Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Purified ferredoxin-(cytochrome c)-NADP+ oxidoreductase and xanthine oxidase were found to catalyse the reduction of nitrofurantoin to the free radical. Under aerobic conditions, the nitrofurantoin radical underwent autoxidation to regenerate the parent compound with the concomitant production of superoxide and eventually hydrogen peroxide. The nitrofurantoin radical was also shown to react with hydrogen peroxide to generate a highly reactive species which was capable of oxidising methionine to ethylene. This active oxygen radical appeared to be identical with the crypto-OH . radical, previously proposed as being formed from the analogous reaction of the methyl viologen radical with hydrogen peroxide [R.J. Youngman and E.F. Elstner, FEBS Lett. 129, 265 (1981)]. Catalase inhibited nitrofurantoin-dependent ethylene formation in both enzyme systems, whereas superoxide dismutase was only inhibitory in the xanthine oxidase mediated reaction. Although the primary function of the respective enzyme systems is to generate the nitrofurantoin radical, the xanthine oxidase reaction is markedly more complex than that of ferredoxin-(cytochrome c)-NADP+ oxidoreductase. The differences between the two enzyme reactions appear to be due to the endogenous autoxidation of xanthine oxidase. The aerobic activation of nitrofurantoin by xanthine oxidase involved the superoxide anion as an intermediate, whereas the nitrofuran was directly reduced by ferredoxin-(cytochrome c)-NADP+ oxidoreductase without a requirement for active oxygen species.
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PMID:Mechanisms of oxygen activation by nitrofurantoin and relevance to its toxicity. 629 96

Patients lacking the primary granulae enzyme, myeloperoxidase (MPO), do not usually show any increased susceptibility to infection or altered inflammatory response, in contrast to several other biochemical defects in polymorphonuclear neutrophils. We have now evaluated the role of MPO on phagocyte function in a patient with complete MPO deficiency suffering from generalized pustular psoriasis. We found that the MPO-deficient neutrophils showed enhanced phagocytosis (greater than 200% of normal) of IgG- and C3b-opsonized yeast particles and prolonged N-formylmethionyl-leucyl-phenylaline-mediated stimulation of superoxide production. When purified human MPO was added to normal neutrophils during cell adhesion, their Fc- and C3b-mediated phagocytosis was reduced without affecting cell viability. 1 microgram/ml of MPO reduced the Fc and C3b phagocytosis to 47 and 65%, respectively, whereas 10 micrograms/ml reduced the activity to 20 and 54%. Both attachment and ingestion were reduced to a similar extent, indicating that MPO affected the receptor function per se. When MPO was added to the hyperactive MPO-deficient cells, phagocytosis was reduced more rapidly. Catalase, azide, and methionine eliminated the inhibitory effect, and catalase and methionine, in fact, enhanced the phagocytic activity of adherent neutrophils. These data indicate that, apart from being a potent antimicrobial system, the oxidizing activity of the MPO-H2O2-halide system may modulate the inflammatory response by impairing certain receptor-mediated recognition mechanisms of phagocytic cells, which otherwise could elicit inflammatory reactions and tissue injury.
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PMID:Myeloperoxidase modulates the phagocytic activity of polymorphonuclear neutrophil leukocytes. Studies with cells from a myeloperoxidase-deficient patient. 632 54

The viability of neutrophils in the condition under which they kill neoplastic cells was studied. In the presence of phorbol myristate acetate (PMA) the 51Cr-release by human neutrophils was markedly stimulated. The PMA-induced 51Cr-release by neutrophils correlated well with the number of nonviable neutrophils as determined by the uptake of trypan blue. Phorbol myristate acetate had no effect on the 51Cr-release by lymphocytes, LPC-1 myeloma cells, ovarian ascites tumor cells, or neutrophils from a patient with chronic granulomatous disease. This suggests that the effect of PMA is not due to its nonspecific toxic effect; instead, it is dependent on the reactive oxygen species produced by the normal neutrophils. Catalase, cytochrome C, histidine, and methionine inhibited the PMA-induced 51Cr-release by human neutrophils, whereas superoxide dismutase, myeloperoxidase inhibitors, and some hydroxyl radical scavengers or singlet oxygen quenchers had no effect. The clumping of neutrophils induced by PMA was also important in the PMA-induced 51Cr-release by human neutrophils.
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PMID:Phorbol myristate acetate induced neutrophil autotoxicity. 719 15

The lung toxicity of a carbide-cobalt mixture is more important than that of each individual component; the mechanism of this interaction is not understood. The capacity of cobalt metal particles alone and mixed with different carbides to generate hydroxyl radicals was examined with the deoxyribose assay. In a chemical system, cobalt ions and cobalt metal particles (Co) were found to catalyse the degradation of deoxyribose in the presence of hydrogen peroxide. Carbides were able to directly oxidize deoxyribose, but their respective activities did not support such a mechanism to explain the carbide-cobalt interactive toxicity, since there was no direct relationship between deoxyribose degradation ability and cytotoxicity toward macrophages. Tungsten, niobium, titanium and chromium carbides (interactive carbides) were only weak oxidants and conversely molybdenum, vanadium and silicon carbides (non-interactive carbides) were the most potent ones. The ability of cobalt metal to produce hydroxyl radicals in the presence of hydrogen peroxide was not increased by tungsten carbide. The role of reactive radical formation in the toxicity of these particles was further assessed in a macrophage culture model. Catalase (4000 U/ml), superoxide dismutase (300 U/ml), sodium azide (1 mM), sodium benzoate, mannitol, taurine and methionine (all 20 mM) were all unable to protect against the cytotoxic effects of cobalt ions and cobalt metal alone or mixed with tungsten carbide. In conclusion, no evidence was found that production of reactive oxygen species contributes to the elective toxicity of carbide-cobalt mixtures.
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PMID:Evaluation of the role of reactive oxygen species in the interactive toxicity of carbide-cobalt mixtures on macrophages in culture. 839 91

Protein synthesis and antioxidant enzyme activities were investigated in gamma-irradiated (300 Gy) and heat shocked (42 degrees C) larval stages of the gastrointestinal parasite, Heligmosomoides polygyrus bakeri (H. polygyrus). No qualitative or quantitative differences were observed in the incorporation of (35S)-methionine into somatic proteins of unirradiated or irradiated exsheathed third-stage (L3) larvae at either 37 degrees C or 42 degrees C. The rate of protein synthesis doubled in L3 stages maintained at 42 degrees C compared with 37 degrees C, irrespective of whether the larvae had been irradiated or not. The composition of excretory/secretory (ES) proteins varied between unirradiated and irradiated exsheathed L3 larvae maintained under identical conditions. Prominent heat-inducible proteins of 26 and 17 kDa were synthesised and excreted at 42 degrees C by both unirradiated and irradiated L3 stages. No major differences in protein synthesis could be detected between unirradiated and irradiated fourth-stage (L4) larvae. Temperature elevation significantly reduced protein synthesis in L4 stages, most notably in unirradiated parasites. Heat-inducible proteins were not detected in response to either irradiation or temperature elevation in L4 larvae. Immune sera recognised a similar spectrum of antigens in both unirradiated and irradiated L4 somatic and ES preparations and reacted with antigens from irradiated L4 parasites with less intensity than with antigens from unirradiated L4 larvae. Catalase was the only antioxidant enzyme examined with activity that changed significantly in irradiated parasites, being reduced to approximately 36% of normal levels in irradiated L4 stages. No significant difference existed between irradiated and unirradiated parasites in the levels of activity of superoxide dismutase and glutathione reductase.
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PMID:The effect of gamma-radiation and heat shock on protein synthesis and antioxidant enzymes in the gastrointestinal parasite, Heligmosomoides polygyrus. 877 22

Mineral dust exposure can result in emphysema and chronic airflow obstruction. We postulated that dust-induced emphysema has a pathogenesis similar to that in cigarette smoke-induced emphysema, namely, excess release of proteolytic enzymes from dust-evoked inflammatory cells, and inactivation of alpha-1-antitrypsin (A1AT) by dust-catalyzed formation of oxidants. To test this theory we examined the antiproteolytic activity of A1AT exposed to quartz in vitro and found that it was decreased in a dose-response fashion. Catalase prevented this effect, which suggested that it was mediated by quartz-generated hydrogen peroxide. We also showed that a variety of dusts could oxidize methionine to methionine sulfoxide in vitro, using either pure amino acid or whole protein. The relative order of activity was coal > quartz > titanium dioxide. Lastly, we used a new high-performance liquid chromatography technique to demonstrate that quartz, coal, and titanium dioxide produced connective tissue breakdown in rat lungs, as determined by the appearance of desmosine and hydroxyproline in lavage fluid after dust instillation. On a particle-for-particle basis, the order of dust potency was similar to that for methionine oxidation. Connective tissue breakdown was associated with elevations of both polymorphonuclear leukocytes and macrophages in lavage fluid, and it is unclear whether one or both of these types of inflammatory cell mediates this process. These observations support our theory that dust-induced emphysema and smoke-induced emphysema occur through similar mechanisms.
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PMID:Mechanisms of mineral dust-induced emphysema. 940 Jul 26

The deficiency of methionine, an essential amino acid, is associated with cardiovascular lesions. Because different types of cardiac pathologies are caused by a decrease in antioxidants, we examined the effects of methionine on myocardial antioxidant enzymes in hemodynamically assessed rats that were treated with methionine (10 mg/ml) in drinking water for 12, 24, and 48 h. Glutathione peroxidase (GSHPx) activity was significantly increased to 150.5 +/- 12.2 and 191.7 +/- 13.7% of the control value at 12 and 24 h, respectively, followed by a decline to 120 +/- 24.6% at 48 h. The mRNA levels of GSHPx at these time points were 151.2 +/- 12.0, 218.7 +/- 35.3, and 173.5 +/- 25.2%, respectively. Superoxide dismutase (SOD) activity was 144.3 +/- 3.7, 114.3 +/- 10.1, and 143.1 +/- 11. 2% at 12, 24, and 48 h, respectively. Catalase (Cat) activity was 272.4 +/- 5.4, 237.8 +/- 16.6, and 224.1 +/- 17.3% of the control value. The expression of Cat and SOD mRNA was unchanged at 12, 24, and 48 h. The lipid peroxidation was decreased by 24.4 +/- 11.2, 54. 9 +/- 0.1, and 6.4 +/- 2.1% at 12, 24, and 48 h, respectively. Methionine had no effect on the ventricular or aortic pressures, heart rate, and myocardial glutathione levels at any of the time points. The study shows that methionine has a significant effect on the myocardial antioxidant enzyme activities, and only changes in GSHPx enzyme activity correlated with the mRNA changes. These antioxidant changes may have a role in the beneficial effects of methionine in pathological rather than physiological conditions.
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PMID:Effects of methionine on endogenous antioxidants in the heart. 1060 Aug 29

Dihydrolipoamide dehydrogenase (LADH) from Trypanosoma cruzi was inactivated by treatment with myeloperoxidase (MPO)-dependent systems. With MPO/H2O2/NaCl, LADH lipoamide reductase and diaphorase activities significantly decreased as a function of incubation time. Iodide, bromide, thiocyanide and chloride effectively supplemented the MPO/H2O2 system, KI and NaCl being the most and the least effective supplements, respectively. LADH inactivation by MPO/H2O2/NaCl and by NaOCl was similarly prevented by thiol compounds such as GSH, L-cysteine, N-acetylcysteine, penicillamine and N-(2-mercaptopropionyl-glycine) in agreement with the role of HOCI in LADH inactivation by MPO/H2O2/NaCl. LADH was also inactivated by MPO/NADH/halide, MPO/H2O2/NaNO2 and MPO/NADH/NaNO2 systems. Catalase prevented the action of the NADH-dependent systems, thus supporting H2O2 production by NADH-supplemented LADH. MPO inhibitors (4-aminobenzoic acid hydrazide, and isoniazid), GSH, L-cysteine, L-methionine and L-tryptophan prevented LADH inactivation by MPO/H2O2/NaNO2. Other MPO systems inactivating LADH were (a) MPO/H2O2/chlorpromazine; (b) MPO/H2O2/monophenolic systems, including L-tyrosine, serotonin and acetaminophen and (c) MPO/H2O2/di- and polyphenolic systems, including norepinephrine, catechol, nordihydroguaiaretic acid, caffeic acid, quercetin and catechin. Comparison of the above effects and those previously reported with pig myocardial LADH indicates that both enzymes were similarly affected by the MPO-dependent systems, allowance being made for T. cruzi LADH diaphorase inactivation and the greater sensitivity of its LADH lipoamide reductase activity towards the MPO/H2O2/NaCl system and NaOCl.
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PMID:Trypanosoma cruzi dihydrolipoamide dehydrogenase is inactivated by myeloperoxidase-generated "reactive species". 1082 17

Moderately elevated plasma homocysteine levels are an important independent risk factor for arterial and venous thrombosis and for atherosclerosis. Some investigators have proposed that homocysteine's effects result from oxidant injury to the vascular endothelium or from an alteration in endothelial function. However, homocysteine may have other cellular targets. We now report that homocysteine, at physiologically relevant concentrations, induces the expression of tissue factor by monocytes. In response to homocysteine, monocytes express procoagulant activity in a dose-dependent and a time-dependent manner. This activity is attributable to tissue factor because it was dependent on factor VII and blocked by anti-tissue factor antibodies. Tissue factor mRNA levels were also increased in monocytes after homocysteine treatment. The effect was found to be specific because analogues of homocysteine (homocystine and homocysteine thiolactone) did not mimic homocysteine's activity, nor did other thiol compounds (cysteine, 2-mercaptoethanol, dithiothreitol). On the other hand, methionine, the metabolic precursor of homocysteine, was active though less potent than homocysteine. Catalase and superoxide dismutase (scavengers of H(2)O(2) and O(2)(-) Radicals, respectively) were unable to block the expression of tissue factor induced by homocysteine, as was a 5-fold excess of the reducing agent 2-mercaptoethanol. We conclude that the induction of tissue factor expression by circulating monocytes is a plausible mechanism by which homocysteine may induce thrombosis and that a nonspecific redox process is not involved.
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PMID:Induction of monocyte tissue factor expression by homocysteine: a possible mechanism for thrombosis. 1091 Sep 11

In order to screen for new microbial D-amino acid oxidase activities a selective and sensitive peroxidase/o-dianisidine assay, detecting the formation of hydrogen peroxide was developed. Catalase, which coexists with oxidases in the peroxisomes or the microsomes and, which competes with peroxidase for hydrogen peroxide, was completely inhibited by o-dianisidine up to a catalase activity of 500 nkat ml(-)(1). Thus, using the peroxidase/o-dianisidine assay and employing crude extracts of microorganisms in a microplate reader, a detection sensitivity for oxidase activity of 0.6 nkat ml(-)(1) was obtained.Wild type colonies which were grown on a selective medium containing D-alanine as carbon, energy and nitrogen source were examined for D-amino acid oxidase activity by the peroxidase/o-dianisidine assay. The oxidase positive colonies possessing an apparent oxidase activity > 2 nkat g dry biomass(-)(1) were isolated. Among them three new D-amino acid oxidase-producers were found and identified as Fusarium oxysporum, Verticilium lutealbum and Candida parapsilosis. The best new D-amino oxidase producer was the fungus F. oxysporum with a D-amino acid oxidase activity of about 900 nkat g dry biomass(-)(1) or 21 nkat mg protein(-)(1). With regard to the use as a biocatalytic tool in biotechnology the substrate specificities of the three new D-amino acid oxidases were compared with those of the known D-amino acid oxidases from Trigonopsis variabilis, Rhodotorula gracilis and pig kidney under the same conditions. All six D-amino acid oxidases accepted the D-enantiomers of alanine, valine, leucine, proline, phenylalanine, serine and glutamine as substrates and, except for the D-amino acid oxidase from V. luteoalbum, D-tryptophane, D-tyrosine, D-arginine and D-histidine were accepted as well. The relative highest activities (>95%) were measured versus D-alanine (C. parapsilosis, F. oxysporum, T. variabilis), D-methionine (V. luteoalbum, R. gracilis), D-valine (T. variabilis, R. gracilis) and D-proline (pig kidney). The D-amino oxidases from F. oxysporum and V. luteoalbum were able to react with the industrially important substrate cephalosporin C although the D-amino acid oxidase from T. variabilis was at least about 20-fold more active with this substrate.As the results of our studies, a reliable oxidase assay was developed, allowing high throughput screening in a microplate reader. Furthermore, three new microbial D-amino acid oxidase-producers with interesting broad substrate specificities were introduced in the field of biotechnology.
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PMID:Detection and substrate selectivity of new microbial D-amino acid oxidases. 1102 24


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