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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

M. luteus catalase dissociates upon treatment with urea, dodecylsulfate and anhydrides into monomers, the molecular weight of which appears to be 1/4 of that of the native enzyme. The urea-induced dissociation depends upon the incubation time, the urea concentration and the pH of the incubation mixture. Reassociation of the subunits proved to be unsuccessful. Native M. luteus catalase only contains 30% alpha-helix. When fully dissociated in presence of urea, it still retains 15% alpha-helix. Catalase from M. luteus was found to lack cysteine residues.
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PMID:Subunit structure of Micrococcus luteus catalase. Dissociation of M. luteus catalase induced by dodecylsulfate, citraconic and 2,3-dimethylmaleic anhydrides and urea. 68 Jun 45

A purification scheme is described for the glyoxylate cycle enzyme isocitrate lyase from maize scutella. Purification involves an acetone precipitation and a heat denaturation step, followed by ammonium sulfate precipitation and chromatography on DEAE-cellulose and on blue-Sepharose. The latter step results in the removal of the remaining malate dehydrogenase activity, and of a high molecular mass (62 kDa) but inactive degradation product of isocitrate lyase. Catalase can be completely removed by performing the DEAE-cellulose chromatography in the presence of Triton X-100. Pure isocitrate lyase can be stored without appreciable loss of activity at -70 degrees C in 5 mM triethanolamine buffer containing 6 mM MgCl2, 7 mM 2-mercaptoethanol, and 50% (v/v) glycerol, pH 7.6. Maize isocitrate lyase is a tetrameric protein with a subunit molecular mass of 64 kDa. Purity of the enzyme preparation was demonstrated by polyacrylamide gel electrophoresis in the presence of dodecylsulfate, in acid (pH 3.2) urea and by isoelectric focusing (pI = 5.1). Maize isocitrate lyase is devoid of covalently linked sugar residues. From circular dichroism measurements we estimate that its structure comprises 30% alpha-helical and 15% beta-pleated sheet segments. The enzyme requires Mg2+ ions for activity, and only Mn2+ apparently is able to replace this cation to a certain extent. The kinetics of the isocitrate lyase-catalyzed cleavage reaction were investigated, and the amino acid composition of the maize enzyme was determined. Finally the occurrence of an association between maize isocitrate lyase and catalase was observed. Such a multienzyme complex may be postulated to play a protective role in vivo.
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PMID:The purification and physicochemical characterization of maize (Zea mays L.) isocitrate lyase. 163 86

The oxidative demethylenation reactions of (methylendioxy)phenyl compounds (MDPs), (methylenedioxy)benzene (MDB), (methylenedioxy)amphetamine (MDA), and (methylenedioxy)methamphetamine (MDMA), were evaluated by using two hydroxyl radical generating systems, the autoxidation of ascorbate in the presence of iron-EDTA and the iron-catalyzed Haber-Weiss reaction conducted by xanthine/xanthine oxidase with iron-EDTA. Reaction products generated when MDB, MDA, and MDMA were incubated with the ascorbate or xanthine oxidase system were catechol, dihydroxyamphetamine (DHA), and dihydroxymethamphetamine (DHMA), respectively. The reaction required the presence of either ascorbic acid or xanthine oxidase. Levels of each catechol increased in proportion to ferric ion concentration and were suppressed by desferrioxamine B methanesulfonate (desferal). Catalase (CAT) inhibited the oxidation by the ascorbate system whereas superoxide dismutase (SOD) had little effect. The addition of hydrogen peroxide to the reaction mixture stimulated the oxidation, but the reaction was not initiated by hydrogen peroxide alone, suggesting that hydrogen peroxide acts as a precursor of hydroxyl radical. SOD and CAT suppressed the demethylenation reactions in the xanthine oxidase system. Hydroxyl radical scavenging agents such as ethanol, benzoate, DMSO, and thiourea effectively inhibited the oxidation by both systems. Urea, which has little effect on hydroxyl radical, was without any effect. These results indicated that hydroxyl radical can effect the cleavage of methylenedioxy group on MDPs.
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PMID:Hydroxyl radical mediated demethylenation of (methylenedioxy)phenyl compounds. 168 Apr 77

The presence of peroxisomes and peroxisomal enzyme activities were investigated in the oleaginous yeast Apiotrichum curvatum ATCC 20509 (formerly Candida curvata D.) Catalase, a marker enzyme for peroxisomes, was measured in cell-free extracts prepared by sonication. The nature of the carbon and nitrogen sources in the growth medium greatly affected catalase activity. Cells grown on corn oil had high specific activity of catalase, but those grown on glucose, sucrose, or maltose had low specific activity. High specific activity of catalase was measured in cultures grown on media that supported poor growth (with soluble starch as carbon source or with methylamine, urea, or asparagine as nitrogen source). Peroxisomes from cells grown on corn oil were separated from other subcellular fractions in a discontinuous sucrose gradient. Major peaks of activity of fatty acid beta-oxidation and of two key enzymes in the glyoxylate cycle were found in fractions containing peroxisomes, but not in fractions corresponding to the mitochondria. Peroxisomal beta-oxidation showed equivalent activity with palmitoyl CoA or n-octanoyl CoA as substrate. Mitochondria did not seem to contain NAD-linked glutamate dehydrogenase. Peroxisomes with a homogeneous matrix and core surrounded by a single-layer membrane were observed with an electron microscope in cells grown on corn oil, but not in those grown on glucose. Staining with 3,3'-diaminobenzidine revealed that catalase activity was located in peroxisomes. Peroxisomes in this oleaginous yeast play important roles in lipid metabolism.
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PMID:Evidence of peroxisomes and peroxisomal enzyme activities in the oleaginous yeast Apiotrichum curvatum. 187 14

A nocardioform bacterium was isolated from the spleen tissue of an armadillo infected with M. leprae and easily propagated in pure culture in mineral salt medium supplemented with only simple C and N sources (e.g., liquid paraffin, tetradecane, ammonium salts, urea, asparagine, gelatin, xanthin, hypoxanthin etc.). Complex organic substances, e.g., tyrosin, casein, peptone, meat extract, egg proteins, serum, blood, yeast extract as well as medium 199, did not support the growth of this organism. Microscopically, the organism consisted of acid-fast, long, slender rods which originated from long, fragmented hyphae, or sporulating mycelial tufts; it was acid-fast (at less than 4.0% H2SO4) which was pyridine-susceptible. It produced DOPA-oxidase and Catalase and was lysozyme resistant; this grew best under reduced O2 tension, at pH 7.0 to 8.0 and 28 degrees C. Serologically, it appeared to be only weakly related to the prototype human multibacillary leprosy-derived (reference) nocardioform strain, Nocardia brasiliensis and N. caviae, but was variably related to several mycobacteria strains.
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PMID:Cultivation of a nocardioform acid-fast chemoautotrophic bacterium from armadillo tissues infected with Mycobacterium leprae. 218 9

Catalase (hydroperoxidase II or HPII) of Escherichia coli K12 has been purified using a protocol that also allows the purification of the second catalase HPI in large amounts. The purified HPII was found to have equal amounts of two subunits with molecular weights of 90,000 and 92,000. Only a single 92,000 subunit was present in the immunoprecipitate created when HPII antiserum was added directly to a crude extract, suggesting that proteolysis was responsible for the smaller subunit. The apparent native molecular weight was determined to be 532,000, suggesting a hexamer structure for the enzyme, an unusual structure for a catalase. HPII was very stable, remaining maximally active over the pH range 4-11 and retaining activity even in a solution of 0.1% sodium dodecyl sulfate and 7 M urea. The heme cofactor associated with HPII was also unusual for a catalase, in resembling heme d (a2) both spectrally and in terms of solubility. On the basis of heme-associated iron, six heme groups were associated with each molecule of enzyme or one per subunit.
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PMID:Purification and characterization of catalase HPII from Escherichia coli K12. 301 70

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.
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PMID:Purification and characterization of spore-specific catalase-2 from Bacillus subtilis. 314 Aug 42

The effects of three-day fasting and one-day refeeding on some blood metabolites and parameters of lipid peroxidation were studied in eight non-pregnant merino ewes. Fasting produced an immediate decrease in blood glucose accompanied by an increase of free fatty acid, total lipid, total cholesterol and urea in the plasma. Starvation increased the concentration of thiobarbituric acid-reactive substances (malondialdehyde), with a slower but more sustained increase in the plasma than in the red blood cell haemolysate. Changes in glutathione peroxidase activity were the reverse of those in malondialdehyde concentration. Catalase activity was not measurable in plasma but was consistently increased in the haemolysate on fasting. Superoxide dismutase activity in the whole blood haemolysate significantly increased only on the first day of food deprivation. The vitamin E content of plasma showed no significant changes. The results indicate that energy deficiency, a well-known phenomenon in ruminants, affects not only the metabolic parameters of the blood but its lipid peroxidative status as well.
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PMID:Effect of fasting on blood lipid peroxidation parameters of sheep. 839 31

The present study examines differences in the hydrogen peroxide (H2O2) detoxifying enzyme, catalase, found in the tails and livers of diploid and haploid Rana rugosa. Investigative techniques include measurement of catalase activity and tests for temperature stability and chemical inhibition. Catalase from the tails of pre-climactic (stage XXIII) haploids was found to be over three times as H2O2 destructive as catalase from similar tails of diploids. Catalase from the livers of newly metamorphosed (stage XXV) froglets, on the other hand, displayed only one third the activity seen in diploid livers. The catalase in haploid tail and liver proved to be more heat resistant, retaining 40-60% of its original activity after 5 min of treatment at 55 degrees C, whereas diploid catalase was totally inactivated under the same conditions. Haploid and diploid catalase also responded differently to inhibition using urea and aminotriazole. These differences suggest that haploid catalase has diverged from normal diploid catalase through molecular modification, resulting in abnormal systems for H2O2 metabolism, which in turn are thought to be responsible for organ dysfunction and early death seen in haploid individuals.
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PMID:Comparison of catalase in diploid and haploid Rana rugosa using heat and chemical inactivation techniques. 946 62

Oxidant injury is considered to be an important mechanism in the pathophysiology of acute renal failure. It has been thought that decrease in extracellular and intracellular fluid and endotoxemia seen in obstructive jaundice may cause an increase in production of oxygen free radicals and impairment in antioxidant defense mechanism. This study is designed to investigate the possible role of oxidant injury in renal failure seen in jaundiced patients. In this study, 28 rats were divided into four groups: Control (C)(N = 7); Renal ischemia (RI)(N = 7); Obstructive jaundice+renal ischemia (OJ+RI)(N = 7); Obstructive jaundice (OJ)(N = 7). All groups were compared with each other according to renal failure findings and enzyme activities, such as Xanthine oxidase (XOD), Superoxide Dismutase (SOD) and Catalase in renal cortex and Glutathione Peroxidase (GSH-Px), in blood at 3rd day after ischemia and reperfusion. Renal failure findings monitored by blood urea and creatinine levels, seemed more evident in OJ+RI than RI group (p < 0.05). When compared with RI, in OJ+RI group, increase in XOD activity at 3rd day was statistically significant [0.259 +/- 0.01 U/g (tissue) and 0.362 +/- 0.03 U/g (tissue) respectively] (p < 0.05). SOD and GSH-Px activities of each ischemic group at 3rd day were decreased compared to non-ischemic groups. This fall was significant (p < 0.05). But there was no statistical difference between jaundiced and non-jaundiced groups. Alterations in catalase activities also had no statistical significance. These findings may suggest that the injury induced by oxygen free radicals at re-oxygenation of tissue after ischemia may also play a role in the pathogenesis of acute renal failure developed in obstructive jaundice.
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PMID:The role of oxygen free radicals in acute renal failure complicating obstructive jaundice: an experimental study. 951 37


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