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)

Normal human monocytes were induced to lyse nonsensitized target cells when triggered by precipitating immune complexes (IC) or soluble heat-aggregated IgG (HAIgG). Catalase, azide, cyanide and three aminoacids employed as quenchers of ClO, significantly inhibited this nonspecific cytotoxicity (NSC), suggesting an important role for the myeloperoxidase (MPO) system. However, HO and/or 1O2 may also be involved in the lysis, since certain scavengers of these species such as mannitol, benzoate, ethanol and histidine, as well as superoxide dismutase (SOD), partially inhibited NSC. Moreover, cyanide and azide were unable to completely abrogate this lytic activity. When NSC was compared to antibody dependent cellular cytotoxicity (ADCC), it was found that neither catalase nor oxygen-species scavengers affected ADCC while azide and cyanide significantly enhanced it. Antibody-coated target cells were also destroyed by IC-triggered monocytes. However, kinetic analysis and studies on the capacity of catalase to inhibit the lysis demonstrated that it was mediated through a NSC-like mechanism. The cytotoxic system described in this report offers a suitable model to study in vitro alternative lytic mechanisms triggered through monocyte receptors for the Fc portion of IgG (Fc gamma R).
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PMID:The role of reactive oxygen intermediates in nonspecific monocyte cytotoxicity induced by immune complexes. 303 42

The mutagenic activities of 6 of the chemicals identified in coffee solutions were assayed with the Salmonella Ara test, under experimental conditions optimized for coffee mutagenicity. Caffeine was the only non-mutagenic compound. Among the other 5 chemicals, hydrogen peroxide was the strongest mutagen and chlorogenic acid the weakest; methylglyoxal, glyoxal and caffeic acid exhibited intermediate mutagenicities. The minimal mutagenic doses of these components correlated negatively with their relative concentrations in coffee. It was concluded that chlorogenic acid, caffeic acid, glyoxal and methylglyoxal cannot contribute alone to the mutagenicity of coffee in the Ara test, since their minimal mutagenic concentrations were much higher than their respective levels in the coffee samples assayed. By contrast, 40-60% of the mutagenic activity in coffee and also in tea could be attributed to their H2O2 contents. Catalase abolished more than 95% of the mutagenic activity of coffee, as detected by the Ara test. A similar sensitivity to catalase has been reported by other authors in relation to the coffee mutagenicity identified by the Salmonella His test. Nevertheless, the results presented in this paper suggest that the Ara forward and the His reverse mutation tests are sensitive to the mutagenicity of different constituents in coffee solutions. We propose that the His test, sensitive at high coffee doses, mainly recognizes the mutagenicity of methylglyoxal, whilst the Ara test, sensitive at low coffee doses, mainly detects the mutagenic activity of hydrogen peroxide. The data reported also suggest that the direct-acting mutagenicity(ies) detected by the Ara test in tea solutions is (are) based on similar, if not identical, mechanisms.
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PMID:Study of the causes of direct-acting mutagenicity in coffee and tea using the Ara test in Salmonella typhimurium. 304 75

Bacteriophages P22, T4+, and T4os (osmotic shock-resistant mutant with altered capsids) were diluted in 0.85% NaCl and exposed to gamma irradiation (2.79 Gy/min) at room temperature (24 degrees C). T4+ was more sensitive to inactivation than was P22, and the T4os mutant was even more sensitive than T4+. Catalase exhibited a strong protective effect and superoxide dismutase a weaker protection, indicating that H2O2 or some product derived therefrom was predominant in causing inactivation of plaque formation. Low but significant (0.1-0.3 mM) reduced glutathione (GSH) enhanced phage inactivation, but a higher (1 mM) GSH concentration protected. A similar effect was found for the polyamine, spermidine. In contrast, 0.1 mM L-ergothioneine (2-thiol-L-histidine betaine) exhibited strong protection and 1 mM afforded essentially complete protection. L-Ergothioneine is present in millimolar concentrations in some fungi and is conserved up to millimolar concentrations in critical tissues when consumed by man. L-Histidine and two histidine-containing dipeptides, carnosine and anserine, protected at a concentration of 1 mM, a level at which they are present in striated muscles of various animals.
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PMID:Ergothioneine, histidine, and two naturally occurring histidine dipeptides as radioprotectors against gamma-irradiation inactivation of bacteriophages T4 and P22. 328 26

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 ability of granulocyte-macrophage colony-stimulating factor (CSF-H) to modulate human neutrophil functions was studied by using an in vitro system in which this cell type interacted with intracellular (amastigote [AMA]) forms of Trypanosoma cruzi. The presence of CSF-H during the 30-min period of neutrophil incubation with the AMA markedly enhanced parasite internalization. This effect was evidenced by significant increases in both the percentage of neutrophils incorporating AMA and the average number of AMA per 100 neutrophils with respect to mock-treated neutrophils. Pretreatment of the neutrophils with CSF-H reproduced the enhancement effect, whereas pretreatment of the AMA had no detectable consequence. The minimal neutrophil CSF-H pretreatment period required to significantly increase the number of AMA per 100 neutrophils was 20 min--suggesting that CSF-H induced time-dependent events ultimately leading to the manifestation of the noted effect--but neutrophil treatment with CSF-H for longer periods of time (up to 60 min) caused a much greater enhancement. Consistent with the notion of a regulatory action of CSF-H on neutrophils was the fact that the enhancing effect subsided gradually after removal of the factor and was no longer detectable after 16 hr. When 3H-labeled AMA were used, CSF-H-treated neutrophils released greater amounts of radiolabeled substances than mock-treated cells, indicating a stimulatory effect of CSF-H on the killing capacity of neutrophils. This was confirmed by the fact that untreated neutrophils that had internalized 3H-AMA killed the parasites at a faster rate when subsequently incubated with CSF-H. Catalase, but not superoxide dismutase, mannitol, benzoate, or histidine, inhibited neutrophil killing of the 3H-AMA whether the granulocytes had been exposed to CSF-H or not. This indicated that the cytotoxic mechanism involved the production of hydrogen peroxide in both cases, but possibly at a higher rate in the CSF-H-treated neutrophils. These results point to a regulatory effect of CSF-H on neutrophils that promotes cellular activities that might be relevant to the mechanisms of clearance of T. cruzi in vivo.
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PMID:Effects of human colony-stimulating factor on the uptake and destruction of a pathogenic parasite (Trypanosoma cruzi) by human neutrophils. 352 88

Two dermatophyte strains, Trichophyton quinckeanum and Trichophyton rubrum, were highly susceptible to in vitro killing by components of the H2O2-peroxidase-halide system. Both strains were, however, resistant to relatively high concentrations of reagent H2O2 or H2O2 enzymatically generated by glucose and glucose oxidase, KI, or lactoperoxidase (LPO) alone. Resistance to hydrogen peroxidase killing was found to be in part due to the presence of endogenous catalase in the fungi; susceptibility was increased by pretreatment of the fungi with a catalase inhibitor. Kinetic studies using small quantities of reagent or enzymatically generated H2O2 and LPO-KI showed that the system was lethal for both fungal strains within 1 min. Furthermore, using the glucose-glucose oxidase-LPO-KI system, it was shown that catalase, superoxide dismutase and histidine scavengers of H2O2, superoxide anion and singlet oxygen, respectively, prevented the killing of fungus, whereas scavengers of hydroxyl radicals such as benzoate and mannitol had no effect. T. quinckeanum was found to contain large quantities of superoxide anion, as judged by the nitroblue-tetrazolium test. Consequently, the xanthine (or hypoxanthine) and xanthine oxidase system in which the main product is superoxide anion had no toxic effect on the fungus. The high sensitivity of dermatophytes to killing by the H2O2-peroxidase-halide system active in polymorphonuclear neutrophils and macrophages may account in part for fungal toxicity in vivo.
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PMID:Susceptibility of Trichophyton quinckeanum and Trichophyton rubrum to products of oxidative metabolism. 361 Feb 10

Autooxidation of reduced glutathione in 50 mM buffer at pH 7.9 is indetectably slow in the presence of 1 mM DETAPAC, EDTA, TET, or tripyridine, but passing buffer through Chelex resin was insufficient to remove traces of catalytically active metals. Production of hydrogen peroxide during glutathione autooxidation was catalyzed by traces of Fe+2 or Cu+2, and to a much lesser extent by Cu+1 and Ni+2, but not to a detectable extent by Na+1, K+1, Fe+3, Al+3, Cd+2, Zn+2, Ca+2, Mg+2, Mn+2, or Hg+2. Cysteine was a much better precursor for hydrogen peroxide production than were cysteine sulfinic or sulfonic acids. The chelators EGTA, NTA, bipyridine, dimethyl glyoxime, salicylate, and Desferal were ineffective at preventing autooxidation. EDDA and 8-hydroxyquinoline were partially effective. Catalase could completely prevent the accumulation of detectable H2O2, but superoxide dismutase was only slightly inhibitory. Hydroxyl radical and singlet oxygen quenching agents (mannitol and histidine) stimulated. A mechanism for the production of H2O2 during trace metal catalyzed oxidation of glutathione is proposed, involving glutathione-complexed metal and dissolved oxygen. Although a radical intermediate can not be ruled out, no radical initiated chain reaction is necessary.
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PMID:Generation of hydrogen peroxide by incidental metal ion-catalyzed autooxidation of glutathione. 376 Aug 59

The susceptibility of axons to oxidative free radicals generated by pro-oxidant neurotoxins and related compounds was tested by applying the reagents to the disheathed ventral nerve trunk of the crayfish. Electrophysiological characteristics of the axons, including spike amplitude and rise time, were recorded, using intracellular glass microelectrodes. L-Dopa, or L-dopa in the presence of copper-(bis)-histidine (Cu-his), did not change significantly the electrophysiological characteristics of the axon. A 20 mM concentration of 6-hydroxydopamine (6-OHDA), 20 mM 6-OHDA in an anaerobic environment, and 20 mM 6-OHDA with inactivated catalase-SOD accelerated the rate of decline of the spike amplitude with time to 5-8 times the control rate. Simultaneously, parallel increases in rise time and spike duration were observed, consistent with partial depolarization of the resting membrane presumably resulting from increased permeability. Catalase, superoxide dismutase (SOD), or a mixture of catalase and SOD all afforded partial protection, catalase having the least protective effect, and catalase + SOD the greatest. In contrast, 20 mM H2O2, 2 mM H2O2, or Cu-his alone did not significantly accelerate deterioration of the axon. Most of the damage results from the interaction of H2O2 with O-2, rather than from the direct action of either species. p-Hydroxyphenylpyruvate (pHPP) in the presence of Cu-his induced a similar accelerated deterioration of the axon to 4.2 times the control rate. Catalase plus SOD partially protected against this effect, but either enzyme alone was not significantly protective.
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PMID:Deterioration of axonal membranes induced by phenolic pro-oxidants. Roles of superoxide radicals and hydrogen peroxide. 609 63

The magnetic circular dichroism (MCD) spectra of three horse heart metmyoglobin compounds, the cyanide, azide and hydroxide forms, have been measured in the visible and near infrared spectral regions at temperatures down to 1.5 K. The three compounds are all virtually completely low-spin at low temperatures with ground g factors of decreasing rhombicity in the order CN- greater than N3- greater than OH-. The MCD magnetization curves have been constructed at selected wavelengths throughout the visible and near infrared regions. The curves are independent of wavelength, showing that all the bands studied are x,y polarized and can, moreover, be satisfactorily fitted to the g factors determined by EPR spectroscopy with theoretical expressions (Thomson, A.J. and Johnson, M.K. (1980) Biochem. J. 191, 411-420). This confirms the assignment and polarizations of the near infrared region low-spin ferric haem charge-transfer bands. The energies of these transitions are markedly dependent upon the added axial ligand, ranging from 1595 to 1295, and 1050 nm for the compounds CN-, N3- and OH-. The MCD spectra of bovine liver catalase and its cyanide adduct have been recorded in the Soret, visible and near infrared regions. Catalase is know to have phenolate anion as the proximal ligand of the haem group. The forms of the spectra make an interesting comparison with those of the analogous metmyoglobin derivatives, in which histidine is the proximal ligand. The MCD spectra of catalase at 4.2 K is an example of a fully high-spin haemoprotein. The cyanide compound is completely low-spin at 4.2 K. The near infrared charge-transfer band is at 1300 nm, showing the effect on the energy of this band of changing from imidazole to phenolate ion as the proximal ligand to haem.
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PMID:A comparative study of the low-temperature magnetic circular dichroism spectra of horse heart metmyoglobin and bovine liver catalase derivatives. 683 94

The peroxidase-supported N-demethylations catalyzed by chloroperoxidase, a heme protein isolated from Caldariomyces fumago, have been investigated as models for cytochrome P-450-catalyzed N-dealkylations. The turnover number for the ethyl hydrogen peroxide-supported dealkylation of N,N-dimethylaniline by chloroperoxidase (1476) was much greater than that for cytochrome P-450-catalyzed dealkylations. The dealkylations of N,N-dimethylaniline by chloroperoxidase yielded N-methylaniline and formaldehyde in equimolar amounts with no other products detectable by high pressure liquid chromatography analysis of the reaction mixture. Ethyl hydrogen peroxidase could be replaced by other hydroperoxides, peroxides, or peracids. Chloride ions stimulated the reaction at low pH. The dealkylation reaction exhibited normal Michaelis-Menten saturation kinetics with respect to N,N-dimethylaniline (Km = 0.08 mM) and ethyl hydrogen peroxide (Km = 0.8 mM) at low substrate concentrations. However, substrate inhibition occurred at higher concentrations of N,N-dimethylaniline. The chloroperoxidase-catalyzed demethylations were inhibited by inhibitors of cytochrome P-450 such as azide or n-propyl gallate, but not by metyrapone, SKF-525A, or piperonyl butoxide. Although tiron and DL-epinephrine, trapping agents for the superoxide anion, inhibited the demethylation reactions, superoxide dismutase had no effect. There was no significant inhibition by alpha-phenyl-t-butyl-nitrone or 5,5-dimethyl-pyrroline-N-oxide, which react with free radicals. Diphenylfuran and DL-histidine, which react with singlet oxygen, did not inhibit the reaction. Substitution of D2O for H2O resulted in a marked inhibition with a solvent isotope effect (VH/VD) of 3.6. Chloroperoxidase did not catalyze the demethylation of N,N-dimethylaniline-N-oxide, indicating that the reaction does not proceed via an N-oxide intermediate.
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PMID:N-Demethylation reactions catalyzed by chloroperoxidase. 719 53


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