Showing papers on "Catalase published in 1968"
TL;DR: Semipermeable microcapsules containing catalase can be used to counteractCatalase deficiency in acatalasaemic mice and have the advantage that they cannot leak out to become involved in immunological reactions.
Abstract: Semipermeable microcapsules containing catalase can be used to counteract catalase deficiency in acatalasaemic mice. The advantage of such microencapsulated enzymes is that they cannot leak out to become involved in immunological reactions.
191 citations
TL;DR: Diquat can stimulate NADH oxidase and NADPH oxidase activity in the postmicrosomal soluble fraction and their significance in relation to the toxicity of the dipyridilium compounds are discussed.
Abstract: 1. Paraquat and diquat produce only a slight increase in the oxygen uptake of rat liver mitochondria, and it is likely that they do not penetrate the mitochondrial membrane. 2. In mitochondrial fragments inhibited by antimycin A or by Amytal, both substances stimulate oxygen uptake with NADH or β-hydroxybutyrate as substrate but not with succinate. The NADH dehydrogenase of the respiratory chain appears to be involved, at a site only partially inhibited by Amytal. 3. An NADPH oxidase activity is stimulated in rat liver microsomes by diquat, and to a smaller extent by paraquat; diquat also causes an NADH oxidase activity to develop. The effect is not inhibited by carbon monoxide or p-chloromercuribenzoate, and it is probable that a flavoprotein is involved by a mechanism not requiring thiol groups. 4. One molecule of oxygen can oxidize two molecules of NADPH in the stimulated microsomal system, the hydrogen peroxide produced being broken down by a catalase activity in the microsomes. 5. Diquat can stimulate NADH oxidase and NADPH oxidase activity in the postmicrosomal soluble fraction; the enzyme involved may be DT-diaphorase. 6. The mechanism of these reactions and their significance in relation to the toxicity of the dipyridilium compounds are discussed.
189 citations
TL;DR: An oxygen requirement of isolated intact chloroplasts reducing PGA and nitrate was indicated by lower reaction rates and faster decay of activity under nitrogen than under air.
Abstract: Oxygen was taken up by both intact and broken chloroplasts when catalase was posioned. In confirmation of other work we found that oxygen enters the electron transport chain of isolated chloroplasts by oxidizing the primary photoreductant of system I. In isolated intact chloroplasts this reaction proceeds in addition to oxygen evolution by PGA reduction. The reductant produced by photosystem II does not react with oxygen at a significant rate. In normal leaves oxygen depresses chlorophyll fluorescence. However, this depression does not take place in DCMU poisoned leaves or in a mutant having a nonfunctional photosystem II; furthermore, another mutant with a weakly functioning photosystem I gave only a very small fluorescence depression with oxygen. This shows that the site of interaction of oxygen is at the reducing end of the electron transport chain. This view is supported by the extent of the fluorescence depression in leaves as a function of oxygen concentration which is very similar to the oxygen dependence of oxygen uptake by isolated chloroplasts. An oxygen requirement of isolated intact chloroplasts reducing PGA and nitrate was indicated by lower reaction rates and faster decay of activity under nitrogen than under air.
89 citations
TL;DR: Catalase can be assayed very simply with the oxygen cathode, by measuring the initial rate of oxygen release from a solution of hydrogen peroxide or sodium perborate, because the substrate concentration is high enough, and the time short enough, to prevent decreasing rates during the reaction.
86 citations
TL;DR: It was concluded that the major hemolysin of the Mycoplasma species examined is a peroxide, and Guinea pig erythrocytes were found to be the most susceptible to lysis by myCoplasma, and rabbit ery Throatcytes was found to been the least susceptible.
Abstract: Various methods for the detection of hemolysin production by Mycoplasma species were compared. Inoculation of blood-agar by the push-block method and by use of concentrated mycoplasma cell suspensions was compared with the agar-overlay technique. The preferred method was direct surface inoculation of concentrated suspensions onto the blood-agar. Among the conditions tested, refrigeration of 48-hr cultures gave the best results. A wide variety of mycoplasma species were tested for hemolytic activity towards rabbit, sheep, guinea pig, duck, and chicken bloods. Guinea pig erythrocytes were found to be the most susceptible to lysis by mycoplasma, and rabbit erythrocytes were found to be the least susceptible. A sensitive technique for the detection of peroxide production by mycoplasma strains, employing agar containing benzidine and sheep blood, was used. With this method, peroxide production could be correlated with hemolysis on blood-agar. Peroxidase and catalase inhibited both the benzidine reaction and hemolysis. It was concluded that the major hemolysin of the Mycoplasma species examined is a peroxide. Images
76 citations
TL;DR: Spectrophotometric determination confirmed the presence of specific bonds between radical tetraaminobiphenyl oxide and heme enzymes, at least cytochrome c, catalase and hemoglobin, and it was concluded that tetraaminationobipenyl oxide has an intense affinity for hemoprotein.
Abstract: During the course of an investigation of the properties of 3, 3′, 4, 4′tetraaminobiphenyl (3, 3′-diaminobenzidine), microscopic observations demonstrated that an oxidized radical intermediater of tetraaminobiphenyl gives sensitive microbody staining in aldehyde-fixed rat liver cells when the tissue slices are incubated for 3 to 6hr in a saturated solution of tetraaminobiphenyl oxide, which was kept in air and light, at pH 7.2 without H2O2. The reagent was precipitated along the inner membranes of the mitochondrial cristae, in some cytoplasmic particles of leucocytes, and in erythrocytes as well as in the microbodies of hepatic cells. This reaction occurred anaerobically and even after dry heating for 30min at 120°C, but was inhibited by 10-3M KCN, 10-3M NaN3 or 10-4M Na2S2O4. Triazole in concentration of 10-2M inhibited the reaction of microbodies.Spectrophotometric determination confirmed the presence of specific bonds between radical tetraaminobiphenyl oxide and heme enzymes, at least cytochrome c, catalase and hemoglobin. It is concluded that tetraaminobiphenyl oxide has an intense affinity for hemoprotein.Catalase-rich microbodies are equally distributed in all the parenchymal cells, and mitochondrial hemoproteins are more abundant in the periportal than in the centrolobular areas.
71 citations
TL;DR: Catalase activity in blood, liver, and kidney of a mutant strain Csb has been found to be decreased as compared to the level in normal mice, however, the extent of the reduction largely depends on the conditions used for activity determination, in particular, temperature and duration of the incubation period.
Abstract: Catalase activity in blood, liver, and kidney of a mutant strain Csb has been found to be decreased as compared to the level in normal mice. However, the extent of the reduction largely depends on the conditions used for activity determination, in particular, temperature and duration of the incubation period. In liver, this effect is most pronounced, the observed activity in mutants varying between 21 and 85% of the normal level. This dependence on the assay conditions is mainly due to the unusual heat lability of the variant enzyme, which undergoes rapid inactivation when incubated at 37 C.
62 citations
TL;DR: Catalase activities of intact cells and cell-free extracts of cultures 25042, 558, and 196E were similar, but resistance to H(2)O( 2) at 37.8 C was greater for culture 196E, and the lower resistance of culture 25042 was related to low catalase activity of whole cells of this culture, which were only one-third that of whole Cells of culture 196 E.
Abstract: Catalase activities of intact cells and cell-free extracts of coagulase-positive staphylococcal cultures 105B and 558D isolated from milk, culture 25042 from a clinical source, and Staphylococcus aureus 196E were determined at 32.2 C. Cultures were treated with 0.025 and 0.05% hydrogen peroxide at 37.8 and 54.4 C and without hydrogen peroxide at 54.4 C to determine the relationship between catalase activity and resistance to these treatments. The relationship held true for cultures 105B and 196E; culture 105B had the lowest catalase activity and lowest resistance to H2O2 at 37.8 C, whereas S. aureus 196E possessed a high catalase activity and was most resistant at 37.8 C. Catalase activities of cell-free extracts of cultures 25042, 558, and 196E were similar, but resistance to H2O2 at 37.8 C was greater for culture 196E. The lower resistance of culture 25042 was related to low catalase activities of whole cells of this culture, which were only one-third that of whole cells of culture 196E. Culture 558 was least resistant to heat treatment at 54.4 C and showed the greatest sensitivity to added H2O2 at this temperature.
43 citations
39 citations
TL;DR: Investigation of the immunological properties of the erythrocyte catalase of mice showed that immunologically identicalCatalase protein was present in large amounts in the acalasemic as well as in the hypocatalasemic mutant strains.
Abstract: The immunological properties of the erythrocyte catalase of mice—normal (wild type) strain, one lacking catalase (acatalasemic), and four with only slight catalase activity (hypocatalasemic strains)—have been investigated. Agardiffusion tests and antigen titration of red-cell lysates against rabbit antiserum to catalase from normal mouse blood showed that immunologically identical catalase protein was present in large amounts in the acatalasemic as well as in the hypocatalasemic mutant strains. Despite lack of catalatic activity, the erythrocytes lacking catalase as well as those with only a little catalase contain catalase protein that has been modified at the site of enzyme activity, although the antigenic determinants are identical with those of normal catalase protein. This mutation is purely structural, being characterized by modification of the enzyme active site but not of the antigenic site.
36 citations
TL;DR: The induction of nitrate reductase by nitrate in Neurospora crassa and its control by amino acids have been studied, providing further evidence to show that these two enzyme activities may reside in the same protein.
TL;DR: The highest specific activity of the enzyme was found to be associated with cellular material that can be readily sedimented, and may be derived from milk leucocytes.
Abstract: A β-N-acetylglucosaminase has been found in bovine milk, and its properties have been investigated. The highest specific activity of the enzyme was found to be associated with cellular material that can be readily sedimented. The enzyme resembles catalase in its distribution within the subfractions of milk, and may be derived from milk leucocytes. The optimum pH for the hydrolysis of p-nitrophenyl β-N-acetylglucosaminide is 4.2 and the apparent Michaelis constant for this hydrolysis is 1.0 mM. The enzyme is inhibited by acetate ions, N-acetylglucosamine, and heparin. Inhibition by p-chloromercuribenzoate is not overcome by excess dithiothreitol.
TL;DR: No catalase activity was detected in four strains of glucose-grown Mycoplasma pneumoniae at any time during the replication of the organism, and the production of hydrogen peroxide was demonstrated by the quantitative enzymatic assay for inorganic peroxide.
Abstract: No catalase activity was detected in four strains of glucose-grown Mycoplasma pneumoniae at any time during the replication of the organism. Exogenous catalase dramatically increased the O2 uptake with glycerol, presumably by releasing inhibition caused by hydrogen peroxide. The effect of added catalase on the O2 uptake of washed organisms with glucose as substrate was moderate and variable in degree. The production of hydrogen peroxide was demonstrated by the quantitative enzymatic assay for inorganic peroxide and by the fact that added pyruvate, which is non-enzymatically oxidized by H2O2 to acetic acid and CO2 could mimic the action of catalase.
TL;DR: Catalase has been purified from spinach in 16% yield by means of acetone fractionation, salting out by (NH4)2SO4 and chromatography on DEAE-cellulose and hydroxylapatite and was found to account for 0.56% of the acetone-soluble nitrogen of the spinach leaf.
Journal Article•
TL;DR: It is indicated that hydrogen peroxide generation is rate-limiting in the peroxidation of methanol in both rat and monkey liver, and the low activity of oxidases in monkey liver may explain the lack of peroxidative oxidation of methnol in this species.
Abstract: Hepatic oxidases were studied in rat and monkey liver homogenates and subcellular fractions for their capacity to provide hydrogen peroxide for the catalase-dependent peroxidative oxidation of methanol. Urate oxidase and glycolate oxidase were the most active hepatic hydrogen peroxide-generating enzymes in the rat; much less activity was found in preparations obtained from monkey liver. Supplementation of solubilized hepatic microbodies or cell sap from either species with an exogenous hydrogen peroxide-generating system stimulated methanol oxidation above rates obtained when uric acid or glycolic acid was used to enhance methanol oxidation. Addition of crystalline catalase did not affect the rate of methanol oxidation. These studies indicate that hydrogen peroxide generation is rate-limiting in the peroxidation of methanol in both rat and monkey liver, and the low activity of oxidases in monkey liver may explain the lack of peroxidative oxidation of methanol in this species.
TL;DR: Under appropriate conditions the activity of catalase is found to increase with time in a manner that is quantitatively consistent with the results of deactivation studies.
Abstract: 1. Kinetic studies of the thermal deactivation of bacterial catalase in the absence of substrate suggest that the reaction involves a protonation-induced reversible dissociation of catalase into catalatically inactive sub-units, followed by an irreversible transformation of the sub-units into deactivated products. It is possible that the sub-units are mono-haem species. The rate of deactivation decreases with increasing pressure in accordance with the predictions of the proposed model. 2. The results also imply that the addition of hydrogen peroxide substrate induces the re-formation of active catalase. Under appropriate conditions the activity of catalase is found to increase with time in a manner that is quantitatively consistent with the results of deactivation studies.
Journal Article•
TL;DR: In this paper, the peroxidative system involving catalase plays an important role in the oxidation of methanol in the rat, but is of little importance for this purpose in the monkey.
Abstract: The peroxidative system involving catalase plays an important role in the oxidation of methanol in the rat, but is of little importance for this purpose in the monkey. Since there is abundant hepatic catalase in the monkey, the question arose why it does not function measurably in the peroxidative oxidation of methanol in this species. Two possibilities were investigated: (a) catalase may be distributed in the hepatic cell in such a way that it is not as accessible to peroxide-generating systems as it is in the rat, and (b) hepatic catalase from the monkey may be less active peroxidatively than that found in the rat. Evidence was presented to show that both these factors combine to explain, at least in part, the failure of the peroxidative system to function appreciably in the oxidation of methanol in the monkey. The mouse and the guinea pig resemble the rat in that they also utilize the peroxidative system for the oxidation of methanol. The rate of methanol oxidation in vivo was found to bear a direct relationship to the amount of particulate catalase in the livers of the rat, mouse, and guinea pig.
TL;DR: In this paper, the electron spin resonance spectra of catalase complexes were examined at a temperature of 77 °K by applying the method of electron spin Resonance Resonance.
TL;DR: Growth of Bacillus subtilis and of Escherichia coli following treatment with oxygen at 10 atmospheres for 18 hr was synchronous and the region of maximum resistance in B. subtil is compared fairly closely with the time of maximum catalase activity.
Abstract: SUMMARY: Growth of Bacillus subtilis and of Escherichia coli following treatment with oxygen at 10 atmospheres for 18 hr was synchronous. Treatment at lower pressures resulted in a much lower degree of synchrony. After exposure to high-pressure oxygen to induce synchronous growth of B. subtilis the resistance of various stages of the cell cycle to further treatment with oxygen at 10 atm. was studied. Maximum resistance occurred immediately following division of the bacilli and then fell to a low value. The region of maximum resistance in B. subtilis compared fairly closely with the time of maximum catalase activity.
TL;DR: The reaction of 4-hydroxyaminoquinoline 1-oxide with sulfhydryl groups of albumin and enzymes with different types of sulfhydRYl groups was studied and may be significant in the mechanism of 4HAQO carcinogenesis.
TL;DR: The theory that drug-induced hemolysis in G6-PD-deficient individuals involves oxidant damage by H 2 O 2 is supported.
TL;DR: Activity of indoleacetic acid oxidase in partially purified extracts from cotton is stimulated by small amounts of malate, succinate, fumarate, and other plant acids, apparently due to inhibition of catalase, which is detectable in certain preparations.
Abstract: Activity of indoleacetic acid oxidase in partially purified extracts from cotton is stimulated by small amounts of malate, succinate, fumarate, and other plant acids The stimulation is apparently due to inhibition of catalase, which is detectable in certain preparations The lag phase of indoleacetic acid oxidation by crude preparations is eliminated by steps in processing which conceivably either denatures or dilutes catalase, or concentrates inhibitors to catalase
TL;DR: It is concluded that crocin is destroyed by an aerobic oxidation mediated by peroxidase, although the exact requirements for the reaction have not been established.
TL;DR: The results of these studies suggest that molecular subunits of erythrocyte catalase and C-reactive protein are antigenically similar.
Journal Article•
TL;DR: In this paper, the hydrogen peroxide-catalase treatment of milk, prior to inoculation with starter cultures containing diacetyl-producing aroma bacteria, has been found to increase synthesis and stabilization of the cultured milk.