Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endogenous hydrogen peroxide (H2O2) release from aortic endothelial cells was studied in the presence of antioxidant enzyme inhibitors, mitochondrial inhibitors, a microsomal cytochrome P-450 inhibitor, and after oxidative stress induced with H2O2 or menadione. Extracellular H2O2 generation was determined spectrofluorometrically using 3-methoxy-4-hydroxy phenylacetic acid, and intracellular H2O2 production (in or near peroxisomes) was measured indirectly using aminotriazole, which inactivates catalase in the presence of H2O2. Extracellular H2O2 release was 0.079 +/- 0.005 nmol/min/mg protein in Hanks' balanced salt solution, was constant during a 120-min incubation period, and was not affected by the cell passage number. The half-life for catalase inactivation with aminotriazole was 23 min. Inhibition of catalase, glutathione reductase, or gamma-glutamylcysteine synthetase did not change the rate of extracellular release of H2O2. Furthermore, inhibition of the mitochondrial respiratory chain (rotenone, antimycin A) or microsomal cytochrome P-450 (8-methoxypsoralen) did not change extracellular H2O2 release or intracellular H2O2 production (at peroxisomes) by endothelial cells or cells in which glutathione reductase was inactivated. When the cells were exposed to exogenous H2O2 (30 microM), extracellular H2O2 was scavenged primarily by the glutathione redox pathway. Exogenously added H2O2 (100 microM) changed intracellular H2O2 production (in or near peroxisomes) only when the glutathione redox cycle was inactivated. Menadione (20 microM), which undergoes intracellular redox cycling, increased extracellular H2O2 release almost 4-fold to 0.3 nmol/min/mg protein. Furthermore, menadione increased peroxisomal H2O2 levels and decreased the half-life for catalase inactivation in the presence of aminotriazole to 13 min. Catalase inhibition increased extracellular H2O2 release during menadione treatment, indicating that H2O2 can diffuse across the plasma membrane during oxidant stress.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Regulation of hydrogen peroxide generation in cultured endothelial cells. 154 Mar 80

The forward mutation assay to L-arabinose resistance (Ara test) in Salmonella typhimurium was used to demonstrate that evaporated residues of brandy had direct-acting mutagenic activity. The mutagenicity covered a 100-fold range, from 13482 to 127 AraR induced mutants/ml brandy equivalent. Rat liver S9 mix suppressed the mutagenic activity of brandy in the Ara test. The inactivating capacity was independent of microsomal monoxygenase enzymes and appeared to be mediated through a heat stable component of the S9 fraction. Catalase was identified as the putative S9 component responsible for its inactivating capacity. The implication of reactive oxygen species in the direct-acting mutagenicity of brandy was supported by the higher sensitivity of Escherichia coli bacterial strains deficient in two major cellular antioxidant defense (glutathione and/or catalase) compared to their parental wild-type. Phenolic compounds of a polar nature could be responsible for the mutagenicity through the production of reactive oxygen intermediates. Non-matured beverages (gin and non-matured rum) were non-mutagenic. It is conceivable that mutagenic phenolics might be extracted from the wood during maturation in the barrel. Autoxidation of phenolic compounds could be a common mechanism in the mutagenicity of complex mixtures of plant origin.
 ...
PMID:Study on the mutagenicity of brandy with the Ara test. 163 59

The Ara forward mutagenicity assay with Salmonella typhimurium detected wine as a strong mutagen in the absence of mammalian microsomal activation and/or glycosidase activities, in agreement with previous findings. The standard amount (50 microliters) of S9 fraction in the preincubation mutagenesis test abolished most of the mutagenic activity of red wine in the Ara assay. The S9 fraction exerted the same inactivating capacity on hydrogen peroxide and coffee, a complex mixture generating H2O2. Catalase was identified as the putative S9 component responsible for its inactivating capacity. This specific scavenger for H2O2 abolished around 90% of the mutagenicity of red wine. The suppressing effect of catalase was much less noticeable in white and rose wines. Phenolics are proposed to be responsible for the direct-acting mutagenicity of wine through an auto-oxidative process leading to the production of H2O2.
 ...
PMID:The involvement of reactive oxygen species in the direct-acting mutagenicity of wine. 194 68

Bovine liver catalase (hydrogen-peroxide:hydrogen peroxide oxidoreductase, EC 1.11.1.6) was derivatized by 9"(10")-[4'-(2-(4,6-dichloro-1,3,5-triazinyl) oxy)butoxy] stearic acid and the fatty acyl-coated enzyme was separated from native catalase and excess reagent by hydroxyapatite chromatography. The derivatization of catalase resulted in coupling the long-chain fatty acyl residues to lysine, histidine and arginine, while other amino acids remained essentially unaffected. The fatty acyl-coated enzyme was water soluble at pH greater than 7.0 but became octanol and ether soluble at pH less than 6.5. The derivatized enzyme retained 50-80% of the catalatic- and peroxidative-specific activities. The free carboxyl function of the coupled long-chain fattyl acyl residues could serve as substrate for ATP-dependent CoA-thioesterification catalyzed by the rat liver microsomal long-chain fatty acyl-CoA synthase.
 ...
PMID:Fatty acyl coupled catalase. 253 62

The role of iron in the peroxidation of polyunsaturated fatty acids is reviewed, especially with respect to the involvement of oxygen radicals. The hydroxyl radical can be generated by a superoxide-driven Haber-Weiss reaction or by Fenton's reaction; and the hydroxyl radical can initiate lipid peroxidation. However, lipid peroxidation is frequently insensitive to hydroxyl radical scavengers or superoxide dismutase. We propose that the hydroxyl radical may not be involved in the peroxidation of membrane lipids, but instead lipid peroxidation requires both Fe2+ and Fe3+. The inability of superoxide dismutase to affect lipid peroxidation can be explained by the fact that the direct reduction of iron can occur, exemplified by rat liver microsomal NADPH-dependent lipid peroxidation. Catalase can be stimulatory, inhibitory or without affect because H2O2 may oxidize some Fe2+ to form the required Fe3+, or, alternatively, excess H2O2 may inhibit by excessive oxidation of the Fe2+. In an analogous manner reductants can form the initiating complex by reduction of Fe3+, but complete reduction would inhibit lipid peroxidation. All of these redox reactions would be influenced by iron chelation.
 ...
PMID:The role of iron in oxygen radical mediated lipid peroxidation. 255 Jan 51

The interaction of mouse liver catalase with subcellular membranes was studied, and an ionic interaction with a variety of membranes, including those derived from the microsomes, was observed. The interaction with microsomal membranes was found to be abolished by pre-treatment of catalase with neuraminidase, indicating a functional significance for catalase-bound sialic acid. Catalase activity was found to be enhanced when bound to membranes, and evidence for a weak association of catalase with peroxisomal structure in mouse liver was also obtained. It is concluded that mouse liver catalase has a capacity to bind to a variety of subcellular membranes in vivo and that this interaction may be consistent with a general protective role for the enzyme, as well as being compatible with a model of peroxisomal biogenesis which involves the interaction of catalase with microsomal membranes.
 ...
PMID:On the interactions of catalase with subcellular structure. 275 57

The direct in vitro effects of alloxan on the Ca2+ handling by microsomal membranes isolated from dog mesenteric arteries were investigated. Preincubation of the vascular muscle microsomal membranes with alloxan showed a suppressive effect on both binding of Ca2+ (in the absence of ATP) and ATP-driven Ca2+ transport. Such an inhibition was time dependent, dose dependent, and temperature dependent. ATP-driven Ca2+ transport was much more susceptible to the inhibitory action of alloxan than Ca2+ binding under all experimental conditions examined. Alloxan inhibited ATP-driven Ca2+ transport at a comparable level over the entire period of Ca2+ uptake, but had no significant effect on the efflux of Ca2+ from preloaded microsomal membranes. This suggests that alloxan exerts its inhibitory effect on the ATP-driven Ca2+ transport via its action on the Ca-pump protein rather than the membrane permeability to Ca2+. Catalase and mannitol but not superoxide dismutase partially protected against such as inhibition by alloxan. The possible involvement of H2O2 mediating the inhibitory action of alloxan was further supported by the finding of a similar in vitro inhibitory effect of H2O2 on the ATP-driven Ca2+ transport by the vascular smooth muscle microsomes.
 ...
PMID:Mechanism of inhibition by alloxan of ATP-driven calcium transport by vascular smooth muscle microsomes. 297 55

Hepatic microsomes prepared from rats pretreated with hematoporphyrin derivative (HPD) undergo rapid enhancement of lipid peroxidation in the presence of solar radiation (approximately 400 nm). Quenchers of singlet oxygen, including 2,5-dimethylfuran, histidine, and beta-carotene, and inhibitors of the hydroxyl radical, including benzoate, mannitol, and ethanol, largely protected against the enhancement of lipid peroxidation caused by HPD photosensitization. Catalase, a scavenger of hydrogen peroxide and superoxide dismutase, a scavenger of superoxide anion, had little or no protective effect against HPD-photosensitized enhancement of lipid peroxidation. Our data indicate that in vitro irradiation of hepatic microsomes prepared from HPD-treated rats results in the generation of both singlet oxygen and hydroxyl radical. These reactive moities are associated with a rapid increase in microsomal lipid peroxidation which may explain the unique susceptibility of membranous components of cells to this type of phototoxic injury.
 ...
PMID:Photoenhancement of lipid peroxidation associated with the generation of reactive oxygen species in hepatic microsomes of hematoporphyrin derivative-treated rats. 299 97

This study examined the characteristics of the active oxygen species involved in generation of the reactive intermediate of methoxychlor which covalently binds to liver microsomal proteins. The possibility that the active oxygen participating in the above reaction is the superoxide anion (O2-) or a species generated from O2- was examined with the help of superoxide dismutase (SOD) and with an SOD-mimetic agent, CuDIPS [Cu2+(3,5-diisopropylsalicylic acid)2]. It was observed that, whereas CuDIPS inhibited covalent binding of methoxychlor metabolite(s), SOD did not. However, ZnDIPS [Zn2+(3,5-diisopropylsalicylic acid)2], which exhibits no SOD-mimetic activity, did not inhibit covalent binding. Furthermore, both CuDIPS and ZnDIPS had little or no effect on the formation of demethylated (polar) metabolites of methoxychlor, demonstrating that the inhibition of covalent binding by CuDIPS was not merely due to a general inhibition of the hepatic monooxygenase system. These findings suggested that O2- was involved in covalent binding, but was not accessible to SOD. Additional support for O2- involvement stems from the observation that alpha-tocopheryl acid succinate markedly inhibited covalent binding of methoxychlor. The possibility that hydrogen peroxide (H2O2) was involved in covalent binding of methoxychlor appears unlikely. Catalase had no effect on covalent binding when NADPH was the cofactor, and the use of H2O2 in place of NADPH did not yield covalent binding. Certain scavengers of hydroxyl radical (ethanol, t-butanol and benzoate) inhibited, and other known scavengers (DMSO and mannitol) did not inhibit, covalent binding. EDTA stimulated binding, desferal (desferrioxamine) exhibited no effect on binding, and diethylenetriaminepentaacetic acid (DETAPAC) inhibited binding. A possible explanation for this observation is that the Fe2+ needed for generation of X OH is much more easily obtained from Fe3+-EDTA than from Fe3+-desferal, which resists reduction. The inhibitory effect by DETAPAC may be due to chelation of another metal which is needed for the reaction. Lastly, certain scavengers of singlet oxygen inhibited covalent binding with little effect on the formation of polar metabolites of methoxychlor. In conclusion, these studies support the involvement of X OH and singlet oxygen, possibly derived from O2-, in the formation of the reactive methoxychlor intermediate.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Characteristics of the active oxygen in covalent binding of the pesticide methoxychlor to hepatic microsomal proteins. 301 61

In the mid-fifth instar larvae of the cabbage looper moth, Trichoplusia ni, the subcellular distribution of total superoxide dismutase was as follows: 3.05 units (70.0%), 0.97 units (22.3%), and 0.33 units (7.6%) mg-1 protein in the mitochondrial, cytosolic and nuclear fractions, respectively. No superoxide dismutase activity was detected in the microsomal fraction. Catalase activity was unusually high and as follows: 283.4 units (47.3%), 150.1 units (25.1%), 142.3 units (23.8%), and 22.9 units (3.8%) mg-1 protein in the mitochondrial, cytosolic, microsomal (containing peroxisomes), and nuclear fractions. No glutathione peroxidase activity was found, but appreciable glutathione reductase activity was detected with broad subcellular distribution as follows: 3.86 units (36.1%), 3.68 units (34.0%), 2.46 units (23.0%), and 0.70 units (6.5%) mg-1 protein in the nuclear, mitochondrial, and cytosolic fractions, respectively. The unusually wide intracellular distribution of catalase in this phytophagous insect is apparently an evolutionary adaptation to the absence of glutathione peroxidase; hence, lack of a glutathione peroxidase-glutathione reductase role in alleviating stress from lipid peroxidation. Catalase working sequentially to superoxide dismutase, may nearly completely prevent the formation of the lipid peroxidizing .OH radical from all intracellular compartments by the destruction of H2O2 which together with O2- is a precursor of .OH.
 ...
PMID:Antioxidant enzymes of larvae of the cabbage looper moth, Trichoplusia ni: subcellular distribution and activities of superoxide dismutase, catalase and glutathione reductase. 324 4


<< Previous 1 2 3 4 5 6 Next >>