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At least 991 records · Page 55Linked to original sources
PubMed2001

In vitro resistance of Burkholderia cepacia complex isolates to reactive oxygen species in relation to catalase and superoxide dismutase production.

The Burkholderia cepacia complex comprises groups of genomovars (genotypically distinct strains with very similar phenotypes) that have emerged as important opportunistic pathogens in cystic fibrosis (CF) patients. The inflammatory response against bacteria in the airways of CF individuals is dominated by polymorphonuclear cells and involves the generation of oxidative stress, which leads to further inflammation and tissue damage. Bacterial catalase, catalase-peroxidase and superoxide dismutase activities may contribute to the survival of B. cepacia following exposure to reactive oxygen metabolites generated by host cells in response to infection. In the present study the authors investigated the production of catalase, peroxidase and SOD by isolates belonging to various genomovars of the B. cepacia complex. Production of both catalase and SOD was maximal during late stationary phase in almost all isolates examined. Native PAGE identified 13 catalase electrophoretotypes and two SOD electrophoretotypes (corresponding to an Fe-SOD class) in strains belonging to the six genomovars of the B. cepacia complex. Seven out of 11 strains displaying high-level survival after H(2)O(2) treatment in vitro had a bifunctional catalase/peroxidase, and included all the genomovar III strains examined. These isolates represent most of the epidemic isolates that are often associated with the cepacia syndrome. The majority of the isolates from all the genomovars were resistant to extracellular O(-)(2), while resistance to intracellularly generated O(-)(2)was highly variable and could not be correlated with the detected levels of SOD activity. Altogether the results suggest that resistance to toxic oxygen metabolites from extracellular sources may be a factor involved in the persistence of B. cepacia in the airways of CF individuals.

Burkholderia Infections↗
PubMed1995

Molecular characterization of katA from Campylobacter jejuni and generation of a catalase-deficient mutant of Campylobacter coli by interspecific allelic exchange.

A gene encoding catalase (hydrogen-peroxide:hydrogen-peroxide oxidoreductase; EC 1.11.1.6) from Campylobacter jejuni was cloned by functional complementation of a catalase-deficient mutant of Escherichia coli. The catalase structural gene, designated katA, was assigned by subcloning and its nucleotide sequence determined. The deduced protein product of 508 amino acids, which had a calculated molecular mass of 58,346 Da, was found to be structurally and enzymically similar to hydrogen-peroxidases from other bacterial species. The region of DNA containing the structural catalase gene was disrupted by insertion of a tetracycline-resistance marker and the modified sequence then introduced into a strain of Campylobacter coli via natural transformation. Genetic and enzymic analyses of a tetracycline-resistant C. coli transformant confirmed that catalase-deficient mutants had arisen via interspecific allelic exchange. Compared to the isogenic parental strain the mutant was more sensitive to killing by H2O2.

Alleles↗
PubMed1996

KatP, a novel catalase-peroxidase encoded by the large plasmid of enterohaemorrhagic Escherichia coli O157:H7.

A gene coding for a catalase-peroxidase activity was identified on a 9-7 kb Smal DNA fragment derived from the large plasmid pO157 of enterohaemorrhagic Escherichia coli (EHEC) O157:H7 strain EDL 933. Nucleotide sequencing revealed an ORF of 2208 bp and predicted a 736 amino acid polypeptide with a molecular mass of 81.8 kDa. This putative protein was found to be highly homologous to members of the bacterial bifunctional catalase-peroxidase family. Analysis of its amino acid sequence revealed the presence of characteristic peroxidase 1 and 2 motifs. In addition, an N-terminal signal sequence was found, suggesting that the catalase-peroxidase is transported through the cytoplasmic membrane. EHEC catalase-peroxidase activities were investigated in cytoplasmic and periplasmic crude extracts as well as in culture supernatants from wild-type and recombinant E. coli strains. EHEC-specific catalase-peroxidase activity was detected primarily in the periplasm in strain EDL 933. The newly discovered enzyme was designated KatP, to indicate its plasmid origin. PCR analysis of representative strains of all enteric E. coli pathogroups (i.e. enterohaemorrhagic, enterotoxigenic, enteropathogenic, enteroaggregative and enteroinvasive E. coli) revealed a close association between the occurrence of EHEC-haemolysin and the katP gene in Shiga-like-toxin-producing E. coli O157 strains.

Amino Acid Sequence↗
PubMed1999

Superoxide dismutase and catalase in Photobacterium damselae subsp. piscicida and their roles in resistance to reactive oxygen species.

Photobacterium damselae subsp. piscicida (formerly Pasteurella piscicida) is the causative agent of pasteurellosis or pseudotuberculosis in warm water marine fish. Enzymes which neutralize reactive oxygen species, produced during aerobic metabolism or during respiratory burst in fish macrophages, are important virulence factors in many pathogens. This study characterizes a periplasmic superoxide dismutase (SOD) and a cytoplasmic catalase in P. damselae. Purification and partial amino-terminal sequencing confirmed the SOD to be iron-cofactored, with a high degree of homology to other bacterial FeSODs. The SOD was common to all strains analysed in terms of type, location and activity, whilst the catalase varied in activity between strains. The catalase was constitutively expressed, but the SOD appeared to be repressed under low oxygen conditions. In spite of the presence of a periplasmic SOD, P. damselae was susceptible to killing by exogenous superoxide anion generated in a cell-free system. Addition of exogenous SOD to this system did not abolish the bactericidal effect; however, addition of catalase was protective. These results suggest that lack of periplasmic catalase may be implicated in susceptiblity to killing by reactive oxygen species.

Amino Acid Sequence↗
PubMed2002

The structures of Micrococcus lysodeikticus catalase, its ferryl intermediate (compound II) and NADPH complex.

The crystal structure of the bacterial catalase from Micrococcus lysodeikticus has been refined using the gene-derived sequence both at 0.88 A resolution using data recorded at 110 K and at 1.5 A resolution with room-temperature data. The atomic resolution structure has been refined with individual anisotropic atomic thermal parameters. This has revealed the geometry of the haem and surrounding protein, including many of the H atoms, with unprecedented accuracy and has characterized functionally important hydrogen-bond interactions in the active site. The positions of the H atoms are consistent with the enzymatic mechanism previously suggested for beef liver catalase. The structure reveals that a 25 A long channel leading to the haem is filled by partially occupied water molecules, suggesting an inherent facile access to the active site. In addition, the structures of the ferryl intermediate of the catalase, the so-called compound II, at 1.96 A resolution and the catalase complex with NADPH at 1.83 A resolution have been determined. Comparison of compound II and the resting state of the enzyme shows that the binding of the O atom to the iron (bond length 1.87 A) is associated with increased haem bending and is accompanied by a distal movement of the iron and the side chain of the proximal tyrosine. Finally, the structure of the NADPH complex shows that the cofactor is bound to the molecule in an equivalent position to that found in beef liver catalase, but that only the adenine part of NADPH is visible in the present structure.

Amino Acid Sequence↗
PubMed2004

The three-dimensional structure of catalase from Enterococcus faecalis.

Enterococcus faecalis haem catalase was crystallized using lithium sulfate at neutral pH. The crystals belong to space group R3, with unit-cell parameters a = b = 236.9, c = 198.1 A. The three-dimensional structure was determined by molecular replacement using a subunit of the Proteus mirabilis catalase structure. It was refined against 2.3 A synchrotron data to a free R factor of 21.8%. Like other catalases, the E. faecalis catalase is a homotetramer with a fold and structure similar to those of its structurally closest relative P. mirabilis. The solvent structure in the active site is identical in the four subunits but differs from that found in other catalases. The structural consequences of the Ramachandran outlier Ser196 are discussed.

Amino Acid Sequence↗
PubMed1999

Crystallization and preliminary structural results of catalase from human erythrocytes.

Catalase (hydrogen peroxide:hydrogen peroxide oxidoreductase, E.C. 1. 11.1.6) is present in most aerobic prokaryotic and eukaryotic cells. Despite a large number of studies on catalases, the only mammalian catalase structure available is that from beef liver, in which about 50% of the haem groups are degraded to bile pigments. Three different crystal forms of human erythrocyte catalase were obtained by the hanging-drop vapour-diffusion technique using PEG as precipitant. Monoclinic crystals, with space group P21 and unit-cell parameters a = 102.9, b = 140.0, c = 173.6 A and beta = 103.2 degrees, require NADP(H) in the crystallization solution. Two types of hexagonal packing, with unit-cell parameters of either a = b = 86. 9, c = 255.5 A or a = b = 90.0, c = 521.2 A, were obtained under identical crystallization conditions in the absence of NADP(H). Only one diffraction data set could be collected: this was obtained from the hexagonal crystals with the smaller c axis using synchrotron radiation, with resolution to 2.65 A. A molecular-replacement solution, determined using a modified beef-liver catalase model as a search structure, corresponds to space group P6422 and contains a single subunit in the asymmetric unit, with an estimated solvent volume of about 50%. The packing determined suggests how minor rearrangements might allow the transition between both hexagonal crystal forms and provides an explanation for the anisotropic character of the corresponding diffractions.

Catalase↗
PubMed2004

Absence of catalase reduces long-term survival of Helicobacter pylori in macrophage phagosomes.

BACKGROUND: Some Helicobacter pylori strains can survive within macrophage phagosomes for up to 24 hours. The factors that play a role in this survival remain ill-defined. Therefore, the contribution of catalase in mediating the survival of H. pylori following phagocytosis was investigated in vitro. METHODS: An isogenic, catalase-deficient strain of H. pylori was generated and tested for sensitivity to hydrogen peroxide and susceptibility to macrophage-mediated killing. RESULTS: The isogenic, catalase-deficient strain of H. pylori was effectively killed by hydrogen peroxide within 3 minutes compared to wild-type H. pylori which maintained 100% survival up to 21 minutes. The catalase-deficient mutant was also significantly more susceptible to macrophage-mediated killing than the parent strain, even when the ratio of bacteria to macrophage was increased. CONCLUSION: These results indicate that although some strains of H. pylori are capable of survival within the macrophage phagosome, survival is dependent on virulence factors such as catalase for evasion of innate host defense.

Animals↗
PubMed1993

Reactive oxygen species in semen of infertile patients: levels of superoxide dismutase- and catalase-like activities in seminal plasma and spermatozoa.

Reactive oxygen species (ROS) can be detected in the semen of 40% of infertile men, whereas none is detected in semen from normal men. The ROS detected in semen are a reflection of the imbalance between ROS production and degradation. The aim of the present study was to determine whether a lowered scavenging capacity or an increased production of ROS was responsible for the ROS detected in semen samples from infertile men. Two activities were investigated: (1) catalase-like activity, which is responsible for the degradation of H2O2 and (2) superoxide dismutase-like (SOD-like) activity which is responsible for the degradation of .O2-. Catalase-like and SOD-like activities were found in whole seminal plasma, in dialyzed seminal plasma (> 12 kD), in an ultrafiltrate of seminal plasma (< 5 kD) and in spermatozoa. There was no significant difference in the SOD-like activities measured in spermatozoa, or in seminal plasma (whole or fractionated) from samples that did or did not produce ROS. SOD-like activity originated mostly from the high molecular weight components of seminal plasma. However, the catalase-like activity of whole seminal plasma and of spermatozoa was significantly greater (P = 0.01) in those samples that produced ROS as compared to those that did not. The catalase-like activity in dialyzed seminal plasma, and an ultrafiltrate of seminal plasma from semen samples that did or did not produce ROS were not statistically different. The catalase-like activity of the seminal plasma originated equally from high and low molecular weight components.(ABSTRACT TRUNCATED AT 250 WORDS)

Catalase↗
PubMed2006

Superoxide dismutase and catalase activities in Photobacterium damselae ssp. piscicida.

The ability of a set of Photobacterium damselae ssp. piscicida strains isolated from different fish species to produce different superoxide dismutase (SOD) and catalase enzymes was determined. Unlike other bacterial pathogens, P. damselae ssp. piscicida is not able to produce different isoforms of SOD or catalase containing different metal cofactors when cultured under oxidative stress induced by hydrogen peroxide or methyl viologen, or under iron depleted conditions. However, iron content of the growth medium influenced the levels of SOD and catalase activity in cells, these levels decreasing with iron availability of the medium. Comparison of virulent and non-virulent strains of P. damselae ssp. piscicida showed similar contents of SOD, but higher levels of catalase were detected in cells of the virulent strain. Incubation of bacteria with sole, Solea senegalensis (Kaup), phagocytes has shown that survival rates range from 19% to 62%, these rates being higher for the virulent strain. The increased levels of catalase activity detected in the virulent strain indicates a possible role for this enzyme in bacterial survival.

2,2'-Dipyridyl↗
PubMed1977

Properties of human erythrocyte catalases after crosslinking with bifunctional reagents. Symmetry of the quaternary structure.

Normal erythrocyte catalase, the enzyme present in the blood of Swiss acatalasemic heterozygotes, and their hybrid produced in vitro, were studied after crosslinking with bifunctional reagents. On theoretical grounds [cf. Hajdu, J., Bartha, F. & Friedrich, P. (1976) Eur. J. Biochem. 68, 373--383] it is inferred from the dodecylsulphate gel electrophoretic patterns obtained after treating catalase with diimidates of various chain lengths that the enzyme is an isologous tetramer (D2 symmetry). The minimal distances between crosslinkable primary amino groups across the three domains of bonding are different. Reaction with diimidates causes a moderate loss of enzyme activity in all three enzyme types due to amidination rather than crosslink formation. On the other hand, crosslinking stabilizes the enzyme against urea and heat inactivation. This is most prominent with heterozygote acatalasemic catalase. Crosslinking markedly prevents the development of peroxidase activity that can be elicited in catalases by urea treatment. The role of the quaternary structure of the protein in the relationship between catalase and peroxidase activities is discussed.

Animals↗
PubMed1982

Catalase is induced by ecdysterone and ethanol in Drosophila cells.

Clones sensitive or resistant to ecdysterone and cultured in vitro were isolated from established cell line of Drosophila melanogaster. Ecdysterone (20-hydroxyecdysone), a hormonal steroid of critical importance in insect physiology, induces catalase activity in the sensitive clones. This catalase induction does not occur in clones known to be resistant to the the hormone. The important role of catalase as a scavenger for H2O2 in the aerobic cells (Drosophila cells in culture are consuming oxygen) led to the demonstration of catalatic properties of this induced enzyme. The peroxidatic property of catalase, useful in alcohol metabolism, was the reason for showing that ethanol can also induce catalase in Drosophila cells.

Acetylcholinesterase↗
PubMed1982

Properties of catalase purified from whole cells and peroxisomes of n-alkane-grown Candida tropicalis.

Peroxisomes appear profusely, in harmony with a marked enhancement of catalase activity level, in yeast cells growing on n-alkanes or higher fatty acids as the sole carbon source. Catalase (H2O2:H2O2 oxidoreductase, EC 1.11.1.6) was purified to homogeneity from the crude extract and from the peroxisome-containing particulate fraction of alkane-grown Candida tropicalis cells. The purified enzyme from each source was a similar protein of molecular weight 210000 composed of four identical subunits of molecular weight 54000, namely a kind of homotetramer. The enzyme contained one molecule of heme per subunit, giving the absorption spectrum characteristic of hemoprotein. Beta-(3,4-Dihydroxyphenyl)-L-alanine served as a substrate for the peroxidatic reaction by the enzyme. Ouchterlony double-diffusion analysis and immunochemical titration with rabbit antiserum against peroxisomal catalase of n-alkane-grown C. tropicalis have indicated that cytoplasmic catalase of the yeast is immunologically indistinguishable with peroxisomal catalase.

Alkanes↗
PubMed1986

Properties of catalase purified from a methanol-grown yeast, Kloeckera sp. 2201.

Catalase, a marker enzyme of peroxisomes, was purified to homogeneity from whole cells of Kloeckera sp. 2201 (a strain of Candida boidinii) grown on methanol by means of ammonium sulfate fractionation followed by hydroxyapatite, Sephacryl S-300 and DEAE-Sepharose column chromatographies. Crystallized catalase was brown-coloured and needle-like. The molecular mass of the enzyme was about 240 000 daltons consisting of four identical subunits of 62 000 daltons. The minimum size of catalase molecule was estimated to be about 6 X 10 nm from an electron micrograph. Judging from the absorption spectrum, the enzyme seemed to belong to a group of T-type catalase. The Km value of the enzyme for hydrogen peroxide (catalatic activity) was 25 mM, while that for methanol (peroxidatic activity) was 83 mM. Catalase from Kloeckera sp. cells showed a certain degree of similarity to the enzyme purified from alkane-grown Candida tropicalis [T. Yamada et al. (1982) Eur. J. Biochem. 125, 517-521 and 129, 251-255] in its immunochemical properties.

Animals↗
PubMed1995

Reversible binding and inhibition of catalase by nitric oxide.

The interactions between nitric oxide (NO), H2O2, and catalase were investigated. H2O2 did not cause detectable breakdown of NO in the absence of catalase, but did cause NO breakdown in the presence of catalase. Catalase bound NO, and NO rapidly and reversibly inhibited catalase with a Ki of 0.18 microM. The significance of these results for NO cytotoxicity is discussed.

Animals↗
PubMed1997

Molecular chaperones protect catalase against thermal stress.

Lenticular alpha-crystallin is generally thought of as having limited chaperone functions. It can efficiently suppress the aggregation of proteins but is unable to promote the functional refolding of proteins after denaturation in many systems unlike other molecular chaperones. However, it has been reported that alpha-crystallin, along with the small heat-shock proteins, is able to promote the functional refolding of some enzymes after thermal and chemical denaturation. These chaperones are also able to confer protection against the thermal inactivation of these enzymes. In results presented here, we demonstrate that alpha-crystallin, along with chaperonin 60 (GroEL), was able to provide statistically significant and specific protection against catalase thermal inactivation at stoichiometrical concentrations. The small heat-shock protein, heat-shock protein 25 (Hsp25), was unable to confer any such protection. alpha-Crystallin however was unable to promote the functional refolding of thermally inactivated catalase. alpha-Crystallin and Hsp25 both efficiently suppressed the thermal aggregation of catalase. A high-molecular-mass (HMM) complex was only observed to develop in solutions containing catalase and alpha-crystallin after solutions were 80-fold more concentrated relative to thermal inactivation assay conditions prior to incubation. SDS/PAGE analysis confirmed that alpha-crystallin had formed a soluble complex with catalase after a period of thermal stress.

Animals↗
PubMed1989

Effects of 3-amino-1,2,4-triazole on ethanol-induced open-field activity: evidence for brain catalase mediation of ethanol's effects.

The role of brain catalase in the mediation of ethanol's effects on motor activity was investigated. Male Long-Evans rats were pretreated with i.p. injections of the catalase inhibitor, 3-amino-1,2,4-triazole (AT) (1 g/kg) or saline (S). Four hours later, animals in each group received i.p. injections of one of two doses of ethanol (ETOH) [1.0 g/kg (E1) or 2.0 g/kg (E2)] or one of two volumes of distilled water (W1 or W2). Ten minutes after the administration of these agents, animals were placed in open-field chambers and motor activity was recorded during a 10-min testing period. Results indicated that the motor depression produced by 2.0 g/kg of ETOH was significantly attenuated in AT pretreated rats (group AT-E2). AT pretreatment, however, had no effect on motor activity for subjects injected with 1.0 g/kg ethanol or water. Total brain catalase activity in AT-pretreated animals was 15% of control animals. No differences in blood ethanol levels were observed between AT- and S-pretreated animals. An interaction between ethanol and AT at the level of the central nervous system is suggested. The results of the present study suggest that brain catalase activity may be involved in ethanol's effects. They also provide further support for the notion that acetaldehyde may be produced directly in the brain via catalase and that it may be a factor mediating some of ethanol's central effects.

Amitrole↗
PubMed1999

Identification of the catalase gene promoter region involved in superinduction in Schizosaccharomyces pombe caused by cycloheximide and hydrogen peroxide.

Superinduction of the catalase gene was observed in Schizosaccharomyces pombe cells treated with cycloheximide and hydrogen peroxide. The promoter analysis of the catalase gene revealed that element A (the region from -111 to -90, numbered with the transcription start site as +1), involved in the induction of the gene under oxidative stress, was required for superinduction by hydrogen peroxide and cycloheximide. Although Atf1 is a transcription factor responsible for the induction of the catalase gene by several stresses, a disruptant of atf1 exhibited superinduction. Moreover, in a deletion mutant that lacks element A but has an Atf1 binding site, the cells treated with hydrogen peroxide and cycloheximide expressed as much catalase mRNA as those treated with hydrogen peroxide alone. This suggests that cycloheximide does not stabilize the catalase mRNA but enhances the transcription via element A. Staurosporine, a strong inhibitor of protein phosphorylation, did not inhibit superinduction.

Base Sequence↗