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.

SourceResearch connectionFrom yearThrough year

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

At least 1,189 records · Page 66Linked to original sources

PubMed1992

(-)Deprenyl increases activities of superoxide dismutase and catalase in striatum but not in hippocampus: the sex and age-related differences in the optimal dose in the rat.

The dose of (-)deprenyl (2.0 mg/kg/day, sc, for 3 weeks) which significantly increased activities of superoxide dismutase (SOD) and catalase in the striatum of young male rats significantly reduced these activities in young female rats but did not change the SOD activity in old female rats. In order to clarify these effects, different doses of the drug were continuously infused sc for 3 weeks in three groups of rats (young males and young and old females). When a 10-fold smaller dose (0.2 mg/kg/day) was applied in young female rats, activities of both SOD and catalase were significantly increased, while a higher dose of 0.5 mg/kg/day was ineffective and a lower dose of 0.1 mg/kg/day was substantially less effective. In old female rats, doses of both 0.5 and 1.0 mg/kg/day were equally effective in elevating activities of SOD and catalase, while a lower dose of 0.1 mg/kg/day was less effective. The activity of glutathione peroxidase (GSH Px) remained unchanged in all groups, except for a significant decrease in the activity of non-selenium-dependent GSH Px in both young and old female rats given the highest drug dose (2.0 mg/kg/day). Furthermore, activities of all three enzymes remained unchanged in the hippocampus in most groups. The results indicate that (-)deprenyl significantly increases activities of both SOD and catalase in the striatum, but not in hippocampus of rats, and that the optimal dose is very different depending on the sex and age of the animal.

Age Factors↗

PubMed1991

The active site structure of E. coli HPII catalase. Evidence favoring coordination of a tyrosinate proximal ligand to the chlorin iron.

E. coli produces 2 catalases known as HPI and HPII. While the heme prosthetic group of the HPII catalase has been established to be a dihydroporphyrin or chlorin, the identity of the proximal ligand to the iron has not been addressed. The magnetic circular dichroism (MCD) spectrum of native ferric HPII catalase is very similar to those of a 5-coordinate phenolate-ligated ferric chlorin complex, a model for tyrosinate proximal ligation, as well as of chlorin-reconstituted ferric horseradish peroxidase, a model for 5-coordinate histidine ligation. However, further MCD comparisons of chlorin-reconstituted myoglobin with parallel ligand-bound adducts of the catalase clearly rule out histidine ligation in the latter, leaving tyrosinate as the best candidate for the proximal ligand.

Binding Sites↗

PubMed1996

Alpha-crystallin acting as a molecular chaperone protects catalase against steroid-induced inactivation.

A link between corticosteroid therapy and the development of cataract has been known for many years. However, the precise underlying molecular mechanism of pathology has not been characterised, although a role for direct deleterious interactions between corticosteroids and lenticular proteins has been investigated. Alpha-crystallin is a major lens protein that has exhibited chaperone properties in vitro. Catalase is a ubiquitous enzyme that is an important scavenger of hydrogen peroxide in vivo. The corticosteroid prednisolone-21-hemisuccinate was found to inactivate bovine liver catalase, in vitro in a progressive manner. Coincubation of alpha-crystallin with catalase in a 1:2 molar ratio (one alpha-crystallin to two catalase molecules) fully protected against this inactivation. The protection was specific. Aspirin-like analgesics, putative anti-cataract drugs offered no such protection.

Animals↗

PubMed1983

Equivalence of the projected structure of thin catalase crystals preserved for electron microscopy by negative stain, glucose or embedding in the presence of tannic acid.

Thin crystals of beef liver catalase have been examined by electron microscopy following various preservation procedures. In the first part of this investigation, micrographs of three principal projections were obtained from thin sections of micro-crystals embedded in the presence of tannic acid. Computer reconstructions confirmed the space group assignment of P2(1)2(1)2(1) and permitted the packing arrangement of the catalase tetramers to be deduced to a resolution of about 20 A. These results corroborate the packing model for this crystal form proposed by Unwin (1975) on the basis of molecular modeling of one projection. In the second part of this investigation, the projected structures of the thin crystals in various preserving media were compared. The negative contrasting of crystals embedded in the presence of tannic acid was confirmed by direct comparison with non-embedded, negatively stained thin platelet crystals. In addition, good agreement at 20 A resolution was observed between the structure of negatively stained crystals and the structure of crystal platelets preserved in glucose and examined by low-dose methods, while moderate agreement was established with the published data of Taylor (1978) for crystals embedded in thin ice films. Tannic acid alone was also found to serve as a suitable medium for preserving catalase crystals to a resolution of 3 X 7 A as judged by electron diffraction. Overall, we demonstrate that projections obtained from thin sections of catalase crystals embedded in the presence of tannic acid can provide a reliable, negatively contrasted representation of the protein structure to 20 A resolution. Examination of sectioned crystals could thus provide a useful adjunct to X-ray crystallographic studies of protein crystals and three-dimensional reconstruction of crystal thin sections should ultimately be possible.

Animals↗

PubMed1988

Peripheral blood catalase in patients undergoing renal transplantation.

Oxygen free radicals are mediators of tissue injury and catalase is an enzyme which is involved in limiting this process. We examined peripheral blood catalase activity (PBCA) to assess its value as a marker in detecting tissue injury related to renal allograft rejection. Thirty-one consecutive recipients of kidney (n = 29) or simultaneous kidney/pancreas (n = 2) transplants and 10 normal volunteers were studied. Catalase activity, measured by the disk-flotation method, was expressed as Sigma units X 10(-3)/ml (SU/ml) of whole blood. Normal PBCA was determined to be greater than 76 SU/ml. Twenty-nine episodes of renal allograft rejection (diagnosed by clinical criteria +/- biopsy [79%]) were observed in 26 patients. PBCA (mean +/- SEM) was found to be low (64 +/- 1 SU/ml) in 28/29 episodes (chi 2 = 46.3, P less than 0.001), and the decrease (at least two consecutive daily catalase values less than 76 SU/ml) occurred 2 days prior to the clinical/biopsy diagnosis of rejection in 26/28 episodes. The sensitivity of PBCA as a discriminant of rejection was 97%, specificity was 96%, and test accuracy was 96%. PBCA less than 50 SU/ml on two or more occasions occurred in five cases and transplant nephrectomy was required in four of these because of uncontrollable rejection. Nine episodes of cyclosporine nephrotoxicity occurred in 7 patients and none of these episodes was associated with a decreased PBCA. Our data suggest that decreased PBCA is a sensitive and specific indicator of renal allograft rejection. PBCA remains normal during episodes of cyclosporine nephrotoxicity and therefore provides a rapid and inexpensive discriminant from allograft rejection.

Adolescent↗

PubMed1994

Superoxide dismutase, catalase, and glutathione peroxidase activities in muscle and lymphoid organs of sedentary and exercise-trained rats.

The effect of swimming-training upon the activities of the enzymes involved in the generation of reducing-equivalents (citrate synthase-mitochondria and glucose-6-phosphate dehydrogenase-cytosol) and of antioxidant enzymes (CuZn- and Mn-SOD, catalase and glutathione peroxidase) in the lymphoid organs (thymus, mesenteric lymph nodes and spleen) was examined. The skeletal muscles (soleus-red and gastrocnemius-white) were also studied. Although our data suggest an apparently random, organ-specific change in enzymatic activity, some interesting trends can be observed. Firstly, the increased citrate synthase and Mn-SOD activities observed in red, but not in white muscle, corroborate the well-known effect of endurance exercise-training on mitochondrial oxidative metabolism. Secondly, there was an inverse relationship between TBARs-monitored lipoperoxidation and glutathione peroxidase activity in all tissues studied, what is in accordance with the previous findings showing that such enzyme exerts the fine control of intracellular lipoperoxide concentration. Except in the case of the spleen, there was a trend for elevated glucose-6-phosphate dehydrogenase activity, coadjuvant of glutathione peroxidase in the antioxidant response to physical exercise in all tissues. Thirdly, Mn-SOD and catalase were conspicuously associated to oxidative stress in the thymus, while glutathione and catalase could be linked to this parameter in the spleen. Fourthly, the lymph nodes seem to be more dependent on the glucose-6-phosphate dehydrogenase/glutathione peroxidase pair for protection against damage promoted by physical exercise. Mn-SOD and catalase activities were lower in the lymph nodes after swimming training.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1988

Resonance Raman spectra of bovine liver catalase: enhancement of proximal tyrosinate vibrations.

Resonance Raman spectra of native bovine liver ferri-catalase have been obtained in the 200-1800 cm-1 region. Excitation at a series of wavelengths ranging from 406.7 to 514.5 nm has been used and gives rise to distinct sets of resonance Raman bands. Excitation within the Soret and Q-bands of the heme group produces the expected set of polarized and nonpolarized porphyrin modes, respectively. The frequencies of the porphyrin skeletal stretching bands in the 1450-1700 cm-1 region indicate that catalase contains only five-coordinate, high-spin heme groups. In addition to the porphyrin modes, bovine liver catalase exhibits bands near 1612 and 1520 cm-1 that are attributable to ring vibrations of the proximal tyrosinate that are enhanced via resonance with a proximal tyrosinate----Fe(III) change transfer transition centered near 490 nm. Similar bands have been observed in mutant hemoglobins that have tyrosinate axial ligands and in other Fe(III)-tyrosinate proteins. No resonance Raman bands have been observed that can be attributed to degraded hemes. The spectra are relatively insensitive to pH over the range of 5-10, and the same spectra are observed for catalase samples that do and do not contain tightly bound NADPH. Resonance Raman spectra of the fluoride complex exhibit porphyrin skeletal stretching modes that show it to be six coordinate, high spin, while the cyanide complex is six coordinate, low spin. Both the azide and thiocyanate complexes, however, are spin-state mixtures with the high-spin form predominant.

Animals↗

PubMed1996

A discontinuous method for catalase determination at 'near physiological' concentrations of H2O2 and its application to the study of H2O2 fluxes within cells.

We describe a discontinuous method for the measurement of catalase using the Ferrous Oxidation in Xylenol orange (FOX) assay. Samples containing catalase are incubated with H2O2 for varying time intervals prior to rapid mixing of aliquots of the incubation mixtures with FOX reagent, which measures residual H2O2. Absorbance is then read at 560 nm after 30-min incubation at room temperature. Decay of H2O2 is proportional to catalase activity in the original sample. An adaptation of the method involves exposure of intact cells to H2O2-generating systems in the presence of aminotriazole. The extent of catalase inactivation allows estimates of total H2O2 accumulation within the cell.

Amitrole↗

PubMed1989

Prosthetic group content and ligand binding properties of a spinach catalase.

A recently discovered form of spinach catalase that contains both a novel heme and protoheme as prosthetic groups has been characterized using immunological and spectroscopic techniques. The enzyme appears to be a dimer of identical Mr 60,000 monomers. Extraction of the non-covalently bound prosthetic groups, followed by thin-layer chromatography of the extract, suggested that the novel heme contains four carboxylic acid side-chain groups. The resonance Raman spectrum of the resting enzyme indicates that the protoheme prosthetic group is five-coordinate and high-spin. The enzyme was shown to bind formate, azide and cyanide. Cyanide and azide binding to catalase are biphasic, suggesting the existence of two different binding sites for cyanide and azide in the enzyme. Results obtained from EPR and resonance Raman spectroscopies also support the hypothesis that two different ligand-binding sites are present in the enzyme. Western blots suggest that the Mr 60,000 peptide of the novel heme-containing catalase is similar or identical to that of a previously characterized, exclusively protoheme-containing, tetrameric catalase.

Azides↗

PubMed1995

Simulations of electron transfer in the NADPH-bound catalase from Proteus mirabilis PR.

Catalase-bound NADPH both prevents and reverses the accumulation of compound II, an inactive form of catalase that is generated from the normal active intermediate form (compound I) when catalase is exposed to a steady flow of hydrogen peroxide. The mechanism for the regeneration reaction is unknown although NADPH could act either as a one-electron or a two-electron donor. Recently, a reaction scheme has been proposed in which the formation of compound II from compound I generates a neighboring radical species within the protein. NADPH would then donate two electrons, one to compound II for reduction of the iron and the other to the protein free radical. In this paper, we report calculations to find the dominant electron tunneling pathways between NADPH and the heme iron in the catalase from the peroxide-resistant mutant of Proteus mirabilis. Two major tunneling pathways are found which fuse together on Ser-196. It is suggested that the sequence Gly-Ser of the loop that divides the beta 5-strand is the key element for shielding a radical amino acid.

Algorithms↗

PubMed1993

Topology of catalase assembly in human skin fibroblasts.

The biogenesis, assembly and import of the peroxisomal enzyme catalase was studied in human skin fibroblasts from control persons and from patients with the Zellweger syndrome. For this purpose, two monoclonal antibodies were generated which are able to discriminate between the monomeric or dimeric form and the tetrameric, enzymically active conformation of the enzyme. Metabolic labelling studies showed that catalase is assembled to the tetrameric conformation within one hour after its synthesis, while it is still in the cytosol of the cell. Subsequently, the enzyme becomes particle-bound in the control cells, a process that is retarded by addition of the catalase inhibitor 3-amino-1,2,4-triazole. However, the tetramer remains in the cytosol in cells from Zellweger patients. It is concluded that newly synthesized catalase can be assembled to a tetramer in the cytosol in human skin fibroblasts. Unfolding of this tetramer prior to import into peroxisomes is indicated.

Antibodies, Monoclonal↗

PubMed1988

Interaction of nitrite with catalase in the perfused rat liver.

The interaction of nitrite with catalase was investigated spectrophotometrically in the perfused rat liver. Real-time spectral changes were obtained using a reflectance scanning spectrophotometer in the liver perfused with a haemoglobin-free medium in a non-recirculating system. Administration of sodium nitrite caused a specific pattern of spectral change indicating the decomposition of catalase compound I to free catalase. The spectral change due to the interaction with nitrite did not occur during potassium cyanide or ethanol infusion, nor in the aminotriazole-pretreated rat liver. The spectral change was observed at concentrations of nitrite in the perfusate over 0.01 mM, and the K0.5 value (the concentration producing half the maximum spectral change) was 0.06 mM. It was concluded that relatively low concentrations of nitrite caused decomposition of catalase compound I in the physiologically functioning liver cell.

Animals↗

PubMed1984

Deficiency of erythrocyte superoxide dismutase and catalase activities in patients with malignant lymphoma and acute myeloid leukemia.

The activity of erythrocyte superoxide dismutase (SOD) and catalase was determined in 38 patients with lung cancers (n = 15), malignant lymphoma (n = 11) and acute myeloid leukemia (n = 12). The patients with malignant lymphoma and acute myeloid leukemia showed a significant decrease in both enzyme activities (P less than 0.01) while the patients with lung cancer (9 squamous cell carcinomas and 6 small cell carcinomas) showed normal values of SOD and catalase activities. Furthermore, the patients with malignant lymphoma and acute myeloid leukemia, in remission, but not treated with anticancer drugs, also showed a significant decrease in SOD and catalase activity. These observations therefore indicate that a deficiency of erythrocyte SOD and catalase activities is caused by cancer and varies with the type of the cancer.

Acatalasia↗

PubMed1978

Superoxide dismutase of the eye: relative functions of superoxide dismutase and catalase in protecting the ocular lens from oxidative damage.

1. Activities of superoxide dismutase (superoxide: superoxide oxidoreductase, EC 1.15.1.1) have been estimated in eye tissues. In rabbit eye, superoxide dismutase is present in corneal epithelium, corneal endothelium, lens, iris, ciliary body and retina. In lens the activity is in capsule epithelium. 2. Copper chelator diethyldithiocarbamate inhibited lens superoxide dismutase in vitro and in vivo in rabbit. 3. H2O2 caused inhibition of superoxide dismutase activity of lens extract, and this inhibition was potentiated by the catalase inhibitor 3-amino-1H-1,2,4-triazole (3-aminotriazole) or NaN3. 3-Aminotriazole or NaN3 had no effect on lens superoxide dismutase. Thus endogenous catalase of lens affords protection to the lens superoxide dismutase from inactivation by H2O2. 4. In rabbit having early cataract (vacuolar stage) induced by feeding-3-aminotriazole, there was a decrease in superoxide dismutase of lens, a fall in ascorbic acid of ocular humors and lens, and a 2--3-Fold increase in H2O2 of aqueous humor and vitreous humor. We conclude that catalase of eye affords protection to the lens from H2O2 and it also protects superoxide dismutase of lens from inactivation by H2O2. Superoxide dismutase, in turn, protects the lens from the superoxide radical, O2.-. It is likely that inhibition of these enzymes may lead to production of the highly reactive oxidant, the hydroxyl radical, under pathological conditions when H2O2 concentration in vivo exceeds physiological limits as in cataract induced by 3-aminotriazole. A scheme of reaction mechanism has been proposed to explain the relative functions of ocular catalase and superoxide dismutase. Such a mechanism may be involved in cataractogenic process in the human.

Amitrole↗

PubMed1986

The effect of three hypolipidemic drugs on catalase activity and peroxisomal and mitochondrial palmitate oxidation in rat cardiac and skeletal muscle.

Catalase activity and peroxisomal and mitochondrial palmitate oxidation have been investigated in cardiac and skeletal muscle from rats fed clofibrate, ciprofibrate or nafenopin in an unrefined diet for different periods of time. Nafenopin was also added to either a high carbohydrate (70% of kilocalories from glucose) or high fat (70% of kilocalories from lard) diet and fed to rats for either 1 or 3 weeks. Catalase activity was elevated in all muscles from rats fed the hypolipidemic drugs. The response of catalase activity in muscle to clofibrate was dose-dependent. The response time of catalase activity was different in individual muscles. Peroxisomal palmitate oxidation was elevated in the heart and soleus muscle from rats fed nafenopin in either the high-carbohydrate or the high-fat diet. There was no change in peroxisomal palmitate oxidation in psoas or extensor digitorum longus muscle from rats fed the drugs. Mitochondrial palmitate oxidation was only slightly increased by nafenopin in the heart and soleus muscles after 3 weeks of nafenopin feeding. The results suggest that the cardiac muscle, like the liver, responds to hypolipidemic drug treatment with an increase in peroxisomal fat oxidation. The skeletal muscle response is less specific and that tissue may not contribute to the hypolipidemic effect of the drugs. The findings also suggest that these drugs do not induce peroxisome proliferation in skeletal muscle.

Animals↗

PubMed1994

Plasmid-encoded catalase of Staphylococcus simulans biovar staphylolyticus.

Staphylococcus simulans biovar staphylolyticus contains five plasmids designated pACK1 through pACK5. Non-denaturing electrophoretic analysis of an extract prepared from wild-type cells revealed three bands of catalase activity, whereas an extract of cells cured of pACK1 produced only two catalase bands. Cloning and Southern hybridization analysis showed that there is a catalase structural gene on pACK1. The plasmid-specified catalase was the major activity produced under both aerobic and anaerobic conditions of growth.

Aerobiosis↗

PubMed1991

The isolation, cloning and identification of a vegetative catalase gene from Bacillus subtilis.

A Bacillus subtilis library of Tn917::lacZ insertions was screened for mutants that were unable to grow in the presence of normally sublethal concentrations of hydrogen peroxide. The identification and subsequent analysis of one mutant strain, YB2003, which carried the mutation designated kat-19, revealed that this strain was deficient in the expression of a vegetative catalase. Regions of the chromosome both 5' and 3' to the site of the Tn917 insertion, as well as the gene without the insertion (kat-19+) were cloned. The presence of the functional kat-19+ gene on a high-copy plasmid restored catalase activity to the kat-19::Tn917 strain as well as to strains of B. subtilis that carried the katA 1 mutation. While the katA+ locus is believed to represent the structural gene for the vegetative catalase of B. subtilis [Loewen and Switala, J. Bacteriol. 169 (1987) 5848-5851], the sequence analysis of the cloned kat-19+ DNA fragments revealed an open reading frame that showed significant homology between the deduced amino acid sequence of this gene product and that of known eukaryotic catalases.

Amino Acid Sequence↗

PubMed1987

Cyanide is a product of the catalase-mediated oxidation of the alcohol deterrent agent, cyanamide.

Cyanide was detected as a product of cyanamide oxidation by bovine liver catalase in vitro under conditions that also produced an active aldehyde dehydrogenase (AlDH) inhibitor. Cyanide formation was directly related to both cyanamide and catalase concentrations and was also dependent on incubation time. The apparent Km for this reaction was 172 microM. Cyanide formation was blocked by ethanol, a known substrate for catalase Compound I. The toxic effects of cyanamide in the dog, a species with limited capacity to conjugate cyanamide by N-acetylation, may be causally related to enhancement of this catalase-mediated pathway for cyanamide metabolism.

Alcohol Deterrents↗