Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CATALASE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,801 records · Page 100Linked to original sources
PubMed1989

Xanthine oxidase, superoxide dismutase, catalase and lipid peroxidation in Mastomys natalensis: effect of Dipetalonema viteae infection.

Status of xanthine oxidase, superoxide dismutase, catalase and lipid peroxidation, the enzymes metabolizing reactive oxygen intermediates in liver, lungs and spleen of M. natalensis during D. viteae infection was investigated. Xanthine oxidase and lipid peroxidation exhibited stimulation, while superoxide dismutase and catalase showed depression in liver and spleen of the infected animals. The filarial infection therefore appears to create O2 toxicity in these tissues. Lungs, on the other hand was found safe as it possessed elevated xanthine oxidase, superoxide dismutase and catalase. Lipid peroxidation in lungs operated below the control level. The impact of these changes in the establishment and development of the infection has been discussed.

Analysis of Variance↗
PubMed1989

Effects of lead acetate on cerebral glutathione peroxidase and catalase in the suckling rat.

Exposure of immature rats to lead acetate results in hemorrhagic encephalopathy of variable evolution. As the maintenance of adequate protection against peroxides may be critical in this condition, the activities of selenium-glutathione peroxidase and catalase in cerebrum and cerebellum of suckling rats poisoned with lead acetate were studied from day six to day sixteen post-exposure. Age-related decreases of glutathione peroxidase and catalase activities in both controls and lead poisoned animals were observed. An increase in catalase activity was observed in cerebrum and cerebellum of lead-treated rats compared to controls. Glutathione peroxidase activity did not change significantly in cerebrum over the period studied. By contrast, glutathione peroxidase activity in cerebellum of lead-treated rats remained at about twice the control level over most of the study period. This apparent increase in glutathione peroxidase activity may be due either to a slower ontogenic decrease of its specific activity or to enzyme induction in response to oxidant stress in cerebellum.

Animals↗
PubMedDate not supplied

[Comparative characteristics of catalase from the fungus Penicillium vitale, which is synthesized under different nutritional conditions].

A comparative study of properties (absorption spectra, thermostability, pH optimum, polyacrylamide gel electrophoresis, DEAE-cellulose separation) and structure (amino acid composition, finger-prints, carbohydrate composition) was performed for P. vitale catalase synthesized under different medium conditions. In all cases the results were similar. The only difference occured in the amount of synthesized proteins. A conclusion is drawn that under different nourishing conditions of the fungus the properties and structure of the catalase are unchanged, but the regulatory mechanisms of catalase and glucosooxidate synthesis undergo changes.

Amino Acids↗
PubMed1986

Purification of a human red blood cell protein supporting the survival of cultured CNS neurons, and its identification as catalase.

We have previously reported that red blood cells contain high levels of a protein that supports the survival of a variety of CNS neurons in vitro for 24 hr. Here we report the isolation of this trophic activity from human red blood cells. The active material, purified over 1000-fold by ion-exchange chromatography and isoelectric point, subunit molecular weight, and ability to degrade hydrogen peroxide. Commercially produced bovine liver catalase, lactoperoxidase, HRP, and vitamin E all mimic the ability of the purified human protein to support neuronal survival in vitro. Pharmacological inhibitors of peroxidase activity inhibit the trophic effects of both commercial catalase and the purified blood-derived protein. These results suggest that peroxidase activity mediates the neuronotrophic activity of these agents. The bioassay culture medium itself generates peroxides in the absence of cells. Removal of this toxic material may be the basis for the trophic effects of catalase.

Animals↗
PubMed1986

[Peroxidase activity of catalase modified by progesterone].

Catalase conjugates with 3, 7, 9 and 42 progesterone molecules were obtained by the reaction between the enzyme and N-oxy-succinimide ether of 3-0-carboxymethyloxime of progesterone. The enzyme modified by 42 progesterone molecules is effective in o-dianisidine oxidation by hydrogen peroxide and has a kcat/KM value of 512 M-1 s-1. The catalase conjugates with 3, 7 and 9 progesterone molecules exhibit a high activity during o-dianisidine oxidation by cumene hydroperoxide. The activity of conjugates is higher than that of the native non-modified enzyme in the same reaction. The maximum effectiveness was observed for catalase modified by 7 progesterone molecules. This conjugate is characterized by kcat/KM of 99,000 M-1 s-1 at 30 degrees C. The effect of the degree of enzyme modification on the kinetic parameters of o-dianisidine oxidation by H2O2 and cumene hydroperoxide is discussed.

Animals↗
PubMed1988

Stable H2O2-resistant variants of Chinese hamster fibroblasts demonstrate increases in catalase activity.

Hydrogen peroxide (H2O2)-resistant variants of the Chinese hamster ovary HA-1 line have been derived by culturing cells in progressively higher concentrations of H2O2 (greater than 200 days, in 50-800 microM H2O2). The H2O2-resistant phenotype has been stable for over 60 passages (240 days) following removal from the H2O2 stress. The resistant cells demonstrate both increased capacity to deplete exogenously added H2O2 from the growth medium and increased catalase activity. H2O2 resistance correlates well with catalase activity. An increase in chromosome number occurred in the cells adapted to 200-800 microM H2O2, but increases in aneuploidy and tetraploidy were not necessary for resistance. These results suggest that adaptation to chronic oxidative stress mediated by H2O2 in mammalian cells is accompanied by a stable heritable change in expression of catalase activity.

Animals↗
PubMed1987

Fatty acids supply H2O2 at high rates for the oxidation of ethanol by catalase.

Fatty acids are physiological substrates for H2O2 production via peroxisomal beta-oxidation and have been shown to increase ethanol metabolism markedly in a system that involves catalase-H2O2. To try to understand why fatty acid-stimulated ethanol uptake occurs much faster than rates of H2O2 generation reported previously, studies were conducted to measure these parameters under identical conditions in the perfused rat liver. New methods were developed to measure H2O2 generation in a recirculating perfusion system based on the fact that methanol is oxidized only by catalase in rat liver. One method for measuring H2O2 generation in the perfused liver was based on the linear decrease in the concentration of methanol per unit time and the stoichiometry between H2O2 production and methanol oxidation of nearly 1:1. A second method relied on quantitation of the time necessary for the steady-state level of catalase-H2O2 measured spectrophotometrically (660-640 nm) through a lobe of the liver to return to basal values following the addition of known quantities of methanol. Basal rates of H2O2 production measured with both new methods and rates of 4-methylpyrazole- insensitive ethanol oxidation were similar (9 to 17 mumol/g/hr). Rates of H2O2 generation were increased up to 80 mumol/g/hr by addition of oleate or palmitate (1 mM), values which compared well with rates of fatty acid-stimulated palmitate (1 mM), values which compared well with rates of fatty acid-stimulated ethanol uptake of 70 to 90 mumol/g/hr measured in the presence of 4-methylpyrazole.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Serum catalase enzyme activity in liver diseases.

Serum catalase activity was moderately increased in fatty liver, acute alcoholic hepatitis and in the decompensated form of cardiac circulatory failure. It showed significant increase in acute yellow atrophy and in toxic hepatitis while no changes were detected in liver cirrhosis and viral hepatitis. Serum catalase activity showed a good correlation (r = 0.820) with the serum glutamate dehydrogenase activity. In accordance with our results, the inexpensive assay of serum catalase activity is suggested for the detection of severe liver cell damage.

Catalase↗
PubMed1987

Biogenesis of peroxisomes in regenerating rat liver. I. Sequential changes of catalase and urate oxidase detected by ultrastructural cytochemistry.

The biogenesis of peroxisomes has been investigated in the model of regenerating rat liver after partial hepatectomy using ultrastructural cytochemical staining methods: catalase as a marker of the peroxisomal matrix and uricase for the cores. The peroxisomes in regenerating rat liver showed several distinctive features: a) marked variation in shape and size, e.g., peroxisomes with tail-like extensions and tortuously elongated rod-shaped ones, b) formation of peroxisomal clusters and, c) interconnections between adjacent peroxisomes suggesting cleavage or budding. Whereas the reaction product for catalase was present at all intervals after hepatectomy in the matrix of all peroxisomes, the pattern of localization of uricase case varied with the time. It was confined to the cores in controls and at 10 days after the operation, while at 24 and 48 h it showed, in addition, a diffuse reaction in the matrix of some peroxisomes. In interconnected apparently dividing peroxisomes, the core with positive uricase reaction was present only in one half, while the other half was devoid of the reaction product. Similarly, the diffuse uricase staining was confined to the half which contained the core with the other half remaining unstained. These observations are consistent with the concept that new peroxisomes are formed from preexisting ones by budding and segmentation. While catalase is transferred uniformly to all new segments, uricase is compartmentalized in certain portions, of the apparently growing "peroxisomal reticulum".

Animals↗
PubMed1987

Bovine ocular squamous cell carcinoma: superoxide dismutase and catalase levels.

Considerable evidence exists for the production of free radicals in the eye region after exposure to ultraviolet light. Failure to remove these radicals adequately may be important in the predisposition of Hereford cattle to ocular carcinoma. The levels of two enzymes, superoxide dismutase and catalase, involved in the removal of superoxide anion and hydrogen peroxide, were compared in Hereford cattle predisposed to ocular carcinoma and a resistant breed, Droughtmaster cattle. The results demonstrate comparable levels of superoxide dismutase in the two breeds in both eye tissue and erythrocytes. Catalase levels also were the same in both breeds. Increased incidence of ocular carcinoma in Herefords does not appear to be due to a deficiency in either superoxide dismutase or catalase.

Animals↗
PubMed1985

Modulation of oxidant lung injury by using liposome-entrapped superoxide dismutase and catalase.

Increased cellular generation of partially reduced species of oxygen mediates the toxicity of hyperoxia to cultured endothelial cells and rats exposed to 95-100% oxygen. Liposomal entrapment and intracellular delivery of superoxide dismutase (SOD) to cultured porcine aortic endothelial cells increased the specific activity of cellular SOD up to 15-fold. The liposome-mediated augmentation of SOD activity persisted in cell monolayers and rendered these cells resistant to oxygen-induced injury in a cell SOD activity-dependent manner. Addition of free SOD to culture medium had no effect on cell SOD activity or resistance to oxygen toxicity. SOD and catalase-containing liposomes injected i.v. into rats increased lung-associated enzyme specific activities two- to fourfold. Liposome entrapment of both SOD and catalase significantly increased the circulating half-lives of these enzymes and was critical for prevention of in vivo oxygen toxicity. Free SOD and catalase injected i.v. in the absence or presence of control liposomes did not increase corresponding lung enzyme activities or survival time in 100% oxygen. These studies show that O2- and H2O2 are important mediators of oxygen toxicity and that intracellular delivery of oxygen protective enzymes can reduce tissue injury owing to overproduction of partially reduced oxygen species.

Animals↗
PubMed1979

X-irradiation effects on lipid peroxidation and superoxide dismutase and catalase activities in copper deficient and copper loaded rat liver.

The whole body X-irradiation was found to intensify the lipoperoxidative processes in rat liver mitochondria and microsomes, which resulted in a two-fold increase of hydroperoxides in the membrane lipids. The moderate copper-loading of the liver cell had a protective effect against X-ray induced lipid peroxidation. The X-ray influence on the superoxide dismutase (SOD) and catalase activity in normocupric state, copper deficiency and copper loading was also studied. The latter two states were used as models of altered enzyme activity. Copper deficiency decreased the specific SOD activity in both mitochondrial fraction and cytosol, while the increased copper cell content activated this enzyme in mitochondria and did not change it in cytosol. Irradiation inhibited SOD in all preparations studied, with the exception of cytosol upon copper deficiency. Whatever the cell level of copper, X-ray exposure resulted in a decrease of catalase activity in cytosol, while in the mitochondrial fraction, including peroxisomes, the irradiation effects were different. It was found that both SOD and catalase after whole-body irradiation exhibited a higher specific activity in mitochondrial fraction upon copper loading compared with normocupric state, which correlates with the delayed lipid peroxidation processes.

Animals↗
PubMedDate not supplied

[Immobilization of Penicillium vitale Pidopl. et Bilai catalase by inorganic carriers].

An efficient method is developed for P. vitale catalase immobilization through the oxidized carbohydrate enzyme component, using silochrome. The method provides the enzyme binding without losing its catalytic capacity in the immobilized preparation. When the enzyme is immobilized by high-dispersed silica containing isocyanate, aldehyde groups or active atoms of chlorine, 8, 15, and 20 mg of the enzyme is bounded per 1 g of the carrier, respectively, its catalytic capacity being completely retained. A dependence is established for the degree of catalase bonding and catalytic capacity of the immobilized enzyme of the enzyme carrier ratio in immobilization. The catalytic activity of the immobilized catalase preparations reaches 2 000 Becker units/l g. The preparations are stable in storage. Some of their properties are studied.

Catalase↗
PubMed1984

[Catalase and superoxide dismutase activity in isogenous bacterial strains with different degrees of radioresistance].

Superoxide dismutase and catalase activity has been studied in isogenous strains of various radioresistance bacteria. In mutants Micrococcus radiodurans having defects in the systems of DNA repair the superoxide dismutase activity is lower than in cells of wild type. The changes of catalase and superoxide dismutase activity have not been revealed in investigated strains Escherichia coli differing in radioresistance. It has been concluded that the survival of bacteria exposed to ionizing radiation is determined by the effectiveness of DNA repair systems realiability of which depends on the catalase and superoxide dismutase activity.

Catalase↗
PubMed1984

Purification of human plasma catalase and monoamine oxidase and the partial characterization of monoamine oxidase.

Human plasma catalase and monoamine oxidase were purified for the first time to homogeneity. Monoamine oxidase purified 3200-fold with the aid of DEAE-Sepharose Cl-6B and Sepharose Cl-6B chromatography was devoid of catalase, aldehyde dehydrogenase and reductase activity. Homogeneous catalase was obtained during DEAE-Sepharose C1-6B chromatography of monoamine oxidase. Monoamine oxidase was characterized physico-chemically in terms of molecular weight, electrophoretic mobility, iso-electric point, amino acid composition and specific activity. The molecular weight was estimated to be 234.5 K by exclusion chromatography and with iso-electric focusing the pI was estimated to be 5.6.

Amino Acids↗
PubMed1983

Polyacrylamide gradient gel electrophoretic studies of residual catalase in acatalasemia.

Erythrocyte catalse in a Japanese-type acatalasemia and a normal control subject was separated by chromatofocusing with or without prior partial purification with DEAE-cellulose. Fractions were analyzed by polyacrylamide gradient gel electrophoresis for catalse activity and protein stain. Chromatofocusing revealed no marked difference in pI values between normal and acatalasemic catalases with or without partial purification. In the gel electrophoresis, molecular weights were also similar; two bands of catalase activity with molecular weights of 290,000 and 350,000 for the acatalasemia and of 280,000 and 360,000 for the normal control were found in the partially purified preparations. The molecular weight of normal catalase in untreated hemolysate was 250,000. Normal catalse was identified as protein bands on polyacrylamide gradient gel after fractionation of hemolysate by chromatofocusing. A more sensitive method for protein stain is still required for demonstration of residual catalse protein on the gel.

Acatalasia↗
PubMed1983

The oxidation mechanism of metallic mercury in vitro by catalase.

Magos et al reported the effect of 3-amino-1,2,4-triazole on mercury uptake by in vitro human blood samples and the mercury contents in blood and brain of rats exposed to metallic mercury vapor. The authors described the oxidation of metallic mercury by human blood cells having different catalase activities, hypocatalasemia and acatalasemia, with or without hydrogen peroxide. Kudsk found that ethyl alcohol inhibited the uptake of metallic mercury by blood in vitro and in vivo. These findings raise a question as to whether or not the inhibition by ethyl alcohol of the uptake of mercury by the blood is due to a direct reaction between ethyl alcohol and the catalase-hydrogen peroxide complex. The present report deals with the mechanism of metallic mercury oxidation in vitro by catalase using ethyl alcohol.

Animals↗
PubMed1984

[Proteolytic resistance and thermostability of catalase and histidine decarboxylase from Micrococcus sp. n].

Catalase from Micrococcus sp. n. is not hydrolyzed by trypsin at the protein/protease (pn/pe) exceeding 10/1. Histidine decarboxylase (HDC) loses 50% of activity after the first nine minutes of hydrolysis at the pn/pe ratio equal to 6/1, followed by a slow linear inactivation. Investigation of thermal stability at varying pH and temperatures demonstrated that catalase and HDC preserve 70-80% of activity after 5 minutes of incubation at 72 degrees C only at pH approaching the optimal pH of enzymatic activity (pH 7.45 for catalase and pH 5.55 for HDC).

Carboxy-Lyases↗

Refine your search to explore more results.