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PubMed1988

Purification and characterization of spore-specific catalase-2 from Bacillus subtilis.

Catalase-2, the catalase found in spores of Bacillus subtilis, has been purified to homogeneity from a nonsporulating strain. The apparent native molecular weight is 504,000. The enzyme appears to be composed of six identical protomers with a molecular weight of 81,000 each. The amino acid composition is similar to the composition of other catalases. Like most catalases, catalase-2 exhibits a broad pH optimum from pH 4 to pH 12 and is sensitive to cyanide, azide, thiol reagents, and amino triazole. The apparent Km for H2O2 is 78 mM. The enzyme exhibits extreme stability, losing activity only slowly at 93 degrees C and remaining active in 1% SDS-7 M urea. The green-colored enzyme exhibits a spectrum like heme d with a Soret absorption at 403 nm and a molar absorptivity consistent with one heme per subunit. The heme cannot be extracted with acetone-HCl or ether, suggesting that it is covalently bound to the protein.

Amino Acids↗
PubMed2005

Antioxidant mechanism of heme oxygenase-1 involves an increase in superoxide dismutase and catalase in experimental diabetes.

Increased heme oxygenase (HO)-1 activity attenuates endothelial cell apoptosis and decreases superoxide anion (O2-) formation in experimental diabetes by unknown mechanisms. We examined the effect of HO-1 protein and HO activity on extracellular SOD (EC-SOD), catalase, O2-, inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS) levels and vascular responses to ACh in control and diabetic rats. Vascular EC-SOD and plasma catalase activities were significantly reduced in diabetic compared with nondiabetic rats (P < 0.05). Upregulation of HO-1 expression by intermittent administration of cobalt protoporphyrin, an inducer of HO-1 protein and activity, resulted in a robust increase in EC-SOD but no significant change in Cu-Zn-SOD. Administration of tin mesoporphyrin, an inhibitor of HO-1 activity, decreased EC-SOD protein. Increased HO-1 activity in diabetic rats was associated with a decrease in iNOS but increases in eNOS and plasma catalase activity. On the other hand, aortic ring segments from diabetic rats exhibited a significant reduction in vascular relaxation to ACh, which was reversed with cobalt protoporphyrin treatment. These data demonstrate that an increase in HO-1 protein and activity, i.e., CO and bilirubin production, in diabetic rats brings about a robust increase in EC-SOD, catalase, and eNOS with a concomitant increase in endothelial relaxation and a decrease in O2-. These observations in experimental diabetes suggest that the vascular cytoprotective mechanism of HO-1 against oxidative stress requires an increase in EC-SOD and catalase.

Acetylcholine↗
PubMed1992

Effect of superoxide dismutase and catalase on regional dysfunction after exercise-induced ischemia.

This study was designed to test the hypothesis that the oxygen free radical scavengers superoxide dismutase (SOD) and catalase may reduce myocardial "stunning" after exercise-induced ischemia. To test this hypothesis, 8 mongrel dogs performed treadmill exercise for 10 min in the presence of a flow-limiting coronary artery stenosis. Regional left ventricular function was measured with ultrasonic microcrystals implanted to measure regional wall thickening. Regional myocardial perfusion was measured with radioactive microspheres. The combination of SOD (5 mg/kg iv) and catalase (5 mg/kg iv) did not affect heart rate, blood pressure, coronary artery flow, or regional myocardial blood flow at rest, during exercise, or in the postexercise period. SOD and catalase had no effect on regional wall thickening at rest before exercise. During exercise in the absence of a coronary artery stenosis, thickening was slightly lower during SOD and catalase infusion (27 +/- 11.0 vs. 30.8 +/- 11.5%, SOD vs. control P = 0.05). During exercise in the presence of a coronary artery stenosis, there was no difference in thickening. Infusion of SOD and catalase affected neither the transient rebound function occurring early after exercise nor the prolonged period of stunning. These results indicate that the myocardial stunning that follows exercise-induced ischemia is unlikely to be mediated by oxygen free radicals.

Animals↗
PubMed1997

Catalase-overexpressing transgenic mouse heart is resistant to ischemia-reperfusion injury.

Myocardial ischemia-reperfusion injury is at least partially mediated by oxygen-derived free radicals. Catalase is a major enzyme involved in the detoxification of hydrogen peroxide. The activity of catalase in the heart is very low, which may be a factor responsible for the high sensitivity of the heart to ischemia-reperfusion injury. The present study was undertaken to determine whether elevation of catalase specifically in the heart of transgenic mice can provide protection against ischemia-reperfusion injury. Hearts isolated from transgenic mice in which catalase in the heart was elevated approximately 60-fold higher than that in nontransgenic heart and from the non-transgenic littermates were subjected to 50 min of warm (37 degrees C) zero-flow ischemia followed by 90 min reflow. Compared with nontransgenic controls, transgenic hearts showed significantly improved recovery of contractile force (75 vs. 25% at the end of 90 min reperfusion, P < 0.01). Efflux of creatine kinase was reduced by approximately 50%, and the zone of myocardial infarction as demarcated by triphenyltetrazolium at the end of reperfusion was reduced by approximately 40% in transgenic hearts compared with nontransgenic controls. These findings support the view that hydrogen peroxide is an important cause of ischemia-reperfusion damage and suggest that protection may be provided by elevation of catalase activity.

Animals↗
PubMed1991

Injury of rat pulmonary alveolar epithelial cells by H2O2: dependence on phenotype and catalase.

In a variety of inflammatory lung diseases, type I alveolar epithelial cells are more likely to be injured than are type II cells. Because oxidants have been implicated as a cause of injury in various inflammatory lung diseases, we evaluated the effects of differentiation on alveolar epithelial cell susceptibility to H2O2-induced injury. With the use of isolated rat type II cells in culture, we found that the cytotoxic effect of H2O2 increased between days 2 and 7, when type II cells are known to lose their distinctive type II properties and assume a more type I-like appearance. We previously reported that type II cells utilized both intracellular catalase and glutathione-dependent reactions to protect against H2O2. We therefore examined whether alterations in either of these protective mechanisms were responsible for the differentiation-dependent changes in sensitivity to H2O2. We found that catalase activity within alveolar epithelial cells decreased between 2 and 7 days in culture, whereas no changes were detected in glutathione-dependent systems. We then used a histochemical technique that detects catalase activity and found that type II cells within rat lungs possessed numerous catalase-containing peroxisomes, whereas very few were detected in type I cells. These findings demonstrate that as type II cells assume a type I-like phenotype, they become more susceptible to H2O2-induced injury. This increased susceptibility is associated with reductions in intracellular catalase activity, both in vitro and in vivo.

Animals↗
PubMed1996

Clinical surfactant preparations mediate SOD and catalase uptake by type II cells and lung tissue.

Pulmonary surfactant mixtures are rapidly taken up by alveolar type II cells and thus may serve as vectors for the pulmonary delivery of antioxidant enzymes to the alveolar epithelium. We prepared emulsions of Survanta with superoxide dismutase (CuZn-SOD) and catalase and quantified their cellular uptake both in vitro and in vivo. Incubations of fetal lung epithelial cells with an emulsion of Survanta plus SOD and catalase mixtures resulted in significant augmentation of SOD and catalase activities (12.8 +/- 4.6 U SOD/microgram DNA; 7.49 +/- 2.21 U catalase/microgram DNA). These numbers were significantly greater than those obtained in controls (1.8 U SOD/microgram DNA; 0.55 +/- 0.52 U catalase/microgram DNA, Survanta alone (0.43 U SOD/microgram DNA; 0.16 U catalase/microgram DNA), and SOD and catalase alone (3.47 +/- 5.2 U SOD/microgram DNA; 4.24 +/- 3.0 U catalase/microgram DNA). Intratracheal instillation of the Survanta plus SOD and catalase mixture resulted in significant augmentation of enzymes by the rat lung homogenates. Confocal microscopic analysis revealed the presence of antioxidant enzymes in the cytoplasm of epithelial cells. We concluded that Survanta supplementation, in addition to replenishing surfactant stores, can also enhance the delivery of antioxidant enzymes to alveolar epithelium both in vitro and in vivo.

Animals↗
PubMed1984

Liposome-mediated augmentation of brain SOD and catalase inhibits CNS O2 toxicity.

Enzymes specific for O-2 and H2O2 metabolism [superoxide dismutase (SOD) and catalase] can be delivered to the rat brain following entrapment in liposomes and intravenous injection and will protect against hyperbaric O2-induced convulsions in rats. Liposome-mediated superoxide dismutase and catalase augmentation of brain enzyme activity was 2.7-fold and 1.9-fold, respectively, 15 min after intravenous injection of superoxide dismutase plus catalase-entrapped liposomes. Rats treated with liposomes containing superoxide dismutase plus catalase 2 h before 6 ATA 100% O2 exposure had the time to convulsion extended three times that of controls. This protective effect was dose-dependent and was primarily due to augmentation of catalase activity. These findings show O-2 and H2O2 are important mediators of hyperbaric O2-induced central nervous system toxicity and that liposome-mediated augmentation of brain antioxidant enzymes has a biological effect.

Animals↗
PubMed1992

Pretreatment with catalase or dimethyl sulfoxide protects alloxan-induced acute lung edema in dogs.

We tested the preventive effects of catalase, an enzymatic scavenger of hydrogen peroxide, or dimethyl sulfoxide (DMSO), a hydroxyl radical scavenger, on intravenous alloxan-induced lung edema in four groups of pentobarbital sodium-anesthetized, ventilated dogs for 3 h: saline (20 ml.kg-1.h-1) infusion alone (n = 5), alloxan (75 mg/kg) + saline infusion (n = 5), catalase (150,000 U/kg) + alloxan + saline infusion (n = 5), or DMSO (4 mg/kg) + alloxan + saline infusion (n = 5). Catalase or DMSO significantly prevented the increase in plasma thromboxane B2 and 6-keto-prostaglandin F1 alpha over 3 h after alloxan and the accumulation of extravascular lung water after 3 h [3.95 +/- 0.52 (SE) g/g with catalase, 3.06 +/- 0.42 g/g with DMSO] but not early pulmonary arterial pressor response. An electron microscopic study indicated that catalase or DMSO significantly reduced the endothelial cellular damages after alloxan. These findings strongly suggest that hydrogen peroxide and hydroxyl radical are major mediators responsible for intravenous alloxan-induced edematous lung injury in anesthetized ventilated dogs.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Reversal of human myeloid leukemia cells into normal granulocytes and macrophages: activity and intracellular distribution of catalase.

The activity and intracellular distribution of catalase was studied in culture human myeloid leukemia cells before and after induction of differentiation with tunicamycin. Activity of catalase was increased 5-fold in acute myeloid leukemia cells (AML) and 3-fold in chronic myeloid leukemia cells in comparison with normal granulocytes. Tunicamycin induced differentiation of HL-60 line and primary AML line characterized by increase in phagocytic cells and changes to resemble mature myeloid cells. Fc receptors were also induced in cells after tunicamycin treatment. Induction of differentiation with tunicamycin decreased high activity of catalase in cultured leukemic cells. The results of digitonin titration experiments showed that in control granulocytes and differentiated leukemic cells most of the catalase activity is present in subcellular particles distinct from mitochondria or lysosomes. In contrast, the catalase activity in undifferentiated cells is present in the same compartment as the other cytosolic markers.

Catalase↗
PubMed2002

Decreasing cellular hydrogen peroxide with catalase mimics the effects of hypoxia on the sensitivity of the L-type Ca2+ channel to beta-adrenergic receptor stimulation in cardiac myocytes.

In cardiac myocytes, hypoxia inhibits the basal L-type Ca2+ current (I(Ca-L)) and increases the sensitivity of I(Ca-L) to beta-adrenergic receptor stimulation. We investigated whether hydrogen peroxide (H2O2) is involved in the hypoxic response. Guinea pig ventricular myocytes were dialyzed with catalase, which specifically catalyzes the conversion of H2O2 to H2O and oxygen, and then I(Ca-L) was recorded during exposure to isoproterenol (Iso). Catalase decreased the K(0.5) for activation of I(Ca-L) by Iso from 2.7+/-0.3 nmol/L (in cells dialyzed with heat-inactivated catalase) to 0.4+/-0.1 nmol/L. The increase in sensitivity to Iso by catalase may be attenuated when cells are preexposed to H2O2. A significant increase in sensitivity of I(Ca-L) to Iso was recorded when mitochondrial function was inhibited with myxothiazol or FCCP, suggesting that the source of H2O2 was from the mitochondria. Prior exposure of cells to H2O2 attenuated the inhibition of basal I(Ca-L) during hypoxia and the increase in sensitivity of I(Ca-L) to Iso during hypoxia. Additionally, extracellularly applied catalase mimicked the effect of hypoxia on basal I(Ca-L). Measurement of the rate of production of hydrogen peroxide using 5- (and 6-)chloromethyl-2', 7'-dichlorodihydrofluorescein diacetate acetyl ester indicated that hypoxia was associated with a significant decrease in the production of hydrogen peroxide in the cells. These data suggest that hypoxia mediates changes in channel activity through a lowering in H2O2 levels and that H2O2 is a key intermediate in modifying basal channel activity and the beta-adrenergic responsiveness of the channel during hypoxia.

Adrenergic beta-Agonists↗
PubMed1990

Inhibition of lung injury, inflammation, and interstitial pulmonary fibrosis by polyethylene glycol-conjugated catalase in a rapid inhalation model of asbestosis.

Several in vitro studies suggest the involvement of active oxygen metabolites in cell damage caused by asbestos. To determine if lung injury, inflammation, and asbestosis could be inhibited in vivo in a rapid-onset, inhalation model of disease, a novel method of chronic administration of antioxidant enzymes was developed. In brief, Fischer 344 rats were treated with polyethylene glycol-conjugated (PEG-) superoxide dismutase or catalase in osmotic pumps over a 10-day (5 days/wk for 2 wk) or 20-day (5 days/wk for 2 wk) period of exposure to crocidolite asbestos. Control rats included sham-exposed animals and those exposed to asbestos but receiving chemically inactivated enzymes. After 10 days of exposure to asbestos, lactic dehydrogenase (LDH), alkaline phosphatase, and total protein in bronchoalveolar lavage (BAL) were measured in one group of rats. Total and differnetial cell counts in BAL also were assessed. After 20 days of exposure, lungs of an additional group of rats were evaluated by histopathology and by measurement of hydroxyproline. Asbestos-associated elevations in LDH, protein, and total cell numbers in BAL were reduced in rats receiving PEG-catalase. Decreases in numbers of alveolar macrophages, polymorphonuclear leukocytes, and lymphocytes occurred in these animals. Exposure to asbestos for 20 days caused significant increases in both the amount of hydroxyproline in lung and the severity and extent of fibrotic lesions as determined by histopathology. These indicators of asbestosis were inhibited in a dosage-dependent fashion in rats receiving PEG-catalase. Use of inactivated PEG-catalase failed to boost serum levels of catalase and did not inhibit asbestos-induced elevation of hydroxyproline in lung.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Increased serum catalase activity in septic patients with the adult respiratory distress syndrome.

Excessive hydrogen peroxide (H2O2) generation appears to contribute to the development of the adult respiratory distress syndrome (ARDS), but H2O2-combatting antioxidant defenses have not been evaluated. We found that serum from septic patients with ARDS scavenged more (p less than 0.05) H2O2 in vitro (82.7 +/- 3.8%) than did serum from septic patients without ARDS (56.9 +/- 3.1%) or control subjects (20.2 +/- 2.4%). Serum from septic patients with ARDS also had more (p less than 0.05) catalase activity (54.9 +/- 10.9 U/ml) than did serum from septic patients without ARDS (28.6 +/- 3.4 U/ml) or control subjects (7.3 +/- 0.8 U/ml). In contrast, serum from septic patients with or without ARDS and control subjects had the same glutathione peroxidase (GPX) activity. Serum H2O2 scavenging activity correlated with serum catalase (r = 0.77) but not GPX (r = 0.33) activity and was inhibitable (greater than 90%) by sodium azide, a catalase inhibitor. Increases in serum catalase activity did not appear to be derived from erythrocytes (RBC) because septic patients with or without ARDS and control subjects had similar RBC hemolysis in response to osmotic stress in vitro and serum haptoglobin concentrations. Serum from septic patients with ARDS also protected endothelial cells against H2O2-mediated damage (34.5 +/- 2.2% 51Cr release) better (p less than 0.05) than serum from septic patients without ARDS (47.3 +/- 7.4%) or control subjects (82.1 +/- 10.2%), but killing of bacteria by neutrophils in vitro was the same in serum from patients and control subjects. Our findings indicate that patients with sepsis and/or ARDS have increased serum catalase activity, which may alter H2O2-dependent processes.

Bacterial Infections↗
PubMed1985

Protection against pulmonary oxygen toxicity in rats by the intratracheal administration of liposome-encapsulated superoxide dismutase or catalase.

To test the feasibility of using liposomes to deliver therapeutic agents to the lungs, the effect of liposome-encapsulated superoxide dismutase (SOD) or catalase on pulmonary oxygen toxicity was studied in rats. The SOD or catalase was encapsulated in negatively changed multilamellar liposomes and administered directly into the trachea of adult rats, which were subsequently exposed to hyperoxia (greater than 95% O2). Response to hyperoxia was examined by studying lung SOD and catalase activities, survival rates, and lung morphology. Rats receiving liposome-encapsulated SOD or catalase showed increased levels of enzyme activities in the lung homogenates compared with those in the control groups after 24 to 72 h of hyperoxic exposure. Elevated enzyme levels in the lungs of rats treated with liposome-encapsulated SOD or catalase were accompanied by a significant improvement in survival rates after 72 h of hyperoxic exposure and less lung injury than in the other control groups.

Animals↗
PubMed1995

DNA repair is more important than catalase for Salmonella virulence in mice.

Pathogenic microorganisms possess antioxidant defense mechanisms for protection from reactive oxygen metabolites such as hydrogen peroxide (H2O2), which are generated during the respiratory burst of phagocytic cells. These defense mechanisms include enzymes such as catalase, which detoxify reactive oxygen species, and DNA repair systems which repair damage resulting from oxidative stress. To determine the relative importance of these two potentially protective defense mechanisms against oxidative stress encountered by Salmonella during infection of the host, a Salmonella typhimurium double mutant unable to produce either the HPI or HPII catalase was constructed, and compared with an isogenic recA mutant deficient in DNA repair. The recA mutant was hypersusceptible to H2O2 at low cell densities in vitro, while the catalase mutant was more susceptible to high H2O2 concentrations at high cell densities. The catalase mutant was found to be resistant to macrophages and retained full murine virulence, in contrast to the recA mutant which previously was shown to be macrophage-sensitive and attenuated in mice. These observations suggest that Salmonella is subjected to low concentrations of H2O2 while at relatively low cell density during infection, conditions requiring an intact DNA repair system but not functional catalase activity.

Acatalasia↗
PubMed1982

Immunoelectron microscopic localization of catalase in human eosinophilic leukocytes.

The immunologic localization of catalase in human eosinophilic leukocytes was studied by use of rabbit anti-human erythrocyte catalase (aHEC) antiserum. Indirect immunofluorescence studies revealed intense localization of fluorescence in the cytoplasm of the eosinophils with a pattern of distribution corresponding to that of the eosinophil granules. Control samples and other nucleated blood elements remained essentially unreactive. Immunoelectron microscopy using aHEC coupled to protein A-gold complexes revealed that catalase was present exclusively within the cytoplasmic granules and equally distributed over the paracrystalline body and the homogeneous granule matrix. The presence of catalase within the paracrystalline body has not been demonstrated before with conventional cytochemical techniques. The results raise the possibility that catalase is stored in the paracrystalline body in an inactive or latent form readily available during eosinophil activation and granule release.

Catalase↗
PubMed1992

Antioxidant defense mechanisms of endothelial cells and renal tubular epithelial cells in vitro: role of the glutathione redox cycle and catalase.

We recently demonstrated that endothelial cells are more susceptible than renal tubular epithelial cells to oxidant injury and that renal tubular epithelial cells with proximal tubular characteristics including porcine proximal tubular epithelial cells, opossum kidney proximal tubular epithelial cells, and normal human kidney cortical epithelial cells are more susceptible to oxidant injury than the distal nephron-derived Madin Darby canine kidney cell line. To determine the basis of this differential response, we evaluated several antioxidant defenses in the five cell lines. Glutathione levels were not significantly different among the five cell lines, but catalase and glutathione reductase levels were significantly (p less than 0.01) lower in endothelial cells compared to all renal tubular epithelial cells. Among renal tubular epithelial cells, Madin Darby canine kidney cells had significantly (p less than 0.05) higher glutathione peroxidase activity. To further evaluate the role of antioxidant defenses in limiting oxidant injury, we determined two responses to oxidant injury (ATP depletion and 51Cr release) when glutathione was depleted with buthionine sulfoxamine and when catalase was inhibited with aminotriazole. Oxidant-induced ATP depletion was accentuated when catalase was inhibited as well as when glutathione was depleted with buthionine sulfoxamine. In contrast, inhibition of catalase had little or no effect on 51Cr release, whereas glutathione depletion resulted in accentuated 51Cr release. We conclude that the increased susceptibility of endothelial cells to oxidant injury as compared with epithelial cells is associated with lower antioxidant defenses. Disruption of the glutathione redox cycle results in accentuated ATP depletion and lytic injury, whereas inhibition of catalase results in accentuated ATP depletion with little effect on lytic injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed2006

Characterization of monofunctional catalase KatA from radioresistant bacterium Deinococcus radiodurans.

Catalase plays a key role in protecting cells against toxic reactive oxygen species. Here we report on the cloning, purification and characterization of a catalase (KatA, DR1998) from the extremely radioresistant bacterium Deinococcus radiodurans. The size of purified D. radiodurans KatA monomer was 65 kDa while gel filtration revealed that the size of the enzyme was 240 kDa, suggesting that KatA formed a homotetramer in solution. Purified KatA displayed a final specific activity of 68,800 U/mg of protein. The catalase activity of KatA was inhibited by sodium azide, sodium cyanide and 3-amino-1,2,4-triazole. The absorption spectrum of KatA exhibited a Soret band at 408 nm. The position of the spectral peak remained unchanged following reduction of KatA with dithionite. No peroxidase activity was found for KatA. These results demonstrate that D. radiodurans KatA is a typical monofunctional heme-containing catalase. The stability of KatA with respect to H2O2 stress was superior to that of commercially available Aspergillus niger and bovine liver catalases. The relative abundance of KatA in cells in addition to the H2O2 resistance property may play a role in the survival strategy of D. radiodurans against oxidative damage.

Amino Acid Sequence↗
PubMed1998

Catalase catalyzes of peroxynitrite-mediated phenolic nitration.

Catalase catalyzed the peroxynitrite-mediated nitration of 4-hydroxyphenylacetic acid. The curve for the pH dependence of nitration was similar to that for the reaction between peroxynitrite and phenol. Cyanide, azide, and 3-amino-1,2,4-triazole inhibited the nitration in a dose-dependent way. When catalase was mixed with peroxynitrite, Compound I was detected as an intermediate. Because azide was an electron donor for the peroxidatic action of catalase, and because 3-amino-1,2,4-triazole inhibited catalase activity by binding with Compound I, peroxynitrite-mediated phenolic nitration was probably accompanied by Compound I formation. Both catalase and superoxide dismutase protected Escherichia coli from peroxynitrite toxicity.

Animals↗