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

Methanol and ethanol were rapidly metabolized to formaldehyde and acetaldehyde in the presence of ascorbate, 1,10-phenanthroline and either guinea pig hepatic 100,000 g supernatant or 12,000 g pellet fractions. The specific activity of methanol oxidation was 1720 nmoles formaldehyde formed/min/mg protein in the 100,000 g fraction and 790 in the 12,000 g pellet fraction. The specific activity of ethanol oxidation was 1590 nmoles acetaldehyde formed/min/mg protein in the 100,000 g fraction and 820 in the 12,000 g pellet fraction. The activity was enzymatic in that it was linear with time, proportional to protein concentration, and sensitive to temperature. Catalase appeared to be the enzymatic component responsible for the oxidation. In this ascorbate-dependent alcohol oxidation system, oxygen was consumed and H2O2 was formed. When purified catalase and ascorbate were used, complex I was detected and methanol was oxidized.
Biochem Pharmacol 1984 Dec 15
PMID:Ascorbic acid and alcohol oxidation. 650 46

Parallel increases in intracellular catalase activity and resistance to extracellular H2O2 and to hyperbaric O2 toxicity were observed when Bacteroides distasonis VPI 4243 (ATCC 8503, type strain) was grown in either complex or defined medium containing graded amounts of hemin. Virtually all of the cells with high catalase activity (greater than 200 U/mg) remained viable upon exposure at 37 degrees C to 100-lb/in2 O2 on agar surfaces for 1 h, whereas low-catalase cells (less than 10 U/mg) lost 1.2 log units of viable cells during that treatment. Upon exposure to 500 microM H2O2, high-catalase cells lost 0.4 log units of the initial viable colonies during the same period in which low-catalase cells lost 3 log units of viable cells. The superoxide dismutase activity was the same in each test culture. These data support the role of intracellular catalase in protecting B. distasonis from oxidative damage resulting from hyperbaric oxygenation or H2O2 exposure. Catalase activity elicited by adding hemin to cells grown previously in medium lacking hemin was inhibited only 40% by prior incubation of the cells with chloramphenicol (30 micrograms/ml) and only 22% with rifampin (5 micrograms/ml). A model which is consistent with these data involves the production of an apocatalase in cells grown in low-hemin medium. Addition of hemin to the cells would result in a rapid chloramphenicolor rifampin-insensitive stimulation of catalase activity followed by further de novo biosynthesis of catalase.
J Bacteriol 1983 Dec
PMID:Effect of heme on Bacteroides distasonis catalase and aerotolerance. 664 89

Intramolecular isotope effects were determined for the N-demethylation of N-methyl-N-trideuteriomethylaniline catalyzed by two isozymes of cytochrome P-450 and several peroxidases in order to differentiate between deprotonation and hydrogen atom abstraction steps. Lactoperoxidase, hemoglobin, myoglobin, and two isozymes of horseradish peroxidase catalyzed the hydroperoxide-dependent N-demethylation at initial rates ranging from 20 to 1700 min-1. These hemeproteins exhibited large and comparable intramolecular isotope effects (kH/kD = 8.6 to 10.1). In contrast, two isozymes of cytochrome P-450 as well as chloroperoxidase (v = 1.5 to 1700 min-1) gave low isotope effects (kH/kD = 1.7 to 3.1) under identical conditions. Catalase exhibited an intermediate intramolecular isotope effect (kH/kD = 5.4). These results have been interpreted to indicate that most of the hemeproteins investigated catalyze N-demethylation reactions via alpha-carbon hydrogen atom abstraction, while the reactions catalyzed by cytochrome P-450 and chloroperoxidase proceed via alpha-carbon deprotonation.
J Biol Chem 1983 Dec 10
PMID:The use of intramolecular isotope effects to distinguish between deprotonation and hydrogen atom abstraction mechanisms in cytochrome P-450- and peroxidase-catalyzed N-demethylation reactions. 664 95

Experiments were carried out to determine if the difference in rates of cell proliferation between normal and neoplastic cells may be related to altered levels of oxidative enzymes. Assays were performed using homogenates from hepatocellular carcinoma HC-252, a rapidly growing and moderately well-differentiated tumor; from normal liver; and from the liver of the tumor-bearing ACI rat. Results of the mitochondrial enzymes indicated that the activities of cytochrome oxidase and succinate dehydrogenase were 3-fold lower in tumor homogenates than in liver homogenates. Monoamine oxidase activity could not be detected in HC-252; mixing experiments indicated no inhibitor was present in HC-252. Activities of th peroxisomal enzymes, urate oxidase, D-amino acid oxidase, and L-alpha-hydroxy acid oxidase were either undetected in the tumor or were 12-fold lower than in liver homogenates. The activity of xanthine oxidase, a cytoplasmic enzyme, was 5- to 6-fold lower in the tumor. Catalase activity in the tumor was also lower than in liver; this may be indicative of a lower oxidative environment at the cellular level. These enzyme activities of the liver of tumor-bearing rats were in the same range as those of normal rat liver, except that D-amino acid oxidase activity was slightly lower, and catalase activity was markedly lower and varied in a wide range. These results show an inverse correlation between the activities of oxygen-utilizing enzymes and rates of proliferation of one tumor line and its control. The possible implications of these results in neoplasia, cell proliferation, and cellular aging are discussed.
Cancer Res 1980 Dec
PMID:Oxidoreductase activities in normal rat liver, tumor-bearing rat liver, and hepatoma HC-252. 689 80

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.
J Gen Microbiol 1980 Dec
PMID:Superoxide dismutase, peroxidatic activity and catalase in Mycobacterium leprae purified from armadillo liver. 702 67

Echis colorata bites cause impairment of platelet aggregation and hemostatic disorders. The mechanism by which the snake venom inhibits platelet aggregation was studied. Upon fractionation, aggregation impairment activity and L-amino acid oxidase activity were similarly separated from the crude venom, unlike other venom enzymes. Preparations of L-amino acid oxidase from E. colorata and from Crotalus adamanteus replaced effectively the crude E. colorata venom in impairment of platelet aggregation. Furthermore, different treatments known to inhibit L-amino acid oxidase reduced in parallel the oxidase activity and the impairment potency of both the venom and the enzyme preparation. H2O2 mimicked characteristically the impairment effects of L-amino acid oxidase and the venom. Catalase completely abolished the impairment effects of the enzyme and the venom. It is concluded that hydrogen peroxide formed by the venom L-amino acid oxidase plays a role in affecting platelet aggregation and thus could contribute to the extended bleeding typical to persons bitten by E. colorata.
Thromb Haemost 1982 Dec 27
PMID:Impairment of platelet aggregation by Echis colorata venom mediated by L-amino acid oxidase or H2O2. 716 17

Glutathione peroxidase (GSH-Px) and catalase activities were evaluated during intake of excess dietary iron. Male Sprague-Dawley rats were randomized into seven dietary treatments. The treatments included three levels of dietary iron (35, 305, and 1255 ppm) plus deficiencies of Se or Se and vitamin E at the two high iron levels. Lipid peroxidation in liver and GSH-Px and catalase activities in erythrocytes and liver were measured. Lipid peroxidation was elevated in all high iron groups compared to controls. Total GSH-Px in erythrocytes and liver remained constant or decreased in animals receiving high iron, but non Se GSH-Px increased significantly in liver from rats fed high iron (305 ppm: 155% and 1255 ppm: 131%) and increased additionally in Se and vitamin E deficient groups. No differences in RBC catalase activity were observed. Liver catalase activity increased at least 72% during deficiencies of Se and vitamin E. In summary, GSH-Px did not respond to increased oxidative stress associated with elevated dietary iron except for the non Se GSH-Px which accounts for a relatively small amount of total activity in liver. Catalase increased in liver only when GSH-Px and vitamin E are limiting.
J Nutr 1981 Dec
PMID:Response of glutathione peroxidase and catalase to excess dietary iron in rats. 731 May 44

Catalase, peroxidase and superoxide dismutase were found to inhibit significantly carrageenin edema and the primary phase of adjuvant arthritis in rats after i.v. injection. Heat-inactivated enzymes were as effective as the native enzymes. None of 10 scavengers of oxygen radicals inhibited the adjuvant arthritis at any time. Accordingly, no evidence for a participation of oxygen radicals in the secondary arthritis phase could be found, whereas a role of oxygen radicals in the primary arthritis phase and in carrageenin edema cannot be ruled out.
Experientia 1981 Dec 15
PMID:Effects of catalase, peroxidase, superoxide dismutase and 10 scavengers of oxygen radicals in carrageenin edema and in adjuvant arthritis of rats. 732 41

To determine the mechanism of hemolysis following organ transplantation, we studied the effect of immunosuppressants and/or superoxide (SO) on the in vitro destruction of red cells. The immunosuppressants tested included cyclosporin A (CyA), deoxyspagarine (DSG), and FK506. SO was obtained from the hypoxanthine-xanthine oxidase reaction. Of the three immunosuppressants studied, only CyA affected the size of red cells and directly produced hemolysis in an isotonic buffer without the involvement of an immune mechanism. In addition, SO and CyA showed a synergistic effect on hemolysis during prolonged incubation. Catalase and allopurinol prevented hemolysis by counteracting the activity of SO. In that SO is produced in excess during the recovery of blood flow after organ transplantation, the prolonged contact of red cells with CyA and SO may be involved in the development and reinforcement of hemolysis in vivo.
Tokushima J Exp Med 1994 Dec
PMID:Reinforcement of cyclosporin A-induced red cell destruction by superoxide. 753 79

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a potent tobacco-specific carcinogen, has been demonstrated to induce lung tumors in animals and is suspected to be a human carcinogen. Cytochromes P450 are the major enzymes responsible for the activation of NNK in microsomes from the lung and liver of rat and mouse, as well as human liver. The present study investigated the enzymes responsible for the metabolic activation of NNK in human lung microsomes. In the presence of a NADPH-generating system, the formation of keto aldehyde and keto alcohol (alpha-hydroxylation products, measured together), keto acid, hydroxy acid, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol was observed in human lung microsomes. Carbon monoxide (90%) decreased the rate of NNK oxidation by 5-49%, depending on the human lung microsomal samples analyzed. Coumarin decreased the oxidation of NNK by 9-34%, and an antibody against human P450 2A6 decreased the metabolism of NNK by 8-37%, suggesting the involvement of P450 2A6 in NNK oxidation. alpha-Napthoflavone inhibited NNK oxidation by 6-26%, possibly due to the inhibition of P450 1A1. P450 1A1-expressed microsomes catalyzed the formation of keto aldehyde and keto alcohol, exhibiting Km values of 1400 microM and 371 microM, respectively. In the absence of NADPH, NNK metabolism resulted in the formation of keto acid, keto aldehyde, and keto alcohol, and the activities in different lung samples were decreased by indomethacin (100 microM; cyclooxygenase inhibitor) or nordihydroguaiaretic acid (100 microM; lipoxygenase inhibitor) by 0-27% or 30-66%, respectively. The addition of arachidonic acid (10-100 microM) increased the rate of the formation of keto aldehyde and keto alcohol approximately 2-fold but inhibited the formation of keto acid. Soybean lipoxygenase increased the rate of formation of keto aldehyde and keto alcohol in a concentration-dependent manner. The increased rate in NNK oxidation by arachidonic acid or lipoxygenase was inhibited completely by nordihydroguaiaretic acid. Catalase, thiourea, and conjugated linoleic acid decreased the rate of NNK oxidation by 47, 20, and 45%, respectively. tert-Butyl-hydroperoxide, cumene hydroperoxide, and hydrogen peroxide increased the rate of formation of keto aldehyde and keto alcohol by 210, 40, and 50%, respectively. The results suggest that P450 enzymes are only partially responsible for the activation of NNK in human lung microsomes, and P450 2A6 or a P450 2A6-related enzyme seems to be involved in the activation. Furthermore, lipoxygenase and lipid hydroxperoxides may play important roles in the oxidation of NNK in human lung microsomes.
Cancer Res 1995 Dec 01
PMID:Activation of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in human lung microsomes by cytochromes P450, lipoxygenase, and hydroperoxides. 758 36


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