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)

Acetonitrile extracts of cigarette tar inhibit state 3 and state 4 respiration of intact mitochondria. Exposure of respiring submitochondrial particles to acetonitrile extracts of cigarette tar results in a dose-dependent inhibition of oxygen consumption and reduced nicotinamide adenine dinucleotide (NADH) oxidation. This inhibition was not due to a solvent effect since acetonitrile alone did not alter oxygen consumption or NADH oxidation. Intact mitochondria are less sensitive to extracts of tar than submitochondrial particles. The NADH-ubiquinone (Q) reductase complex is more sensitive to inhibition by tar extract than the succinate-Q reductase and cytochrome complexes. Nicotine or catechol did not inhibit respiration of intact mitochondria. Treatment of submitochondrial particles with cigarette tar results in the formation of hydroxyl radicals, detected by electron spin resonance (ESR) spin trapping. The ESR signal attributable to the hydroxyl radical spin adduct requires the presence of NADH and is completely abolished by catalase and to a lesser extent superoxide dismutase (SOD). Catalase and SOD did not protect the mitochondrial respiratory chain from inhibition by tar extract, indicating that the radicals detected by ESR spin trapping are not responsible for the inhibition of the electron transport. We propose that tar causes at least two effects: (1) Tar components interact with the electron transport chain and inhibit electron flow, and (2) tar components interact with the electron transport chain, ultimately to form hydroxyl radicals.
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PMID:The inhibitory effect of extracts of cigarette tar on electron transport of mitochondria and submitochondrial particles. 131 24

The effect in vitro of the naturally occurring flavonoid silybin on human polymorphonuclear leukocyte (PMN) functions has been studied. Preincubation of PMNs for 10 min at 37 degrees C with silybin inhibited, in a dose-dependent way, the luminol-enhanced chemiluminescence (CL) generated by stimulated cells without affecting the non-enhanced CL or superoxide anion production evaluated by the cytochrome C reduction assay. No significant effect of silybin on PMN phagocytic or chemotactic activities were found. Silybin did not absorb light at the wavelength of luminol-enhanced CL and was not toxic to PMNs at the concentrations used. Catalase, a scavenger of H2O2, inhibited luminol-enhanced CL to a similar degree as silybin; moreover, when incubated together with PMNs, silybin and catalase did not produce an additive inhibition of CL. On the contrary, the simultaneous addition of silybin and sodium azide, an inhibitor of myeloperoxidase, further increased inhibition over that seen with azide alone. These results suggest that inhibition of H2O2 may be the mechanism by which silybin inhibits the luminol-enhanced CL generated by stimulated PMNs. Such results indicate a possible anti-inflammatory activity for silybin even if their clinical relevance remains to be elucidated.
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PMID:Modulation of human polymorphonuclear leukocyte function by the flavonoid silybin. 285 72

Fairly pure leprosy bacilli were easily collected from nude mouse foot pad lepromas by the Ficoll density gradient centrifugation and alkali treatment methods. The yield of bacilli available for biochemical study was 42.6%. The density of Mycobacterium leprae was very heterogeneous. The percent of solid bacilli in the light bacilli fraction was 23%; that in the heavy bacilli fraction was 40%. The endogenous respiration activity in the heavy bacilli was greater than that in light bacilli. The average coefficient of respiration in M. leprae was 1 microliter O2/mg X hr. In the whole cells of M. leprae, a cytochrome b1 absorption peak and its Soret peak were detected at wavelengths of 560 nm and 426 nm, respectively. However, a cytochrome a2-like peak (which was observed in M. lepraemurium), and a cyt c and cyt a were not detected. Catalase activity was not found in whole cells, the cell-free extract, or particle fractions of M. leprae. Any catalase activity associated with M. leprae suspensions is a tissue contaminant. NAD-peroxidase activity was also not detected in the cell-free extract of the leprosy bacillus. These results would indicate that leprosy bacilli cannot degrade hydrogen peroxide.
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PMID:Respiration in Mycobacterium leprae. 300 14

Catalase activity and cytochrome content were measured in kidneys of Fisher 344 rats injected with aurothioglucose (ATG) either daily for 3 days or 5 days a week for up to 8 wk. Catalase activity was decreased 39%, 59%, and 48% (all p less than 0.001) after 3 days, 2 wk, and 8 wk, respectively. Microsomal cytochrome P-450 levels decreased 71%, 86%, and 80% (all p less than 0.001) after 3 days, 2 wk, and 8 wk, respectively. In contrast, cytochrome b5 was significantly increased at 3 days and 2 wk, but not at 8 wk. Microsomal heme contents decreased 44% (p less than 0.001), 34% (p less than 0.001), and 22% (p greater than 0.05) at 3 days, 2 wk, and 8 wk, respectively. The content of mitochondrial cytochromes aa3, b, c1, and c were not affected after 8 wk of ATG treatment. In vitro inhibition of the heme-containing enzyme delta-aminolevulinic acid dehydratase by ATG was reversible in the presence of physiological concentrations of small thiols. Although the activity of this enzyme in kidneys of ATG-treated rats was not measured, its significant inhibition in vivo by ATG appears unlikely. This study demonstrates that there were differential effects of gold on the various cytochromes and that changes in catalase activity paralleled changes in cytochrome P-450 and heme contents in the kidneys of ATG-treated rats. The findings are relevant to nephrotoxicity during chrysotherapy.
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PMID:Effect of chronic aurothioglucose treatment of rats on kidney catalase and cytochromes. 313 83

Nomenclature changes of pediococci postdate the publication of Bergey's Manual. Pediococci possess both a "group" and a "type" antigen. They are gram positive, asporogenous, nonmotile, generally catalase negative, but may possess catalase-like activity. The pediococci may have either a cytochrome or a flavoprotein enzyme system. Anaerobically they are homofermentative using the PEP:PTS and the EMP pathway. Catalase positive strains utilize glucose aerobically and anaerobically while lactose and glycerol are only used aerobically. Some pentoses are fermented to lactate and acetate. Absolute requirement for folinic acid and nearly all amino acids is observed. Pediococci grow luxuriously in All Purpose Tween (APT) broth and are isolated on Rogosa SL agar. Detection can be done by electrical impedance and fluorescent antibody techniques. The Arrhenius concept was utilized in selecting metabolically efficient strains. Antibiotics, antioxidants, some chloride salts and some spices are detrimental to the pediococci. On the other hand, some chloride salts, manganese, and some spices are stimulant. Dialysis-fermentation and immobilization of pediococcal cells were recorded. Some strains decarboxylate histidine to histamine. The resting cell metabolism and the production of bacteriocin have been utilized in antibiosis. An intra and intergeneric genetic transfer system of plasmids from pediococci was by a conjugation-like mechanism. Formation of bacteriocin and fermentation of carbohydrates were linked to plasmids. Lytic bacteriophages to pediococci have not yet been identified. Industrial cultures are mainly frozen concentrates. Linear equations were developed to model the fermentative activity of pediococci and the effects of environmental factors.
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PMID:Pediococci and biotechnology. 330 17

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

Rat liver microsomes catalyzed the oxidative delta 6-desaturation of linoleoyl-CoA (C18: 2, delta 9.12.) to gamma-linolenoyl-CoA (c18: 3, delta 6.9.12.) by using molecular oxygen and NADH or NADPH as the electron donors. The antibodies against cytochrome b5 inhibited markedly the delta 6-desaturation in the intact microsomes of the rat liver, suggesting that cytochrome b5 participated in the delta 6-desaturation. These experimental results led us to the hypothesis that the delta 6-desaturation of linoleoyl-CoA followed the scheme. (See formula in text). Terminal "delta 6-desaturase" was purified from rat liver microsomes for the first time by Triton X-100 solubilization, DEAE-cellulose, CM-Sephadex and cytochrome b5-Sepharose chromatography using its high affinity for cytochrome b5. The final enzyme preparation was homogeneous when applied to sodium dodecyl sulfate disc gel electrophoresis. delta 6-desaturase appeared as a single polypeptide of 66,000 daltons containing 49% nonpolar amino acid residues and one atom of non-heme iron. We confirmed that delta 6-desaturase differed from delta 9-desaturase, which converted stearoyl-CoA to oleoyl-CoA. The delta 6-desaturase activity required NADH (or NADPH), linoleoyl-CoA, oxygen, lipid or detergent and three enzymes, such as NADH-cytochrome b5 reductase (or NADPH-cytochrome P -450 reductase), cytochrome b5, and delta 6-desaturase. The reconstituted system of these components also confirmed the electron flow represented in Scheme 1. The delta 6-desaturase activity was inhibited by iron chelators, cyanine and p-chloromercuriphenyl sulfonate. In the reconstituted system of Km value for linoleoyl-CoA was 47 micro M, the maximal velocity was 83nmol/min/mg protein of delta 6-desaturase and the optimal pH was 7.0. Catalase, superoxide dismutase and t-butanol showed supportive effects on the delta 6-desaturation of the reconstituted system when purified enzymes were employed.
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PMID:[Purification and characterization of Linoleoyl-CoA desaturase from rat liver microsomes (author's transl)]. 726 18

The production of ferryl-type oxidants by microsomes from ethanol-fed rats and pair-fed controls was determined by assaying for the production of formaldehyde from ethylene glycol. Microsomes from the ethanol-fed rats were more reactive than controls in oxidizing ethylene glycol. Catalase was a powerful inhibitor for this reaction, superoxide dismutase was slightly inhibitory and hydroxyl radical scavengers had no effect. These results suggest an important role for H2O2, but not O2-. or .OH in the overall pathway for oxidizing ethylene glycol to formaldehyde. The production of H2O2 by microsomes was increased after ethanol treatment, the extent of increase corresponding to the increase in oxidation of ethylene glycol. A variety of inhibitors and ligands of cytochrome P450, including miconazole, diethyldithiocarbamate, tryptamine, and 4-methylpyrazole, inhibited formaldehyde production by both microsomal preparations. Anti-cytochrome P4502E1 IgG also inhibited the reaction with both microsomal preparations and prevented the increase caused by ethanol treatment. These results indicate that microsomes from ethanol-treated rats are more reactive than pair-fed controls in generating ferryl-type oxidants and that increased production of H2O2 by cytochrome P4502E1 plays a role in the elevated oxidation of ethylene glycol to formaldehyde.
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PMID:Increased oxidation of ethylene glycol to formaldehyde by microsomes after ethanol treatment: role of oxygen radicals and cytochrome P450. 760 3

The role of cytochrome c and catalase in hydroperoxide-induced lipid peroxidation of rat heart mitochondria was investigated. Mitoplasts were prepared from hearts of aminotriazole-treated rats which displayed both an 80-90% reduction in matrix catalase activity and rate of H2O2 consumption. Catalase-depleted mitochondria were more susceptible to H2O2-dependent lipid peroxidation and had similar extents of tert-butyl hydroperoxide (t-BuOOH)-induced lipid peroxidation compared with control mitochondria. The magnitude of lipid peroxidation induced by H2O2 was greater than that for t-BuOOH in catalase-depleted mitochondria, while t-BuOOH induced soybean phosphatidylcholine (PC) liposome lipid peroxidation to a greater extent than H2O2. The t-BuOOH- and H2O2-dependent mitochondrial lipid peroxidation was inhibited 50 and 7%, respectively, by cytochrome c3+ depletion of mitochondria. Similar relative sensitivities to t-BuOOH- and H2O2-dependent peroxidation occurred for cytochrome c(3+)-supplemented soybean PC liposomes. These data show a critical role for cytochrome c3+ in hydroperoxide-induced mitochondrial lipid peroxidation and demonstrate the importance of matrix catalase in protecting heart mitochondria from the toxicity of H2O2.
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PMID:The role of cytochrome c and mitochondrial catalase in hydroperoxide-induced heart mitochondrial lipid peroxidation. 838 Sep 70

The purpose of this study was to gain direct insights into mechanisms by which myoglobin induces proximal tubular cell death. To avoid confounding systemic and hemodynamic influences, an in vitro model of myoglobin cytotoxicity was employed. Human proximal tubular (HK-2) cells were incubated with 10 mg/ml myoglobin, and after 24 hours the lethal cell injury was assessed (vital dye uptake; LDH release). The roles played by heme oxygenase (HO), cytochrome p450, free iron, intracellular Ca2+, nitric oxide, H2O2, hydroxyl radical (-OH), and mitochondrial electron transport were assessed. HO inhibition (Sn protoporphyrin) conferred almost complete protection against myoglobin cytotoxicity (92% vs. 22% cell viability). This benefit was fully reproduced by iron chelation therapy (deferoxamine). Conversely, divergent cytochrome p450 inhibitors (cimetidine, aminobenzotriazole, troleandomycin) were without effect Catalase induced dose dependent cytoprotection, virtually complete, at a 5000 U/ml dose. Conversely, -OH scavengers (benzoate, DMTU, mannitol), xanthine oxidase inhibition (oxypurinol), superoxide dismutase, and manipulators of nitric oxide expression (L-NAME, L-arginine) were without effect. Intracellular (but not extracellular) calcium chelation (BAPTA-AM) caused approximately 50% reductions in myoglobin-induced cell death. The ability of Ca2+ (plus iron) to drive H2O2 production (phenol red assay) suggests one potential mechanism. Blockade of site 2 (antimycin) and site 3 (azide), but not site 1 (rotenone), mitochondrial electron transport significantly reduced myoglobin cytotoxicity. Inhibition of Na, K-ATPase driven respiration (ouabain) produced a similar protective effect. We conclude that: (1) HO-generated iron release initiates myoglobin toxicity in HK-2 cells; (2) myoglobin, rather than cytochrome p450, appears to be the more likely source of toxic iron release; (3) H2O2 generation, perhaps facilitated by intracellular Ca2+/iron, appears to play a critical role; and (4) cellular respiration/terminal mitochondrial electron transport ultimately helps mediate myoglobin's cytotoxic effect. Formation of poorly characterized toxic iron/H2O2-based reactive intermediates at this site seems likely to be involved.
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PMID:Myoglobin toxicity in proximal human kidney cells: roles of Fe, Ca2+, H2O2, and terminal mitochondrial electron transport. 906 5


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