme activities in host-derived M. leprae. The implications for the growth of M. leprae in vivo and its non-cultivability are discussed in the light of these findings.
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PMID:Superoxide dismutase, peroxidatic activity and catalase in Mycobacterium leprae purified from armadillo liver. 702 67

In this study, we evaluated the ability of low molecular weight manganese-based superoxide dismutase mimetics to attenuate neutrophil-mediated oxygen radical damage to human aortic endothelial cells in vitro. Human neutrophils, when exposed to tumor necrosis factor-alpha and the complement compound C5a, induced endothelial damage assessed by the release of 51Cr into the medium. This damage correlated with the amount of superoxide generated by neutrophils. Three superoxide dismutase mimetics, with catalytic rate constants for superoxide dismutation ranging from 4 to 9 x 10(7) M-1 S-1, inhibited neutrophil- or xanthine oxidase-mediated endothelial cell injury in a concentration-dependent manner. A similar manganese-based compound with no detectable superoxide dismutase activity was ineffective in inhibiting injury. Fluorescent studies of the neutrophil respiratory burst showed that the superoxide dismutase mimetics were protective without interfering with the generation of superoxide by activated neutrophils. Catalase, elastase inhibitors, and desferrioxamine mesylate (an iron chelator and hydroxyl radical scavenger) were not protective against cell injury. This investigation demonstrates that neutrophil-mediated human aortic endothelial cell injury in vitro is mediated by the superoxide anion and that low molecular weight manganese-based superoxide dismutase mimetics are effective in abrogating this damage.
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PMID:Superoxide dismutase mimetics inhibit neutrophil-mediated human aortic endothelial cell injury in vitro. 803 1


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