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)

The effects of aging on the activities of drug-metabolizing enzymes and antioxidant enzymes were studied in male and female White-Footed mice (Peromyscus leucopus) at ages of 6, 8, 12, 18, 24, 30, 36, and 48 months. Male mice had significantly higher liver microsomal cytochrome P450 (P450) content and NADPH:cytochrome P450 oxidoreductase (P450 reductase) activities than females at all age groups. Many of the P450-dependent enzyme activities were also generally higher in males. Female mice showed age-dependent decreases in P450 content and the activities of P450 reductase, pentoxyresorufin O-dealkylase (PROD) and N-nitrosodimethylamine demethylase (NDMAd) in the liver from 6 to 24 months; while, the males showed an age-dependent decrease only for the liver PROD activity from 6 to 24 months. The old males (30-month old) appeared to have significantly higher activities for 6 beta-, 2 beta-, 16 alpha- and 16 beta-testosterone and androstenedione formation than the middle-aged (6- to 18-month old) and very old (48-month old) males. Females showed age-dependent decreases for the formation of 6 beta-, 2 beta-, 16 alpha- and 16 beta-testosterone in liver microsomes from 6 to 24 months. Lung microsomes from 6- and 8-month old males had much higher activities of ethoxyresorufin O-deethylase (EROD) and PROD than older males. The total NNK alpha-hydroxylation activities changed in the same pattern as lung microsomal EROD and PROD activities in both male and female mice. The activities of several phase II drug-metabolizing enzymes: glutathione S-transferase (GST), DT-diaphorase, sulfotransferase and UDP-glucuronosyl-transferase (UDPGT) did not show any significant age-dependent changes, with the possible exception that the GST activity in males decreased from 18 to 36 months. Males had about 3-fold higher UDPGT activities than females among all age groups. Glutathione peroxidase activities were drastically lower in old and very old males, and 6 to 24 months old males had significantly higher activities than the corresponding females. In females, superoxide dismutase activities decreased linearly to extremely low levels as mice aged. Catalase activities showed a tendency for increase with age in males. In conclusion, some P450-dependent activities and antioxidant enzymes, but not phase II drug-metabolizing enzymes, showed age-dependent changes; and most of these changes occur from 6 to 24 months. The demographic attributes of the White-Footed mouse are well-suited for physiological and biochemical studies of aging and can complement the more standard laboratory mouse model with its typical two year life span.
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PMID:Age- and gender-related variations in the activities of drug-metabolizing and antioxidant enzymes in the white-footed mouse (Peromyscus leucopus). 849 97

NADPH-cytochrome1 P450 reductase and DT-diaphorase catalyze and one- and two-electron reduction of adrenochrome to its o-semiquinone and o-hydroquinone, respectively. Under aerobic conditions both adrenochrome o-semiquinone and o-hydroquinone proved to be unstable, undergoing autoxidation with concomitant oxygen consumption and continuous NADPH and NADH oxidation. Molecular oxygen was found to play a predominant role in autoxidation of o-semiquinone during reduction of adrenochrome catalyzed by NADPH-cytochrome P450 reductase. In addition, molecular oxygen, in the presence of manganese, was found to be responsible for the majority of autoxidation of o-semiquinone. However, the role of superoxide radicals in the autoxidation of leucoadrenochrome during the reduction of adrenochrome by DT-diaphorase was found to be predominant. Catalase different significantly with respect to NADPH and NADH oxidation during reduction of adrenochrome catalyzed by NADPH-cytochrome P450 reductase and DT-diaphorase. Catalase increased NADPH oxidation slightly, while NADH oxidation was inhibited during reduction of adrenochrome by NADPH cytochrome P450 reductase and DT-diaphorase, respectively. The presence of manganese in the incubation mixture was found to increase the prooxidant role of catalase on autoxidation during one-electron reduction of aminochrome catalyzed by NADPH cytochrome P450 reductase. A marked difference in the inhibitory effect of superoxide dismutase on oxygen consumption during adrenochrome reduction catalyzed by NADPH-cytochrome P450 reductase and DT-diaphorase was also observed. A possible mechanism for reduction of adrenochrome by NADPH-cytochrome P450 reductase and DT-diaphorase and a role for superoxide dismutase and catalase are proposed.
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PMID:Effects of superoxide dismutase and catalase during reduction of adrenochrome by DT-diaphorase and NADPH-cytochrome P450 reductase. 859 36

Ethanol can be oxidized to the 1-hydroxyethyl radical (HER) by rat and deer mice liver microsomal systems. Experiments were carried out to evaluate the ability of human liver microsomes to catalyze this reaction, compare the effectiveness of NADH with that of NADPH, and assess the possible role of cytochrome b5 in HER formation. HER was detected as the alpha-(4-pyridly-1 -oxide)-N-t-butylnitrone/HER adduct. Human liver microsomes catalyzed HER formation with either NADPH or NADH as cofactor; rates with NADH were approximately 50% those found with NADPH. Chelex-100 treatment of the reaction mixture produced marked inhibition of HER formation, suggesting that a transition metal, such as iron, was required to catalyze the reaction. The addition of ferric chloride restore HER formation. Catalase (2600 units/ml) and superoxide dismutases (500 units/ml) nearly completely inhibited the reaction with either NADPH or NADH. The NADH-dependent rates of superoxide production, detected as 5,5-dimethyl-1-pyrroline-N-oxide-O2H, were approximately 50% the NADPH-dependent rates, which is consistent with the rates of HER formation. Anti-cytochrome b5 IgG decreased NADPH- and NADH-dependent HER formation, and this was associated with inhibition of superoxide formation with both reductants. These results indicate that human liver microsomes can catalyze the oxidation of ethanol of HER with either NADPH or NADH as reductant. The effectiveness of NADH may be significant in view of the increased NADH/NAD+ redox ratio in the liver as a consequence of ethanol oxidation by alcohol dehydrogenase. HER formation by human liver microsomes seems to be catalyzed by an oxidant derived from the interaction of iron with superoxide or H2O2, and a close association exists between HER formation and superoxide production. Cytochrome b5 seems to play a role in HER formation, most likely due to its effect on superoxide production.
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PMID:1-Hydroxyethyl radical formation during NADPH- and NADH-dependent oxidation of ethanol by human liver microsomes. 862 31

Ferritin is the major storage form of iron within cells, and iron released from ferritin has been shown to stimulate lipid peroxidation. Microsomes from rats chronically fed ethanol are more active in generating reactive oxygen intermediates than control microsomes. Since superoxide is one of the reductants capable of releasing iron from ferritin, and superoxide generation by microsomes is increased after chronic ethanol treatment, the ability of ferritin to stimulate lipid peroxidation of microsomes isolated from control rats and rats treated chronically with ethanol was evaluated. Ferritin was much more effective in stimulating lipid peroxidation of microsomes after ethanol treatment; net increases in thiobarbituric acid-reactive components by ferritin were 4-fold greater in the presence of NADPH with microsomes from the ethanol-treated rats compared to pair-fed controls and 10-fold greater with NADH as the microsomal reductant. Net increases in chemiluminescence by ferritin were about 10-fold greater with microsomes from the ethanol-treated rats. The NADPH- and NADH-dependent increases in lipid peroxidation produced by ferritin were prevented by superoxide dismutase, which lowered the rates found in the presence of ferritin to values found in the absence of ferritin. Catalase and hydroxyl radical scavengers had no effect on the stimulation by ferritin. Nonheme iron chelators prevented the ferritin stimulation as did glutathione, propylgallate, and trolox. Basal rates of lipid peroxidation were inhibited by anti-CYP2E1 IgG; the stimulation by ferritin was decreased by anti-CYP2E1 IgG. These results show that microsomes from ethanol-fed rats are more reactive than control microsomes in interacting with ferritin to produce oxidants capable of catalyzing lipid peroxidation. The inhibition of the ferritin-catalyzed lipid peroxidation by superoxide dismutase and anti-CYP2E1 IgG is consistent with a role for CYP2E1-generated superoxide radical in mobilizing iron from ferritin and in the subsequent catalysis of lipid peroxidation. Since ferritin is the major cellular storage form of iron, increased mobilization of iron from ferritin by CYP2E1-derived superoxide radical may play a role in the development of oxidative stress after ethanol treatment.
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PMID:Ferritin stimulation of lipid peroxidation by microsomes after chronic ethanol treatment: role of cytochrome P4502E1. 880 16

Oocysts of Cryptosporidium parvum showed relatively low levels of SOD activity. The SOD which had a pI of 4.8 and an approximate molecular weight of 35 kDa appeared to be iron dependent. Catalase, glutathione transferase, glutathione reductase and glutathione peroxidase activity could not be detected, nor could trypanothione reductase. No NADH or NADPH oxidase activity could be detected, nor could peroxidase activity be demonstrated using o-dianisidine, guaiacol, NADPH or NADH as co-substrates. However, an NADPH-dependent H2O2 scavenging system was detected in the insoluble fraction.
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PMID:Anti-oxidant enzymes in Cryptosporidium parvum oocysts. 901 Oct 70

The aim of this study was to determine whether neural cells exposed to beta amyloid (A beta) activate the pentose phosphate pathway (PPP), a critical oxidative stress defense mechanism. A beta stimulated H2O2 production in neural (B12) and non-neural (HepG2) cells and stimulated PPP activity, the source of the main intracellular reductant NADPH, in HepG2 cells (67% increase). Catalase blocked the A beta-induced increase in PPP, demonstrating that H2O2 mediated the increase in PPP activity. B12 cells showed no increase in PPP following A beta exposure. Fifty-five per cent of HepG2 cells but only 11.1% of B12 cells remained viable after A beta exposure. Lack of PPP activation may contribute to A beta cytotoxicity in neural calls and may lead to differences in survival between neural and non-neural cells.
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PMID:beta Amyloid does not activate the antioxidant pentose phosphate pathway within the B12 neural cell line. 917 13

The free-living anaerobic flagellate Hexamita sp. was observed to actively consume O2 with a K(m) O2 of 13 microM. Oxygen consumption increased linearly with O2 tension up to a threshold level of 100 microM, above which it was inhibited. Oxygen uptake was supported by a number of substrates but probably not coupled to energy conservation as cytochromes could not be detected spectro-photometrically. In addition, inhibitors specific for respiratory chain components did not significantly affect O2 uptake. Respiration was however, partially inhibited by flavoprotein and iron-sulfur protein inhibitors. NAD(P)H supported O2 consumption was measured in both particulate and soluble fractions; this activity was partially inhibited by quinacrine. A chemosensory response was observed in cells exposed to air, however no response was observed in the presence of superoxide dismutase plus catalase. Catalase and nonspecific peroxidase activity could not be detected, but superoxide dismutase plus catalase. Catalase and nonspecific peroxidase activity could not be detected, but superoxide dismutase activity was present. Superoxide dismutase was sensitive to NaN3, and H2O2 but not KCN, suggesting a Fe prosthetic group. Flow cytometric analysis revealed that thiol levels in live cells were depleted in the presence of t-butyl H2O2. The observed NADPH-driven glutathione reductase activity is believed to recycle oxidized thiols in order to re-establish reduced thiol levels in the cell. The corresponding thiol cycling enzyme glutathione peroxidase could not be detected. The ability to withstand high O2 tensions (100 microM) would enable Hexamita to spend short periods in a wider range of habitats. Prolonged exposure to O2 tensions higher than 100 microM leads to irreversible damage and cell death.
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PMID:Oxygen uptake and antioxidant responses of the free-living diplomonad Hexamita sp. 930 13

Alloxan-induced diabetic rats were treated with insulin (i.p.) or with Capparis decidua powder as a hypoglycaemic agent mixed with diet. The effect was assessed on lipid peroxidation (LPO) and the antioxidant defense system in rat tissues. The increased levels of blood glucose in diabetes produce superoxide anions and hydroxyl radicals in the presence of transition metal ions which cause oxidative damage to cell membranes. The heart tissue showed an increased lipid peroxidation (LPO) in diabetic rats while no significant change was observed in the liver and kidney. The treatment with C. decidua lowered LPO in these tissues even more effectively than insulin-treated rats. The superoxide dismutase (SOD) activity increased in the heart and kidneys in the diabetic group of rats probably to increase dismutation of superoxide anions. However, treatment with C. decidua decreased SOD activity in the liver and kidney and was comparable to control rats. Catalase (CAT) activity was not significantly affected in any of the tissues in diabetic and insulin-treated animals, however, CAT activity markedly increased in tissues with C. decidua treatment. Total and Se-dependent glutathione peroxidase (GSH-Px) in the heart was markedly lowered in diabetic rats which recovered with insulin as well as with C. decidua treatment. The increase in GSH-Px and CAT activity with C. decidua treatment may lower H2O2 toxicity and reduce oxidative stress in diabetes. However, glutathione (GSH) content in the heart and kidney and glutathione reductase (GSH-R) activity in all the tissues studied increased in diabetic rats while treatment with insulin lowered GSH content and GSH-R activity in these tissues. The treatment with C. decidua also decreased GSH-R activity in the kidney and heart which resulted in the decrease in GSH content in these tissues. The changes such as the increase in kidney and heart SOD may be an adaptive response in order to neutralize superoxide anions. The increase in GSH content and GSH-R activity in the tissue are in response to neutralize superoxide anions and to counteract oxidative stress in diabetes. Glutathione S-transferase (GST) was not significantly affected in diabetic rat tissue, however, heart GST increased with antidiabetic treatments. The increase in glucose-6-phosphate dehydrogenase (G6PDH) in the kidney and heart of diabetic rats subsequently decreased with C. decidua treatment. The increase in G6PDH in tissues may increase NADPH generation required for GSH-R activity and GSH production. It is suggested that these changes initially counteract the oxidative stress in diabetes, however, a gradual decrease in the antioxidative process may be one of the factors which results in chronic diabetes. The data indicate that C. decidua may have potential use as an antidiabetic agent and in lowering oxidative stress in diabetes.
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PMID:Action of capparis decidua against alloxan-induced oxidative stress and diabetes in rat tissues. 936 67

Reactive oxygen species such as superoxides, hydrogen peroxide (H2O2) and hydroxyl radicals have been suggested to be involved in the catalytic action of nitric oxide synthase (NOS) to produce NO from L-arginine. An examination was conducted on the effects of oxygen radical scavengers and oxygen radical-generating systems on the activity of neuronal NOS and guanylate cyclase (GC) in rat brains and NOS from the activated murine macrophage cell line J774. Catalase and superoxide dismutase (SOD) showed no significant effects on NOS or GC activity. Nitroblue tetrazolium (NBT, known as a superoxide radical scavenger) and peroxidase (POD) inhibited NOS, but their inhibitory actions were removed by increasing the concentration of arginine or NADPH respectively, in the reaction mixture. NOS and NO-dependent GC were inactivated by ascorbate/FeSO4 (a metal-catalyzed oxidation system), 2'2'-azobis-amidinopropane (a peroxy radical producer), and xanthine/xanthine oxidase (a superoxide generating system). The effects of oxygen radicals or antioxidants on the two isoforms of NOS were almost similar. However, H2O2 activated GC in a dose-dependent manner from 100 microM to 1 mM without significant effects on NOS. H2O2-induced GC activation was blocked by catalase. These results suggested that oxygen radicals inhibited NOS and GC, but H2O2 could activate GC directly.
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PMID:The effects of oxygen radicals on the activity of nitric oxide synthase and guanylate cyclase. 989 52

Catalase HPII from Escherichia coli, a homotetramer of subunits with 753 residues, is the largest known catalase. The structure of native HPII has been refined at 1.9 A resolution using X-ray synchrotron data collected from crystals flash-cooled with liquid nitrogen. The crystallographic agreement factors R and R(free) are respectively 16.6% and 21.0%. The asymmetric unit of the crystal contains a whole molecule that shows accurate 222-point group symmetry. The structure of the central part of the HPII subunit gives a root mean square deviation of 1.5 A for 477 equivalencies with beef liver catalase. Most of the additional 276 residues of HPII are located in either an extended N-terminal arm or in a C-terminal domain organized with a flavodoxin-like topology. A small number of mostly hydrophilic interactions stabilize the relative orientation between the C-terminal domain and the core of the enzyme. The heme component of HPII is a cis-hydroxychlorin gamma-spirolactone in an orientation that is flipped 180 degrees with respect to the orientation of the heme found in beef liver catalase. The proximal ligand of the heme is Tyr415 which is joined by a covalent bond between its Cbeta atom and the Ndelta atom of His392. Over 2,700 well-defined solvent molecules have been identified filling a complex network of cavities and channels formed inside the molecule. Two channels lead close to the distal side heme pocket of each subunit suggesting separate inlet and exhaust functions. The longest channel, that begins in an adjacent subunit, is over 50 A in length, and the second channel is about 30 A in length. A third channel reaching the heme proximal side may provide access for the substrate needed to catalyze the heme modification and His-Tyr bond formation. HPII does not bind NADPH and the equivalent region to the NADPH binding pocket of bovine catalase, partially occluded in HPII by residues 585-590, corresponds to the entrance to the second channel. The heme distal pocket contains two solvent molecules, and the one closer to the iron atom appears to exhibit high mobility or low occupancy compatible with weak coordination.
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PMID:Structure of catalase HPII from Escherichia coli at 1.9 A resolution. 1002 51


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