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PubMed1975

Biosynthesis of liver catalase in rats treated with allylisopropylacetylcarbamide. I. Immunochemical assay of catalase in liver cell fractions.

Rats were injected twice intraperitoneally with 20 mg of allylisopropylacetylcarbamide (Sedormid) per 100 g of body weight at an interval of 12 hr. The level of catalase [EC 1.11.1.6] in various liver cell fractions was determined both enzymatically and immunochemically 12 hr after the second injection. 1. The decrease in catalase protein assayed by the immunochemical method directly confirmed the inhibition of biosynthesis of the enzyme by this porphyrinogenic drug. 2. The occurrence of a considerable amount of catalase protein with no enzymatic activity was demonstrated both in the peroxisomes and in the supernatant fraction. 3. The amount of catalase-synthesizing polysomes in hepatic cell was reduced in Sedormid-treated rats by the extent comparable to the decrease in the concentration of liver catalase.

Animals↗
PubMed2001

Plasmid-encoded catalase KatA, the main catalase of Pseudomonas fluorescens strain Cb36.

The plasmid-state catalase gene katA of the phenol gradative Pseudomonas fluorescens isolate Cb36 has been characterized and shown to be the major catalase of this strain. The predicted amino acid sequence of KatA revealed significant similarity with the catalase sequence from Neisseria meningitidis and has probably the non-pseudomonad origin. The specific activity of catalase was investigated and elevated catalase activity was found in stationary phase cells. The consensus sequence for promoters recognized by the stationary phase sigma factor sigma(s) was found 212 bp upstream of the putative ATG start codon. The ability of KatA to detoxify a high concentration of hydrogen peroxide and protect Pseudomonas putida and Escherichia coli cells was shown.

Amino Acid Sequence↗
PubMed1984

Isolation of catalase-deficient Escherichia coli mutants and genetic mapping of katE, a locus that affects catalase activity.

A number of catalase-deficient mutants of Escherichia coli which exhibit no assayable catalase activity were isolated. The only physiological difference between the catalase mutants and their parents was a 50- to 60-fold greater sensitivity to killing by hydrogen peroxide. For comparison, mutations in the xthA and recA genes of the same strains increased the sensitivity of the mutants to hydrogen peroxide by seven- and fivefold, respectively, showing that catalase was the primary defense against hydrogen peroxide. One class of mutants named katE was localized between pfkB and xthA at 37.8 min on the E. coli genome. A second class of catalase mutants was found which did not map in this region.

Catalase↗
PubMed1999

Differential regulation of two divergent Sinorhizobium meliloti genes for HPII-like catalases during free-living growth and protective role of both catalases during symbiosis.

Two catalases, KatA and KatB, have been detected in Sinorhizobium meliloti growing on rich medium. Here we characterize a new catalase gene encoding a third catalase (KatC). KatC activity was detectable only at the end of the stationary phase in S. meliloti growing in minimum medium, whereas KatA activity was found during the exponential phase. Analysis with a katC-lacZ fusion demonstrated that katC expression is mainly regulated at the transcription level. An increase of catalase activity correlating with KatA induction was detected in bacteroids. A dramatic decrease of nitrogen fixation capacity in a katA katC double mutant was observed, suggesting that these catalases are very important for the protection of the nitrogen fixation process.

Arabidopsis Proteins↗
PubMed1984

The reaction of superoxide radical with catalase. Mechanism of the inhibition of catalase by superoxide radical.

We have studied the time course of the absorption of bovine liver catalase after pulse radiolysis with oxygen saturation in the presence and absence of superoxide dismutase. In the absence of superoxide dismutase, catalase produced Compound I and another species. The formation of Compound I is due to the reaction of ferric catalase with hydrogen peroxide, which is generated by the disproportionation of the superoxide anion (O-2). The kinetic difference spectrum showed that the other species was neither Compound I nor II. In the presence of superoxide dismutase, the formation of this species was found to be inhibited, whereas that of Compound I was little affected. This suggests that this species is formed by the reaction of ferric catalase with O-2 and is probably the oxy form of this enzyme (Compound III). The rate constant for the reaction of O-2 and ferric catalase increased with a decrease in pH (cf. 4.5 X 10(4) M-1 s-1 at pH 9 and 4.6 X 10(6) M-1 s-1 at pH 5.). The pH dependence of the rate constant can be explained by assuming that HO2 reacts with this enzyme more rapidly than O-2.

Animals↗
PubMed1983

[Isolation from Micrococcus sp. n. of a homogeneous heme-containing catalase and a crystalline protein with catalase activity].

A method for isolation and purification of catalases from the culture of Micrococcus sp. n. grown under aeration conditions is described. Heme-containing catalase (I) and the protein possessing a catalase activity (II) were separated by fractionation with ammonium sulfate. The specific activity of the highly purified protein causing degradation of H2O2 is 200 times less than that of the heme-containing enzyme. The molecular weights of catalases I and II as determined by electrophoresis in polyacrylamide gel gradient 4/30% are 240000 and 130000, respectively. The method described is designed at rapid isolation of preparative amounts of catalases from Micrococcus sp. n.

Catalase↗
PubMed2003

Distal site aspartate is essential in the catalase activity of catalase-peroxidases.

Structural and biochemical characterization of aspartate 152 at the distal heme side of catalase-peroxidase (KatG) from Synechocystis PCC 6803 reveals an important functional role for this residue. In the wild-type protein, the side chain carboxyl group of Asp152 is 7.8 A apart from the heme iron and is hydrogen-bonded to two water molecules and a KatG-specific large loop. We have prepared the site-specific variants Asp152Asn, Asp152Ser, Asp152Trp, and Pro151Ala. Exchange of Asp152 exhibited dramatic consequences on the bifunctional activity of this unique peroxidase. The turnover number of catalase activity of Asp152Asn is 2.7%, Asp152Ser 5.7%, and Asp152Trp is 0.6% of wild-type activity. By contrast, the peroxidase activity of the Asp152 variants was 2-7 times higher than that of wild-type KatG or Pro151Ala. The KatG-specific pH profile of the catalase activity was completely different in these variants and exchange of Asp152 made it possible to follow the transition of the ferric enzyme to the redox intermediate compound I by hydrogen peroxide spectroscopically and to determine the corresponding bimolecular rate constant to be 7.5 x 10(6) M(-1) s(-1) (pH 7 and 15 degrees C). The reactivity of compound I toward aromatic one-electron donors was enhanced in the Asp152 variants compared with the wild-type protein, whereas the reactivity toward hydrogen peroxide was dramatically decreased. A mechanism for the hydrogen peroxide oxidation, which is different from monofunctional catalases and involves the distal residues Trp122 and Asp152, is proposed.

Amino Acid Sequence↗
PubMed1968

The catalase-hydrogen peroxide system. Role of sub-units in the thermal deactivation of bacterial catalase in the absence of substrate.

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.

Catalase↗
PubMed2001

Encapsulation of catalase and PEG-catalase in erythrocyte.

Reactive partially reduced oxygen species such as superoxide anion (O2-), hydrogen peroxide (H2O2) and hydroxyl radical (OH) are produced in aerobically growing organisms during normal cellular respiration. To provide an effective defense against these reactive species, many aerobic organisms have evolved a multienzyme defense which includes superoxide dismutase, catalase and peroxidase. The superoxide anion may cause appreciable cellular damage by oxidizing aminoacids or by causing DNA strand breakage. Catalase was covalently immobilized on activated methoxypolyethyleneglycol-5000 and catalase and PEG-catalase were encapsulated in erythrocyte. Enzyme activity, encapsulation yield and hemograme analysis were determined for each sample. The erythrocyte shape of the samples were investigated by using phase contrast microscopy.

Catalase↗
PubMed1975

Biosynthesis of liver catalase in rats treated with allylisopropylacetylcarbamide. II. Double-labeling of catalase with (14C)leucine and delta-(3H)aminolevulinic acid.

Double-labeling of liver catalase [EC 1.11.1.6] with [14-c]leucine and delta-[3H]aminolevulinic acid was carried out both in vivo and in vitro using rats treated with allylisopropylacetylcarbamide (Sedormid). These radioactive precursors were incorporated into catalase at a lower rate than in normal rats. In particular, the incorporation of 3H was remarkably inhibited. The results suggest that the administration of Sedormid can inhibit synthesis of the protein moiety of catalase, and possibly interfere with the binding of heme to the catalase protein.

Aminolevulinic Acid↗
PubMed1979

Studies on rat liver catalase. X. Effect of hemin and an inhibitor on the translation of catalase messenger RNA1.

Rat liver catalase mRNA was translated in a rabbit reticulocyte lysates and wheat germ cell-free system in the presence or absence of hemin and/or a translational inhibitor prepared from reticulocytes, liver cells, and wheat germs. Failure to add hemin to the lysates, or the addition of a hemin-regulated translational inhibitor (HRI) to the hemin-supplemented lysates caused a repressed translation. A preparation of inhibitor from rat liver showed activity similar to that of HRI for this translating system. The translation repression by rat liver inhibitor was reversed by eIF-2 (initiation factor) or GTP, but ATP enhanced the repression. The translation of catalase mRNA in the wheat germ system was not affected by the addition of hemin. An inhibitor prepared from wheat germ extracts, as well as the rat liver inhibitor, markedly decreased the rate of translation. eIF-2, GTP, and ATP behaved in the manner described above. Catalase synthesis in a cell-free system derived from rat liver (using endogenous mRNA) was not influenced by either hemin or the inhibitor. The possibilities are discussed that the synthesis of catalase in liver cells is controlled by a translational inhibitor at the level of chain initiation, and that the formation of the inhibitor from its inactive proinhibitor is regulated by the amount of heme.

Adenosine Triphosphate↗
PubMed1998

Changes in catalase activity and hydrogen peroxide level in rat ovary during estrous cycle and induction of catalase in rat ovary by estradiol-17 beta.

Catalase activity in the whole ovary homogenate and hydrogen peroxide level in the differentially centrifuged fractions of the ovary homogenate during each stage of estrous cycle were measured. The highest catalase activity was observed in the metestrous which declined in the estrous and proestrous and was lowest in the diestrous. An inverse relationship was found between catalase activity and hydrogen peroxide production. Treatment of immature (28-29 days old) female rats with estradiol-17 beta (5 micrograms in 0.2 ml oil/animal/day for consecutive 3 days, s.c.) increased the ovarian catalase activity. The findings indicate that the free radical-scavanger system may have functional role in the ovary.

Animals↗
PubMed1993

Characterization of a catalase-deficient strain of Neisseria gonorrhoeae: evidence for the significance of catalase in the biology of N. gonorrhoeae.

We obtained a catalase-deficient (Kat-) strain of Neisseria gonorrhoeae isolated from a patient who had been unsuccessfully treated with penicillin. Quantitative enzyme assays and electrophoresis of cell extracts on native polyacrylamide gels subsequently stained for catalase and peroxidase activities failed to detect both enzymes. The strain exhibited no growth anomalies or unusual requirements when grown under ordinary laboratory conditions. However, the Kat- strain proved extremely sensitive to exogenous hydrogen peroxide, and analysis of the bacterial DNA after such exposure showed extensive single-strand breakage in both chromosomal and plasmid DNAs. Partial characterization of the gonococcal catalase from a Kat+ laboratory strain revealed that the enzyme had the physical and chemical properties of both catalase and peroxidase.

Acatalasia↗
PubMed1979

Catalase anabolism in yeast: loss of regulation by oxygen of catalase apoprotein synthesis after mutation.

A mutant of Saccharomyces cerevisiae which displays catalase activity when grown under strictly anaerobic conditions has been selected on solid media. Although some preformed holoenzyme has accumulated in anaerobic cells, a sharp increase of activity is still measured during adaptation to oxygen in glucose-buffer; however, a striking difference with the wild-type strain is that in the mutant, catalase formation is observed in the presence of cycloheximide that totally inhibits cytoplasmic translation. It is concluded that kat 80 mutant has lost the regulatory control by oxygen of apocatalase synthesis; the later precursor, characterized as apocatalase synthesis; the latter precursor, characterized as apocatalase T, is thought to be activated in vivo, under aerobic conditions, by inclusion of prosthetic group. Regulation of enzyme synthesis by catabolite repression (glucose erfect) persists, unmodified by reference to the wild-type parental strain. Mutation kat 80 specifically hits catalase anabolism, as no significant variations were observed for the edification of the respiratory system and (apo)cytochrome c peroxidase production. Genetic analysis shows that kat 80 phenotype, recessive in heterozygotes, results from a single nuclear mutation.

Anaerobiosis↗
PubMed2003

Cloning and characterization of katA, encoding the major monofunctional catalase from Xanthomonas campestris pv. phaseoli and characterization of the encoded catalase KatA.

The first cloning and characterization of the gene katA, encoding the major catalase (KatA), from Xanthomonas is reported. A reverse genetic approach using a synthesized katA-specific DNA probe to screen a X. campestris pv. phaseoli genomic library was employed. A positively hybridizing clone designated pKat29 that contained a full-length katA was isolated. Analysis of the nucleotide sequence revealed an open reading frame of 1,521 bp encoding a 507-amino acid protein with a theoretical molecular mass of 56 kDa. The deduced amino acid sequence of KatA revealed 84% and 78% identity to CatF of Pseudomonas syringae and KatB of P. aeruginosa, respectively. Phylogenetic analysis places Xanthomonas katA in the clade I group of bacterial catalases. Unexpectedly, expression of katA in a heterologous Escherichia coli host resulted in a temperature-sensitive expression. The KatA enzyme was purified from an overproducing mutant of X. campestris and was characterized. It has apparent K(m) and V(max) values of 75 m M [H(2)O(2)] and 2.55 x 10(5) micromol H(2)O(2) micromol heme(-1) s(-1), respectively. The enzyme is highly sensitive to 3-amino-1,2,4-triazole and NaN(3), has a narrower optimal pH range than other catalases, and is more sensitive to heat inactivation.

Catalase↗
PubMed2001

A common functional C-T substitution polymorphism in the promoter region of the human catalase gene influences transcription factor binding, reporter gene transcription and is correlated to blood catalase levels.

Oxidative stress is implicated in disease and aging. In order to obtain molecular genetic tools that can be used to determine the potential impact of oxidative stress we examined the human catalase gene promoter for possible variation. Genomic DNA isolated from 10 individuals was screened for polymorphisms in the 5'-flanking region by direct sequence analysis of PCR products (nt -307 to -46 from the transcription start site). A common C/T polymorphism -262 base pairs from the transcription start site was detected. Computer analysis indicated that the two variants bound different transcription factors. Indeed, gel retardation analysis revealed different protein binding patterns to the two variants. Expression studies with reporter constructs showed significantly higher transcriptional activity of the T variant in HepG2 and K562 cells (1.5-fold,p <.05 Wilcoxon test). Thus a higher expression in human liver and blood cells is possible. In order to test this hypothesis, catalase levels in red blood cells were determined in 29 donors. The corresponding genotype was determined with a restriction enzyme-based assay. It was found that catalase levels were significantly higher in donors carrying the T allele in comparison to donors homozygous for the C allele (p <.03). In conclusion, we report here the first common (allele frequency in a Swedish population, 28%) genetic variant in a fundamental oxidative stress protection gene with a defined phenotype.

Alleles↗
PubMed1970

Dissociation of catalase. A correlation between changes in sedimentation and spectroscopic properties accompanying dissociation of bacterial catalase in alkaline solution.

1. At high concentrations, in 10mm-phosphate buffer, pH7.0, the sedimentation coefficient of bacterial catalase varies with concentration according to: [Formula: see text] with S(0) (20,w)=11.30S and k(s)=6.29x10(-3)ml mg(-1). Sedimentation-equilibrium experiments yield a molecular weight of 240000. 2. Parallel studies of changes in sedimentation-velocity behaviour and in electronic spectra of bacterial catalase at pH>11 were made. Dissociation is indicated by the appearance of a slow-moving (2.9S) component in sedimentation patterns and this is accompanied by marked changes in absorption spectrum in the Soret region. Values of R=E(406)/E(355) show a theoretically predictable near-linear dependence on alpha, the degree of dissociation calculated from ultracentrifuge data. 3. The Soret absorption of bacterial catalase subunits is much lower than that of the native enzyme, and it is suggested that dissociation produces an environmental constraint on the prosthetic group that results in distortion of the porphyrin ring.

Catalase↗
PubMed2004

Catalase reaction by myoglobin mutants and native catalase: mechanistic investigation by kinetic isotope effect.

The catalase reaction has been studied in detail by using myoglobin (Mb) mutants. Compound I of Mb mutants (Mb-I), a ferryl species (Fe(IV)=O) paired with a porphyrin radical cation, is readily prepared by the reaction with a nearly stoichiometric amount of m-chloroperbenzoic acid. Upon the addition of H2O2 to an Mb-I solution, Mb-I is reduced back to the ferric state without forming any intermediates. This indicates that Mb-I is capable of performing two-electron oxidation of H2O2 (catalatic reaction). Gas chromatography-mass spectroscopy analysis of the evolved O2 from a 50:50 mixture of H2(18)O2/H2(16)O2 solution containing H64D or F43H/H64L Mb showed the formation of 18O2 (m/e = 36) and 16O2 (m/e = 32) but not 16O18O (m/e = 34). This implies that O2 is formed by two-electron oxidation of H2O2 without breaking the O-O bond. Deuterium isotope effects on the catalatic reactions of Mb mutants and catalase suggest that the catalatic reactions of Micrococcus lysodeikticus catalase and F43H/H64L Mb proceed via an ionic mechanism with a small isotope effect of less than 4.0, since the distal histidine residue is located at a proper position to act as a general acid-base catalyst for the ionic reaction. In contrast, other Mb mutants such as H64X (X is Ala, Ser, and Asp) and L29H/H64L Mb oxidize H2O2 via a radical mechanism in which a hydrogen atom is abstracted by Mb-I with a large isotope effect in a range of 10-29, due to a lack of the general acid-base catalyst.

Animals↗