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Sample records for n-acetylcysteine-mediated catalase upregulation

  1. A rapid and transient ROS generation by cadmium triggers apoptosis via caspase-dependent pathway in HepG2 cells and this is inhibited through N-acetylcysteine-mediated catalase upregulation

    SciTech Connect

    Oh, Seon-Hee; Lim, Sung-Chul . E-mail: sclim@chosun.ac.kr

    2006-05-01

    Although reactive oxygen species (ROS) have been implicated in cadmium (Cd)-induced hepatotoxicity, the role of ROS in this pathway remains unclear. Therefore, we attempted to determine the molecular mechanisms relevant to Cd-induced cell death in HepG2 cells. Cd was found to induce apoptosis in the HepG2 cells in a time- and dose-dependent fashion, as confirmed by DNA fragmentation analysis and TUNEL staining. In the early stages, both rapid and transient ROS generation triggered apoptosis via Fas activation and subsequent caspase-8-dependent Bid cleavage, as well as by calpain-mediated mitochondrial Bax cleavage. The timing of Bid activation was coincided with the timing at which the mitochondrial transmembrane potential (MMP) collapsed as well as the cytochrome c (Cyt c) released into the cytosol. Furthermore, mitochondrial permeability transition (MPT) pore inhibitors, such as cyclosporin A (CsA) and bongkrekic acid (BA), did not block Cd-induced ROS generation, MMP collapse and Cyt c release. N-acetylcysteine (NAC) pretreatment resulted in the complete inhibition of the Cd-induced apoptosis via catalase upregulation and subsequent Fas downregulation. NAC treatment also completely blocked the Cd-induced intracellular ROS generation, MMP collapse and Cyt c release, indicating that Cd-induced mitochondrial dysfunction may be regulated indirectly by ROS-mediated signaling pathway. Taken together, a rapid and transient ROS generation by Cd triggers apoptosis via caspase-dependent pathway and subsequent mitochondrial pathway. NAC inhibits Cd-induced apoptosis through the blocking of ROS generation as well as the catalase upregulation.

  2. Overexpression of Cu/Zn-superoxide dismutase and/or catalase accelerates benzo(?) pyrene detoxification by upregulation of the aryl hydrocarbon receptor in mouse endothelial cells

    PubMed Central

    Wang, Zefen; Yang, Hong; Ramesh, Aramandla; Roberts, L. Jackson; Zhou, LiChun; Lin, Xinhua; Zhao, Yanfeng; Guo, ZhongMao

    2010-01-01

    A reduction in endogenously generated reactive oxygen species in vivo delays benzo(?)pyrene (BaP)-accelerated atherosclerosis, as revealed in hypercholesterolemic mice overexpressing Cu/Zn-superoxide dismutase (SOD) and/or catalase. To understand the molecular events involved in this protective action, we studied the effects of Cu/Zn-SOD and/or catalase overexpression on BaP detoxification and on aryl hydrocarbon receptor (AhR) expression and its target gene expression in mouse aortic endothelial cells (MAECs). Our data demonstrate that overexpression of Cu/Zn-SOD and/or catalase leads to an 18- to 20-fold increase in the expression of AhR protein in MAECs. After BaP exposure, the amount of AhR binding to the cytochrome P450 (CYP) 1A1 promoter was significantly greater, and the concentrations of BaP reactive intermediates were significantly less in MAECs overexpressing Cu/Zn-SOD and/or catalase than in wild-type cells. In addition, the BaP-induced CYP1A1 and 1B1 protein levels and BaP-elevated glutathione S-transferase (GST) activity were significantly higher in these transgenic cells, in parallel with elevated GSTp1, CYP1A1, and CYP1B1 mRNA levels, compared to wild-type MAECs. Moreover, knockdown of AhR with RNA interference diminished the Cu/Zn-SOD and catalase enhancement of CYP1A1 expression, GST activity, and BaP detoxification. These data demonstrate that overexpression of Cu/Zn-SOD and/or catalase is associated with upregulation of AhR and its target genes, such as xenobiotic-metabolizing enzymes. PMID:19666105

  3. Non-heme manganese catalase the other catalase

    PubMed Central

    Whittaker, James W.

    2012-01-01

    Non-heme manganese catalases are widely distributed over microbial life and represent an environmentally important alternative to heme-containing catalases in antioxidant defense. Manganese catalases contain a binuclear manganese complex as their catalytic active site rather than a heme, and cycle between Mn2(II,II) and Mn2(III,III) states during turnover. X-ray crystallography has revealed the key structural elements of the binuclear manganese active site complex that can serve as the starting point for computational studies on the protein. Four manganese catalase enzymes have been isolated and characterized, and the enzyme appears to have a broad phylogenetic distribution including both bacteria and archae. More than 100 manganese catalase genes have been annotated in genomic databases, although the assignment of many of these putative manganese catalases needs to be experimentally verified. Iron limitation, exposure to low levels of peroxide stress, thermostability and cyanide resistance may provide the biological and environmental context for the occurrence of manganese catalases. PMID:22198285

  4. Possible involvement of the JAK/STAT signaling pathway in N-acetylcysteine-mediated antidepressant-like effects.

    PubMed

    Al-Samhari, Marwa M; Al-Rasheed, Nouf M; Al-Rejaie, Salim; Al-Rasheed, Nawal M; Hasan, Iman H; Mahmoud, Ayman M; Dzimiri, Nduna

    2016-03-01

    Advances in depression research have targeted inflammation and oxidative stress to develop novel types of treatment. The JAK/STAT signaling pathway plays pivotal roles in immune and inflammatory responses. The present study was designed to investigate the effects of N-acetylcysteine, a putative precursor of the antioxidant glutathione, in an animal model of depression, with an emphasis on the JAK/STAT signaling pathway. Fluoxetine, a classical antidepressant drug was also under investigation. Male Wistar rats were subjected to forced swimming test and given N-acetylcysteine and fluoxetine immediately after the pre-test session, 5 h later and 1 h before the test session of the forced swimming test. N-acetylcysteine decreased immobility time (P < 0.05), serum corticosterone (P < 0.001), and hydrogen peroxide (P < 0.001), while restored glutathione concentration. Treatment of the rats with N-acetylcysteine produced significant (P < 0.001) down-regulation of STAT3 mRNA expression and protein phosphorylation. On the other hand, N-acetylcysteine significantly (P < 0.001) increased SOCS3 gene expression; however, SOCS3 protein was not changed. In conclusion, our study suggests that modulation of the JAK/STAT pathway might mediate the antidepressant-like effects of N-acetylcysteine. Therefore, depression research may target the JAK/STAT signaling pathway to provide a novel effective therapy. PMID:26643864

  5. 7 CFR 58.432 - Catalase.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Catalase. 58.432 Section 58.432 Agriculture... Material § 58.432 Catalase. The catalase preparation shall be a stable, buffered solution, neutral in pH, having a potency of not less than 100 Keil units per milliliter. The source of the catalase,...

  6. 7 CFR 58.432 - Catalase.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Catalase. 58.432 Section 58.432 Agriculture... Material § 58.432 Catalase. The catalase preparation shall be a stable, buffered solution, neutral in pH, having a potency of not less than 100 Keil units per milliliter. The source of the catalase,...

  7. 7 CFR 58.432 - Catalase.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Catalase. 58.432 Section 58.432 Agriculture... Material § 58.432 Catalase. The catalase preparation shall be a stable, buffered solution, neutral in pH, having a potency of not less than 100 Keil units per milliliter. The source of the catalase,...

  8. 7 CFR 58.432 - Catalase.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Catalase. 58.432 Section 58.432 Agriculture... Material § 58.432 Catalase. The catalase preparation shall be a stable, buffered solution, neutral in pH, having a potency of not less than 100 Keil units per milliliter. The source of the catalase,...

  9. 7 CFR 58.432 - Catalase.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Catalase. 58.432 Section 58.432 Agriculture... Material § 58.432 Catalase. The catalase preparation shall be a stable, buffered solution, neutral in pH, having a potency of not less than 100 Keil units per milliliter. The source of the catalase,...

  10. Radiation immobilization of catalase and its application

    NASA Astrophysics Data System (ADS)

    Guanghui, Wang; Hongfei, Ha; Xia, Wang; Jilan, Wu

    Catalase was immobilized by chemical method on porous polyacrylamide particles which produced through radiation polymerization of acrylamide monomer at low temperature (-78C). Activity of immobilized catalase was enhanced distinctly by joining a chemical "arm" to the support. The method of recovery of catalase activity on immobilized polymer was found by soaking it in certain buffer. The treatment of H 2O 2 both in aqueous solution and alcoholic solution by using the immobilized catalase was performed.

  11. Factors affecting production of catalase by Bacteroides.

    PubMed Central

    Wilkins, T D; Wagner, D L; Veltri, B J; Gregory, E M

    1978-01-01

    Several variables affected the production of catalase by members of the "Bacteroides fragilis group" of anaerobic bacteria. Both media yielded higher catalase levels than the respective agar media. Addition of hemin to media after autoclave sterilization, rather than before, significantly increased production of catalase. Both of these variables could be related to the available hemin concentration present in the medium being tested. Significantly higher amounts of hemin were required for catalase production than were required for growth. For catalase production by B. fragilis ATCC 25285, 1 microgram of hemin per ml was required. Of the various media tested, the use of chopped meat broth resulted in the highest levels of catalase production (up to 50 to 60 U of catalase per mg of protein). Of the various species and DNA homology groups tested, strains of B. fragilis and Bacteroides distasonis were catalase positive. Strains of Bacteroides thetaiotaomicron, Bacteroides ovatus, and Bacteroides eggerthi possessed variable catalase activity. Bacteroides vulgatus, Bacteroides uniformis, and DNA homology groups "3452A" and "subsp. a" were catalase negative. A catalase well test, in which equal volumes of 3% H2O2 and chopped meat culture are mixed, is described and recommended for routine catalase tests. PMID:730827

  12. Sirt1 protects against oxidative stress-induced renal tubular cell apoptosis by the bidirectional regulation of catalase expression

    SciTech Connect

    Hasegawa, Kazuhiro; Wakino, Shu Yoshioka, Kyoko; Tatematsu, Satoru; Hara, Yoshikazu; Minakuchi, Hitoshi; Washida, Naoki; Tokuyama, Hirobumi; Hayashi, Koichi; Itoh, Hiroshi

    2008-07-18

    NAD{sup +}-dependent protein deacetylase Sirt1 regulates cellular apoptosis. We examined the role of Sirt1 in renal tubular cell apoptosis by using HK-2 cells, proximal tubular cell lines with or without reactive oxygen species (ROS), H{sub 2}O{sub 2}. Without any ROS, Sirt1 inhibitors enhanced apoptosis and the expression of ROS scavenger, catalase, and Sirt1 overexpression downregulated catalase. When apoptosis was induced with H{sub 2}O{sub 2}, Sirt1 was upregulated with the concomitant increase in catalase expression. Sirt1 overexpression rescued H{sub 2}O{sub 2}-induced apoptosis through the upregulation of catalase. H{sub 2}O{sub 2} induced the nuclear accumulation of forkhead transcription factor, FoxO3a and the gene silencing of FoxO3a enhanced H{sub 2}O{sub 2}-induced apoptosis. In conclusion, endogenous Sirt1 maintains cell survival by regulating catalase expression and by preventing the depletion of ROS required for cell survival. In contrast, excess ROS upregulates Sirt1, which activates FoxO3a and catalase leading to rescuing apoptosis. Thus, Sirt1 constitutes a determinant of renal tubular cell apoptosis by regulating cellular ROS levels.

  13. Evolution of catalases from bacteria to humans.

    PubMed

    Zamocky, Marcel; Furtmller, Paul G; Obinger, Christian

    2008-09-01

    Excessive hydrogen peroxide is harmful for almost all cell components, so its rapid and efficient removal is of essential importance for aerobically living organisms. Conversely, hydrogen peroxide acts as a second messenger in signal-transduction pathways. H(2)O(2) is degraded by peroxidases and catalases, the latter being able both to reduce H(2)O(2) to water and to oxidize it to molecular oxygen. Nature has evolved three protein families that are able to catalyze this dismutation at reasonable rates. Two of the protein families are heme enzymes: typical catalases and catalase-peroxidases. Typical catalases comprise the most abundant group found in Eubacteria, Archaeabacteria, Protista, Fungi, Plantae, and Animalia, whereas catalase-peroxidases are not found in plants and animals and exhibit both catalatic and peroxidatic activities. The third group is a minor bacterial protein family with a dimanganese active site called manganese catalases. Although catalyzing the same reaction (2 H(2)O(2)--> 2 H(2)O+ O(2)), the three groups differ significantly in their overall and active-site architecture and the mechanism of reaction. Here, we present an overview of the distribution, phylogeny, structure, and function of these enzymes. Additionally, we report about their physiologic role, response to oxidative stress, and about diseases related to catalase deficiency in humans. PMID:18498226

  14. Characterization of Catalase from Psychrotolerant Psychrobacter piscatorii T-3 Exhibiting High Catalase Activity

    PubMed Central

    Kimoto, Hideyuki; Yoshimune, Kazuaki; Matsuyma, Hidetoshi; Yumoto, Isao

    2012-01-01

    A psychrotolerant bacterium, strain T-3 (identified as Psychrobacter piscatorii), that exhibited an extraordinarily high catalase activity was isolated from the drain pool of a plant that uses H2O2 as a bleaching agent. Its cell extract exhibited a catalase activity (19,700 Umg protein?1) that was higher than that of Micrococcus luteus used for industrial catalase production. Catalase was approximately 10% of the total proteins in the cell extract of the strain. The catalase (PktA) was purified homogeneously by only two purification steps, anion exchange and hydrophobic chromatographies. The purified catalase exhibited higher catalytic efficiency and higher sensitivity of activity at high temperatures than M. luteus catalase. The deduced amino acid sequence showed the highest homology with catalase of Psycrobacter cryohalolentis, a psychrotolelant bacterium obtained from Siberian permafrost. These findings suggest that the characteristics of the PktA molecule reflected the taxonomic relationship of the isolate as well as the environmental conditions (low temperatures and high concentrations of H2O2) under which the bacterium survives. Strain T-3 efficiently produces a catalase (PktA) at a higher rate than Exiguobacterium oxidotolerans, which produces a very strong activity of catalase (EktA) at a moderate rate, in order to adapt to high concentration of H2O2. PMID:22408420

  15. The three catalases in Deinococcus radiodurans: Only two show catalase activity.

    PubMed

    Jeong, Sun-Wook; Jung, Jong-Hyun; Kim, Min-Kyu; Seo, Ho Seong; Lim, Heon-Man; Lim, Sangyong

    2016-01-15

    Deinococcus radiodurans, which is extremely resistant to ionizing radiation and oxidative stress, is known to have three catalases (DR1998, DRA0146, and DRA0259). In this study, to investigate the role of each catalase, we constructed catalase mutants (?dr1998, ?drA0146, and ?drA0259) of D.radiodurans. Of the three mutants, ?dr1998 exhibited the greatest decrease in hydrogen peroxide (H2O2) resistance and the highest increase in intracellular reactive oxygen species (ROS) levels following H2O2 treatments, whereas ?drA0146 showed no change in its H2O2 resistance or ROS level. Catalase activity was not attenuated in ?drA0146, and none of the three bands detected in an in-gel catalase activity assay disappeared in ?drA0146. The purified His-tagged recombinant DRA0146 did not show catalase activity. In addition, the phylogenetic analysis of the deinococcal catalases revealed that the DR1998-type catalase is common in the genus Deinococcus, but the DRA0146-type catalase was found in only 4 of 23 Deinococcus species. Taken together, these results indicate that DR1998 plays a critical role in the anti-oxidative system of D. radiodurans by detoxifying H2O2, but DRA0146 does not have catalase activity and is not involved in the resistance to H2O2 stress. PMID:26692481

  16. Catalases play differentiated roles in the adaptation of a fungal entomopathogen to environmental stresses.

    PubMed

    Wang, Zheng-Liang; Zhang, Long-Bin; Ying, Sheng-Hua; Feng, Ming-Guang

    2013-02-01

    The catalase family of Beauveria bassiana (fungal entomopathogen) consists of catA (spore-specific), catB (secreted), catP (peroxisomal), catC (cytoplasmic) and catD (secreted peroxidase/catalase), which were distinguished in phylogeny and structure and functionally characterized by constructing single-gene disrupted and rescued mutants for enzymatic and multi-phenotypic analyses. Total catalase activity decreased 89% and 56% in ?catB and ?catP, corresponding to the losses of upper and lower active bands gel-profiled for all catalases respectively, but only 9-12% in other knockout mutants. Compared with wild type and complement mutants sharing similar enzymatic and phenotypic parameters, all knockout mutants showed significant (9-56%) decreases in the antioxidant capability of their conidia (active ingredients of mycoinsecticides), followed by remarkable phenotypic defects associated with the fungal biocontrol potential. These defects included mainly the losses of 40% thermotolerance (45C) in ?catA, 46-48% UV-B resistance in ?catA and ?catD, and 33-47% virulence to Spodoptera litura larvae in ?catA, ?catP and ?catD respectively. Moreover, the drastic transcript upregulation of some other catalase genes observed in the normal culture of each knockout mutant revealed functionally complimentary effects among some of the catalase genes, particularly between catB and catC whose knockout mutants displayed little or minor phenotypic changes. However, the five catalase genes functioned redundantly in mediating the fungal tolerance to either hyperosmotic or fungicidal stress. The differentiated roles of five catalases in regulating the B.?bassiana virulence and tolerances to oxidative stress, high temperature and UV-B irradiation provide new insights into fungal adaptation to stressful environment and host invasion. PMID:22891860

  17. Immobilization of bovine catalase onto magnetic nanoparticles.

    PubMed

    Do?a, Yasemin ?spirli; Teke, Mustafa

    2013-01-01

    The scope of this study is to achieve carrier-bound immobilization of catalase onto magnetic particles (Fe?O? and Fe?O?NiO? H?O) to specify the optimum conditions of immobilization. Removal of H2O2 and the properties of immobilized sets were also investigated. To that end, adsorption and then cross-linking methods onto magnetic particles were performed. The optimum immobilization conditions were found for catalase: immobilization time (15 min for Fe?O?; 10 min for Fe2O?NiO? H?O), the initial enzyme concentration (1 mg/mL), amount of magnetic particles (25 mg), and glutaraldehyde concentration (3%). The activity reaction conditions (optimum temperature, optimum pH, pH stability, thermal stability, operational stability, and reusability) were characterized. Also kinetic parameters were calculated by Lineweaver-Burk plots. The optimum pH values were found to be 7.0, 7.0, and 8.0 for free enzyme, Fe?O?-immobilized catalases, and Fe?O?NiO? H?O-immobilized catalases, respectively. All immobilized catalase systems displayed the optimum temperature between 25 and 35C. Reusability studies showed that Fe?O?-immobilized catalase can be used 11 times with 50% loss in original activity, while Fe2O?NiO? H?O-immobilized catalase lost 67% of activity after the same number of uses. Furthermore, immobilized catalase systems exhibited improved thermal and pH stability. The results transparently indicate that it is possible to have binding between enzyme and magnetic nanoparticles. PMID:23876136

  18. Mechanisms of oxidant generation by catalase

    PubMed Central

    Heck, Diane E.; Shakarjian, Michael; Kim, Hong Duck; Laskin, Jeffrey D.; Vetrano, Anna M.

    2015-01-01

    The enzyme catalase converts solar radiation into reactive oxidant species (ROS). In this study, we report that several bacterial catalases (hydroperoxidases, HP), including Escherichia coli HP-I and HP-II also generate reactive oxidants in response to ultraviolet B light (UVB). HP-I and HP-II are identical except for the presence of NADPH. We found that only one of the catalases, HPI, produces oxidants in response to UVB light, indicating a potential role for the nucleotide in ROS production. This prompts us to speculate that NADPH may act as a cofactor regulating ROS generation by mammalian catalases. Structural analysis of the NADPH domains of several mammalian catalases revealed that the nucleotide is bound in a constrained conformation and that UVB irradiation induces NADPH oxidation and positional changes. Biochemical and kinetic analysis indicate that ROS formation by the enzyme is enhanced by oxidation of the cofactor. Conformational changes following absorption of UVB light by catalase NADPH have the potential to facilitate ROS production by the enzyme. PMID:20716293

  19. Protection of Bacillus pumilus Spores by Catalases

    PubMed Central

    Checinska, Aleksandra; Burbank, Malcolm

    2012-01-01

    Bacillus pumilus SAFR-032, isolated at spacecraft assembly facilities of the National Aeronautics and Space Administration Jet Propulsion Laboratory, is difficult to kill by the sterilization method of choice, which uses liquid or vapor hydrogen peroxide. We identified two manganese catalases, YjqC and BPUM_1305, in spore protein extracts of several B. pumilus strains by using PAGE and mass spectrometric analyses. While the BPUM_1305 catalase was present in six of the B. pumilus strains tested, YjqC was not detected in ATCC 7061 and BG-B79. Furthermore, both catalases were localized in the spore coat layer along with laccase and superoxide dismutase. Although the initial catalase activity in ATCC 7061 spores was higher, it was less stable over time than the SAFR-032 enzyme. We propose that synergistic activity of YjqC and BPUM_1305, along with other coat oxidoreductases, contributes to the enhanced resistance of B. pumilus spores to hydrogen peroxide. We observed that the product of the catalase reaction, gaseous oxygen, forms expanding vesicles on the spore surface, affecting the mechanical integrity of the coat layer, resulting in aggregation of the spores. The accumulation of oxygen gas and aggregations may play a crucial role in limiting further exposure of Bacilli spore surfaces to hydrogen peroxide or other toxic chemicals when water is present. PMID:22752169

  20. Protection of Bacillus pumilus spores by catalases.

    PubMed

    Checinska, Aleksandra; Burbank, Malcolm; Paszczynski, Andrzej J

    2012-09-01

    Bacillus pumilus SAFR-032, isolated at spacecraft assembly facilities of the National Aeronautics and Space Administration Jet Propulsion Laboratory, is difficult to kill by the sterilization method of choice, which uses liquid or vapor hydrogen peroxide. We identified two manganese catalases, YjqC and BPUM_1305, in spore protein extracts of several B. pumilus strains by using PAGE and mass spectrometric analyses. While the BPUM_1305 catalase was present in six of the B. pumilus strains tested, YjqC was not detected in ATCC 7061 and BG-B79. Furthermore, both catalases were localized in the spore coat layer along with laccase and superoxide dismutase. Although the initial catalase activity in ATCC 7061 spores was higher, it was less stable over time than the SAFR-032 enzyme. We propose that synergistic activity of YjqC and BPUM_1305, along with other coat oxidoreductases, contributes to the enhanced resistance of B. pumilus spores to hydrogen peroxide. We observed that the product of the catalase reaction, gaseous oxygen, forms expanding vesicles on the spore surface, affecting the mechanical integrity of the coat layer, resulting in aggregation of the spores. The accumulation of oxygen gas and aggregations may play a crucial role in limiting further exposure of Bacilli spore surfaces to hydrogen peroxide or other toxic chemicals when water is present. PMID:22752169

  1. Catalases Induction in High Virulence Pinewood Nematode Bursaphelenchus xylophilus under Hydrogen Peroxide-Induced Stress.

    PubMed

    Vicente, Cláudia S L; Ikuyo, Yoriko; Shinya, Ryoji; Mota, Manuel; Hasegawa, Koichi

    2015-01-01

    Considered an EPPO A2 quarantine pest, Bursaphelenchus xylophilus is the causal agent of the pine wilt disease and the most devastating plant parasitic nematode attacking coniferous trees in the world. In the early stages of invasion, this nematode has to manage host defence mechanisms, such as strong oxidative stress. Only successful, virulent nematodes are able to tolerate the basal plant defences, and furthermore migrate and proliferate inside of the host tree. In this work, our main objective was to understand to what extent B. xylophilus catalases are involved in their tolerance to oxidative stress and virulence, using as oxidant agent the reactive oxygen species hydrogen peroxide (H2O2). After 24 hours of exposure, high virulence isolates of B. xylophilus could withstand higher H2O2 concentrations in comparison with low virulence B. xylophilus and B. mucronatus, corroborating our observation of Bxy-ctl-1 and Bxy-ctl-2 catalase up-regulation under the same experimental conditions. Both catalases are expressed throughout the nematode intestine. In addition, transgenic strains of Caenorhabditis elegans overexpressing B. xylophilus catalases were constructed and evaluated for survival under similar conditions as previously. Our results suggest that catalases of high virulence B. xylophilus were crucial for nematode survival under prolonged exposure to in vitro oxidative stress, highlighting their adaptive response, which could contribute to their success in host conditions. PMID:25894519

  2. Catalases Induction in High Virulence Pinewood Nematode Bursaphelenchus xylophilus under Hydrogen Peroxide-Induced Stress

    PubMed Central

    Vicente, Cláudia S. L.; Ikuyo, Yoriko; Shinya, Ryoji; Mota, Manuel; Hasegawa, Koichi

    2015-01-01

    Considered an EPPO A2 quarantine pest, Bursaphelenchus xylophilus is the causal agent of the pine wilt disease and the most devastating plant parasitic nematode attacking coniferous trees in the world. In the early stages of invasion, this nematode has to manage host defence mechanisms, such as strong oxidative stress. Only successful, virulent nematodes are able to tolerate the basal plant defences, and furthermore migrate and proliferate inside of the host tree. In this work, our main objective was to understand to what extent B. xylophilus catalases are involved in their tolerance to oxidative stress and virulence, using as oxidant agent the reactive oxygen species hydrogen peroxide (H2O2). After 24 hours of exposure, high virulence isolates of B. xylophilus could withstand higher H2O2 concentrations in comparison with low virulence B. xylophilus and B. mucronatus, corroborating our observation of Bxy-ctl-1 and Bxy-ctl-2 catalase up-regulation under the same experimental conditions. Both catalases are expressed throughout the nematode intestine. In addition, transgenic strains of Caenorhabditis elegans overexpressing B. xylophilus catalases were constructed and evaluated for survival under similar conditions as previously. Our results suggest that catalases of high virulence B. xylophilus were crucial for nematode survival under prolonged exposure to in vitro oxidative stress, highlighting their adaptive response, which could contribute to their success in host conditions. PMID:25894519

  3. Molecular cloning, characterization and gene expression of an antioxidant enzyme catalase (MrCat) from Macrobrachium rosenbergii.

    PubMed

    Arockiaraj, Jesu; Easwvaran, Sarasvathi; Vanaraja, Puganeshwaran; Singh, Arun; Othman, Rofina Yasmin; Bhassu, Subha

    2012-05-01

    In this study, we reported a full length of catalase gene (designated as MrCat), identified from the transcriptome database of freshwater prawn Macrobrachium rosenbergii. The complete gene sequence of the MrCat is 2504 base pairs in length, and encodes 516 amino acids. The MrCat protein contains three domains such as catalase 1 (catalase proximal heme-ligand signature) at 350-358, catalase 2 (catalase proximal active site signature) at 60-76 and catalase 3 (catalase family profile) at 20-499. The mRNA expressions of MrCat in healthy and the infectious hypodermal and hematopoietic necrosis virus (IHHNV) challenged M. rosenbergii were examined using quantitative real time polymerase chain reaction (qRT-PCR). The MrCat is highly expressed in digestive tract and all the other tissues (walking leg, gills, muscle, hemocyte, hepatopancreas, pleopods, brain and eye stalk) of M. rosenbergii taken for analysis. The expression is strongly up-regulated in digestive tract after IHHNV challenge. To understand its biological activity, the recombinant MrCat gene was constructed and expressed in Escherichia coli BL21 (DE3). The recombinant MrCat existed in high thermal stability and broad spectrum of pH, which showed over 95% enzyme activity between pH 5 and 10.5, and was stable from 40 C to 70 C, and exhibited 85-100% enzyme activity from 30 C to 40 C. PMID:22293093

  4. Discovery of Catalases in Members of the Chlamydiales Order

    PubMed Central

    Rusconi, Brigida

    2013-01-01

    Catalase is an important virulence factor for survival in macrophages and other phagocytic cells. In Chlamydiaceae, no catalase had been described so far. With the sequencing and annotation of the full genomes of Chlamydia-related bacteria, the presence of different catalase-encoding genes has been documented. However, their distribution in the Chlamydiales order and the functionality of these catalases remain unknown. Phylogeny of chlamydial catalases was inferred using MrBayes, maximum likelihood, and maximum parsimony algorithms, allowing the description of three clade 3 and two clade 2 catalases. Only monofunctional catalases were found (no catalase-peroxidase or Mn-catalase). All presented a conserved catalytic domain and tertiary structure. Enzymatic activity of cloned chlamydial catalases was assessed by measuring hydrogen peroxide degradation. The catalases are enzymatically active with different efficiencies. The catalase of Parachlamydia acanthamoebae is the least efficient of all (its catalytic activity was 2 logs lower than that of Pseudomonas aeruginosa). Based on the phylogenetic analysis, we hypothesize that an ancestral class 2 catalase probably was present in the common ancestor of all current Chlamydiales but was retained only in Criblamydia sequanensis and Neochlamydia hartmannellae. The catalases of class 3, present in Estrella lausannensis and Parachlamydia acanthamoebae, probably were acquired by lateral gene transfer from Rhizobiales, whereas for Waddlia chondrophila they likely originated from Legionellales or Actinomycetales. The acquisition of catalases on several occasions in the Chlamydiales suggests the importance of this enzyme for the bacteria in their host environment. PMID:23729651

  5. Gold nanoparticles and/or N-acetylcysteine mediate carrageenan-induced inflammation and oxidative stress in a concentration-dependent manner.

    PubMed

    Paula, Marcos M S; Petronilho, Fabricia; Vuolo, Francieli; Ferreira, Gabriela K; De Costa, Leandro; Santos, Giulia P; Effting, Pauline S; Dal-Pizzol, Felipe; Dal-B, Alexandre G; Frizon, Tiago E; Silveira, Paulo C L; Pinho, Ricardo A

    2015-10-01

    We report the effect of gold nanoparticles (AuNP) in an acute inflammation model induced by carrageenan (CG) and compared this effect with those induced by the antioxidant N-acetylcysteine (NAC) alone and by the synergistic effect of NAC and AuNP together. Male Wistar rats received saline or saline containing CG administered into the pleural cavity, and some rats also received NAC (20 mg/kg) subcutaneously and/or AuNP administered into the pleural cavity immediately after surgery. Four hours later, the rats were sacrificed and pleural exudates obtained for evaluation of cytokine levels and myeloperoxidase activities. Oxidative stress parameters were also evaluated in the lungs. The results demonstrated that the inflammatory process caused by the administration of CG into the pleural cavity resulted in a substantial increase in the levels of tumor necrosis factor-?, interleukin-1?, and myeloperoxidase and a reduction in interleukin-10 levels. These levels seem to be reversed after different treatments in animals. Antioxidant enzymes exhibited positive responses after treatment of NAC?+?AuNP, and all treatments were effective at reducing lipid peroxidation and oxidation of thiol groups induced by CG. These findings suggest that small compounds, such as NAC plus AuNP, may be useful in the treatment of conditions associated with local inflammation. PMID:25917538

  6. Mechanisms of catalase activity of heme peroxidases.

    PubMed

    Vlasits, Jutta; Jakopitsch, Christa; Bernroitner, Margit; Zamocky, Marcel; Furtmller, Paul G; Obinger, Christian

    2010-08-01

    In the absence of exogenous electron donors monofunctional heme peroxidases can slowly degrade hydrogen peroxide following a mechanism different from monofunctional catalases. This pseudo-catalase cycle involves several redox intermediates including Compounds I, II and III, hydrogen peroxide reduction and oxidation reactions as well as release of both dioxygen and superoxide. The rate of decay of oxyferrous complex determines the rate-limiting step and the enzymes' resistance to inactivation. Homologous bifunctional catalase-peroxidases (KatGs) are unique in having both a peroxidase and high hydrogen dismutation activity without inhibition reactions. It is demonstrated that KatGs follow a similar reaction pathway as monofunctional peroxidases, but use a unique post-translational distal modification (Met+-Tyr-Trp adduct) in close vicinity to the heme as radical site that enhances turnover of oxyferrous heme and avoids release of superoxide. Similarities and differences between monofunctional peroxidases and bifunctional KatGs are discussed and mechanisms of pseudo-catalase activity are proposed. PMID:20434429

  7. Catalytic scavenging of peroxynitrite by catalase.

    PubMed

    Gebicka, Lidia; Didik, Joanna

    2009-10-01

    Peroxynitrite (ONOO(-)/ONOOH), the product of the diffusion controlled reaction between nitric oxide (*NO) and superoxide anion (O(2)(-)*), is a strong oxidizing and nitrating agent. Several heme proteins react rapidly with peroxynitrite, some of them catalyze its decomposition. In this work we found, contrary to previous reports, that catalase, a ferriheme enzyme, catalytically scavenges peroxynitrite. The second-order reaction rate constants of peroxynitrite decay catalyzed by catalase increase with decreasing pH and are equal to (2.7+/-0.2) x 10(6), (1.7+/-0.1) x 10(6) and (0.8+/-0.1) x 10(6) M(-1) s(-1) at pH 6.1, 7.1 and 8.0, respectively. This dependence suggests that peroxynitrous acid, ONOOH, is the species that reacts with heme center of catalase. The possible reaction mechanisms of the decay of peroxynitrite catalyzed by catalase and physiological relevance of this reaction are discussed. PMID:19709751

  8. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Catalase derived from Micrococcus lysodeikticus... FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.135 Catalase derived from Micrococcus lysodeikticus. Bacterial catalase derived from Micrococcus lysodeikticus by a pure...

  9. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Catalase derived from Micrococcus lysodeikticus... FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.135 Catalase derived from Micrococcus lysodeikticus. Bacterial catalase derived from Micrococcus lysodeikticus by a pure...

  10. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Catalase derived from Micrococcus lysodeikticus... FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.135 Catalase derived from Micrococcus lysodeikticus. Bacterial catalase derived from Micrococcus lysodeikticus by a pure...

  11. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Catalase derived from Micrococcus lysodeikticus... FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.135 Catalase derived from Micrococcus lysodeikticus. Bacterial catalase derived from Micrococcus lysodeikticus by a pure...

  12. Growth-Dependent Catalase Localization in Exiguobacterium oxidotolerans T-2-2T Reflected by Catalase Activity of Cells

    PubMed Central

    Hanaoka, Yoshiko; Takebe, Fumihiko; Nodasaka, Yoshinobu; Hara, Isao; Matsuyama, Hidetoshi; Yumoto, Isao

    2013-01-01

    A psychrotolerant and H2O2-resistant bacterium, Exiguobacterium oxidotolerans T-2-2T, exhibits extraordinary H2O2 resistance and produces catalase not only intracellularly but also extracellularly. The intracellular and extracellular catalases exhibited the same enzymatic characteristics, that is, they exhibited the temperature-dependent activity characteristic of a cold-adapted enzyme, their heat stabilities were similar to those of mesophilic enzymes and very high catalytic intensity. In addition, catalase gene analysis indicated that the bacterium possessed the sole clade 1 catalase gene corresponding to intracellular catalase. Hence, intracellular catalase is secreted into the extracellular space. In addition to intracellular and extracellular catalases, the inner circumference of the cells showed the localization of catalase in the mid-stationary growth phase, which was observed by immunoelectron microscopy using an antibody against the intracellular catalase of the strain. The cells demonstrated higher catalase activity in the mid-stationary growth phase than in the exponential growth phase. The catalase localized in the inner circumference can be dissociated by treatment with Tween 60. Thus, the localized catalase is not tightly bound to the inner circumference of the cells and may play a role in the oxidative defense of the cells under low metabolic state. PMID:24204687

  13. Role of oxyradicals in the inactivation of catalase by ozone

    SciTech Connect

    Whiteside, C.; Hassan, H.M. )

    1988-01-01

    The antioxidant enzymes, catalase and superoxide dismutase, are inactivated upon exposure to ozone. In this study, the mechanism of this inactivation was examined using catalase as a model system. The data show that the inactivation of catalase is dependent on ozone concentration, time of exposure, and pH. Loss of catalase activity is accompanied with loss of the heme spectra. Tiron, desferal-Mn, trolox-c, and pyruvate protect the enzyme against ozone inactivation. SOD is less effective due to its inactivation by ozone. On the other hand, alcohols do not provide significant protection. The data suggest the possible involvement of superoxide radicals in the inactivation of catalase by ozone.

  14. Probing the binding of flavonoids to catalase by molecular spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhu, Jingfeng; Zhang, Xia; Li, Daojin; Jin, Jing

    2007-10-01

    The binding of flavonoids (quercetin and myricetin) to catalase was investigated by fluorescence and circular dichroism (CD) techniques under physiological conditions. The binding parameters and binding mode between flavonoids and catalase were determined, and the results of synchronous fluorescence spectra and CD indicated a conformational change of catalase with addition of flavonoids. The effect of both Cu 2+ and vitamin C on the binding constant of flavonoid-catalase was also examined. The experiment data show that the difference of the structure characteristics of quercetin and myricetin has a significant effect on their binding affinity for catalase.

  15. Molecular Characterization of a Catalase from Hydra vulgaris

    PubMed Central

    Dash, Bhagirathi; Phillips, Timothy D.

    2012-01-01

    Catalase, an antioxidant and hydroperoxidase enzyme protects the cellular environment from harmful effects of hydrogen peroxide by facilitating its degradation to oxygen and water. Molecular information on a cnidarian catalase and/or peroxidase is, however, limited. In this work an apparent full length cDNA sequence coding for a catalase (HvCatalase) was isolated from Hydra vulgaris using 3’- and 5’- (RLM) RACE approaches. The 1859 bp HvCatalase cDNA included an open reading frame of 1518 bp encoding a putative protein of 505 amino acids with a predicted molecular mass of 57.44 kDa. The deduced amino acid sequence of HvCatalase contained several highly conserved motifs including the heme-ligand signature sequence RLFSYGDTH and the active site signature FXRERIPERVVHAKGXGA. A comparative analysis showed the presence of conserved catalytic amino acids [His(71), Asn(145), and Tyr(354)] in HvCatalase as well. Homology modeling indicated the presence of the conserved features of mammalian catalase fold. Hydrae exposed to thermal, starvation, metal and oxidative stress responded by regulating its catalase mRNA transcription. These results indicated that the HvCatalase gene is involved in the cellular stress response and (anti)oxidative processes triggered by stressor and contaminant exposure. PMID:22521743

  16. Catalase-positive microbial detection by using different ultrasonic parameters

    NASA Astrophysics Data System (ADS)

    Shukla, S. K.; Durn, C.; Elvira, L.

    2012-12-01

    A method for rapid detection of catalase enzyme activity using ultrasonic parameters is presented in this work. It is based on the detection of the hydrolysis of hydrogen peroxide molecule into water and oxygen induced by the enzyme catalase. A special medium was made to amplify changes produced by catalase enzyme during the hydrolysis process. Enzymatic process can be monitored by means of ultrasonic parameters such as wave amplitude, time of flight (TOF), and backscattering measurements which are sensitive to oxygen bubble production. It is shown that catalase activity of the order of 10-3unit/ml can be detected using different ultrasonic parameters. The sensitivity provided by them is discussed.

  17. Characterization of a Heme-Dependent Catalase from Methanobrevibacter arboriphilus†

    PubMed Central

    Shima, Seigo; Sordel-Klippert, Melanie; Brioukhanov, Andrei; Netrusov, Alexander; Linder, Dietmar; Thauer, Rudolf K.

    2001-01-01

    Recently it was reported that methanogens of the genus Methanobrevibacter exhibit catalase activity. This was surprising, since Methanobrevibacter species belong to the order Methanobacteriales, which are known not to contain cytochromes and to lack the ability to synthesize heme. We report here that Methanobrevibacter arboriphilus strains AZ and DH1 contained catalase activity only when the growth medium was supplemented with hemin. The heme catalase was purified and characterized, and the encoding gene was cloned. The amino acid sequence of the catalase from the methanogens is most similar to that of Methanosarcina barkeri. PMID:11425719

  18. Inhibition of catalase activity in vitro by diesel exhaust particles

    SciTech Connect

    Mori, Yoki; Murakami, Sumika; Sagae, Toshiyuki

    1996-02-09

    The effect of diesel exhaust particles (DEP) on the activity of catalase, an intracellular anti-oxidant, was investigated because H{sub 2}O{sub 2} is a cytotoxic oxidant, and catalase released from alveolar cells is an important antioxidant in the epithelial lining fluid in the lung. DEP inhibited the activity of bovine liver catalase dose-dependently, to 25-30% of its original value. The inhibition of catalase by DEP was observed only in the presence of anions such as Cl{sup {minus}}, Br{sup {minus}}, or thiocyanate. Other anions, such as CH{sub 3}COO{sup {minus}} or SO{sub 4}{sup {minus}}, and cations such as K{sup +}, Na{sup +}, Mg{sup 2+}, or Fe{sup 2+}, did not affect the activity of catalase, even in the presence of DEP extract. Catalase from guinea pig alveolar cells and catalase from red blood cells were also inhibited by DEP extracts, as was catalase from bovine liver. These results suggest that DEP taken up in the lung and located on alveolar spaces might cause cell injury by inhibiting the activity of catalase in epithelial lining fluid, enhancing the toxicity of H{sub 2}O{sub 2} generated from cells in addition to that of O{sub 2}{sup {minus}} generated by the chemical reaction of DEP with oxygen. 10 refs., 6 figs.

  19. Hydrogen peroxide production regulates the mitochondrial function in insulin resistant muscle cells: effect of catalase overexpression.

    PubMed

    Barbosa, Marina R; Sampaio, Igor H; Teodoro, Bruno G; Sousa, Thais A; Zoppi, Claudio C; Queiroz, Andr L; Passos, Madla A; Alberici, Luciane C; Teixeira, Felipe R; Manfiolli, Adriana O; Batista, Thiago M; Cappelli, Ana Paula Gameiro; Reis, Rosana I; Frasson, Danbia; Kettelhut, Isis C; Parreiras-e-Silva, Lucas T; Costa-Neto, Claudio M; Carneiro, Everardo M; Curi, Rui; Silveira, Leonardo R

    2013-10-01

    The mitochondrial redox state plays a central role in the link between mitochondrial overloading and insulin resistance. However, the mechanism by which the ROS induce insulin resistance in skeletal muscle cells is not completely understood. We examined the association between mitochondrial function and H2O2 production in insulin resistant cells. Our hypothesis is that the low mitochondrial oxygen consumption leads to elevated ROS production by a mechanism associated with reduced PGC1? transcription and low content of phosphorylated CREB. The cells were transfected with either the encoded sequence for catalase overexpression or the specific siRNA for catalase inhibition. After transfection, myotubes were incubated with palmitic acid (500?M) and the insulin response, as well as mitochondrial function and fatty acid metabolism, was determined. The low mitochondrial oxygen consumption led to elevated ROS production by a mechanism associated with ?-oxidation of fatty acids. Rotenone was observed to reduce the ratio of ROS production. The elevated H2O2 production markedly decreased the PGC1? transcription, an effect that was accompanied by a reduced phosphorylation of Akt and CREB. The catalase transfection prevented the reduction in the phosphorylated level of Akt and upregulated the levels of phosphorylated CREB. The mitochondrial function was elevated and H2O2 production reduced, thus increasing the insulin sensitivity. The catalase overexpression improved mitochondrial respiration protecting the cells from fatty acid-induced, insulin resistance. This effect indicates that control of hydrogen peroxide production regulates the mitochondrial respiration preventing the insulin resistance in skeletal muscle cells by a mechanism associated with CREB phosphorylation and ?-oxidation of fatty acids. PMID:23643711

  20. High catalase production by Rhizobium radiobacter strain 2-1.

    PubMed

    Nakayama, Mami; Nakajima-Kambe, Toshiaki; Katayama, Hideki; Higuchi, Kazuhiko; Kawasaki, Yoshio; Fuji, Ryujiro

    2008-12-01

    To promote the application of catalase for treating wastewater containing hydrogen peroxide, bacteria exhibiting high catalase activity were screened. A bacterium, designated strain 2-1, with high catalase activity was isolated from the wastewater of a beverage factory that uses hydrogen peroxide. Strain 2-1 was identified as Rhizobium radiobacter (formerly known as Agrobacterium tumefaciens) on the basis of both phenotypic and genotypic characterizations. Although some strains of R. radiobacter are known plant pathogens, polymerase chain reaction (PCR) analysis showed that strain 2-1 has no phytopathogenic factor. Compared with a type strain of R. radiobacter, the specific catalase activity of strain 2-1 was approximately 1000-fold. Moreover, Strain 2-1 grew faster and exhibited considerably higher catalase activity than other microorganisms that have been used for industrial catalase production. Strain 2-1 is harmless to humans and the environment and produces catalase efficiently, suggesting that strain 2-1 is a good resource for the mass production of catalase for the treatment of hydrogen peroxide-containing wastewater. PMID:19134550

  1. Interaction of Nitric Oxide with Catalase: Structural and Kinetic Analysis

    PubMed Central

    2011-01-01

    We present the structures of bovine catalase in its native form and complexed with ammonia and nitric oxide, obtained by X-ray crystallography. Using the NO generator 1-(N,N-diethylamino)diazen-1-ium-1,2-diolate, we were able to generate sufficiently high NO concentrations within the catalase crystals that substantial occupation was observed despite a high dissociation rate. Nitric oxide seems to be slightly bent from the heme normal that may indicate some iron(II) character in the formally ferric catalase. Microspectrophotometric investigations inline with the synchrotron X-ray beam reveal photoreduction of the central heme iron. In the cases of the native and ammonia-complexed catalase, reduction is accompanied by a relaxation phase. This is likely not the case for the catalase NO complex. The kinetics of binding of NO to catalase were investigated using NO photolyzed from N,N?-bis(carboxymethyl)-N,N?-dinitroso-p-phenylenediamine using an assay that combines catalase with myoglobin binding kinetics. The off rate is 1.5 s1. Implications for catalase function are discussed. PMID:21524057

  2. IS CATALASE ACTIVITY ASSOCIATED WITH MAIZE RESISTANCE TO ASPERGILLUS FLAVUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Catalase activity was measured in various cob tissues during maize ear development because of its role in maintaining reactive oxygen homeostasis during biotic and abiotic stress. Catalase activity was determined in immature and mature embryos, pericarp, and rachis tissues of maize lines that are re...

  3. The catalase activity of diiron adenine deaminase

    PubMed Central

    Kamat, Siddhesh S; Holmes-Hampton, Gregory P; Bagaria, Ashima; Kumaran, Desigan; Tichy, Shane E; Gheyi, Tarun; Zheng, Xiaojing; Bain, Kevin; Groshong, Chris; Emtage, Spencer; Sauder, J Michael; Burley, Stephen K; Swaminathan, Subramanyam; Lindahl, Paul A; Raushel, Frank M

    2011-01-01

    Adenine deaminase (ADE) from the amidohydrolase superfamily (AHS) of enzymes catalyzes the conversion of adenine to hypoxanthine and ammonia. Enzyme isolated from Escherichia coli was largely inactive toward the deamination of adenine. Molecular weight determinations by mass spectrometry provided evidence that multiple histidine and methionine residues were oxygenated. When iron was sequestered with a metal chelator and the growth medium supplemented with Mn2+ before induction, the post-translational modifications disappeared. Enzyme expressed and purified under these conditions was substantially more active for adenine deamination. Apo-enzyme was prepared and reconstituted with two equivalents of FeSO4. Inductively coupled plasma mass spectrometry and Mssbauer spectroscopy demonstrated that this protein contained two high-spin ferrous ions per monomer of ADE. In addition to the adenine deaminase activity, [FeII/FeII]-ADE catalyzed the conversion of H2O2 to O2 and H2O. The values of kcat and kcat/Km for the catalase activity are 200 s?1 and 2.4 104 M?1 s?1, respectively. [FeII/FeII]-ADE underwent more than 100 turnovers with H2O2 before the enzyme was inactivated due to oxygenation of histidine residues critical for metal binding. The iron in the inactive enzyme was high-spin ferric with gave = 4.3 EPR signal and no evidence of anti-ferromagnetic spin-coupling. A model is proposed for the disproportionation of H2O2 by [FeII/FeII]-ADE that involves the cycling of the binuclear metal center between the di-ferric and di-ferrous oxidation states. Oxygenation of active site residues occurs via release of hydroxyl radicals. These findings represent the first report of redox reaction catalysis by any member of the AHS. PMID:21998098

  4. The effect of alcohol and hydrogen peroxide on liver hepcidin gene expression in mice lacking antioxidant enzymes, glutathione peroxidase-1 or catalase.

    PubMed

    Harrison-Findik, Duygu Dee; Lu, Sizhao

    2015-01-01

    This study investigates the regulation of hepcidin, the key iron-regulatory molecule, by alcohol and hydrogen peroxide (H2O2) in glutathione peroxidase-1 (gpx-1(-/-)) and catalase (catalase(-/-)) knockout mice. For alcohol studies, 10% ethanol was administered in the drinking water for 7 days. Gpx-1(-/-) displayed significantly higher hepatic H2O2 levels than catalase(-/-) compared to wild-type mice, as measured by 2'-7'-dichlorodihydrofluorescein diacetate (DCFH-DA). The basal level of liver hepcidin expression was attenuated in gpx-1(-/-) mice. Alcohol increased H2O2 production in catalase(-/-) and wild-type, but not gpx-1(-/-), mice. Hepcidin expression was inhibited in alcohol-fed catalase(-/-) and wild-type mice. In contrast, alcohol elevated hepcidin expression in gpx-1(-/-) mice. Gpx-1(-/-) mice also displayed higher level of basal liver CHOP protein expression than catalase(-/-) mice. Alcohol induced CHOP and to a lesser extent GRP78/BiP expression, but not XBP1 splicing or binding of CREBH to hepcidin gene promoter, in gpx-1(-/-) mice. The up-regulation of hepatic ATF4 mRNA levels, which was observed in gpx-1(-/-) mice, was attenuated by alcohol. In conclusion, our findings strongly suggest that H2O2 inhibits hepcidin expression in vivo. Synergistic induction of CHOP by alcohol and H2O2, in the absence of gpx-1, stimulates liver hepcidin gene expression by ER stress independent of CREBH. PMID:25955433

  5. Investigating the active centre of the Scytalidium thermophilum catalase

    PubMed Central

    Yuzugullu, Yonca; Trinh, Chi H.; Fairhurst, Lucy; Ogel, Zumrut B.; McPherson, Michael J.; Pearson, Arwen R.

    2013-01-01

    Almost all monofunctional haem catalases contain a highly conserved core containing the active site, which is connected to the exterior of the enzyme by three channels. These channels have been identified as potential routes for substrate flow and product release. To further investigate the role of these molecular channels, a series of mutants of Scytalidium thermophilum catalase were generated. The three-dimensional structures of four catalase variants, N155A, V123A, V123C and V123T, have been determined at resolutions of 2.25, 1.93, 1.9 and 1.7?, respectively. The V123C variant contains a new covalent bond between the S atom of Cys123 and the imidazole ring of the essential His82. This variant enzyme has only residual catalase activity and contains haem b instead of the normal haem d. The H82A variant demonstrates low catalase and phenol oxidase activities (0.2 and 20% of those of recombinant wild-type catalasephenol oxidase, respectively). The N155A and N155H variants exhibit 4.5 and 3% of the wild-type catalase activity and contain haem d, showing that Asn155 is essential for catalysis but is not required for the conversion of haem b to haem d. Structural analysis suggests that the cause of the effect of these mutations on catalysis is the disruption of the ability of dioxygen substrates to efficiently access the active site. Additional mutants have been characterized biochemically to further probe the roles of the different channels. Introducing smaller or polar side chains in place of Val123 reduces the catalase activity. The F160V, F161V and F168V mutants show a marked decrease in catalase activity but have a much lower effect on the phenol oxidase activity, despite containing substoichiometric amounts of haem. PMID:23545640

  6. Effect of heme on Bacteroides distasonis catalase and aerotolerance.

    PubMed Central

    Gregory, E M; Fanning, D D

    1983-01-01

    Parallel increases in intracellular catalase activity and resistance to extracellular H2O2 and to hyperbaric O2 toxicity were observed when Bacteroides distasonis VPI 4243 (ATCC 8503, type strain) was grown in either complex or defined medium containing graded amounts of hemin. Virtually all of the cells with high catalase activity (greater than 200 U/mg) remained viable upon exposure at 37 degrees C to 100-lb/in2 O2 on agar surfaces for 1 h, whereas low-catalase cells (less than 10 U/mg) lost 1.2 log units of viable cells during that treatment. Upon exposure to 500 microM H2O2, high-catalase cells lost 0.4 log units of the initial viable colonies during the same period in which low-catalase cells lost 3 log units of viable cells. The superoxide dismutase activity was the same in each test culture. These data support the role of intracellular catalase in protecting B. distasonis from oxidative damage resulting from hyperbaric oxygenation or H2O2 exposure. Catalase activity elicited by adding hemin to cells grown previously in medium lacking hemin was inhibited only 40% by prior incubation of the cells with chloramphenicol (30 micrograms/ml) and only 22% with rifampin (5 micrograms/ml). A model which is consistent with these data involves the production of an apocatalase in cells grown in low-hemin medium. Addition of hemin to the cells would result in a rapid chloramphenicolor rifampin-insensitive stimulation of catalase activity followed by further de novo biosynthesis of catalase. PMID:6643389

  7. Catalase Enhances Growth and Biofilm Production of Mycoplasma pneumoniae.

    PubMed

    Simmons, Warren L; Dybvig, Kevin

    2015-08-01

    Mycoplasma pneumoniae causes chronic respiratory disease in humans. Factors thought to be important for colonization include the ability of the mycoplasma to form a biofilm on epithelial surfaces and the production of hydrogen peroxide to damage host tissue. Almost all of the mycoplasmas, including M. pneumoniae, lack superoxide dismutase and catalase and a balance should exist between peroxide production and growth. We show here that the addition of catalase to cultures enhanced the formation of biofilms and altered the structure. The incorporation of catalase in agar increased the number of colony-forming units detected and hence could improve the clinical diagnosis of mycoplasmal diseases. PMID:25894997

  8. Production of IFN-? and IL-4 Against Intact Catalase and Constructed Catalase Epitopes of Helicobacter pylori From T-Cells

    PubMed Central

    Ghasemian Safaei, Hajieh; Faghri, Jamshid; Moghim, Sharareh; Nasr Esfahani, Bahram; Fazeli, Hossein; Makvandi, Manoochehr; Adib, Minoo; Rashidi, Niloufar

    2015-01-01

    Background: Helicobacter pylori infection is highly prevalent in the developing countries. It causes gastritis, peptic ulcer disease, and gastrocarcinoma. Treatment with drugs and antibiotics is problematic due to the following reasons: cost, resistance to antibiotics, prolonged treatment and using multiple drugs. Catalase is highly conserved among the Helicobacter species and is important to the survival of the organism. It is expressed in high amounts and is exposed to the surface of this bacterium; therefore it represents a suitable candidate vaccine antigen. Objectives: A suitable approach in H. pylori vaccinology is the administration of epitope based vaccines. Therefore the responses of T-cells (IFN-? and IL-4 production) against the catalase of H. pylori were determined. Then the quality of the immune responses against intact catalase and three epitopes of catalase were compared. Materials and Methods: In this study, a composition of three epitopes of the H. pylori catalase was selected based on Propred software. The effect of catalase epitopes on T-cells were assayed and immune responses identified. Results: The results of IFN-?, IL-4 production against antigens, epitopes, and recombinant catalase by T-cells were compared for better understanding of epitope efficiency. Conclusions: The current research demonstrated that epitope sequence stimulates cellular immune responses effectively. In addition, increased safety and potency as well as a reduction in time and cost were advantages of this method. Authors are going to use this sequence as a suitable vaccine candidate for further research on animal models and humans in future. PMID:26862387

  9. Nrf2-Dependent Induction of NQO1 in Mouse Aortic Endothelial Cells Overexpressing Catalase

    PubMed Central

    Lin, Xinghua; Yang, Hong; Zhou, LiChun; Guo, ZhongMao

    2011-01-01

    Overexpression of catalase has been shown to accelerate benzo(a)pyrene (BaP) detoxification in mouse aortic endothelial cells (MAECs ). NAD(P)H:quinone oxidoreductase1 (NQO1) is an enzyme that catalyzes BaP-quinone detoxification. Aryl hydrocarbon receptor (AhR) and nuclear factor erythroid 2-related factor-2 (Nrf2) are transcription factors that control NQO1 expression. Here, we investigated the effect of catalase overexpression on NQO1, Nrf2 and AhR expressions. The levels of NQO1 mRNA and protein were comparable in MAECs isolated from wild-type and transgenic mice that overexpress human catalase (hCatTg). BaP treatment increased NQO1 mRNA and protein levels in both groups, with a significantly greater induction in hCatTg MAECs than in wild-type cells. BaP-induced NQO1 promoter activity was dramatically higher in hCatTg MAECs than in wild-type cells. Our data also showed that the basal level of AhR and the BaP-induced level of Nrf2 were significantly higher in hCatTg MAECs than in wild-type cells. Inhibition of specificity protein-1 (Sp1) binding to the AhR promoter region by mithramycin A reversed the enhanced effect of catalase overexpression on AhR expression. Knockdown of AhR by RNA interference diminished BaP-induced expression of Nrf2 and NQO1. Knockdown of Nrf2 significantly decreased NQO1 mRNA and protein levels in cells with or without BaP treatment. NQO1 promoter activity was abrogated by mutation of the Nrf2-binding site in this promoter. In contrast, mutation of the AhR-binding site in NQO1 promoter did not affect the promoter activity. These results suggest that catalase overexpression upregulates BaP-induced NQO1 expression via enhancing the Sp1-AhR-Nrf2 signaling cascade. PMID:21569840

  10. The catalase activity of diiron adenine deaminase

    SciTech Connect

    Kamat S. S.; Swaminathan S.; Holmes-Hampton, G. P.; Bagaria, A.; Kumaran, D.; Tichy, S. E.; Gheyi, T.; Zheng, X.; Bain, K.; Groshong, C.; Emtage, S.; Sauder, J. M.; Burley, S. K.; Lindahl, P. A.; Raushel, F. M.

    2011-12-01

    Adenine deaminase (ADE) from the amidohydrolase superfamily (AHS) of enzymes catalyzes the conversion of adenine to hypoxanthine and ammonia. Enzyme isolated from Escherichia coli was largely inactive toward the deamination of adenine. Molecular weight determinations by mass spectrometry provided evidence that multiple histidine and methionine residues were oxygenated. When iron was sequestered with a metal chelator and the growth medium supplemented with Mn{sup 2+} before induction, the post-translational modifications disappeared. Enzyme expressed and purified under these conditions was substantially more active for adenine deamination. Apo-enzyme was prepared and reconstituted with two equivalents of FeSO{sub 4}. Inductively coupled plasma mass spectrometry and Moessbauer spectroscopy demonstrated that this protein contained two high-spin ferrous ions per monomer of ADE. In addition to the adenine deaminase activity, [Fe{sup II}/Fe{sup II}]-ADE catalyzed the conversion of H{sub 2}O{sub 2} to O{sub 2} and H{sub 2}O. The values of k{sub cat} and k{sub cat}/K{sub m} for the catalase activity are 200 s{sup -1} and 2.4 x 10{sup 4} M{sup -1} s{sup -1}, respectively. [Fe{sup II}/Fe{sup II}]-ADE underwent more than 100 turnovers with H{sub 2}O{sub 2} before the enzyme was inactivated due to oxygenation of histidine residues critical for metal binding. The iron in the inactive enzyme was high-spin ferric with g{sub ave} = 4.3 EPR signal and no evidence of anti-ferromagnetic spin-coupling. A model is proposed for the disproportionation of H{sub 2}O{sub 2} by [Fe{sup II}/Fe{sup II}]-ADE that involves the cycling of the binuclear metal center between the di-ferric and di-ferrous oxidation states. Oxygenation of active site residues occurs via release of hydroxyl radicals. These findings represent the first report of redox reaction catalysis by any member of the AHS.

  11. Recent insights into microbial catalases: isolation, production and purification.

    PubMed

    Sooch, Balwinder Singh; Kauldhar, Baljinder Singh; Puri, Munish

    2014-12-01

    Catalase, an oxidoreductase enzyme, works as a detoxification system inside living cells against reactive oxygen species formed as a by-product of different metabolic reactions. The enzyme is found in a wide range of aerobic and anaerobic organisms. Catalase has also been employed in various analytical and diagnostic methods in the form of biosensors and biomarkers in addition to its other applications in textile, paper, food and pharmaceutical industries. New applications for catalases are constantly emerging thanks to their high turnover rate, distinct evolutionary origin, relatively simple and well-defined reaction mechanisms. The following review provides comprehensive information on isolation, production and purification of catalases with different techniques from various microbial sources along with their types, structure, mechanism of action and applications. PMID:25261851

  12. A Laboratory Experiment of the Purification of Catalase.

    ERIC Educational Resources Information Center

    Busquets, Montserrat; Franco, Rafael

    1986-01-01

    Describes a simple method for purifying catalase for the study of proteins. Procedures are systematically and diagramatically presented. Also identifies polyacrylamide gel electrophoresis, kinetic studies, and apparent molecular weight determination as possible techniques to be used in studying proteins. (ML)

  13. Catalases as biocatalysts in technical applications: current state and perspectives.

    PubMed

    Lončar, Nikola; Fraaije, Marco W

    2015-04-01

    Catalases represent a class of enzymes which has found its place among industrially relevant biocatalysts due to their exceptional catalytic rate and high stability. Textile bleaching prior to the dyeing process is the main application and has been performed on a large scale for the past few decades. Their limited substrate scope has not prevented the development of various other catalase-based applications. Newly developed approaches continue to exploit their excellent catalytic potential to degrade hydrogen peroxide while (per)oxidase activity of catalases is opening a new range of possibilities as well. This review provides an overview of applications that involve heme-containing catalases that have been demonstrated in recent years. PMID:25761626

  14. MicroRNA-30b-Mediated Regulation of Catalase Expression in Human ARPE-19 Cells

    PubMed Central

    Haque, Rashidul; Chun, Eugene; Howell, Jennifer C.; Sengupta, Trisha; Chen, Dan; Kim, Hana

    2012-01-01

    Background Oxidative injury to retinal pigment epithelium (RPE) and retinal photoreceptors has been linked to a number of retinal diseases, including age-related macular degeneration (AMD). Reactive oxygen species (ROS)-mediated gene expression has been extensively studied at transcriptional levels. Also, the post-transcriptional control of gene expression at the level of translational regulation has been recently reported. However, the microRNA (miRNA/miR)-mediated post-transcriptional regulation in human RPE cells has not been thoroughly looked at. Increasing evidence points to a potential role of miRNAs in diverse physiological processes. Methodology/Principal Findings We demonstrated for the first time in a human retinal pigment epithelial cell line (ARPE-19) that the post-transcriptional control of gene expression via miRNA modulation regulates human catalase, an important and potent component of cell's antioxidant defensive network, which detoxifies hydrogen peroxide (H2O2) radicals. Exposure to several stress-inducing agents including H2O2 has been reported to alter miRNA expression profile. Here, we demonstrated that a sublethal dose of H2O2 (200 µM) up-regulated the expression of miR-30b, a member of the miR-30 family, which inhibited the expression of endogenous catalase both at the transcript and protein levels. However, antisense (antagomirs) of miR-30b was not only found to suppress the miR-30b mimics-mediated inhibitions, but also to dramatically increase the expression of catalase even under an oxidant environment. Conclusions/Significance We propose that a microRNA antisense approach could enhance cytoprotective mechanisms against oxidative stress by increasing the antioxidant defense system. PMID:22880027

  15. Increased microglial catalase activity in multiple sclerosis grey matter.

    PubMed

    Gray, Elizabeth; Kemp, Kevin; Hares, Kelly; Redondo, Julianna; Rice, Claire; Scolding, Neil; Wilkins, Alastair

    2014-04-22

    Chronic demyelination, on-going inflammation, axonal loss and grey matter neuronal injury are likely pathological processes that contribute to disease progression in multiple sclerosis (MS). Although the precise contribution of each process and their aetiological substrates is not fully known, recent evidence has implicated oxidative damage as a major cause of tissue injury in MS. The degree of tissue injury caused by oxidative molecules, such as reactive oxygen species (ROS), is balanced by endogenous anti-oxidant enzymes which detoxify ROS. Understanding endogenous mechanisms which protect the brain against oxidative injury in MS is important, since enhancing anti-oxidant responses is a major therapeutic strategy for preventing irreversible tissue injury in the disease. Our aims were to determine expression and activity levels of the hydrogen peroxide-reducing enzyme catalase in MS grey matter (GM). In MS GM, a catalase enzyme activity was elevated compared to control GM. We measured catalase protein expression by immune dot-blotting and catalase mRNA by a real-time polymerase chain reaction (RT-PCR). Protein analysis studies showed a strong positive correlation between catalase and microglial marker IBA-1 in MS GM. In addition, calibration of catalase mRNA level with reference to the microglial-specific transcript AIF-1 revealed an increase in this transcript in MS. This was reflected by the extent of HLA-DR immunolabeling in MS GM which was significantly elevated compared to control GM. Collectively, these observations provide evidence that microglial catalase activity is elevated in MS grey matter and may be an important endogenous anti-oxidant defence mechanism in MS. PMID:24602691

  16. The Catalase C-262T Gene Polymorphism and Cancer Risk

    PubMed Central

    Shen, Yongchun; Li, Diandian; Tian, Panwen; Shen, Konglong; Zhu, Jing; Feng, Mei; Wan, Chun; Yang, Ting; Chen, Lei; Wen, Fuqiang

    2015-01-01

    Abstract Many studies suggest that catalase C-262T gene polymorphism is associated with cancer risk, but with inconsistent results. This study aimed to summarize the overall association between catalase C-262T polymorphism and cancer risk. Literature search was performed in PubMed, Embase, and other databases, studies regarding the association between catalase C-262T polymorphism and cancer risk were identified, and data were retrieved and analyzed by using Review Manager 5.0.24 and STATA 12.0. A total of 18 publications with 22 casecontrol studies, including 9777 cancer patients and 12,223 controls, met the inclusion criteria. Meta-analysis results showed significant association between catalase C-262 T polymorphism and cancer risk (TT vs CT?+?CC: odds ratio [OR]?=?1.17, 95% confidence interval [CI]?=?1.031.31, P?=?0.01). Subgroup analyses stratified by cancer types suggested the catalase C-262T polymorphism was significantly associated with an increased prostate cancer risk (TT vs CT?+?CC: OR?=?1.61, 95% CI?=?1.172.22, P?=?0.004); for subgroup analyses stratified by ethnicity, no associations between this polymorphism and Asians or whites were identified (CT?+?TT vs CC: OR?=?1.11, 95% CI?=?0.981.26, P?=?0.09 for whites; OR?=?1.19, 95% CI?=?0.781.80, P?=?0.42 for Asians). In summary, the catalase C-262T polymorphism may be a risk factor for cancer with cancer type-specific effects. Further studies should be performed to confirm these findings. PMID:25837760

  17. Protandim attenuates intimal hyperplasia in human saphenous veins cultured ex vivo via a catalase-dependent pathway.

    PubMed

    Joddar, Binata; Reen, Rashmeet K; Firstenberg, Michael S; Varadharaj, Saradhadevi; McCord, Joe M; Zweier, Jay L; Gooch, Keith J

    2011-03-15

    Human saphenous veins (HSVs) are widely used for bypass grafts despite their relatively low long-term patency. To evaluate the role of reactive oxygen species (ROS) signaling in intima hyperplasia (IH), an early stage pathology of vein-graft disease, and to explore the potential therapeutic effects of up-regulating endogenous antioxidant enzymes, we studied segments of HSV cultured ex vivo in an established ex vivo model of HSV IH. Results showed that HSV cultured ex vivo exhibit an ~3-fold increase in proliferation and ~3.6-fold increase in intimal area relative to freshly isolated HSV. Treatment of HSV during culture with Protandim, a nutritional supplement known to activate Nrf2 and increase the expression of antioxidant enzymes in several in vitro and in vivo models, blocks IH and reduces cellular proliferation to that of freshly isolated HSV. Protandim treatment increased the activity of SOD, HO-1, and catalase 3-, 7-, and 12-fold, respectively, and decreased the levels of superoxide (O(2)(•-)) and the lipid peroxidation product 4-HNE. Blocking catalase activity by cotreating with 3-amino-1,2,4-triazole abrogated the protective effect of Protandim on IH and proliferation. In conclusion, these results suggest that ROS-sensitive signaling mediates the observed IH in cultured HSV and that up-regulation of endogenous antioxidant enzymes can have a protective effect. PMID:21167278

  18. 21 CFR 184.1034 - Catalase (bovine liver).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the National Academy Press, 2101... liver) (CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of bovine liver. It is a partially purified liquid or powder. Its characterizing enzyme activity is catalase (EC...

  19. 21 CFR 184.1034 - Catalase (bovine liver).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the National Academy Press, 2101... liver) (CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of bovine liver. It is a partially purified liquid or powder. Its characterizing enzyme activity is catalase (EC...

  20. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Catalase derived from Micrococcus lysodeikticus. 173.135 Section 173.135 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION...

  1. 21 CFR 184.1034 - Catalase (bovine liver).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... 110, which is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies... enzyme preparation obtained from extracts of bovine liver. It is a partially purified liquid or powder. Its characterizing enzyme activity is catalase (EC 1.11.1.6). (b) The ingredient meets the...

  2. 21 CFR 184.1034 - Catalase (bovine liver).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the National Academy Press, 2101... liver) (CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of bovine liver. It is a partially purified liquid or powder. Its characterizing enzyme activity is catalase (EC...

  3. The catalase activity of Nalpha-acetyl-microperoxidase-8.

    PubMed

    Jeng, W-Y; Tsai, Y-H; Chuang, W-J

    2004-09-01

    Nalpha-Acetylated microperoxidase-8 (Ac-MP-8) is a water soluble, ferric heme model for peroxidases. We report here that Ac-MP-8 catalyzes catalase-type reaction in addition to peroxidase-type and cytochrome P450-type reactions. The catalase activity of Ac-MP-8 was determined by the Clark oxygen electrode, which measures the production of oxygen in solution. The Km and kcat of the decomposition of hydrogen peroxide (H2O2) catalyzed by Ac-MP-8 are 40.9 mm and 4.1 per s, respectively. The specificity constant (kcat/Km) of Ac-MP-8 in catalase-type reaction of H2O2 is 100.2,/m/s, which is 5- to 12- and 50- to 100-fold less than those of MPs in cytochrome P450-type reaction of aniline/H2O2 and peroxidase-type reaction of o-methoxyphenol/H2O2, respectively. These results indicate that Ac-MP-8 can catalyze three different types of reactions, and the relative catalytic specificities of Ac-MP-8 with a histidyl ligand exhibit the following orders: peroxidase-type > cytochrome P450-type > catalase-type reactions. Comparisons of the enzyme activities of Ac-MP-8 suggest that the fifth ligands of hemoproteins influence the ratio of the three types of reactions. PMID:15317500

  4. Improving catalase-based propelled motor endurance by enzyme encapsulation

    NASA Astrophysics Data System (ADS)

    Simmchen, Juliane; Baeza, Alejandro; Ruiz-Molina, Daniel; Vallet-Regí, Maria

    2014-07-01

    Biocatalytic propulsion is expected to play an important role in the future of micromotors as it might drastically increase the number of available fuelling reactions. However, most of the enzyme-propelled micromotors so far reported still rely on the degradation of peroxide by catalase, in spite of being vulnerable to relatively high peroxide concentrations. To overcome this limitation, herein we present a strategy to encapsulate the catalase and to graft the resulting enzyme capsules on motor particles. Significant improvement of the stability in the presence of peroxide and other aggressive agents has been observed.Biocatalytic propulsion is expected to play an important role in the future of micromotors as it might drastically increase the number of available fuelling reactions. However, most of the enzyme-propelled micromotors so far reported still rely on the degradation of peroxide by catalase, in spite of being vulnerable to relatively high peroxide concentrations. To overcome this limitation, herein we present a strategy to encapsulate the catalase and to graft the resulting enzyme capsules on motor particles. Significant improvement of the stability in the presence of peroxide and other aggressive agents has been observed. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr02459a

  5. Heterogeneity of Catalase in Maturing and Germinated Cotton Seeds 1

    PubMed Central

    Kunce, Christine M.; Trelease, Richard N.

    1986-01-01

    To investigate possible charge and size heterogeneity of catalase (EC 1.11.1.6) in cotton (Gossypium hirsutum L. cv Deltapine 62), extracts of cotyledons from different developmental ages were subjected to nondenaturing polyacrylamide gel electrophoresis and isoelectric focusing. Special precautions (e.g. fresh homogenates, reducing media) were necessary to prevent artefacts due to enzyme modification during extraction and storage. When the gels were stained for enzyme activity, two distinct electrophoretic forms of catalase were resolved in extracts of maturing and mature cotton seeds. In germinated seeds, three additional cathodic forms were detected revealing a total of five electrophoretic variants. In green cotyledons, the two anodic forms characteristic of ungerminated seeds were less active; whereas, the most cathodic form was predominant. All forms of catalase were found in isolated glyoxysomes. Corresponding electrophoretic patterns were found on Western blots probed with anticatalase serum; no immunoreactive, catalytically inactive forms were detected. Western blots of sodium dodecyl sulfate-polyacrylamide gels revealed only one immunoreactive (55 kilodaltons) polypeptide in cotton extracts of all developmental ages. Results from isoelectric focusing and Ferguson plots indicate that the electrophoretic variants of catalase are charge isomers with a molecular weight of approximately 230,000. Images Fig. 1 Fig. 2 Fig. 3 Fig. 6 Fig. 7 PMID:16664956

  6. Development of lyophilization cycle and effect of excipients on the stability of catalase during lyophilization

    PubMed Central

    Lale, Shantanu V; Goyal, Monu; Bansal, Arvind K

    2011-01-01

    Introduction: The purpose of the present study was to screen excipients such as amino acids and non-aqueous solvents for their stabilizing effect on catalase, a model protein, for lyophilization. The present study also includes optimization of lyophilization cycle for catalase formulations, which is essential from the commercial point of view, since lyophilization is an extremely costly process. Materials and Methods: Activity of catalase was determined using catalase activity assay. Differential scanning calorimetry was used to determine eutectic melting temperature of the frozen catalase solution, which is essential for the optimization of lyophilization cycle. Results: When catalase was lyophilized without excipients, it was found that about 65-78% of the initial activity of catalase was lost during the lyophilization process in a concentration dependent manner. The maximum stability of catalase during lyophilization was observed at pH 7.0. Amino acids like alanine, glycine, lysine, serine and 4-hydroxy proline showed strong stabilizing effect on catalase during lyophilization by protecting catalase activity above 95%, whereas valine and cysteine hydrochloride showed destabilizing effect on catalase. Non-aqueous solvents such as dimethyl formamide, dimethyl sulphoxide, polyethylene glycol (PEG) 200, PEG 400, PEG 600 and ethylene glycol also showed destabilizing effect on catalase during lyophilization. Conclusions: In order to prevent loss of catalase activity during lyophilization of catalase, use of amino acids like alanine, glycine, lysine, serine and 4-hydroxy proline in optimum concentration is highly advisable. PMID:23071946

  7. Cloning and genetic characterization of Helicobacter pylori catalase and construction of a catalase-deficient mutant strain.

    PubMed

    Odenbreit, S; Wieland, B; Haas, R

    1996-12-01

    The N-terminal sequence of a protein, originally described as an adhesin of Helicobacter pylori, was used in an oligonucleotide-based screening procedure of an H. pylori plasmid library in Escherichia coli. Five independent plasmid clones were isolated, all mapping to the same chromosomal region and encoding the H. pylori catalase. The gene, designated katA, comprises 1,518 nucleotides and encodes a putative protein of 505 amino acids with a predicted Mr of 58,599. A second open reading frame, orf2, encoding a putative 32,715-Da protein of unknown function, follows katA. The transcriptional start site of katA mRNA was determined, but no typical consensus promoter sequence was present. A potential binding site for the Fur protein is located upstream of katA. When introduced into the catalase-deficient E. coli double-mutant UM255, the cloned gene readily complemented E. coli for catalase activity. H. pylori KatA is highly homologous to catalases in both prokaryotes and eukaryotes, with the highest homology being shown to Bordetella pertussis (64.9%), Bacteroides fragilis (59.8%), and Haemophilus influenzae (57.9%) catalases. Transposon insertion mutants were generated in three independent H. pylori strains by TnMax5-mediated transposon shuttle mutagenesis. In contrast to the wild-type strains, no significant catalase-specific enzymatic activity could be detected in the mutant strains, consistent with the fact that no additional katA-homologous gene copies were found in the H. pylori chromosome. No significant difference between wild-type and mutant strains for binding to epithelial cells was apparent, suggesting that KatA is not involved in H. pylori adhesion. The cloning and genetic characterization of katA are essential steps for further investigation of the role of catalase in the defense of H. pylori against oxygen-dependent killing mechanisms by polymorphonuclear granulocytes, a process not well understood for this chronically persisting pathogen. PMID:8955320

  8. Altered methanol embryopathies in embryo culture with mutant catalase-deficient mice and transgenic mice expressing human catalase

    SciTech Connect

    Miller, Lutfiya; Wells, Peter G.

    2011-04-01

    The mechanisms underlying the teratogenicity of methanol (MeOH) in rodents, unlike its acute toxicity in humans, are unclear, but may involve reactive oxygen species (ROS). Embryonic catalase, although expressed at about 5% of maternal activity, may protect the embryo by detoxifying ROS. This hypothesis was investigated in whole embryo culture to remove confounding maternal factors, including metabolism of MeOH by maternal catalase. C57BL/6 (C57) mouse embryos expressing human catalase (hCat) or their wild-type (C57 WT) controls, and C3Ga.Cg-Catb/J acatalasemic (aCat) mouse embryos or their wild-type C3HeB/FeJ (C3H WT) controls, were explanted on gestational day (GD) 9 (plug = GD 1), exposed for 24 h to 4 mg/ml MeOH or vehicle, and evaluated for functional and morphological changes. hCat and C57 WT vehicle-exposed embryos developed normally. MeOH was embryopathic in C57 WT embryos, evidenced by decreases in anterior neuropore closure, somites developed and turning, whereas hCat embryos were protected. Vehicle-exposed aCat mouse embryos had lower yolk sac diameters compared to C3H WT controls, suggesting that endogenous ROS are embryopathic. MeOH was more embryopathic in aCat embryos than WT controls, with reduced anterior neuropore closure and head length only in catalase-deficient embryos. These data suggest that ROS may be involved in the embryopathic mechanism of methanol, and that embryonic catalase activity may be a determinant of teratological risk.

  9. Comparative immunological study of catalases in the genus Micrococcus.

    PubMed

    Rupprecht, M; Schleifer, K H

    1977-07-26

    Double immunodiffusion tests were performed with crude extracts from various Micrococcus species and antisera against catalase of Micrococcus luteus CCM 169. Cell-free extracts of M. lylae ATCC 27566 exhibited good cross-reaction. Cell-free extracts or catalase enriched preparations of M. varians reacted very weakly and no reaction has been found with preparation of M. kristinae, M. nishinomiyaensis, M. roseus and M. sedentarius. The quantitative microcomplement fixation assay also revealed a closer relationship between M. luteus and M. lylae than between M. luteus and M. varians. Strains of other Micrococcus species reacted in the microcomplement assay with M. luteus antiserum just a weakly as non-related strains, e.g. Staphylococcus aureus or Cellulomonas cartalyticum. PMID:71880

  10. Embryonic catalase protects against ethanol embryopathies in acatalasemic mice and transgenic human catalase-expressing mice in embryo culture.

    PubMed

    Miller-Pinsler, Lutfiya; Wells, Peter G

    2015-09-15

    Reactive oxygen species (ROS) have been implicated in the mechanism of ethanol (EtOH) teratogenicity, but the protective role of the embryonic antioxidative enzyme catalase is unclear, as embryonic activity is only about 5% of maternal levels. We addressed this question in a whole embryo culture model. C57BL/6 mouse embryos expressing human catalase (hCat) or their wild-type (C57BL/6 WT) controls, and C3Ga.Cg-Cat(b)/J catalase-deficient, acatalasemic (aCat) mouse embryos or their wild-type C3HeB/FeJ (C3H WT) controls, were explanted on gestational day (GD) 9 (plug=GD 1), exposed for 24h to 2 or 4mg/mL EtOH or vehicle, and evaluated for functional and morphological changes. hCat and C57BL/6 WT vehicle-exposed embryos developed normally, while EtOH was embryopathic in C57BL/6 WT embryos, evidenced by decreases in anterior neuropore closure, somites developed, turning and head length, whereas hCat embryos were protected (p<0.001). Maternal pretreatment of C57BL/6 WT dams with 50kU/kg PEG-catalase (PEG-cat) 8h prior to embryo culture, which increases embryonic catalase activity, blocked all EtOH embryopathies (p<0.001). Vehicle-exposed aCat mouse embryos had lower yolk sac diameters compared to WT controls, suggesting that endogenous ROS are embryopathic. EtOH was more embryopathic in aCat embryos than WT controls, evidenced by reduced head length and somite development (p<0.01), and trends for reduced anterior neuropore closure, turning and crown-rump length. Maternal pretreatment of aCat dams with PEG-Cat blocked all EtOH embryopathies (p<0.05). These data suggest that embryonic catalase is a determinant of risk for EtOH embryopathies. PMID:26074427

  11. Overexpression of Catalase Diminishes Oxidative Cysteine Modifications of Cardiac Proteins

    PubMed Central

    Yao, Chunxiang; Behring, Jessica B.; Shao, Di; Sverdlov, Aaron L.; Whelan, Stephen A.; Elezaby, Aly; Yin, Xiaoyan; Siwik, Deborah A.; Seta, Francesca; Costello, Catherine E.; Cohen, Richard A.; Matsui, Reiko; Colucci, Wilson S.; McComb, Mark E.; Bachschmid, Markus M.

    2015-01-01

    Reactive protein cysteine thiolates are instrumental in redox regulation. Oxidants, such as hydrogen peroxide (H2O2), react with thiolates to form oxidative post-translational modifications, enabling physiological redox signaling. Cardiac disease and aging are associated with oxidative stress which can impair redox signaling by altering essential cysteine thiolates. We previously found that cardiac-specific overexpression of catalase (Cat), an enzyme that detoxifies excess H2O2, protected from oxidative stress and delayed cardiac aging in mice. Using redox proteomics and systems biology, we sought to identify the cysteines that could play a key role in cardiac disease and aging. With a ‘Tandem Mass Tag’ (TMT) labeling strategy and mass spectrometry, we investigated differential reversible cysteine oxidation in the cardiac proteome of wild type and Cat transgenic (Tg) mice. Reversible cysteine oxidation was measured as thiol occupancy, the ratio of total available versus reversibly oxidized cysteine thiols. Catalase overexpression globally decreased thiol occupancy by ≥1.3 fold in 82 proteins, including numerous mitochondrial and contractile proteins. Systems biology analysis assigned the majority of proteins with differentially modified thiols in Cat Tg mice to pathways of aging and cardiac disease, including cellular stress response, proteostasis, and apoptosis. In addition, Cat Tg mice exhibited diminished protein glutathione adducts and decreased H2O2 production from mitochondrial complex I and II, suggesting improved function of cardiac mitochondria. In conclusion, our data suggest that catalase may alleviate cardiac disease and aging by moderating global protein cysteine thiol oxidation. PMID:26642319

  12. Progeric effects of catalase inactivation in human cells

    SciTech Connect

    Koepke, Jay I.; Wood, Christopher S.; Terlecky, Laura J.; Walton, Paul A.; Terlecky, Stanley R.

    2008-10-01

    Peroxisomes generate hydrogen peroxide, a reactive oxygen species, as part of their normal metabolism. A number of pathological situations exist in which the organelle's capacity to degrade the potentially toxic oxidant is compromised. It is the peroxidase, catalase, which largely determines the functional antioxidant capacity of the organelle, and it is this enzyme that is affected in aging, in certain diseases, and in response to exposure to specific chemical agents. To more tightly control the enzymatic activity of peroxisomal catalase and carefully document the effects of its impaired action on human cells, we employed the inhibitor 3-amino-1,2,4-triazole. We show that by chronically reducing catalase activity to approximately 38% of normal, cells respond in a dramatic manner, displaying a cascade of accelerated aging reactions. Hydrogen peroxide and related reactive oxygen species are produced, protein and DNA are oxidatively damaged, import into peroxisomes and organelle biogenesis is corrupted, and matrix metalloproteinases are hyper-secreted from cells. In addition, mitochondria are functionally impaired, losing their ability to maintain a membrane potential and synthesize reactive oxygen species themselves. These latter results suggest an important redox-regulated connection between the two organelle systems, a topic of considerable interest for future study.

  13. Listeriosis due to infection with a catalase-negative strain of Listeria monocytogenes.

    PubMed

    Cepeda, J A; Millar, M; Sheridan, E A; Warwick, S; Raftery, M; Bean, D C; Wareham, D W

    2006-05-01

    A strain of Listeria monocytogenes recovered from blood and cerebrospinal fluid had no detectable catalase activity, a characteristic used for primary identification. The sporadic occurrence of pathogenic catalase-negative strains highlights the need for a reconsideration of diagnostic criteria and questions the role of catalase in the pathogenesis of listeria infection. PMID:16672441

  14. Structure–Function Relationships in Fungal Large-Subunit Catalases

    SciTech Connect

    Diaz, A.; Valdez, V; Rudino-Pinera, E; Horjales, E; Hansberg, W

    2009-01-01

    Neurospora crassa has two large-subunit catalases, CAT-1 and CAT-3. CAT-1 is associated with non-growing cells and accumulates particularly in asexual spores; CAT-3 is associated with growing cells and is induced under different stress conditions. It is our interest to elucidate the structure-function relationships in large-subunit catalases. Here we have determined the CAT-3 crystal structure and compared it with the previously determined CAT-1 structure. Similar to CAT-1, CAT-3 hydrogen peroxide (H{sub 2}O{sub 2}) saturation kinetics exhibited two components, consistent with the existence of two active sites: one saturated in the millimolar range and the other in the molar range. In the CAT-1 structure, we found three interesting features related to its unusual kinetics: (a) a constriction in the channel that conveys H{sub 2}O{sub 2} to the active site; (b) a covalent bond between the tyrosine, which forms the fifth coordination bound to the iron of the heme, and a vicinal cysteine; (c) oxidation of the pyrrole ring III to form a cis-hydroxyl group in C5 and a cis-{gamma}-spirolactone in C6. The site of heme oxidation marks the starts of the central channel that communicates to the central cavity and the shortest way products can exit the active site. CAT-3 has a similar constriction in its major channel, which could function as a gating system regulated by the H{sub 2}O{sub 2} concentration before the gate. CAT-3 functional tyrosine is not covalently bonded, but has instead the electron relay mechanism described for the human catalase to divert electrons from it. Pyrrole ring III in CAT-3 is not oxidized as it is in other large-subunit catalases whose structure has been determined. Different in CAT-3 from these enzymes is an occupied central cavity. Results presented here indicate that CAT-3 and CAT-1 enzymes represent a functional group of catalases with distinctive structural characteristics that determine similar kinetics.

  15. Cloning, characterization, and expression in Escherichia coli of a gene encoding Listeria seeligeri catalase, a bacterial enzyme highly homologous to mammalian catalases.

    PubMed Central

    Haas, A; Brehm, K; Kreft, J; Goebel, W

    1991-01-01

    A gene coding for catalase (hydrogen-peroxide:hydrogen-peroxide oxidoreductase; EC 1.11.1.6) of the gram-positive bacterium Listeria seeligeri was cloned from a plasmid library of EcoRI-digested chromosomal DNA, with Escherichia coli DH5 alpha as a host. The recombinant catalase was expressed in E. coli to an enzymatic activity approximately 50 times that of the combined E. coli catalases. The nucleotide sequence was determined, and the deduced amino acid sequence revealed 43.2% amino acid sequence identity between bovine liver catalase and L. seeligeri catalase. Most of the amino acid residues which are involved in catalytic activity, the formation of the active center accession channel, and heme binding in bovine liver catalase were also present in L. seeligeri catalase at the corresponding positions. The recombinant protein contained 488 amino acid residues and had a calculated molecular weight of 55,869. The predicted isoelectric point was 5.0. Enzymatic and genetic analyses showed that there is most probably a single catalase of this type in L. seeligeri. A perfect 21-bp inverted repeat, which was highly homologous to previously reported binding sequences of the Fur (ferric uptake regulon) protein of E. coli, was detected next to the putative promoter region of the L. seeligeri catalase gene. Images PMID:1860824

  16. Structural analysis of catalase from two Musa accessions, FHIA18 and Williams, and from Ravenala madagascariensis.

    PubMed

    Khoyratty, Sher-ullah S S; Souza, Manoel T; Jaufeerally-Fakim, Yasmina

    2008-01-01

    Nucleotide sequences of catalase were obtained following amplification using specific primers and were blasted against Musa acuminata catalase 2 mRNA from NCBI (157418810). Clustering of the amino acid sequences from NCBI was done using Clustal X. The latter revealed that FHIA18 catalase is more related to Ravenala madagascariensis (Musa relative) catalase while the Williams catalase is more related to a clade containing a Musa acuminata (Musa ancestor) catalase from NCBI. The tertiary structures and the catalase consensus functional sites, based on the Pseudomonas syringae catalase structural template, were obtained for FHIA18, Williams, Ravenala madagascariensis and Musa acuminata catalases. They were found to differ slightly. Using known features of catalase active sites, four pre-requisite criteria were defined to find such sites: (1) Position of tyrosine axial to heme determined by X-ray diffraction, (2) 7 conserved amino acids in the active site found by sequence alignment, (3) favourable docking energy, and (4) presence of an unobstructed long tunnel that leads the ligand to the active site. Two differing potential docking sites were found for both FHIA18 and Williams that fit a maximum number of criteria. In terms of 1D sequence, the region of the docking site for Williams is within the catalase domains as seen upon NCBI blast. The counterpart of FHIA18 for the same region is not. This sequence difference between FHIA18 and Williams affects the best docking site in FHIA18 and Williams in silico. PMID:19374128

  17. Novel insights in mammalian catalase heme maturation: effect of NO and thioredoxin-1.

    PubMed

    Chakravarti, Ritu; Gupta, Karishma; Majors, Alana; Ruple, Lisa; Aronica, Mark; Stuehr, Dennis J

    2015-05-01

    Catalase is a tetrameric heme-containing enzyme with essential antioxidant functions in biology. Multiple factors including nitric oxide (NO) have been shown to attenuate its activity. However, the possible impact of NO in relation to the maturation of active catalase, including its heme acquisition and tetramer formation, has not been investigated. We found that NO attenuates heme insertion into catalase in both short-term and long-term incubations. The NO inhibition in catalase heme incorporation was associated with defective oligomerization of catalase, such that inactive catalase monomers and dimers accumulated in place of the mature tetrameric enzyme. We also found that GAPDH plays a key role in mediating these NO effects on the structure and activity of catalase. Moreover, the NO sensitivity of catalase maturation could be altered up or down by manipulating the cellular expression level or activity of thioredoxin-1, a known protein-SNO denitrosylase enzyme. In a mouse model of allergic inflammatory asthma, we found that lungs from allergen-challenged mice contained a greater percentage of dimeric catalase relative to tetrameric catalase in the unchallenged control, suggesting that the mechanisms described here are in play in the allergic asthma model. Together, our study shows how maturation of active catalase can be influenced by NO, S-nitrosylated GAPDH, and thioredoxin-1, and how maturation may become compromised in inflammatory conditions such as asthma. PMID:25659933

  18. A simple method for determination of serum catalase activity and revision of reference range.

    PubMed

    Gth, L

    1991-02-15

    A rapid, cost-efficient, spectrophotometric assay for serum catalase activity was developed. It was a combination of optimized enzymatic conditions and the spectrophotometric assay of hydrogen peroxide based on formation of its stable complex with ammonium molybdate. Lipemic and icteric sera increased the absorbance without influencing the catalase assay. Due to the high catalase activity in erythrocytes artificial hemolysis increased serum catalase activity. The imprecision of the method was CV less than 5.8% within run as well and day-to-day. The catalase assay performed using polarographic and spectrophotometric determination of hydrogen peroxide yielded a good correlation (r = 0.9602, b = 1.011, a = -0.648, n = 440). In 742 healthy individuals the mean and SD values of serum catalase were 50.5 +/- 18.1 kU/l with 17.7% higher activity in males than in females. Between 14-60 yr the serum catalase increased with age. PMID:2029780

  19. Catalase eliminates reactive oxygen species and influences the intestinal microbiota of shrimp.

    PubMed

    Yang, Hui-Ting; Yang, Ming-Chong; Sun, Jie-Jie; Guo, Fang; Lan, Jiang-Feng; Wang, Xian-Wei; Zhao, Xiao-Fan; Wang, Jin-Xing

    2015-11-01

    Intestinal innate immune response is an important defense mechanism of animals and humans against external pathogens. The mechanism of microbiota homeostasis in host intestines has been well studied in mammals and Drosophila. The reactive oxygen species (ROS) and antimicrobial peptides have been reported to play important roles in homeostasis. However, how to maintain the microbiota homeostasis in crustacean intestine needs to be elucidated. In this study, we identified a novel catalase (MjCAT) involved in ROS elimination in kuruma shrimp, Marsupenaeus japonicus. MjCAT mRNA was widely distributed in hemocytes, heart, hepatopancreas, gills, stomach, and intestine. After the shrimp were challenged with pathogenic bacteria via oral infection, the expression level of MjCAT was upregulated, and the enzyme activity was increased in the intestine. ROS level was also increased in the intestine at early time after oral infection and recovered rapidly. When MjCAT was knocked down by RNA interference (RNAi), high ROS level maintained longer time, and the number of bacteria number was declined in the shrimp intestinal lumen than those in the control group, but the survival rate of the MjCAT-RNAi shrimp was declined. Further study demonstrated that the intestinal villi protruded from epithelial lining of the intestinal wall were damaged by the high ROS level in MjCAT-knockdown shrimp. These results suggested that MjCAT participated in the intestinal host-microbe homeostasis by regulating ROS level. PMID:26314524

  20. EPR spectroscopy and catalase activity of manganese-bound DNA-binding protein from nutrient starved cells.

    PubMed

    Hayden, Joshua Allen; Hendrich, Michael P

    2010-06-01

    DNA-binding proteins from nutrient-starved cells (DPS) protect cells from oxidative stress by removing H(2)O(2) and iron. A new class of DPS-like proteins has recently been identified, with DPS-like protein from Sulfolobus solfataricus (SsDPS) being the best characterized to date. SsDPS protects cells from oxidative stress and is upregulated in response to H(2)O(2) but also in response to iron depletion. The ferroxidase active site of SsDPS is structurally similar to the active sites of manganese catalase and rat liver arginase. The present work shows that the ferroxidase center in SsDPS binds two Mn(2+) ions with K (D) = (1/K (1) K (2))(1/2) = 48(3) microM. The binding constant of the second Mn(2+) is significantly higher than that of the first, inducing dinuclear Mn(II) cluster formation for all but the lowest concentrations of added Mn(2+). In competition experiments, equimolar amounts of Fe(2+) were unable to displace the bound manganese. EPR spectroscopy of the Mn(2) (2+) cluster showed signals comparable to those of other characterized dimanganese clusters. The exchange coupling for the cluster was determined, J = -1.4(3) cm(-1) (H = -2JS (1) S (2)), and is within the range expected for a mu(1,1)-carboxylato bridge between the manganese ions. Manganese-bound SsDPS showed catalase activity at a rate 10-100 times slower than for manganese catalases. EPR spectra of SsDPS after addition of H(2)O(2) showed the appearance of an intermediate in the reaction with H(2)O(2). PMID:20221652

  1. Plating isolation of various catalase-negative microorganisms from soil

    NASA Technical Reports Server (NTRS)

    Labeda, D. P.; Hunt, C. M.; Casida, L. E., Jr.

    1974-01-01

    A unique plating procedure was developed that allows isolation, but not enumeration, of representatives of the catalase-negative soil microflora. The numbers recovered, however, are low as compared to the numbers recovered when the modified dilution-to-extinction isolation procedure is used. The latter procedure provides prolonged inoculation in sealed tubes containing a nutritionally rich broth medium over small submerged agar slants. In contrast, the plating procedure utilizes nutritionally minimal media and the shorter incubations mandated by the inherent problems associated with plating.

  2. A new PANI biosensor based on catalase for cyanide determination.

    PubMed

    Özcan, Hakkı Mevlüt; Aydin, Tuba

    2016-03-01

    Cyanide is one of the most widespread of compounds measured in environmental analysis due to their toxic effects on environment and health. We report a highly sensitive, reliable, selective amperometric sensor for determination of cyanide, using a polyaniline conductive polymer. The enzyme catalase was immobilized by electropolymerization. The steps during the immobilization were controlled by electrochemical impedance spectroscopy. Optimum pH, temperature, aniline concentration, enzyme concentration, and the number of scans obtained during electropolymerization, were investigated. In addition, the cyanide present in artificial waste water samples was determined. In the characterization studies of the biosensor, some parameters such as reproducibility and storage stability, were analyzed. PMID:25386729

  3. Peroxisomal catalase deficiency modulates yeast lifespan depending on growth conditions

    PubMed Central

    Kawa?ek, Adam; Lefevre, Sophie D.; Veenhuis, Marten; van der Klei, Ida J.

    2013-01-01

    We studied the role of peroxisomal catalase in chronological aging of the yeastHansenula polymorpha in relation to various growth substrates. Catalase-deficient (cat) cells showed a similar chronological life span (CLS) relative to the wild-type control upon growth on carbon and nitrogen sources that are not oxidized by peroxisomal enzymes. However, when media contained methylamine, which is oxidized by peroxisomal amine oxidase, the CLS of cat cells was significantly reduced. Conversely, the CLS of cat cells was enhanced relative to the wild-type control, when cells were grown on methanol, which is oxidized by peroxisomal alcohol oxidase. At these conditions strongly enhanced ROS levels were observed during the exponential growth phase of cat cells. This was paralleled by activation of the transcription factor Yap1, as well as an increase in the levels of the antioxidant enzymes cytochrome c peroxidase and superoxide dismutase. Upon deletion of the genes encoding Yap1 or cytochrome c peroxidase, the CLS extension of cat cells on methanol was abolished. These findings reveal for the first time an important role of enhanced cytochrome c peroxidase levels in yeast CLS extension. PMID:23425686

  4. Catalase degradation in sunflower cotyledons during peroxisome transition from glyoxysomal to leaf peroxisomal function. [Helianthus annuus

    SciTech Connect

    Eising, R.; Gerhardt, B.

    1987-06-01

    First order rate constant for the degradation (degradation constants) of catalase in the cotyledons of sunflower (Helianthus annuus L.) were determined by measuring the loss of catalase containing /sup 14/C-labeled heme. During greening of the cotyledons, a period when peroxisomes change from glyoxysomal to leaf peroxisomal function, the degradation of glyoxysomal catalase is significantly slower than during all other stages of cotyledon development in light or darkness. The degradation constant during the transition stage of peroxisome function amounts to 0.205 day/sup -1/ in contrast to the constants ranging from 0.304 day/sup -1/ to 0.515 day/sup -1/ during the other developmental stages. Density labeling experiments comprising labeling of catalase with /sup 2/H/sub 2/O and its isopycnic centrifugation on CsCl gradients demonstrated that the determinations of the degradation constants were not substantially affected by reutilization of /sup 14/C-labeled compounds for catalase synthesis. The degradation constants for both glyoxysomal catalase and catalase synthesized during the transition of peroxisome function do not differ. This was shown by labeling the catalases with different isotopes and measuring the isotope ratio during the development of the cotyledons. The results are inconsistent with the concept that an accelerated and selective degradation of glyoxysomes underlies the change in peroxisome function. The data suggest that catalase degradation is at least partially due to an individual turnover of catalase and does not only result from a turnover of the whole peroxisomes.

  5. Catalase activity of different Candida species after exposition to specific antiserum

    PubMed Central

    Miyasaka, Natlia R.S.; Unterkircher, Carmelinda S.; Shimizu, Mario T.

    2008-01-01

    Antisera were developed in rabbits after challenge with intracellular antigens of Candida albicans, C. tropicalis and C. parapsilosis. Microorganism catalase has been correlated with virulence, resistance to drugs and immunogenicity. The intracellular catalase is consistently present in strains of Candida and in this paper, the enzyme activity was analysed by PAGE after exposition to antisera. The catalases of C. albicans, C. parapsilosis and C. tropicalis were immunogenic and differed in their binding to specific antibodies raised in rabbits. Tests of cross-reactivity between different Candida species showed that when antiserum from C. albicans immunized rabbit was incubated with intracellular extracts of these three Candida species, the catalases activities were abolished. However, the antisera from C. parapsilosis or C. tropicalis immunized rabbits did not affect the catalase activity of C. albicans; the enzyme of C. albicans was inactivated only by the antiserum to the catalase of own C. albicans. The antiserum to the catalase of C. tropicalis was species-specific and did not cross-react with catalases of C. albicans and C. parapsilosis. The activities of Aspergillus niger and bovine catalases were not affected by the antiserum from any Candida immunized rabbits. This report is a preliminary study of specific antisera that react against intracellular catalase of Candida sp. and neutralize the enzymatic activity. Further study is necessary to develop species-specific antibody once differences in the susceptibility of the Candida species to commonly used antifungal drugs make identification to the species level important. PMID:24031174

  6. Nanoparticle-mediated catalase delivery protects human neurons from oxidative stress.

    PubMed

    Singhal, A; Morris, V B; Labhasetwar, V; Ghorpade, A

    2013-01-01

    Several neurodegenerative diseases and brain injury involve reactive oxygen species and implicate oxidative stress in disease mechanisms. Hydrogen peroxide (H2O2) formation due to mitochondrial superoxide leakage perpetuates oxidative stress in neuronal injury. Catalase, an H2O2-degrading enzyme, thus remains an important antioxidant therapy target. However, catalase therapy is restricted by its labile nature and inadequate delivery. Here, a nanotechnology approach was evaluated using catalase-loaded, poly(lactic co-glycolic acid) nanoparticles (NPs) in human neuronal protection against oxidative damage. This study showed highly efficient catalase encapsulation capable of retaining ~99% enzymatic activity. NPs released catalase rapidly, and antioxidant activity was sustained for over a month. NP uptake in human neurons was rapid and nontoxic. Although human neurons were highly sensitive to H2O2, NP-mediated catalase delivery successfully protected cultured neurons from H2O2-induced oxidative stress. Catalase-loaded NPs significantly reduced H2O2-induced protein oxidation, DNA damage, mitochondrial membrane transition pore opening and loss of cell membrane integrity and restored neuronal morphology, neurite network and microtubule-associated protein-2 levels. Further, catalase-loaded NPs improved neuronal recovery from H2O2 pre-exposure better than free catalase, suggesting possible applications in ameliorating stroke-relevant oxidative stress. Brain targeting of catalase-loaded NPs may find wide therapeutic applications for oxidative stress-associated acute and chronic neurodegenerative disorders. PMID:24201802

  7. Identification of a Catalase-Phenol Oxidase in Betalain Biosynthesis in Red Amaranth (Amaranthus cruentus).

    PubMed

    Teng, Xiao-Lu; Chen, Ning; Xiao, Xing-Guo

    2015-01-01

    Betalains are a group of nitrogen-containing pigments that color plants in most families of Caryophyllales. Their biosynthesis has long been proposed to begin with hydroxylation of L-tyrosine to L-DOPA through monophenolase activity of tyrosinase, but biochemical evidence in vivo remains lacking. Here we report that a Group 4 catalase, catalase-phenol oxidase (named as AcCATPO), was identified, purified and characterized from leaves of Amaranthus cruentus, a betalain plant. The purified enzyme appeared to be a homotrimeric protein composed of subunits of about 58 kDa, and demonstrated not only the catalase activity toward H2O2, but also the monophenolase activity toward L-tyrosine and diphenolase activity toward L-DOPA. Its catalase and phenol oxidase activities were inhibited by common classic catalase and tyrosinase inhibitors, respectively. All its peptide fragments identified by nano-LC-MS/MS were targeted to catalases, and matched with a cDNA-encoded polypeptide which contains both classic catalase and phenol oxidase active sites. These sites were also present in catalases of non-betalain plants analyzed. AcCATPO transcript abundance was positively correlated with the ratio of betaxanthin to betacyanin in both green and red leaf sectors of A. tricolor. These data shows that the fourth group catalase, catalase-phenol oxidase, is present in plant, and might be involved in betaxanthin biosynthesis. PMID:26779247

  8. Identification of a Catalase-Phenol Oxidase in Betalain Biosynthesis in Red Amaranth (Amaranthus cruentus)

    PubMed Central

    Teng, Xiao-Lu; Chen, Ning; Xiao, Xing-Guo

    2016-01-01

    Betalains are a group of nitrogen-containing pigments that color plants in most families of Caryophyllales. Their biosynthesis has long been proposed to begin with hydroxylation of L-tyrosine to L-DOPA through monophenolase activity of tyrosinase, but biochemical evidence in vivo remains lacking. Here we report that a Group 4 catalase, catalase-phenol oxidase (named as AcCATPO), was identified, purified and characterized from leaves of Amaranthus cruentus, a betalain plant. The purified enzyme appeared to be a homotrimeric protein composed of subunits of about 58 kDa, and demonstrated not only the catalase activity toward H2O2, but also the monophenolase activity toward L-tyrosine and diphenolase activity toward L-DOPA. Its catalase and phenol oxidase activities were inhibited by common classic catalase and tyrosinase inhibitors, respectively. All its peptide fragments identified by nano-LC-MS/MS were targeted to catalases, and matched with a cDNA-encoded polypeptide which contains both classic catalase and phenol oxidase active sites. These sites were also present in catalases of non-betalain plants analyzed. AcCATPO transcript abundance was positively correlated with the ratio of betaxanthin to betacyanin in both green and red leaf sectors of A. tricolor. These data shows that the fourth group catalase, catalase-phenol oxidase, is present in plant, and might be involved in betaxanthin biosynthesis. PMID:26779247

  9. Purification and characterization of catalase from marine bacterium Acinetobacter sp. YS0810.

    PubMed

    Fu, Xinhua; Wang, Wei; Hao, Jianhua; Zhu, Xianglin; Sun, Mi

    2014-01-01

    The catalase from marine bacterium Acinetobacter sp. YS0810 (YS0810CAT) was purified and characterized. Consecutive steps were used to achieve the purified enzyme as follows: ethanol precipitation, DEAE Sepharose ion exchange, Superdex 200 gel filtration, and Resource Q ion exchange. The active enzyme consisted of four identical subunits of 57.256 kDa. It showed a Soret peak at 405 nm, indicating the presence of iron protoporphyrin IX. The catalase was not apparently reduced by sodium dithionite but was inhibited by 3-amino-1,2,4-triazole, hydroxylamine hydrochloride, and sodium azide. Peroxidase-like activity was not found with the substrate o-phenylenediamine. So the catalase was determined to be a monofunctional catalase. N-terminal amino acid of the catalase analysis gave the sequence SQDPKKCPVTHLTTE, which showed high degree of homology with those of known catalases from bacteria. The analysis of amino acid sequence of the purified catalase by matrix-assisted laser desorption ionization time-of-flight mass spectrometry showed that it was a new catalase, in spite of its high homology with those of known catalases from other bacteria. The catalase showed high alkali stability and thermostability. PMID:25045672

  10. Endothelin-1 stimulates catalase activity through the PKC? mediated phosphorylation of Serine 167

    PubMed Central

    Rafikov, Ruslan; Kumar, Sanjiv; Aggarwal, Saurabh; Hou, Yali; Kangath, Archana; Pardo, Daniel; Fineman, Jeffrey R.; Black, Stephen M.

    2013-01-01

    Our previous studies have shown that endothelin-1 (ET-1) stimulates catalase activity in endothelial cells and lambs with acute increases in pulmonary blood flow (PBF), without altering gene expression. The purpose of this study was to investigate the molecular mechanism by which this occurs. Exposing pulmonary arterial endothelial cells (PAEC) to ET-1 increased catalase activity and decreased cellular hydrogen peroxide (H2O2) levels. These changes correlated with an increase in serine phosphorylated catalase. Using the inhibitory peptide ?V1.1, this phosphorylation was shown to be PKC? dependent. Mass spectrometry identified serine167 as the phosphorylation site. Site-directed mutagenesis was used to generate a phospho-mimic (S167D) catalase. Activity assays using recombinant protein purified from E.coli or transiently transfected COS-7 cells, demonstrated that S167D-catalase had an increased ability to degrade H2O2 compared to the wildtype enzyme. Using a phospho-specific antibody, we were able to verify that pS167 catalase levels are modulated in lambs with acute increases in PBF in the presence and absence of the ET receptor antagonist, tezosentan. S167 is being located on the dimeric interface suggesting it could be involved in regulating the formation of catalase tetramers. To evaluate this possibility we utilized analytical gel-filtration to examine the multimeric structure of recombinant wildtype- and S167D-catalase. We found that recombinant wildtype catalase was present as a mixture of monomers and dimers while S167D catalase was primarily tetrameric. Further, the incubation of wildtype catalase with PKC? was sufficient to convert wildtype catalase into a tetrameric structure. In conclusion, this is the first report indicating that the phosphorylation of catalase regulates its multimeric structure and activity. PMID:24211614

  11. OVEREXPRESSION OF ANTIOXIDANT ENZYMES UPREGULATES ARYL HYDROCARBON RECEPTOR EXPRESSION VIA INCREASED SP1 DNA-BINDING ACTIVITY

    PubMed Central

    Tang, Tian; Lin, Xinghua; Yang, Hong; Zhou, LiChun; Wang, Zefen; Shan, Guang; Guo, ZhongMao

    2010-01-01

    We previously reported up-regulation of aryl hydrocarbon receptor (AhR) expression as a mechanism by which overexpression of Cu/Zn-superoxide dismutase (SOD) and/or catalase accelerates benzo(a)pyrene (BaP) detoxification in mouse aorta endothelial cells (MAECs). The objective of this study was to investigate the regulatory role of specificity protein-1 (Sp1) in AhR expression in MAECs that overexpress Cu/Zn-SOD and/or catalase. Our data demonstrated comparable levels of nuclear Sp1 protein in the transgenic and wild-type MAECs; however, binding of Sp1 protein to the AhR promoter region was more than 2-fold higher in MAECs overexpressing Cu/Zn-SOD and/or catalase than in wild-type cells. Inhibition of Sp1 binding to the AhR promoter by mithramycin A reduced AhR expression and eliminated the differences between wild-type MAECs, and three lines of transgenic cells. Functional promoter analysis indicated that AhR promoter activity was significantly higher in MAECs overexpressing catalase than in wild-type cells. Mutation of an AhR promoter Sp1-binding site or addition of hydrogen peroxide to the culture medium reduced AhR promoter activity, and decreased the differences between wild-type MAECs and transgenic cells overexpressing catalase. These results suggest that increased Sp1 binding to the AhR promoter region is an underlying mechanism for up-regulation of AhR expression in MAECs that overexpress Cu/Zn-SOD and/or catalase. PMID:20478378

  12. A Chaperone Function of NO CATALASE ACTIVITY1 Is Required to Maintain Catalase Activity and for Multiple Stress Responses in Arabidopsis

    PubMed Central

    Li, Jing; Liu, Juntao; Wang, Guoqiang; Cha, Joon-Yung; Li, Guannan; Chen, She; Li, Zhen; Guo, Jinghua; Zhang, Caiguo; Yang, Yongqing; Kim, Woe-Yeon; Yun, Dae-Jin; Schumaker, Karen S.; Chen, Zhongzhou; Guo, Yan

    2015-01-01

    Catalases are key regulators of reactive oxygen species homeostasis in plant cells. However, the regulation of catalase activity is not well understood. In this study, we isolated an Arabidopsis thaliana mutant, no catalase activity1-3 (nca1-3) that is hypersensitive to many abiotic stress treatments. The mutated gene was identified by map-based cloning as NCA1, which encodes a protein containing an N-terminal RING-finger domain and a C-terminal tetratricopeptide repeat-like helical domain. NCA1 interacts with and increases catalase activity maximally in a 240-kD complex in planta. In vitro, NCA1 interacts with CATALASE2 (CAT2) in a 1:1 molar ratio, and the NCA1 C terminus is essential for this interaction. CAT2 activity increased 10-fold in the presence of NCA1, and zinc ion binding of the NCA1 N terminus is required for this increase. NCA1 has chaperone protein activity that may maintain the folding of catalase in a functional state. NCA1 is a cytosol-located protein. Expression of NCA1 in the mitochondrion of the nca1-3 mutant does not rescue the abiotic stress phenotypes of the mutant, while expression in the cytosol or peroxisome does. Our results suggest that NCA1 is essential for catalase activity. PMID:25700484

  13. A method for molecular analysis of catalase gene diversity in seawater.

    PubMed

    Wang, Wei; Ji, Xiaofeng; Yuan, Cui; Dai, Fangqun; Zhu, Jiancheng; Sun, Mi

    2013-12-01

    Catalase plays an important role in the metabolism of marine bacteria and has potential impact on the marine environment. Four PCR primers were designed to amplify the catalase gene fragments in marine bacteria by applying metagenomic DNA from Yellow Sea surface water as the template. Of the four reproducible target PCR products, the longest one with 900bp were chosen for catalase gene library construction by the T-vector and the white Escherichia coli colonies in the library was screened through restriction-digesting the reamplified insert fragments by the selected restriction endonuclease MboI, and then the bands of the resulting products were displayed in the agarose gel by electrophoresis. The unique restriction fragment length polymorphism (RFLP) pattern was selected and the corresponding catalase gene fragments were sequenced, which verified that every unique RFLP pattern represented one type of catalase. This PCR-RFLP method above was established to investigate the bacterial catalase diversity in seawater. PMID:24426153

  14. Isolation and characterization of catalase from Penicillium chrysogenum.

    PubMed

    Chaga, G S; Medin, A S; Chaga, S G; Porath, J O

    1992-06-26

    Catalase from a crude preparation of Penicillium chrysogenum was isolated in a single chromatographic step by immobilized metal ion affinity chromatography (IMAC) on Cu(II)-Chelating Sepharose Fast Flow. A chromatographically and electrophoretically homogeneous enzyme was obtained in 89% yield. IMAC was found to be superior to ion-exchange, hydrophobic interaction, size-exclusion and concanavalin A affinity chromatography. Analytical and preparative chromatography gave essentially the same chromatograms. Isoelectric point, molecular weight (by ultracentrifugation), amino acid composition, carbohydrate content and subunit organization were determined. The apparent Michaelis-Menten constant, KM, and the azide competitor constant, Ki, were calculated and found to be 59 microM and 6.1 microM, respectively. PMID:1639925

  15. Layer-by-layer self-assembly immobilization of catalases on wool fabrics.

    PubMed

    Liu, J; Wang, Q; Fan, X R; Sun, X J; Huang, P H

    2013-04-01

    A new immobilization strategy of catalases on natural fibers was reported in this paper. Catalase (CAT) from Bacillus subtilis was assembled into multiple layers together with poly(diallyldimethylammonium chloride) (PDDA) on wool fabrics via layer-by-layer (LBL) electrostatic self-assembly deposition. The mechanism and structural evaluation of LBL electrostatic self-assembly were studied in terms of scanning electron microscopy (SEM), surface zeta potential, and apparent color depth (K/S). The SEM pictures showed obvious deposits absorbed on the wool surfaces after LBL self-assembly. The surface zeta potential and dyeing depth of CAT/PDDA-assembled wool fabrics presented a regular layer-by-layer alternating trend along with the change of deposited materials, revealing the multilayer structure of the wool fiber immobilized catalases. The V(max) values were found to be 2,500238 U/mg protein for the free catalase and 1,000102 U/mg protein for the immobilized catalase. The K(m) value of free catalase (11.252.3 mM) was found to be lower than that of the immobilized catalase (222.236.5 mM). The immobilized catalase remained high enzymatic activity and showed a measureable amount of reusability, which proved that LBL electrostatic self-assembly deposition is a promising approach to immobilize catalases. PMID:23420488

  16. Gut Catalase-Positive Bacteria Cross-Protect Adjacent Bifidobacteria from Oxidative Stress.

    PubMed

    Rodríguez, Eva; Peirotén, Ángela; Landete, José María; Medina, Margarita; Arqués, Juan Luis

    2015-01-01

    Bifidobacteria isolated from infant gut and breast milk exhibited different abilities to grow under microaerobic conditions, alone or in the presence of added catalase. In the present study, we demonstrated that some Bifidobacterium strains unable to grow under microaerobic conditions were cross-protected on solid media from oxidative stress by adjacent colonies of gut catalase-positive Staphylococcus epidermidis or Escherichia coli, but not by a catalase-deficient E. coli. The results of this study support the possible contribution of catalase-positive bacteria to the establishment of certain bifidobacteria in non-anaerobic human niches of the infant gastrointestinal tract or mammary gland. PMID:26040451

  17. Gut Catalase-Positive Bacteria Cross-Protect Adjacent Bifidobacteria from Oxidative Stress

    PubMed Central

    Rodríguez, Eva; Peirotén, Ángela; Landete, José María; Medina, Margarita; Arqués, Juan Luis

    2015-01-01

    Bifidobacteria isolated from infant gut and breast milk exhibited different abilities to grow under microaerobic conditions, alone or in the presence of added catalase. In the present study, we demonstrated that some Bifidobacterium strains unable to grow under microaerobic conditions were cross-protected on solid media from oxidative stress by adjacent colonies of gut catalase-positive Staphylococcus epidermidis or Escherichia coli, but not by a catalase-deficient E. coli. The results of this study support the possible contribution of catalase-positive bacteria to the establishment of certain bifidobacteria in non-anaerobic human niches of the infant gastrointestinal tract or mammary gland. PMID:26040451

  18. Extracellular localization of catalase is associated with the transformed state of malignant cells.

    PubMed

    Bhm, Britta; Heinzelmann, Sonja; Motz, Manfred; Bauer, Georg

    2015-12-01

    Oncogenic transformation is dependent on activated membrane-associated NADPH oxidase (NOX). However, the resultant extracellular superoxide anions are also driving the NO/peroxynitrite and the HOCl pathway, which eliminates NOX-expressing transformed cells through selective apoptosis induction. Tumor progression is dependent on dominant interference with intercellular apoptosis-inducing ROS signaling through membrane-associated catalase, which decomposes H2O2 and peroxynitrite and oxidizes NO. Particularly, the decomposition of extracellular peroxynitrite strictly requires membrane-associated catalase. We utilized small interfering RNA (siRNA)-mediated knockdown of catalase and neutralizing antibodies directed against the enzyme in combination with challenging H2O2 or peroxynitrite to determine activity and localization of catalase in cells from three distinct steps of multistage oncogenesis. Nontransformed cells did not generate extracellular superoxide anions and only showed intracellular catalase activity. Transformed cells showed superoxide anion-dependent intercellular apoptosis-inducing ROS signaling in the presence of suboptimal catalase activity in their membrane. Tumor cells exhibited tight control of intercellular apoptosis-inducing ROS signaling through a high local concentration of membrane-associated catalase. These data demonstrate that translocation of catalase to the outside of the cell membrane is already associated with the transformation step. A strong local increase in the concentration of membrane-associated catalase is achieved during tumor progression and is controlled by tumor cell-derived H2O2 and by transglutaminase. PMID:26140730

  19. Regulation of Catalase Activity in Leaves of Nicotiana sylvestris by High CO2

    PubMed Central

    Havir, Evelyn A.; McHale, Neil A.

    1989-01-01

    The effect of high CO2 (1% CO2/21% O2) on the activity of specific forms of catalase (CAT-1, -2, and -3) (EA Havir, NA McHale [1987] Plant Physiol 84: 450-455) in seedling leaves of tobacco (Nicotiana sylvestris, Nicotlana tabacum) was examined. In high CO2, total catalase activity decreased by 50% in the first 2 days, followed by a more gradual decline in the next 4 days. The loss of total activity resulted primarily from a decrease in CAT-1 catalase. In contrast, the activity of CAT-3 catalase, a form with enhanced peroxidatic activity, increased 3-fold in high CO2 relative to air controls after 4 days. Short-term exposure to high CO2 indicated that the 50% loss of total activity occurs in the first 12 hours. Catalase levels increased to normal within 12 hours after seedlings were returned to air. When seedlings were transferred to air after prolonged exposure to high CO2 (13 days), the levels of CAT-1 catalase were partially restored while CAT-3 remained at its elevated level. Levels of superoxide dismutase activity and those of several peroxisomal enzymes were not affected by high CO2. Total catalase levels did not decline when seedlings were exposed to atmospheres of 0.04% CO2/5% O2 or 0.04% CO2/1% O2, indicating that regulation of catalase in high CO2 is not related directly to suppression of photorespiration. Antibodies prepared against CAT-1 catalase from N. tabacum reacted strongly against CAT-1 catalase from both N. sylvestris and N. tabacum but not against CAT-3 catalase from either species. This observation, along with the rapid changes in CAT-1 and the much slower changes in CAT-3 suggest that one form is not directly derived from the other. Images Figure 4 PMID:16666647

  20. Regulation of catalase activity in leaves of Nicotiana sylvestris by high CO sub 2

    SciTech Connect

    Havir, E.A.; McHale, N.A. )

    1989-03-01

    The effect of high CO{sub 2} (1% CO{sub 2}/21% O{sub 2}) on the activity of specific forms of catalase (CAT-1, -2, and -3) in seedling leaves of tobacco (Nicotiana sylvestris, Nicotiana tabacum) was examined. In high CO{sub 2} total catalase activity decreased by 50% in the first 2 days, followed by a more gradual decline in the next 4 days. The loss of total activity resulted primarily from a decrease in CAT-1 catalase. In contrast, the activity of CAT-3 catalase, a form with enhanced peroxidatic activity, increased 3-fold in high CO{sub 2} relative to air controls after 4 days. Short-term exposure to high CO{sub 2} indicated that the 50% loss of total activity occurs in the firs 12 hours. Catalase levels increased to normal within 12 hours after seedlings were returned to air. When seedlings were transferred to air after prolonged exposure to high CO{sub 2} (13 days), the levels of CAT-1 catalase were partially restored while CAT-3 remained at its elevated level. Levels of superoxide dismutase activity and those of several peroxisomal enzymes were not affected by high CO{sub 2}. Total catalase levels did not decline when seedlings were exposed to atmospheres of 0.04% CO{sub 2}/5% O{sub 2} or 0.04% CO{sub 2}/1% O{sub 2}, indicating that regulation of catalase in high CO{sub 2} is not related directly to suppression of photorespiration. Antibodies prepared against CAT-1 catalase from N. tabacum reacted strongly against CAT-1 catalase from both N. sylvestris and N. tabacum but not against CAT-3 catalase from either species.

  1. Catalase Activity of Psychrophilic Bacteria Grown at 2 and 30 C1

    PubMed Central

    Frank, Hilmer A.; Ishibashi, Sandra T.; Reid, Ann; Ito, June S.

    1963-01-01

    Catalase activity was measured in resting-cell suspensions of psychrophilic bacteria grown at 2 and at 30 C. Enzyme activity decreased in both cell-suspension types as harvest age increased. At comparable physiological age, cells grown at 2 C had more catalase than cells grown at 30 C. PMID:13959237

  2. CATALASE AND SUPEROXIDE DISMUTASE OF ROOT-COLONIZING SAPROPHYTIC FLUORESCENT PSEUDOMONADS

    EPA Science Inventory

    Root-colonizing, saprophytic fluorescent pseudomonads of the Pseudomonas putida-P. fluorescens group express similar levels of catalase and superoxide dismutase activities during growth on a sucrose- and amino acid-rich medium. ncreased specific activities of catalase but not sup...

  3. Catalase depression in malignant liver from chickens with myeloblastosis and Marek's disease.

    PubMed

    Williams-Smith, D L; Payne, L N; Wyard, S J

    1984-09-01

    In rapidly frozen livers from chickens affected with myeloblastosis and Marek's disease and from unaffected control birds there exists a strong correlation between catalase activity and catalase Electron Paramagnetic Resonance (EPR) signal intensities. The diseased chickens had activities and signals reduced to as little as 10% of control values. There were no changes in the EPR parameters in diseased liver and the data support the hypothesis that the lowering in activity is due to lowered catalase levels rather than to catalase inhibition. The rate of transformation of catalase to catalase-formate in liver was studied by freeze-clamping liver in anaesthetised chickens, then warming to 37 degrees for 1 or 2 minutes anaerobiosis, and then refreezing. The only difference of significance in this transformation between diseased and normal livers was the greater percentage of total catalase present as catalase-formate (approximately + 15%) in aerobic diseased liver, which may indicate a lowered production of hydrogen peroxide, relative to formate, in these livers. The rate of transformation was far faster in chickens (t1/2 less than 1 min) than in the rat (t1/2 = 7.7 min). PMID:6087870

  4. Covalent Immobilization of Catalase onto Regenerated Silk Fibroins via Tyrosinase-Catalyzed Cross-Linking.

    PubMed

    Wang, Ping; Qi, Chenglong; Yu, Yuanyuan; Yuan, Jiugang; Cui, Li; Tang, Gengtie; Wang, Qiang; Fan, Xuerong

    2015-09-01

    Regenerated silk fibroins could be used as medical scaffolds and carrier materials for enzyme immobilization. In the present work, tyrosinase enzyme was used for enzymatic oxidation of silk fibroins, followed by immobilization of catalase onto the fibroin surfaces through physical adsorption and covalent cross-linking as well. Spectrophotometry, SDS-PAGE, and Fourier transform infrared spectroscopy (FTIR) were used to examine the efficiency of enzymatic oxidation and catalase immobilization, respectively. The results indicate that tyrosine residues in silk fibroins could be oxidized and converted to the active o-quinones. Incubating silk fibroins with catalase and tyrosinase led to a noticeable change of molecular weight distribution, indicating the occurrence of the cross-links between silk fibroins and catalase molecules. Two different pathways were proposed for the catalase immobilizations, and the method based on grafting of catalase onto the freeze-dried fibroin membrane is more acceptable. The residual enzyme activity for the immobilized catalase exhibited higher than that of the control after repeated washing cycles. Meanwhile, the thermal stability and alkali resistance were also slightly improved as compared to free catalase. The mechanisms of enzymatic immobilization are also concerned. PMID:26189105

  5. Production of catalases by Comamonas spp. and resistance to oxidative stress.

    PubMed

    Godockov, J; Bohcov, V; Zmock, M; Polek, B

    2005-01-01

    Bacterial isolates Comamonas terrigena N3H (from soil contaminated with crude oil) and C. testosteroni (isolated from the sludge of a wastewater treatment plant), exhibit much higher total catalase activity than the same species from laboratory collection cultures. Electrophoretic resolution of catalases revealed only one corresponding band in cell-free extracts of both C. testosteroni cultures. Isolates of C. terrigena N3H exhibited catalase-1 and catalase-2 activity, whereas in the collection culture C. terrigena ATCC 8461 only catalase-1 was detected. The environmental isolates exhibited much higher resistance to exogenous H2O2 (20, 40 mmol/L) than collection cultures, mainly in the middle and late exponential growth phases. The stepwise H2O2-adapted culture of C. terrigena N3H, which was more resistant to oxidative stress than the original isolate, exhibited an increase of catalase and peroxidase activity represented by catalase-1. Pretreatment of cells with 0.5 mmol/L H2O2 followed by an application of the oxidative agent in toxic concentrations (up to 40 mmol/L) increased the rate of cell survival in the original isolate, but not in the H2O2-adapted variant. The protection of bacteria caused by such pretreatment corresponded with stimulation of catalase activity in pretreated culture. PMID:16110914

  6. Profiling catalase gene expression in Drosophila melanogaster during development and aging.

    PubMed

    Klichko, Vladimir I; Radyuk, Svetlana N; Orr, William C

    2004-05-01

    Catalase represents one of the key antioxidant enzymes (AOE) in the metabolism of oxygen free radicals. A comprehensive analysis was brought to bear on establishing catalase gene expression profiles during development and aging, with the underlying objective being to identify potential regulatory factors. Expression of the catalase gene exhibits substantial variations during development and aging in a stage- and tissue-specific manner. At the temporal level, previous observations of the coincidence of ecdysteroid pulses with peaks in catalase expression during developmental stages were largely corroborated. In adults, a small but significant decline in catalase expression was noted in adults as a function of age. Spatially, it was ascertained that catalase expression is mostly confined to tissues related to intermediary metabolism, digestive and adipose systems as well as oenocytes. By combining histochemical analysis of reporter gene expression with immunostaining of the endogenous product, it was possible to identify putative positive and negative regulatory elements that control catalase expression. Finally, when adult flies were subjected to various environmental insults, such as heat, paraquat, hyperoxia and H(2)O(2), no significant responses were observed, suggesting that catalase gene expression is largely governed by intrinsic genetic programs. PMID:15101064

  7. Inhibition of Catalase by Tea Catechins in Free and Cellular State: A Biophysical Approach

    PubMed Central

    Pal, Sandip; Dey, Subrata Kumar; Saha, Chabita

    2014-01-01

    Tea flavonoids bind to variety of enzymes and inhibit their activities. In the present study, binding and inhibition of catalase activity by catechins with respect to their structure-affinity relationship has been elucidated. Fluorimetrically determined binding constants for (?)-epigallocatechin gallate (EGCG) and (?)-epicatechin gallate (ECG) with catalase were observed to be 2.27106 M?1 and 1.66106 M?1, respectively. Thermodynamic parameters evidence exothermic and spontaneous interaction between catechins and catalase. Major forces of interaction are suggested to be through hydrogen bonding along with electrostatic contributions and conformational changes. Distinct loss of ?-helical structure of catalase by interaction with EGCG was captured in circular dichroism (CD) spectra. Gallated catechins demonstrated higher binding constants and inhibition efficacy than non-gallated catechins. EGCG exhibited maximum inhibition of pure catalase. It also inhibited cellular catalase in K562 cancer cells with significant increase in cellular ROS and suppression of cell viability (IC50 54.5 M). These results decipher the molecular mechanism by which tea catechins interact with catalase and highlight the potential of gallated catechin like EGCG as an anticancer drug. EGCG may have other non-specific targets in the cell, but its anticancer property is mainly defined by ROS accumulation due to catalase inhibition. PMID:25025898

  8. CHARACTERIZATION OF CATALASE ACTIVITIES IN A ROOT-CLEANING ISOLATE OF PSEUDOMONAS PUTIDA

    EPA Science Inventory

    Psuedomonas putida, a saprophytic root-colonizing bacterium, produces multiple forms of catalase Catalase A which increases in specific activity during growth phase and after treatment with H2O2, is located in the and is inhibited by 3-amino-1,2-4-triazole, EDTA, and cyanide, but...

  9. Encapsulation of catalase in polyelectrolyte microspheres composed of melamine formaldehyde, dextran sulfate, and protamine.

    PubMed

    Balabushevich, N G; Zimina, E P; Larionova, N I

    2004-07-01

    Immobilization of catalase (molecular weight 240,000 daltons) in polyelectrolyte microspheres was studied. The microspheres were obtained by alternating adsorption of dextran sulfate and protamine on commercially available melamine formaldehyde cores followed by the core hydrolysis at pH 1.7. As the interior of the microspheres was filled with homogeneous matrix, the catalase distribution inside the microspheres was uniform. The quantity of entrapped catalase was dependent on the initial concentration of the enzyme and pH of solution, and the peak value was 10(8)-10(9) molecules per microsphere. It was demonstrated that catalase was entrapped in the microspheres via electrostatic and hydrophobic interactions. The catalase activity inside the microspheres increased as the quantity of enzyme decreased, which was due to the switch between diffusion and kinetic regimes of the enzymatic reaction. The microspheres could be applied for separation and concentration of high molecular weight proteins. PMID:15310276

  10. Enzyme activity of catalase immobilized in Langmuir-Blodgett films of phospholipids.

    PubMed

    Goto, Thiago E; Lopez, Ricardo F; Oliveira, Osvaldo N; Caseli, Luciano

    2010-07-01

    A major challenge for producing low cost biosensors based on nanostructured films with control of molecular architectures is to preserve the catalytic activity of the immobilized biomolecules. In this study, we show that catalase (HRP) keeps its activity if immobilized in Langmuir-Blodgett (LB) films of dipalmitoyl phosphatidylglycerol (DPPG). The incorporation of catalase into a DPPG monolayer at the air-water interface was demonstrated with surface pressure and surface potential isotherms, in addition to polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS). According to the PM-IRRAS data, catalase was not denatured upon adsorption on a preformed DPPG monolayer and could be transferred onto a solid substrate. The catalytic activity of catalase in a mixed LB film with DPPG was ca. 13% higher than in solution. The control of molecular architecture and choice of a suitable phospholipid matrix allows catalase-containing LB films to be used in sensing hydrogen peroxide. PMID:20491464

  11. Forchlorfenuron detection based on its inhibitory effect towards catalase immobilized on boron nitride substrate.

    PubMed

    Xu, Qin; Cai, Lijuan; Zhao, Huijie; Tang, Jiaqian; Shen, Yuanyuan; Hu, Xiaoya; Zeng, Haibo

    2015-01-15

    An enzymatic procedure based on a catalase biosensor for the detection of forchlorfenuron (CPPU) has been reported in this work. Catalase was immobilized on boron nitride (BN) sheets dispersed in chitosan by adsorption. The immobilized catalase exhibited direct electron transfer character and excellent electrocatalytic activity towards H2O2 reduction. After introducing CPPU into the H2O2 containing phosphate buffer solution, the catalase-catalyzed H2O2 reduction current decreased. By measuring the current decrease, CPPU can be determined in the range of 0.5-10.0 M with the detection limit of 0.07 ?M. The non-competitive inhibition behavior of CPPU towards catalase was verified by the Lineweaver-Burk plots. Long stability character has been ascribed to this biosensor. Possible use of this biosensor in flow systems is illustrated. The proposed biosensor has been successfully applied to CPPU determination in fruits samples with satisfactory results. PMID:25108110

  12. [The catalase inhibitor aminotriazole alleviates acute alcoholic liver injury].

    PubMed

    Ai, Qing; Ge, Pu; Dai, Jie; Liang, Tian-Cai; Yang, Qing; Lin, Ling; Zhang, Li

    2015-02-25

    In this study, the effects of catalase (CAT) inhibitor aminotriazole (ATZ) on alcohol-induced acute liver injury were investigated to explore the potential roles of CAT in alcoholic liver injury. Acute liver injury was induced by intraperitoneal injection of alcohol in Sprague Dawley (SD) rats, and various doses of ATZ (100-400 mg/kg) or vehicle were administered intraperitoneally at 30 min before alcohol exposure. After 24 h of alcohol exposure, the levels of aspartate transaminase (AST), alanine transaminase (ALT) and lactate dehydrogenase (LDH) in plasma were determined. The degree of hepatic histopathological abnormality was observed by HE staining. The activity of hepatic CAT, hydrogen peroxide (H₂O₂) level and malondialdehyde (MDA) content in liver tissue were measured by corresponding kits. The levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in plasma were determined by ELISA method. The results showed that treatment with ATZ dose-dependently suppressed the elevation of ALT, AST and LDH levels induced by alcohol exposure, and that ATZ alleviated alcohol-induced histopathological alterations. Furthermore, ATZ inhibited the activity of CAT, reduced hepatic levels of H₂O₂and MDA in alcohol exposed rats. ATZ also decreased the levels of plasma TNF-α and IL-6 in rats with alcohol exposure. These results indicated that ATZ attenuated alcohol-induced acute liver injury in rats, suggesting that CAT might play important pathological roles in the pathogenesis of alcoholic liver injury. PMID:25672632

  13. Amelioration of hepatic reperfusion injury by superoxide dismutase and catalase

    SciTech Connect

    Clemens, M.G.; Burke, F.; Chaudry, I.H.

    1986-03-05

    Oxygen-derived free radicals have been implicated in reperfusion injury in various tissues. The present study determined if enzymatic scavenging of free radicals could improve recovery of hepatic function following ischemia. Livers from fasted rats were perfused with Krebs-HCO/sub 3/ buffer with substrates for gluconeogenesis for 30 min (control) followed by 60 min warm ischemia and 90 min reperfusion. At the beginning and end of ischemia the liver was flushed with buffered Ringer's with superoxide dismutase + catalase (150,000 U/L each)(SOD) or without additions (Untreated). Bile flow and glucose release were monitored during control and reperfusion periods and tissue sampled at the end of the experiment to determine tissue water and electrolytes. Bile flow and gluconeogenesis were markedly depressed after ischemia in both groups. At the end of 90 min reperfusion bile flow in Untreated and SOD were 23 +/- 6 and 46 +/- 8 ..mu..l/15 min (20% and 41% of control respectively, p < .01). Gluconeogenesis recovered to 83 +/- 4% of control in Untreated vs 103 +/- 6% with SOD (p < .05). Tissue water and electrolytes were not different. These results suggest that generation of oxygen-derived free radicals contributes to functional deficits in the liver following ischemia and that these defects can be attenuated by enzymatic scavenging.

  14. Catalase inhibits ionizing radiation-induced apoptosis in hematopoietic stem and progenitor cells.

    PubMed

    Xiao, Xia; Luo, Hongmei; Vanek, Kenneth N; LaRue, Amanda C; Schulte, Bradley A; Wang, Gavin Y

    2015-06-01

    Hematologic toxicity is a major cause of mortality in radiation emergency scenarios and a primary side effect concern in patients undergoing chemo-radiotherapy. Therefore, there is a critical need for the development of novel and more effective approaches to manage this side effect. Catalase is a potent antioxidant enzyme that coverts hydrogen peroxide into hydrogen and water. In this study, we evaluated the efficacy of catalase as a protectant against ionizing radiation (IR)-induced toxicity in hematopoietic stem and progenitor cells (HSPCs). The results revealed that catalase treatment markedly inhibits IR-induced apoptosis in murine hematopoietic stem cells and hematopoietic progenitor cells. Subsequent colony-forming cell and cobble-stone area-forming cell assays showed that catalase-treated HSPCs can not only survive irradiation-induced apoptosis but also have higher clonogenic capacity, compared with vehicle-treated cells. Moreover, transplantation of catalase-treated irradiated HSPCs results in high levels of multi-lineage and long-term engraftments, whereas vehicle-treated irradiated HSPCs exhibit very limited hematopoiesis reconstituting capacity. Mechanistically, catalase treatment attenuates IR-induced DNA double-strand breaks and inhibits reactive oxygen species. Unexpectedly, we found that the radioprotective effect of catalase is associated with activation of the signal transducer and activator of transcription 3 (STAT3) signaling pathway and pharmacological inhibition of STAT3 abolishes the protective activity of catalase, suggesting that catalase may protect HSPCs against IR-induced toxicity via promoting STAT3 activation. Collectively, these results demonstrate a previously unrecognized mechanism by which catalase inhibits IR-induced DNA damage and apoptosis in HSPCs. PMID:25603016

  15. Over-Expression of Catalase in Myeloid Cells Confers Acute Protection Following Myocardial Infarction

    PubMed Central

    Cabigas, E. Bernadette; Somasuntharam, Inthirai; Brown, Milton E.; Che, Pao Lin; Pendergrass, Karl D.; Chiang, Bryce; Taylor, W. Robert; Davis, Michael E.

    2014-01-01

    Cardiovascular disease is the leading cause of death in the United States and new treatment options are greatly needed. Oxidative stress is increased following myocardial infarction and levels of antioxidants decrease, causing imbalance that leads to dysfunction. Therapy involving catalase, the endogenous scavenger of hydrogen peroxide (H2O2), has been met with mixed results. When over-expressed in cardiomyocytes from birth, catalase improves function following injury. When expressed in the same cells in an inducible manner, catalase showed a time-dependent response with no acute benefit, but a chronic benefit due to altered remodeling. In myeloid cells, catalase over-expression reduced angiogenesis during hindlimb ischemia and prevented monocyte migration. In the present study, due to the large inflammatory response following infarction, we examined myeloid-specific catalase over-expression on post-infarct healing. We found a significant increase in catalase levels following infarction that led to a decrease in H2O2 levels, leading to improved acute function. This increase in function could be attributed to reduced infarct size and improved angiogenesis. Despite these initial improvements, there was no improvement in chronic function, likely due to increased fibrosis. These data combined with what has been previously shown underscore the need for temporal, cell-specific catalase delivery as a potential therapeutic option. PMID:24853285

  16. GM1 ganglioside induces vasodilation and increases catalase content in the brain.

    PubMed

    Furian, Ana Flvia; Oliveira, Mauro Schneider; Royes, Luiz Fernando Freire; Fiorenza, Natlia Gindri; Fighera, Michele Rechia; Myskiw, Jociane Carvalho; Weiblen, Rudi; Rubin, Maribel Antonello; Frussa-Filho, Roberto; Mello, Carlos Fernando

    2007-09-15

    Monosialoganglioside (GM1) is a glycosphingolipid present in most cell membranes that displays antioxidant and neuroprotective properties. GM1 increases catalase activity in cerebral cortices in vivo, but the mechanisms underlying this effect of GM1 are not known. In the current study we investigated the effect of GM1 (50 mg/kg, ip) on the content of hemoglobin and catalase activity of hippocampus, cortex, and striatum of rats. GM1 administration increased catalase activity and hemoglobin content in brain samples after 30 min, but had no effect on blood catalase activity. GM1-induced increase in catalase activity was abolished by brain perfusion with heparinized saline. Brain catalase activity in the absence of blood, estimated by regression analysis of data from perfused and nonperfused animals, was not altered by the systemic injection of GM1. Moreover, the addition of GM1 (30 or 100 microM) did not increase catalase activity in slices of cerebral cortex in situ, further suggesting that blood circulation is required for this effect. The GM1-induced vasodilation was confirmed in vivo, because the systemic injection of GM1 (50 mg/kg, ip) increased (1.2-1.6 times) the width of pial vessels. PMID:17697937

  17. Catalase is a key enzyme in seed recovery from ageing during priming.

    PubMed

    Kibinza, Serge; Bazin, Jrmie; Bailly, Christophe; Farrant, Jill M; Corbineau, Franoise; El-Maarouf-Bouteau, Hayat

    2011-09-01

    Ageing induces seed deterioration expressed as the loss of seed vigour and/or viability. Priming treatment, which consists in soaking of seeds in a solution of low water potential, has been shown to reinvigorate aged seeds. We investigate the importance of catalase in oxidation protection during accelerated ageing and repair during subsequent priming treatment of sunflower (Helianthus annuus L.) seeds. Seeds equilibrated to 0.29g H2Og(-1) dry matter (DM) were aged at 35C for different durations and then primed by incubation for 7 days at 15C in a solution of polyethylene glycol 8000 at -2MPa. Accelerated ageing affected seed germination and priming treatment reversed partially the ageing effect. The inhibition of catalase by the addition of aminotriazol during priming treatment reduced seed repair indicating that catalase plays a key role in protection and repair systems during ageing. Ageing was associated with H2O2 accumulation as showed by biochemical quantification and CeCl3 staining. Catalase was reduced at the level of gene expression, protein content and affinity. Interestingly, priming induced catalase synthesis by activating expression and translation of the enzyme. Immunocytolocalization of catalase showed that the enzyme co-localized with H2O2 in the cytosol. These results clearly indicate that priming induce the synthesis of catalase which is involved in seed recovery during priming. PMID:21763542

  18. Catalase characterization and implication in bleaching of a symbiotic sea anemone.

    PubMed

    Merle, Pierre-Laurent; Sabourault, Cécile; Richier, Sophie; Allemand, Denis; Furla, Paola

    2007-01-15

    Symbiotic cnidarians are marine invertebrates harboring photosynthesizing microalgae (named zooxanthellae), which produce great amounts of oxygen and free radicals upon illumination. Studying antioxidative balance is then crucial to understanding how symbiotic cnidarians cope with ROS production. In particular, it is suspected that oxidative stress triggers cnidarian bleaching, i.e., the expulsion of zooxanthellae from the animal host, responsible for symbiotic cnidarian mass mortality worldwide. This study therefore investigates catalase antioxidant enzymes and their role in bleaching of the temperate symbiotic sea anemone Anemonia viridis. Using specific separation of animal tissues (ectoderm and endoderm) from the symbionts (zooxanthellae), spectrophotometric assays and native PAGE revealed both tissue-specific and activity pattern distribution of two catalase electrophoretypes, E1 and E2. E1, expressed in all three tissues, presents high sensitivity to the catalase inhibitor aminotriazole (ATZ) and elevated temperatures. The ectodermal E1 form is responsible for 67% of total catalase activity. The E2 form, expressed only within zooxanthellae and their host endodermal cells, displays low sensitivity to ATZ and relative thermostability. We further cloned an ectodermal catalase, which shares 68% identity with mammalian monofunctional catalases. Last, 6 days of exposure of whole sea anemones to ATZ (0.5 mM) led to effective catalase inhibition and initiated symbiont expulsion. This demonstrates the crucial role of this enzyme in cnidarian bleaching, a phenomenon responsible for worldwide climate-change-induced mass mortalities, with catastrophic consequences for marine biodiversity. PMID:17189829

  19. Differential expression of catalases in Vibrio parahaemolyticus under various stress conditions.

    PubMed

    Lin, Ling-Chun; Lin, Guang-Huey; Wang, Zi-Li; Tseng, Yi-Hsiung; Yu, Mei-Shiuan

    2015-10-01

    Among antioxidant enzymes, catalases protect microorganisms by degrading hydrogen peroxide under oxidative stress. In this study, the activities of at least four Vibrio parahaemolyticus catalases (Kat1 to Kat4) were differentially detected during different growth stages and under various stress conditions using zymographic analysis. Our results showed that only Kat2 is stable at 55C. Kat1 and Kat2 respond to hydrogen peroxide during the early stationary and exponential growth phases, respectively and the response decreases upon entering the stationary phase. Kat3 and Kat4 are bifunctional, exhibiting both catalase and peroxidase activities and are only expressed during the stationary phase, under starvation or under stress at pH 5.5. Our study also shows that expression of Kat3 and Kat4 depends on RpoS. We confirm that both monofunctional and bifunctional catalases are expressed and function differentially under various stresses to contribute total catalase activities for the survival of V. parahaemolyticus. A comparative genomic study among Vibrio species revealed that only V. parahaemolyticus contains two copies of genes that encode monofunctional and bifunctional catalases. We propose that both types of catalases, whether evolved or acquired horizontally through long-term evolution, may play crucial protective roles in V. parahaemolyticus in response to environmental fluctuations. PMID:26192211

  20. Do pH and flavonoids influence hypochlorous acid-induced catalase inhibition and heme modification?

    PubMed

    Krych-Madej, Justyna; Gebicka, Lidia

    2015-09-01

    Hypochlorous acid (HOCl), highly reactive oxidizing and chlorinating species, is formed in the immune response to invading pathogens by the reaction of hydrogen peroxide with chloride catalyzed by the enzyme myeloperoxidase. Catalase, an important antioxidant enzyme, catalyzing decomposition of hydrogen peroxide to water and molecular oxygen, hampers in vitro HOCl formation, but is also one of the main targets for HOCl. In this work we have investigated HOCl-induced catalase inhibition at different pH, and the influence of flavonoids (catechin, epigallocatechin gallate and quercetin) on this process. It has been shown that HOCl-induced catalase inhibition is independent on pH in the range 6.0-7.4. Preincubation of catalase with epigallocatechin gallate and quercetin before HOCl treatment enhances the degree of catalase inhibition, whereas catechin does not affect this process. Our rapid kinetic measurements of absorption changes around the heme group have revealed that heme modification by HOCl is mainly due to secondary, intramolecular processes. The presence of flavonoids, which reduce active catalase intermediate, Compound I to inactive Compound II have not influenced the kinetics of HOCl-induced heme modification. Possible mechanisms of the reaction of hypochlorous acid with catalase are proposed and the biological consequences are discussed. PMID:26116387

  1. The regulation of catalase activity by PPAR ? is affected by ?-synuclein

    PubMed Central

    Yakunin, Eugenia; Kisos, Haya; Kulik, Willem; Grigoletto, Jessica; Wanders, Ronald J A; Sharon, Ronit

    2014-01-01

    Objective While evidence for oxidative injury is frequently detected in brains of humans affected by Parkinson's disease (PD) and in relevant animal models, there is uncertainty regarding its cause. We tested the potential role of catalase in the oxidative injury that characterizes PD. Methods Utilizing brains of A53T ?-Syn and ntg mice, and cultured cells, we analyzed catalase activity and expression, and performed biochemical analyses of peroxisomal metabolites. Results Lower catalase expression and lower activity levels were detected in A53T ?-Syn brains and ?-Syn-expressing cells. The effect on catalase activity was independent of disease progression, represented by mouse age and ?-Syn mutation, suggesting a potential physiological function for ?-Syn. Notably, catalase activity and expression were unaffected in brains of mice modeling Alzheimer's disease. Moreover, we found that ?-Syn expression downregulate the peroxisome proliferator-activated receptor (PPAR)?, which controls catalase transcription. Importantly, activation of either PPAR?2, PPAR? or retinoic X receptor eliminated the inhibiting effect of ?-Syn on catalase activity. In addition, activation of these nuclear receptors enhanced the accumulation of soluble ?-Syn oligomers, resulting in a positive association between the degree of soluble ?-Syn oligomers and catalase activity. Of note, a comprehensive biochemical analysis of specific peroxisomal metabolites indicated no signs of dysfunction in specific peroxisomal activities in brains of A53T ?-Syn mice. Interpretation Our results suggest that ?-Syn expression may interfere with the complex and overlapping network of nuclear receptors transcription activation. In result, catalase activity is affected through mechanisms involved in the regulation of soluble ?-Syn oligomers. PMID:25356396

  2. Biochemical and Developmental Characterization of Multiple Forms of Catalase in Tobacco Leaves

    PubMed Central

    Havir, Evelyn A.; McHale, Neil A.

    1987-01-01

    Leaf extracts of both Nicotiana tabacum and Nicotiana sylvestris contain multiple forms of catalase (H2O2:H2O2 oxidoreductase, EC 1.11.1.6) which are separable at different pH values by chromatofocusing columns. Marked changes in distribution of these catalases occur during seedling development and leaf maturation. The form of catalase eluting first (peak 1) was predominant during early seedling growth and present at all stages of development. Two more acidic forms (peaks 2 and 3) appeared later and comprised 29% of the total activity by 11 days postgermination. Mature leaves of N. tabacum contained peak 1 catalase, but peaks 2 and 3 represented 62% of the total activity. No interconversion of peaks 1, 2, and 3 was detected. The three forms of catalase differed in thermal stability with peak 1 > peak 2 ≫ peak 3. For N. sylvestris, t½ at 55°C was 31.5 and 3.0 min for peaks 1 and 3, respectively, and for N. tabacum, t½ was 41.5 and 3.2 min, respectively. All forms of catalase in tobacco show peroxidatic (measured as ethanol to acetaldehyde conversion) as well as catalatic activities. However, for both Nicotiana species the ratio peroxidatic/catalatic activity is at least 30-fold higher in peak 3 than in peaks 1 and 2. Chromatofocusing of extracts from spinach leaves separated at least four peaks of catalase activity, one of which had a 10-fold higher ratio of peroxidatic/catalatic activity than the others. Short-term growth (5 days) of tobacco seedlings under atmospheric conditions suppressing photorespiration (1% CO2/21% O2) reduced total catalase activity and caused a decline in peak 1 catalase and a substantial increase in the activity of peaks 2 and 3 relative to air-grown seedlings at the same stage. PMID:16665461

  3. The Molecular Mechanism of the Catalase-like Activity in Horseradish Peroxidase.

    PubMed

    Campomanes, Pablo; Rothlisberger, Ursula; Alfonso-Prieto, Mercedes; Rovira, Carme

    2015-09-01

    Horseradish peroxidase (HRP) is one of the most relevant peroxidase enzymes, used extensively in immunochemistry and biocatalysis applications. Unlike the closely related catalase enzymes, it exhibits a low activity to disproportionate hydrogen peroxide (H2O2). The origin of this disparity remains unknown due to the lack of atomistic information on the catalase-like reaction in HRP. Using QM(DFT)/MM metadynamics simulations, we uncover the mechanism for reduction of the HRP Compound I intermediate by H2O2 at atomic detail. The reaction begins with a hydrogen atom transfer, forming a peroxyl radical and a Compound II-like species. Reorientation of the peroxyl radical in the active site, concomitant with the transfer of the second hydrogen atom, is the rate-limiting step, with a computed free energy barrier (18.7 kcal/mol, ? 6 kcal/mol higher than the one obtained for catalase) in good agreement with experiments. Our simulations reveal the crucial role played by the distal pocket residues in accommodating H2O2, enabling formation of a Compound II-like intermediate, similar to catalases. However, out of the two pathways for Compound II reduction found in catalases, only one is operative in HRP. Moreover, the hydrogen bond network in the distal side of HRP compensates less efficiently than in catalases for the energetic cost required to reorient the peroxyl radical at the rate-determining step. The distal Arg and a water molecule in the "wet" active site of HRP have a substantial impact on the reaction barrier, compared to the "dry" active site in catalase. Therefore, the lower catalase-like efficiency of heme peroxidases compared to catalases can be directly attributed to the different distal pocket architecture, providing hints to engineer peroxidases with a higher rate of H2O2 disproportionation. PMID:26274391

  4. Effects of pergolide mesylate on transduction efficiency of PEP-1-catalase protein

    SciTech Connect

    Sohn, Eun Jeong; Kim, Dae Won; Kim, Young Nam; Kim, So Mi; Lim, Soon Sung; Kang, Tae-Cheon; Kwon, Hyeok Yil; Kim, Duk-Soo; Cho, Sung-Woo; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Hwang, Hyun Sook; Choi, Soo Young

    2011-03-18

    Research highlights: {yields} We studied effects of pergolide mesylate (PM) on in vitro and in vivo transduction of PEP-1-catalase. {yields} PEP-1-catatase inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation. {yields} PM enhanced the transduction of PEP-1-catalase into HaCaT cells and skin tissue. {yields} PM increased anti-inflammatory activity of PEP-1-catalase. {yields} PM stimulated therapeutic action of anti-oxidant enzyme catalase in oxidative-related diseases. -- Abstract: The low transduction efficiency of various proteins is an obstacle to their therapeutic application. However, protein transduction domains (PTDs) are well-known for a highly effective tool for exogenous protein delivery to cells. We examined the effects of pergolide mesylate (PM) on the transduction of PEP-1-catalase into HaCaT human keratinocytes and mice skin and on the anti-inflammatory activity of PEP-1-catatase against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation using Western blot and histological analysis. PM enhanced the time- and dose-dependent transduction of PEP-1-catalase into HaCaT cells without affecting the cellular toxicity. In a mouse edema model, PEP-1-catalase inhibited the increased expressions of inflammatory mediators and cytokines such as cyclooxygenase-2, inducible nitric oxide synthase, interleukin-6 and -1{beta}, and tumor necrosis factor-{alpha} induced by TPA. On the other hand, PM alone failed to exert any significant anti-inflammatory effects. However, the anti-inflammatory effect of co-treatment with PEP-1-catalase and PM was more potent than that of PEP-1-catalase alone. Our results indicate that PM may enhance the delivery of PTDs fusion therapeutic proteins to target cells and tissues and has potential to increase their therapeutic effects of such drugs against various diseases.

  5. Physicochemical peculiarities of iron porphyrin-containing electrodes in catalase- and peroxidase-type biomimetic sensors

    NASA Astrophysics Data System (ADS)

    Sardarly, N. A.; Nagiev, T. M.

    2009-08-01

    New catalase- and peroxidase-type iron porphyrin biomimetic electrodes have been developed for determining ultralow concentrations of H2O2 and C2H5OH in aqueous solutions. Their physicochemical features have been studied. A mechanism of catalase and peroxidase reactions was suggested. Biomimetic electrodes did not lose their activity for a long time under the action of the oxidant, intermediates, and the final products of the decomposition of H2O2. Potentiometric biomimetic sensors of catalase and peroxidase types have been designed and studied.

  6. An Oxyferrous Heme/Protein-based Radical Intermediate Is Catalytically Competent in the Catalase Reaction of Mycobacterium tuberculosis Catalase-Peroxidase (KatG)*S?

    PubMed Central

    Suarez, Javier; Ranguelova, Kalina; Jarzecki, Andrzej A.; Manzerova, Julia; Krymov, Vladimir; Zhao, Xiangbo; Yu, Shengwei; Metlitsky, Leonid; Gerfen, Gary J.; Magliozzo, Richard S.

    2009-01-01

    A mechanism accounting for the robust catalase activity in catalase-peroxidases (KatG) presents a new challenge in heme protein enzymology. In Mycobacterium tuberculosis, KatG is the sole catalase and is also responsible for peroxidative activation of isoniazid, an anti-tuberculosis pro-drug. Here, optical stopped-flow spectrophotometry, rapid freeze-quench EPR spectroscopy both at the X-band and at the D-band, and mutagenesis are used to identify catalase reaction intermediates in M. tuberculosis KatG. In the presence of millimolar H2O2 at neutral pH, oxyferrous heme is formed within milliseconds from ferric (resting) KatG, whereas at pH 8.5, low spin ferric heme is formed. Using rapid freeze-quench EPR at X-band under both of these conditions, a narrow doublet radical signal with an 11 G principal hyperfine splitting was detected within the first milliseconds of turnover. The radical and the unique heme intermediates persist in wild-type KatG only during the time course of turnover of excess H2O2 (1000-fold or more). Mutation of Met255, Tyr229, or Trp107, which have covalently linked side chains in a unique distal side adduct (MYW) in wild-type KatG, abolishes this radical and the catalase activity. The D-band EPR spectrum of the radical exhibits a rhombic g tensor with dual gx values (2.00550 and 2.00606) and unique gy (2.00344) and gz values (2.00186) similar to but not typical of native tyrosyl radicals. Density functional theory calculations based on a model of an MYW adduct radical built from x-ray coordinates predict experimentally observed hyperfine interactions and a shift in g values away from the native tyrosyl radical. A catalytic role for an MYW adduct radical in the catalase mechanism of KatG is proposed. PMID:19139099

  7. Mitochondrial catalase suppresses naturally occurring lung cancer in old mice

    PubMed Central

    Ge, Xuang; Pettan-Brewer, Christina; Morton, John; Carter, Katrina; Fatemi, Sy; Rabinovitch, Peter; Ladiges, Warren C.

    2015-01-01

    Lung cancer is generally difficult to detect until the late stages of disease, when it is much more difficult to treat because of the more aggressive and invasive behavior. Advanced lung cancer is much more common in older adults making it even more challenging to treat. Adenocarcinoma belongs to a category of non-small cell lung cancers, which comprise up to 40% of all lung cancers, and about half of these have an activating K-ras mutation. Because treatment relapses are common, more effective unconventional treatment and prevention methods are needed. In this regard, the antioxidant enzyme catalase targeted to mitochondria (mCAT) has been shown to delay aging and cancer in mice, and the progression of transgenic oncogene and syngeneic tumors was suppressed, helping support the notion that attenuation of mitochondria-generated hydrogen peroxide signaling is associated with an antitumor effect. In order to determine if mCAT has any effect on naturally occurring lung cancer of the adenocarcinoma type in old mice, the tumor incidence and progression were examined in the lungs of old mCAT transgenic and wild-type (WT) mice with a CB6F1 (Balb/c X C57BL/6) background. CB6F1 mice with a WT genotype were found to have a high incidence of adenomas at 24 months of age, which progressed to adenocarcinomas at 32 months of age. CB6F1 mice with the mCAT genotype had significantly reduced incidence and severity of lung tumors at both ages. Fibroblasts isolated from the lungs of old mCAT mice, but not WT mice, were shown to secrete soluble factors that inhibited lung tumor cell growth suggesting that stromal fibroblasts play a role in mediating the antitumor effects of mCAT. The aged CB6F1 mouse, with its high incidence of K-ras mutant lung cancer, is an excellent model to further study the anticancer potential of mitochondria-targeted therapy. PMID:26400209

  8. Immobilization of catalase on chitosan and amino acid- modified chitosan beads.

    PubMed

    Ba?ak, Esra; Aydemir, Tlin

    2013-08-01

    Bovine liver catalase was covalently immobilized onto amino acid-modified chitosan beads. The beads were characterized with SEM, FTIR, TGA and the effects of immobilization on optimum pH and temperature, thermostability, reusability were evaluated. Immobilized catalase showed the maximal enzyme activity at pH 7.0 at 30C. The kinetic parameters, Km and Vmax, for immobilized catalase on alanine-chitosan beads and lysine-chitosan beads were estimated to be 25.67 mM, 27 mM and 201.39 ?mol H2O2/min, 197.50 ?mol H2O2/min, respectively. The activity of the immobilized catalase on Ala-CB and Lys-CB retained 40% of its high initial activity after 100 times of reuse. PMID:23316810

  9. Spectroscopic study on the interaction of catalase with bifendate and analogs

    NASA Astrophysics Data System (ADS)

    Wang, Ruiqiang; Zhang, Lu; Wang, Rui; Dou, Huanjing; Li, Hua; Wang, Yi; Pu, Juanjuan; Wang, Ruiyong

    2013-02-01

    The interactions of bifendate (DDB) or analogs (Bicyclol, I, II and III) with catalase are analyzed by spectrophotometric methods. The fluorescence spectra results show the intrinsic fluorescence of catalase is strongly quenched by DDB or analogs with a static quenching procedure. The binding constants are obtained at three temperatures. The thermodynamics parameters (?H, ?S, ?G) indicate the hydrophobic and electrostatic interactions play a major role in the interaction. The results of synchronous fluorescence, UV-vis absorption and three-dimensional fluorescence spectra demonstrate that the microenvironments of Trp residue of catalase are disturbed by the analogs. Thermodynamic results showed that DDB is the strongest quencher and bind to catalase with the highest affinity among five compounds.

  10. A Simple Method for Demonstrating Enzyme Kinetics Using Catalase from Beef Liver Extract

    NASA Astrophysics Data System (ADS)

    Johnson, Kristin A.

    2000-11-01

    This paper describes a simple visual method of demonstrating enzyme kinetics using beef liver catalase. A catalase solution is obtained by homogenizing beef liver in a phosphate buffer. In the demonstration, filter paper is saturated with beef liver extract and placed into a solution of hydrogen peroxide. The catalase in the extract decomposes the hydrogen peroxide to water and oxygen. Oxygen forms on the filter paper, and the filter paper rises to the top of the beaker. Catalase activity is measured by timing the rise of the enzyme-soaked filter paper to the top of beakers containing different concentrations of hydrogen peroxide. The data are plotted as a Lineweaver-Burk double-reciprocal plot, and the Km and Vmax for the reaction are calculated.

  11. Purification, crystallization and phase determination of the DR1998 haem b catalase from Deinococcus radiodurans.

    PubMed

    Borges, Patrcia T; Miranda, Ceclia S; Santos, Sandra P; Carita, Joo N; Frazo, Carlos; Romo, Clia V

    2014-05-01

    The protective mechanisms of Deinococcus radiodurans against primary reactive oxygen species involve nonenzymatic scavengers and a powerful enzymatic antioxidant system including catalases, peroxidases and superoxide dismutases that prevents oxidative damage. Catalase is an enzyme that is responsible for the conversion of H2O2 to O2 and H2O, protecting the organism from the oxidative effect of H2O2. This study reports the purification and crystallization of the DR1998 catalase from D. radiodurans. The crystals diffracted to 2.6 resolution and belonged to space group C2221, with unit-cell parameters a = 97.33, b = 311.88, c = 145.63 , suggesting that they contain four molecules per asymmetric unit. The initial phases were determined by molecular replacement and the obtained solution shows the typical catalase quaternary structure. A preliminary model of the protein structure has been built and refinement is currently in progress. PMID:24817732

  12. Stability of catalase and its potential role in lipid oxidation in meat.

    PubMed

    Pradhan, A A; Rhee, K S; Hernndez, P

    2000-04-01

    The activity of catalase in microbial growth-controlled and uncontrolled ground beef muscle (semimembranosus, SM) did not change (P>0.05) during 6-day storage at 4C. Likewise, catalase activity in ground, beef SM and longissimus dorsi (LD), pork LD, and chicken breast (B) and thigh (T) muscles was not affected (P>0.05) by 2-month storage at -20C, with or without mid-month thawing/refreezing. When sodium azide (a catalase inhibitor) was added to ground beef SM, lipid oxidation (as measured by peroxide values) during 4-day refrigeration was higher (P<0.05) in treated samples - 43 and 55% higher at day 2 and day 4, respectively- than in the controls. It was concluded that catalase would be stable during meat storage/distribution and contribute significantly to the antioxidative process in raw meat products. PMID:22060796

  13. Protection against oxygen toxicity by intravenous injection of liposome-entrapped catalase and superoxide dismutase.

    PubMed Central

    Turrens, J F; Crapo, J D; Freeman, B A

    1984-01-01

    Survival of rats exposed to 100% oxygen was increased from 69.5 +/- 1.5 to 118.1 +/- 9.9 h (mean +/- SEM, P less than 0.05) when liposomes containing catalase and superoxide dismutase were injected intravenously before and during exposure. The increased survival time in 100% oxygen was also associated with significantly less fluid in the pleural cavity. Rats injected with catalase- and superoxide dismutase-containing liposomes, which had increased survival in 100% oxygen, had increased lung wet weight upon autopsy compared with saline-injected controls (2.9 +/- 0.2 g/lung vs. 4.8 +/- 0.4 g/lung, mean +/- SE, P less than 0.05). Intravenous injection of control liposomes along with catalase and superoxide dismutase in the suspending buffer decreased the mean pleural effusion volume 89% and had no significant effect on survival time. Lung catalase and superoxide dismutase activities were increased 3.1- and 1.7-fold, respectively, 2 h after a single intravenous injection of liposomes containing catalase or superoxide dismutase. Superoxide dismutase activity was also significantly greater than controls in both air- and 100% oxygen-exposed rat lungs, when enzyme activity was assayed 24 h after cessation of injection of control and oxygen-exposed rats with enzyme-containing liposomes every 12 h for 36 h. Free superoxide dismutase and catalase injected intravenously in the absence of liposomes did not increase corresponding lung enzyme activities, affect pleural effusion volume, lung wet weight, or extend the mean survival time of rats exposed to 100% oxygen. The clearance of liposome-augmented 125I-labeled catalase from lung and plasma obeyed first order kinetics according to a one-compartment model. When clearance of liposome-augmented catalase activity or radioactivity were the parameters used for pharmacokinetic studies, the half-life of augmented lung catalase was 1.9 and 2.6 h, respectively. The half-life of liposome-entrapped catalase and superoxide dismutase activity in the circulation was 2.5 and 4 h, respectively, while intravenously injected catalase and superoxide dismutase had a circulation half-life of 23 and 6 min, respectively. PMID:6690485

  14. Effects of autogamy in Paramecium tetraurelia on catalase activity and on radiosensitivity to natural ionizing radiations

    SciTech Connect

    Croute, F.; Dupouy, D.; Charley, J.P.; Soleilhavoup, J.P.; Planel, H.

    1980-02-01

    Catalase activity of Paramecium tetraurelia decreased during autogamy and recovered to normal 5 days later. Autogamy also caused changes in the ciliate's sensitivity sensitivity to natural ionizing radiations - the decrease in cell growth rate previously described in shielded cultures did not occur when autogamous cells were used. Maximum effect of shielding was observed in 11-day-old postautogamous cells. The role of the catalase in the mechanism of natural irradiation effect is discussed.

  15. Human catalase is imported and assembled in peroxisomes of Saccharomyces cerevisiae.

    PubMed

    de Hoop, M J; Holtman, W L; Ab, G

    1993-01-01

    To study the conservation of peroxisomal targeting signals, we have determined the intracellular localization of human peroxisomal catalase when expressed in yeast. Using immunofluorescence, differential centrifugation and immunoelectron microscopy, we show that the protein is targeted to the peroxisomes of the heterologous cell and assembled in its active tetrameric form. These data show the conservation of the catalase targeting signal and import specificity between human and yeast peroxisomes. PMID:8442388

  16. Purification, characterization, and identification of a novel bifunctional catalase-phenol oxidase from Scytalidium thermophilum.

    PubMed

    Sutay Kocabas, Didem; Bakir, Ufuk; Phillips, Simon E V; McPherson, Michael J; Ogel, Zumrut B

    2008-06-01

    A novel bifunctional catalase with an additional phenol oxidase activity was isolated from a thermophilic fungus, Scytalidium thermophilum. This extracellular enzyme was purified ca. 10-fold with 46% yield and was biochemically characterized. The enzyme contains heme and has a molecular weight of 320 kDa with four 80 kDa subunits and an isoelectric point of 5.0. Catalase and phenol oxidase activities were most stable at pH 7.0. The activation energies of catalase and phenol oxidase activities of the enzyme were found to be 2.7 +/- 0.2 and 10.1 +/- 0.4 kcal/mol, respectively. The pure enzyme can oxidize o-diphenols such as catechol, caffeic acid, and L-DOPA in the absence of hydrogen peroxide and the highest oxidase activity is observed against catechol. No activity is detected against tyrosine and common laccase substrates such as ABTS and syringaldazine with the exception of weak activity with p-hydroquinone. Common catechol oxidase inhibitors, salicylhydroxamic acid and p-coumaric acid, inhibit the oxidase activity. Catechol oxidation activity was also detected in three other catalases tested, from Aspergillus niger, human erythrocyte, and bovine liver, suggesting that this dual catalase-phenol oxidase activity may be a common feature of catalases. PMID:18369615

  17. [Kinetic properties of catalase and its conjugates with strophanthin K in ethanol oxidation by cumyl hydroperoxide].

    PubMed

    Pliugacheva, E I; Metelitsa, D I

    1986-08-01

    The gluconic fragment of strophantin K oxidation by sodium metaperiodate yields a dialdehyde derivate conjugated with catalase. The conjugate obtained contains 11 molecules of cardiac glucoside. Adsorption and circular dichroism spectra of the native enzyme and its conjugate were compared and structural differences between both samples were revealed. The kinetics of ethanol oxidation into acetaldehyde by cumene hydroperoxide was studied at 30 degrees C in the phosphate buffer pH 6.6; this reaction was shown to proceed with the participation of catalase and its cat-str conjugate. The catalytic constants for catalase are 1.2-1.5 times as high as those for cat-str, whereas the Km values for both substrates for the conjugate as 1.5-2 times as high as those for catalase. Catalase modification by strophantin K increases the enzyme thermostability up to the isokinetic point of 40 degrees C; above this threshold the cat-str thermostability decreases as compared with the native enzyme. The thermodynamical activation parameters for catalase and cat-str inactivation were determined. PMID:3768432

  18. Protecting Peroxidase Activity of Multilayer Enzyme-Polyion Films Using Outer Catalase Layers

    PubMed Central

    Lu, Haiyun; Rusling, James F.; Hu, Naifei

    2008-01-01

    Films constructed layer-by-layer on electrodes with architecture {protein/hyaluronic acid (HA)}n containing myoglobin (Mb) or horseradish peroxidase (HRP) were protected against protein damage by H2O2 by using outer catalase layers. Peroxidase activity for substrate oxidation requires activation by H2O2, but {protein/HA}n films without outer catalase layers are damaged slowly and irreversibly by H2O2. The rate and extent of damage were decreased dramatically by adding outer catalase layers to decompose H2O2. Comparative studies suggest that protection results from catalase decomposing a fraction of the H2O2 as it enters the film, rather than by an in-film diffusion barrier. The outer catalase layers controlled the rate of H2O2 entry into inner regions of the film, and biased the system to favor electrocatalytic peroxide reduction over enzyme damage. Catalase-protected {protein/HA}n films had an increased linear concentration range for H2O2 detection. This approach offers an effective way to protect biosensors from damage by H2O2. PMID:18052272

  19. CATALASE ACTIVITY OF TWO STREPTOCOCCUS FAECALIS STRAINS AND ITS ENHANCEMENT BY AEROBIOSIS AND ADDED CATIONS.

    PubMed

    JONES, D; DEIBEL, R H; NIVEN, C F

    1964-09-01

    Jones, Dorothy (American Meat Institute Foundation, Chicago, Ill.), R. H. Deibel, and C. F. Niven, Jr. Catalase activity of two Streptococcus faecalis strains and its enhancement by aerobiosis and added cations. J. Bacteriol. 88:602-610. 1964.-The nature of catalase activity noted in two unusual Streptococcus faecalis strains was determined. Enzyme activity was lost slowly when cultures were maintained by daily transfer in test tubes of broth media. Loss of activity could be prevented by aerobic culture. Supplementation of the growth medium with ferric, manganese, and zinc ions, as well as aerobiosis, enhanced catalase activity. However, addition of these cations to cell suspensions or to cell-free extracts did not increase catalase activity. Although oxygen was observed to be one of the reaction end products, the catalase activity was not inhibited by cyanide or azide, and the iron-porphyrin coenzyme of classical catalase was not detected. The enzyme was purified 185-fold by precipitation with ammonium sulfate, followed by chromotography on a diethylaminoethyl cellulose column. PMID:14208495

  20. Not so monofunctional--a case of thermostable Thermobifida fusca catalase with peroxidase activity.

    PubMed

    Lon?ar, Nikola; Fraaije, Marco W

    2015-03-01

    Thermobifida fusca is a mesothermophilic organism known for its ability to degrade plant biomass and other organics, and it was demonstrated that it represents a rich resource of genes encoding for potent enzymes for biocatalysis. The thermostable catalase from T. fusca has been cloned and overexpressed in Escherichia coli with a yield of 400mg/L. Heat treatment of disrupted cells at 60C for 1h resulted in enzyme preparation of high purity; hence, no chromatography steps are needed for large-scale production. Except for catalyzing the dismutation of hydrogen peroxide, TfuCat was also found to catalyze oxidations of phenolic compounds. The catalase activity was comparable to other described catalases while peroxidase activity was quite remarkable with a k obs of nearly 1000s(-1) for catechol. Site directed mutagenesis was used to alter the ratio of peroxidase/catalase activity. Resistance to inhibition by classic catalase inhibitors and an apparent melting temperature of 74C classifies this enzyme as a robust biocatalyst. As such, it could compete with other commercially available catalases while the relatively high peroxidase activity also offers new biocatalytic possibilities. PMID:25227535

  1. Reversible adsorption of catalase onto Fe(3+) chelated poly(AAm-GMA)-IDA cryogels.

    PubMed

    Aktaş Uygun, Deniz; Uygun, Murat; Akgöl, Sinan; Denizli, Adil

    2015-05-01

    In this presented study, poly(acrylamide-glycidyl methacrylate) [poly(AAm-GMA)] cryogels were synthesized by cryopolymerization technique at sub-zero temperature. Prepared cryogels were then functionalized with iminodiacetic acid (IDA) and chelated with Fe(3+) ions in order produce the metal chelate affinity matrix. Synthesized cryogels were characterized with FTIR, ESEM and EDX analysis, and it was found that the cryogel had sponge like structure with interconnected pores and their pore diameter was about 200 μm. Fe(3+) chelated poly(AAm-GMA)-IDA cryogels were used for the adsorption of catalase and optimum adsorption conditions were determined by varying the medium pH, initial catalase concentration, temperature and ionic strength. Maximum catalase adsorption onto Fe(3+) chelated poly(AAm-GMA)-IDA cryogel was found to be 12.99 mg/g cryogel at 25 °C, by using pH 5.0 acetate buffer. Adsorbed catalase was removed from the cryogel by using 1.0M of NaCl solution and desorption yield was found to be 96%. Additionally, reusability profile of the Fe(3+) chelated poly(AAm-GMA)-IDA cryogel was also investigated and it was found that, adsorption capacity of the cryogels didn't decrease significantly at the end of the 40 reuses. Catalase activity studies were also tested and it was demonstrated that desorbed catalase retained 70% of its initial activity. PMID:25746283

  2. The water effect on the kinetic of the bovine liver catalase.

    PubMed

    Seixas, Flavio Augusto Vicente; da Silva, Milene Ribeiro; Murakami, Mario Tyago; Tosqui, Priscilla; Colombo, Marcio Francisco

    2011-09-01

    Catalase is an enzyme that occurs in almost all aerobic organisms. Its main metabolic function is to prevent oxidative damage to tissues induced by hydrogen peroxide which is a strong oxidizing agent. Catalase is very effective in performing this task, since it has the highest turnover rate among all the enzymes. The properties of catalase have been investigated extensively for many years; however, the role of the solvent molecules in the catalytic reaction of this enzyme has not yet been investigated. Therefore, the objective of this work was to investigate the contribution of the solvent molecules on the catalytic reaction of bovine liver catalase with its substrate H2O2 by the osmotic stress method. As a probe for protein structural changes in solution, the differential number of water molecules released during the transition from free to bound form of the enzyme was measured. These assays were correlated with protein structural data provided by the SAXS technique and crystallographic structures of free and CN(-) bonded enzymes. The results showed that the difference in surface accessible area of the crystal structures does not reflect the variation that is observed in solution. Moreover, catalase is not influenced by the solvent during the catalytic reaction, which represents a lower energy barrier to be crossed in the overall energetics of the reaction, a fact that contributes to the high turnover rate of catalase. PMID:21529340

  3. Determination of catalase activity using chromogenic probe involving iso-nicotinicacidhydrazide and pyrocatechol.

    PubMed

    Shivakumar, Anantharaman; Nagaraja, Padmarajaiah; Chamaraja, Nelligere Arkeshwaraiah; Krishna, Honnur; Avinash, Krishnegowda

    2011-10-10

    A biocatalatic pathway involving chromogenic probe has been proposed for the determination of catalase activity by means of iso-nicotinicacidhydrazide (INH) and pyrocatechol (PC). The assay is based on the enzymatic consumption of hydrogen peroxide using INH-PC system. The response of the catalase activity was ascertained by the rate of the reaction involving 14.10mM H(2)O(2). On addition of H(2)O(2), INH-PC indicator system formed a chromogenic product with absorbance maxima at 490 nm. Hence the activity of catalase was directly measured by the chromogenic response in the formation of the coupled product. The catalase assay was elaborated by the kinetic response of the INH-PC system. The linearity of the catalase activity and H(2)O(2) was in the range 0.2-7.0 units and 1.76-7.0mM, respectively in 3 ml solution. The catalytic efficiency and catalytic power were calculated. The Michaelis-Menten constant of INH, PC and H(2)O(2) were found to be 0.344, 0.176 and 8.82 mM, respectively. The indicator reaction was applied in the determination of catalase activity in mycelia mats and culture media. PMID:21839122

  4. Inhibitory effects of a novel Val to Thr mutation on the distal heme of human catalase

    PubMed Central

    Mashhadi, Zahra; Boeglin, William E.; Brash, Alan R.

    2014-01-01

    True catalases efficiently breakdown hydrogen peroxide, whereas the catalase-related enzyme allene oxide synthase (cAOS) is completely unreactive and instead metabolizes a fatty acid hydroperoxide. In cAOS a Thr residue adjacent to the distal His restrains reaction with H2O2 (Tosha et al (2006) J. Biol. Chem. 281:12610; De Luna et al (2013) J. Phys. Chem. B 117: 14635) and its mutation to the consensus Val of true catalases permits the interaction. Here we investigated the effects of the reciprocal experiment in which the Val74 of human catalase is mutated to Thr, Ser, Met, Pro, or Ala. The Val74Thr substitution decreased catalatic activity by 3.5-fold and peroxidatic activity by 3-fold. Substitution with Ser had similar negative effects (5- and 3-fold decreases). Met decreased catalatic activity 2-fold and eliminated peroxidatic activity altogether, whereas the Val74Ala substitution was well tolerated. (The Val74Pro protein lacked heme). We conclude that the conserved Val74 of true catalases helps optimize catalysis. There are rare substitutions of Val74 with Ala, Met, or Pro, but not with Ser of Thr, possibly due their hydrogen bonding affecting the conformation of His75, the essential distal heme residue for activity in catalases. PMID:25086217

  5. A novel impedimetric nanobiosensor for low level determination of hydrogen peroxide based on biocatalysis of catalase.

    PubMed

    Shamsipur, Mojtaba; Asgari, Mehdi; Maragheh, Mohammad Ghannadi; Moosavi-Movahedi, Ali Akbar

    2012-02-01

    A robust and effective nanocomposite film-glassy carbon modified electrode based on multi-walled carbon nanotubes and a room temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate was prepared by a layer-by-layer self-assembly method. The fabricated modified electrode was used as a novel impedimetric catalase nanobiosensor for the determination of H(2)O(2). Direct electron transfer and electrocatalysis of catalase were fully investigated. The results suggested that catalase could be firmly adsorbed at the modified electrode. A pair of quasi-reversible redox peaks of catalase was observed in a 0.20 M degassed phosphate buffer solution of pH 7.0. The nanocomposite film showed a pronounced increase in direct electron transfer between catalase and the electrode. The immobilized catalase exhibited an excellent electrocatalytic activity towards the reduction of H(2)O(2). The electrochemical impedance spectroscopy measurements revealed that the charge transfer resistance decreases significantly after enzymatic reaction with hydrogen peroxide, so that the prepared modified electrode can be used for the detection of ultra traces of H(2)O(2) (5-1700 nM). PMID:21880554

  6. Inhibitory effects of a novel Val to Thr mutation on the distal heme of human catalase.

    PubMed

    Mashhadi, Zahra; Boeglin, William E; Brash, Alan R

    2014-11-01

    True catalases efficiently breakdown hydrogen peroxide, whereas the catalase-related enzyme allene oxide synthase (cAOS) is completely unreactive and instead metabolizes a fatty acid hydroperoxide. In cAOS a Thr residue adjacent to the distal His restrains reaction with H2O2 (Tosha et al. (2006) J. Biol. Chem. 281:12610; De Luna et al. (2013) J. Phys. Chem. B 117: 14635) and its mutation to the consensus Val of true catalases permits the interaction. Here we investigated the effects of the reciprocal experiment in which the Val74 of human catalase is mutated to Thr, Ser, Met, Pro, or Ala. The Val74Thr substitution decreased catalatic activity by 3.5-fold and peroxidatic activity by 3-fold. Substitution with Ser had similar negative effects (5- and 3-fold decreases). Met decreased catalatic activity 2-fold and eliminated peroxidatic activity altogether, whereas the Val74Ala substitution was well tolerated. (The Val74Pro protein lacked heme). We conclude that the conserved Val74 of true catalases helps optimize catalysis. There are rare substitutions of Val74 with Ala, Met, or Pro, but not with Ser of Thr, possibly due their hydrogen bonding affecting the conformation of His75, the essential distal heme residue for activity in catalases. PMID:25086217

  7. Fluorescence Spectrometry of the Interaction of Multi-Walled Carbon Nanotubes with Catalase

    NASA Astrophysics Data System (ADS)

    Fan, Y.; Li, Y.; Cai, H.; Li, J.; Miao, J.; Fu, D.; Yang, Q.

    2014-11-01

    The interaction of multi-walled carbon nanotubes (MWCNTs) with catalase is investigated using fluorescence and circular dichroism spectroscopic techniques. The results of the fluorescence experiments suggest that MWCNTs quench the intrinsic fluorescence of catalase via a static quenching mechanism. The circular dichroism spectral results reveal the unfolding of catalase with a significant decrease in the α-helix content in the presence of MWCNTs, which indicates that the conformation of catalase is changed in the binding process, thereby remarkably decreasing its activity. The binding constants and the number of binding sites of the MWCNT to the catalase are calculated at different temperatures. The thermodynamic parameters, such as the changes in free energy (ΔG), enthalpy (ΔH), and entropy (ΔS), are calculated using thermodynamic equations. The fact that all negative values of ΔG, ΔH, and ΔS are obtained suggests that the interaction of the MWCNTs with catalase is spontaneous, and that hydrogen bonding and van der Waals interactions play an important role in the binding process.

  8. Redundant Catalases Detoxify Phagocyte Reactive Oxygen and Facilitate Histoplasma capsulatum Pathogenesis

    PubMed Central

    Holbrook, Eric D.; Smolnycki, Katherine A.; Youseff, Brian H.

    2013-01-01

    Histoplasma capsulatum is a respiratory pathogen that infects phagocytic cells. The mechanisms allowing Histoplasma to overcome toxic reactive oxygen molecules produced by the innate immune system are an integral part of Histoplasma's ability to survive during infection. To probe the contribution of Histoplasma catalases in oxidative stress defense, we created and analyzed the virulence defects of mutants lacking CatB and CatP, which are responsible for extracellular and intracellular catalase activities, respectively. Both CatB and CatP protected Histoplasma from peroxide challenge in vitro and from antimicrobial reactive oxygen produced by human neutrophils and activated macrophages. Optimal protection required both catalases, as the survival of a double mutant lacking both CatB and CatP was lower than that of single-catalase-deficient cells. Although CatB contributed to reactive oxygen species defenses in vitro, CatB was dispensable for lung infection and extrapulmonary dissemination in vivo. Loss of CatB from a strain also lacking superoxide dismutase (Sod3) did not further reduce the survival of Histoplasma yeasts. Nevertheless, some catalase function was required for pathogenesis since simultaneous loss of both CatB and CatP attenuated Histoplasma virulence in vivo. These results demonstrate that Histoplasma's dual catalases comprise a system that enables Histoplasma to efficiently overcome the reactive oxygen produced by the innate immune system. PMID:23589579

  9. Benfotiamine upregulates antioxidative system in activated BV-2 microglia cells

    PubMed Central

    Bozic, Iva; Savic, Danijela; Stevanovic, Ivana; Pekovic, Sanja; Nedeljkovic, Nadezda; Lavrnja, Irena

    2015-01-01

    Chronic microglial activation and resulting sustained neuroinflammatory reaction are generally associated with neurodegeneration. Activated microglia acquires proinflammatory cellular profile that generates oxidative burst. Their persistent activation exacerbates inflammation, which damages healthy neurons via cytotoxic mediators, such as superoxide radical anion and nitric oxide. In our recent study, we have shown that benfotiamine (S-benzoylthiamine O-monophosphate) possesses anti-inflammatory effects. Here, the effects of benfotiamine on the pro-oxidative component of activity of LPS-stimulated BV-2 cells were investigated. The activation of microglia was accompanied by upregulation of intracellular antioxidative defense, which was further promoted in the presence of benfotiamine. Namely, activated microglia exposed to non-cytotoxic doses of benfotiamine showed increased levels and activities of hydrogen peroxide- and superoxide-removing enzymes—catalase and glutathione system, and superoxide dismutase. In addition, benfotiamine showed the capacity to directly scavenge superoxide radical anion. As a consequence, benfotiamine suppressed the activation of microglia and provoked a decrease in NO and ·O−2 production and lipid peroxidation. In conclusion, benfotiamine might silence pro-oxidative activity of microglia to alleviate/prevent oxidative damage of neighboring CNS cells. PMID:26388737

  10. Purification and Characterization of a Novel Thermo-Alkali-Stable Catalase from Thermus brockianus

    SciTech Connect

    Thompson, Vicki Sue; Schaller, Kastli Dianne; Apel, William Arnold

    2003-10-01

    A novel thermo-alkali-stable catalase from Thermus brockianus was purified and characterized. The protein was purified from a T. brockianus cell extract in a three-step procedure that resulted in 65-fold purification to a specific activity of 5300 U/mg. The enzyme consisted of four identical subunits of 42.5 kDa as determined by SDS-PAGE and a total molecular mass measured by gel filtration of 178 kDa. The catalase was active over a temperature range from 30 to 94 C and a pH range from 6 to 10, with optimum activity occurring at 90 C and pH 8. At pH 8, the enzyme was extremely stable at elevated temperatures with half-lives of 330 h at 80 C and 3 h at 90 C. The enzyme also demonstrated excellent stability at 70 C and alkaline pH with measured half-lives of 510 h and 360 h at pHs of 9 and 10, respectively. The enzyme had an unusual pyridine hemochrome spectrum and appears to utilize eight molecules of heme c per tetramer rather than protoheme IX present in the majority of catalases studied to date. The absorption spectrum suggested that the heme iron of the catalase was in a 6-coordinate low spin state rather than the typical 5-coordinate high spin state. A Km of 35.5 mM and a Vmax of 20.3 mM/min·mg protein for hydrogen peroxide was measured, and the enzyme was not inhibited by hydrogen peroxide at concentrations up to 450 mM. The enzyme was strongly inhibited by cyanide and the traditional catalase inhibitor 3-amino-1,2,4-triazole. The enzyme also showed no peroxidase activity to peroxidase substrates o-dianisidine and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), a trait of typical monofunctional catalases. However, unlike traditional monofunctional catalases, the T. brockianus catalase was easily reduced by dithionite, a characteristic of catalase-peroxidases. The above properties indicate that this catalase has potential for applications in industrial bleaching processes to remove residual hydrogen peroxide from process streams.

  11. Two Cytoplasmic Effectors of Phytophthora sojae Regulate Plant Cell Death via Interactions with Plant Catalases1

    PubMed Central

    Zhang, Meixiang; Li, Qi; Liu, Tingli; Liu, Li; Shen, Danyu; Zhu, Ye; Liu, Peihan; Zhou, Jian-Min; Dou, Daolong

    2015-01-01

    Plant pathogenic oomycetes, such as Phytophthora sojae, secrete an arsenal of host cytoplasmic effectors to promote infection. We have shown previously that P. sojae PsCRN63 (for crinkling- and necrosis-inducing proteins) induces programmed cell death (PCD) while PsCRN115 blocks PCD in planta; however, they are jointly required for full pathogenesis. Here, we find that PsCRN63 alone or PsCRN63 and PsCRN115 together might suppress the immune responses of Nicotiana benthamiana and demonstrate that these two cytoplasmic effectors interact with catalases from N. benthamiana and soybean (Glycine max). Transient expression of PsCRN63 increases hydrogen peroxide (H2O2) accumulation, whereas PsCRN115 suppresses this process. Transient overexpression of NbCAT1 (for N. benthamiana CATALASE1) or GmCAT1 specifically alleviates PsCRN63-induced PCD. Suppression of the PsCRN63-induced PCD by PsCRN115 is compromised when catalases are silenced in N. benthamiana. Interestingly, the NbCAT1 is recruited into the plant nucleus in the presence of PsCRN63 or PsCRN115; NbCAT1 and GmCAT1 are destabilized when PsCRN63 is coexpressed, and PsCRN115 inhibits the processes. Thus, PsCRN63/115 manipulates plant PCD through interfering with catalases and perturbing H2O2 homeostasis. Furthermore, silencing of catalase genes enhances susceptibility to Phytophthora capsici, indicating that catalases are essential for plant resistance. Taken together, we suggest that P. sojae secretes these two effectors to regulate plant PCD and H2O2 homeostasis through direct interaction with catalases and, therefore, overcome host immune responses. PMID:25424308

  12. Adeno-Associated Viral-Mediated Catalase Expression Suppresses Optic Neuritis in Experimental Allergic Encephalomyelitis

    NASA Astrophysics Data System (ADS)

    Guy, John; Qi, Xiaoping; Hauswirth, William W.

    1998-11-01

    Suppression of oxidative injury by viral-mediated transfer of the human catalase gene was tested in the optic nerves of animals with experimental allergic encephalomyelitis (EAE). EAE is an inflammatory autoimmune disorder of primary central nervous system demyelination that has been frequently used as an animal model for the human disease multiple sclerosis (MS). The optic nerve is a frequent site of involvement common to both EAE and MS. Recombinant adeno-associated virus containing the human gene for catalase was injected over the right optic nerve heads of SJL/J mice that were simultaneously sensitized for EAE. After 1 month, cell-specific catalase activity, evaluated by quantitation of catalase immunogold, was increased approximately 2-fold each in endothelia, oligodendroglia, astrocytes, and axons of the optic nerve. Effects of catalase on the histologic lesions of EAE were measured by computerized analysis of the myelin sheath area (for demyelination), optic disc area (for optic nerve head swelling), extent of the cellular infiltrate, extravasated serum albumin labeled by immunogold (for blood-brain barrier disruption), and in vivo H2O2 reaction product. Relative to control, contralateral optic nerves injected with the recombinant virus without a therapeutic gene, catalase gene inoculation reduced demyelination by 38%, optic nerve head swelling by 29%, cellular infiltration by 34%, disruption of the blood-brain barrier by 64%, and in vivo levels of H2O2 by 61%. Because the efficacy of potential treatments for MS are usually initially tested in the EAE animal model, this study suggests that catalase gene delivery by using viral vectors may be a therapeutic strategy for suppression of MS.

  13. Restoring catalase activity in Staphylococcus aureus subsp. anaerobius leads to loss of pathogenicity for lambs

    PubMed Central

    de la Fuente, Ricardo; Díez, Rosa M.; Domínguez-Bernal, Gustavo; Orden, José A.; Martínez-Pulgarín, Susana

    2010-01-01

    Staphylococcus aureus subsp. anaerobius, a microaerophilic and catalase-negative bacterium, is the etiological agent of abscess disease, a specific chronic condition of sheep and goats, which is characterized by formation of necrotic lesions that are located typically in superficial lymph nodes. We constructed an isogenic mutant of S. aureus subsp. anaerobius (RDKA84) that carried a repaired and functional catalase gene from S. aureus ATCC 12600, to investigate whether the lack of catalase in S. aureus subsp. anaerobius plays a role in its physiological and pathogenic characteristics. The catalase activity had no apparent influence on the in vitro growth characteristics of RDKA84, which, like the wild-type, did not grow on aerobically incubated agar plates. Restoration of catalase activity in RDKA84 substantially increased resistance to H2O2 when analyzed in a death assay. The intracellular survival rates of the catalase-positive mutant RDKA84 in polymorphonuclear neutrophils (PMN) isolated from adult sheep were significantly higher than those of the wild-type, while no differences were found with PMN isolated from lambs. RDKA84 showed significantly lower survival rates in murine macrophages (J774A.1 cells) than the wild-type strains did, whereas, in bovine mammary epithelial cells (MAC-T), no differences in intracellular survival were observed. Interestingly, the virulence for lambs, the natural host for abscess disease, of the catalase-positive mutant RDKA84 was reduced dramatically in comparison with wild-type S. aureus subsp. anaerobius in two experimental models of infection. PMID:20167202

  14. Intron loss and gain during evolution of the catalase gene family in angiosperms.

    PubMed Central

    Frugoli, J A; McPeek, M A; Thomas, T L; McClung, C R

    1998-01-01

    Angiosperms (flowering plants), including both monocots and dicots, contain small catalase gene families. In the dicot, Arabidopsis thaliana, two catalase (CAT) genes, CAT1 and CAT3, are tightly linked on chromosome 1 and a third, CAT2, which is more similar to CAT1 than to CAT3, is unlinked on chromosome 4. Comparison of positions and numbers of introns among 13 angiosperm catalase genomic sequences indicates that intron positions are conserved, and suggests that an ancestral catalase gene common to monocots and dicots contained seven introns. Arabidopsis CAT2 has seven introns; both CAT1 and CAT3 have six introns in positions conserved with CAT2, but each has lost a different intron. We suggest the following sequence of events during the evolution of the Arabidopsis catalase gene family. An initial duplication of an ancestral catalase gene gave rise to CAT3 and CAT1. CAT1 then served as the template for a second duplication, yielding CAT2. Intron losses from CAT1 and CAT3 followed these duplications. One subclade of monocot catalases has lost all but the 5'-most and 3'-most introns, which is consistent with a mechanism of intron loss by replacement of an ancestral intron-containing gene with a reverse-transcribed DNA copy of a fully spliced mRNA. Following this event of concerted intron loss, the Oryza sativa (rice, a monocot) CAT1 lineage acquired an intron in a novel position, consistent with a mechanism of intron gain at proto-splice sites. PMID:9584109

  15. Relationship between uptake of mercury vapor by mushrooms and its catalase activity

    SciTech Connect

    Ogata, M.; Kenmotsu, K.; Hirota, N.; Naito, M.

    1981-12-01

    The uptake of mercury vapor by mushrooms (Shiitake) artifically grown on an oak tree and the uptake in vitro by catalase extracts prepared from mushroom Hay Bacillus and spinach are reported. Mushrooms were exposed to 1.4 mg/Hg/cu m for 11 days. Measurement of total mercury was as previously described (Ogata et al. 1978, 1979). Levels in mushrooms ranged from 0.4 +/- 0.1 ..mu..g/g at 0.5 days to 4.6 +/- 0.2 ..mu..g/g at 10.5 days and steady-state thereafter. In in vitro studies Hy uptake by mushroom catalase extract was estimated by the perborate method. Uptake was found to parallel catalase activity and was inhibited by potassium cyanide, sodium azide, and 3-amino-1,2,4-triazole. Similar results were obtained with Hay Bacillus and spinach catalase extracts. Results suggest that the level of mercury in the mushroom can be used as an indicator of mercury pollution in the environment. It is also suggested that catalase has an important role in uptake of mercury vapor in the plant. 2 tables (JMT)

  16. Production of catalases by Aspergillus niger isolates as a response to pollutant stress by heavy metals

    SciTech Connect

    Buckova, M.; Godocikova, J.; Simonovicova, A.; Polek, B.

    2005-04-15

    Isolates of Aspergillus niger, selected from the coal dust of a mine containing arsenic (As; 400 mg/kg) and from the river sediment of mine surroundings (As, 1651 mg/kg, Sb, 362 mg/kg), growing in minimal nitrate medium in the phase of hyphal development and spore formation, exhibited much higher levels of total catalase activity than the same species from the culture collection or a culture adapted to soil contaminated with As (5 mg/L). Electrophoretic resolution of catalases in cell-free extracts revealed three isozymes of catalases and production of individual isozymes was not significantly affected by stress environments. Exogenously added stressors (As{sup 5+}, Cd{sup 2+}, Cu{sup 2+}) at final concentrations of 25 and 50 mg/L and H{sub 2}O{sub 2} (20 or 40 m(M)) mostly stimulated production of catalases only in isolates from mines surroundings, and H{sub 2}O{sub 2} and Hg{sup 2+} caused the disappearance of the smallest catalase I. Isolates exhibited a higher tolerance of the toxic effects of heavy metals and H{sub 2}O{sub 2}, as monitored by growth, than did the strain from the culture collection.

  17. Development of a new catalase activity assay for biological samples using optical CUPRAC sensor.

    PubMed

    Bekdeşer, Burcu; Özyürek, Mustafa; Güçlü, Kubilay; Alkan, Fulya Üstün; Apak, Reşat

    2014-11-11

    A novel catalase activity assay was developed for biological samples (liver and kidney tissue homogenates) using a rapid and low-cost optical sensor-based 'cupric reducing antioxidant capacity' (CUPRAC) method. The reagent, copper(II)-neocuproine (Cu(II)-Nc) complex, was immobilized onto a cation-exchanger film of Nafion, and the absorbance changes associated with the formation of the highly-colored Cu(I)-Nc chelate as a result of reaction with hydrogen peroxide (H2O2) was measured at 450 nm. When catalase was absent, H2O2 produced the CUPRAC chromophore, whereas catalase, being an effective H2O2 scavenger, completely annihilated the CUPRAC signal due to H2O2. Thus, the CUPRAC absorbance due to H2O2 oxidation concomitant with Cu(I)-Nc formation decreased proportionally with catalase. The developed sensor gave a linear response over a wide concentration range of H2O2 (0.68-78.6 μM). This optical sensor-based method applicable to tissue homogenates proved to be efficient for low hydrogen peroxide concentrations (physiological and nontoxic levels) to which the widely used UV method is not accurately responsive. Thus, conventional problems of the UV method arising from relatively low sensitivity and selectivity, and absorbance disturbance due to gaseous oxygen evolution were overcome. The catalase findings of the proposed method for tissue homogenates were statistically alike with those of HPLC. PMID:24887508

  18. Effect of Catalase and Sodium Fluoride on Human Enamel bleached with 35% Carbamide Peroxide

    PubMed Central

    Shigli, Anand L; Sharma, Divya S; Thakur, Gagan

    2015-01-01

    ABSTRACT Aim: To evaluate the effects of postbleaching antioxidant application fluoridation treatment on the surface morphology and microhardness of human enamel. Materials and methods: Ten freshly extracted human maxillary central incisors were cut at cementoenamel junction. Crown portion was sectioned into six slabs which were divided into five groups: group A – untreated controls; group B – 35% carbamide peroxide (CP); group C – 35% CP and catalase; group D – treatment with 35% CP and 5% sodium fluoride; group E – 35% CP, catalase and 5% sodium fluoride. Thirty-five percent carbamide peroxide application included two applications of 30 minutes each at a 5-day interval. After treatment, the slabs were thoroughly washed with water for 10 seconds and stored in artificial saliva at 37°C until the next treatment. Two percent sodium fluoride included application for 5 minutes. Three catalase included application for 3 minutes. Results: After 5 days, groups B and C showed significantly decreased enamel microhardness compared to control. Group D specimens showed relatively less reduction in enamel micro-hardness than group C specimens. There is a marked increase in enamel microhardness in group E specimens. Conclusions: Fluoride take up was comparatively enhanced after catalase application resulting in less demineralization and increased microhardness. How to cite this article: Thakur R, Shigli AL, Sharma DS, Thakur G. Effect of Catalase and Sodium Fluoride on Human Enamel bleached with 35% Carbamide Peroxide. Int J Clin Pediatr Dent 2015;8(1):12-17. PMID:26124575

  19. Direct measurement of catalase activity in living cells and tissue biopsies.

    PubMed

    Scaglione, Christine N; Xu, Qijin; Ramanujan, V Krishnan

    2016-01-29

    Spatiotemporal regulation of enzyme-substrate interactions governs the decision-making steps in biological systems. Enzymes, being functional units of every living cell, contribute to the macromolecular stability of cell survival, proliferation and hence are vital windows to unraveling the biological complexity. Experimental measurements capturing this dynamics of enzyme-substrate interactions in real time add value to this understanding. Furthermore these measurements, upon validation in realistic biological specimens such as clinical biopsies - can further improve our capability in disease diagnostics and treatment monitoring. Towards this direction, we describe here a novel, high-sensitive measurement system for measuring diffusion-limited enzyme-substrate kinetics in real time. Using catalase (enzyme) and hydrogen peroxide (substrate) as the example pair, we demonstrate that this system is capable of direct measurement of catalase activity invitro and the measured kinetics follows the classical Michaelis-Menten reaction kinetics. We further demonstrate the system performance by measuring catalase activity in living cells and in very small amounts of liver biopsies (down to 1?g total protein). Catalase-specific enzyme activity is demonstrated by genetic and pharmacological tools. Finally we show the clinically-relevant diagnostic capability of our system by comparing the catalase activities in liver biopsies from young and old mouse (liver and serum) samples. We discuss the potential applicability of this system in clinical diagnostics as well as in intraoperative surgical settings. PMID:26772884

  20. Silencing an Anopheles gambiae catalase and sulfhydryl oxidase increases mosquito mortality after a blood meal.

    PubMed

    Magalhaes, T; Brackney, D E; Beier, J C; Foy, B D

    2008-07-01

    Catalase is a potent antioxidant, likely involved in post-blood meal homeostasis in mosquitoes. This enzyme breaks down H2O2, preventing the formation of the hydroxyl radical (HO*). Quiescins are newly classified sulfhydryl oxidases that bear a thioredoxin motif at the N-terminal and an ERV1-like portion at the C-terminal. These proteins have a major role in generating disulfides in intra- or extracellular environments, and thus participate in redox reactions. In the search for molecules to serve as targets for novel anti-mosquito strategies, we have silenced a catalase and a putative quiescin/sulfhydryl oxidase (QSOX), from the African malaria vector Anopheles gambiae, through RNA interference (RNAi) experiments. We observed that the survival of catalase- and QSOX-silenced insects was reduced over controls following blood digestion, most likely due to the compromised ability of mosquitoes to scavenge and/or prevent damage caused by blood meal-derived oxidative stress. The higher mortality effect was more accentuated in catalase-silenced mosquitoes, where catalase activity was reduced to low levels. Lipid peroxidation was higher in QSOX-silenced mosquitoes suggesting the involvement of this protein in redox homeostasis following a blood meal. This study points to the potential of molecules involved in antioxidant response and redox metabolism to serve as targets of novel anti-mosquito strategies and offers a screening methodology for finding targetable mosquito molecules. PMID:18454489

  1. A molecular dynamics examination on mutation-induced catalase activity in coral allene oxide synthase.

    PubMed

    De Luna, Phil; Bushnell, Eric A C; Gauld, James W

    2013-11-27

    Coral allene oxide synthase (cAOS) catalyzes the formation of allene oxides from fatty acid hydroperoxides. Interestingly, its active site differs from that of catalase by only a single residue yet is incapable of catalase activity. That is, it is unable to catalyze the decomposition of hydrogen peroxide to molecular oxygen and water. However, the single active-site mutation T66V allows cAOS to exhibit catalase activity. We have performed a series of molecular dynamics (MD) simulations in order to gain insights into the differences in substrate (8R-hydroperoxyeicosatetraenoic) and H2O2 active site binding between wild-type cAOS and the T66V mutant cAOS. It is observed that in wild-type cAOS the active site Thr66 residue consistently forms a strong hydrogen-bonding interaction with H2O2 (catalase substrate) and, importantly, with the aid of His67 helps to pull H2O2 away from the heme Fe center. In contrast, in the T66V-cAOS mutant the H2O2 is much closer to the heme's Fe center and now forms a consistent FeO2H2 interaction. In addition, the His67H2O2 distance shortens considerably, increasing the likelihood of a Cpd I intermediate and hence exhibiting catalase activity. PMID:24164352

  2. Development of a new catalase activity assay for biological samples using optical CUPRAC sensor

    NASA Astrophysics Data System (ADS)

    Bekdeşer, Burcu; Özyürek, Mustafa; Güçlü, Kubilay; Alkan, Fulya Üstün; Apak, Reşat

    2014-11-01

    A novel catalase activity assay was developed for biological samples (liver and kidney tissue homogenates) using a rapid and low-cost optical sensor-based ‘cupric reducing antioxidant capacity' (CUPRAC) method. The reagent, copper(II)-neocuproine (Cu(II)-Nc) complex, was immobilized onto a cation-exchanger film of Nafion, and the absorbance changes associated with the formation of the highly-colored Cu(I)-Nc chelate as a result of reaction with hydrogen peroxide (H2O2) was measured at 450 nm. When catalase was absent, H2O2 produced the CUPRAC chromophore, whereas catalase, being an effective H2O2 scavenger, completely annihilated the CUPRAC signal due to H2O2. Thus, the CUPRAC absorbance due to H2O2 oxidation concomitant with Cu(I)-Nc formation decreased proportionally with catalase. The developed sensor gave a linear response over a wide concentration range of H2O2 (0.68-78.6 μM). This optical sensor-based method applicable to tissue homogenates proved to be efficient for low hydrogen peroxide concentrations (physiological and nontoxic levels) to which the widely used UV method is not accurately responsive. Thus, conventional problems of the UV method arising from relatively low sensitivity and selectivity, and absorbance disturbance due to gaseous oxygen evolution were overcome. The catalase findings of the proposed method for tissue homogenates were statistically alike with those of HPLC.

  3. The oxidation of chiral alcohols catalyzed by catalase in organic solvents

    SciTech Connect

    Magner, E.; Klibanov, A.M.

    1995-04-20

    The catalytic properties of bovine liver catalase have been investigated in organic solvents. In tetrahydrofuran, dioxane, and acetone (all containing 1% to 3% of water), the enzyme breaks down tert-butyl hydroperoxide several fold faster than in pure water. Furthermore, the rate of catalase-catalyzed production of tert-butanol from tert-butyl hydroperoxide increases more than 400-fold upon transition from aqueous buffer to ethanol as the reaction medium. The mechanistic rationale for this striking effect is that in aqueous buffer the rate-limiting step of the enzymatic process involves the reduction of catalase`s compound 1 by tert-butyl hydroperoxide. In ethanol, an additional step in the reaction scheme becomes available in which ethanol, greatly outcompeting the hydroperoxide, is oxidized by compound 1 regenerating the free enzyme. In solvents, such as acetonitrile or tetrahydrofuran, which themselves are not oxidizable by compound 1, catalase catalyzes the oxidation of numerous primary and secondary alcohols with tert-butyl hydroperoxide to the corresponding aldehydes or ketones. The enzymatic oxidation of some chiral alcohols (2,3-butanediol, citronellol, and menthol) under these conditions occurs enantioselectively. Examination of the enantioselectivity for the oxidation of 2,3-butanediol in a series of organic solvents reveals a considerable solvent dependence.

  4. Metabolic Damage and Premature Thymus Aging Caused by Stromal Catalase Deficiency.

    PubMed

    Griffith, Ann V; Venables, Thomas; Shi, Jianjun; Farr, Andrew; van Remmen, Holly; Szweda, Luke; Fallahi, Mohammad; Rabinovitch, Peter; Petrie, Howard T

    2015-08-18

    T lymphocytes are essential mediators of immunity that are produced by the thymus in proportion to its size. The thymus atrophies rapidly with age, resulting in progressive diminution of new T cell production. This decreased output is compensated by duplication of existing T cells, but it results in gradual dominance by memory T cells and decreased ability to respond to new pathogens or vaccines. Here, we show that accelerated and irreversible thymic atrophy results from stromal deficiency in the reducing enzyme catalase, leading to increased damage by hydrogen peroxide generated by aerobic metabolism. Genetic complementation of catalase in stromal cells diminished atrophy, as did chemical antioxidants, thus providing a mechanistic link between antioxidants, metabolism, and normal immune function. We propose that irreversible thymic atrophy represents a conventional aging process that is accelerated by stromal catalase deficiency in the context of an intensely anabolic (lymphoid) environment. PMID:26257169

  5. Decrease in catalase activity of cultured cells by Mycoplasma gallisepticum infection.

    PubMed

    Nunoya, T; Tajima, M; Yagihashi, T

    1987-04-01

    The effect of Mycoplasma gallisepticum infection on the host cell catalase activity was histochemically examined in cultured chicken embryo fibroblasts (CEF) and kidney cells. The activity in normal cells was detected as fine, brown granules in the cytoplasm, which appeared ultrastructurally to correspond to anucleoid microbodies. By infecting cultured cells with a CEF-passaged strain of M. gallisepticum, the catalase-positive granules clearly decreased in amount, whereas the UV light-killed mycoplasma and the original strain failed to decrease the granules. The cell-passaged strain was able to induce cytopathic effects and this appeared to be due to its enhanced adherent ability as compared with the original strain. These findings suggest that attachment of viable organisms to cells is crucial to decrease the catalase activity and that the decreased activity may be an important process for the subsequent development of cytopathic effects. PMID:3604054

  6. ENVIRONMENTAL EFFECTS ON SUPEROXIDE DISMUTASE AND CATALASE ACTIVITY AND EXPRESSION IN HONEY BEE.

    PubMed

    Nikolić, Tatjana V; Purać, Jelena; Orčić, Snežana; Kojić, Danijela; Vujanović, Dragana; Stanimirović, Zoran; Gržetić, Ivan; Ilijević, Konstantin; Šikoparija, Branko; Blagojević, Duško P

    2015-12-01

    Understanding the cellular stress response in honey bees will significantly contribute to their conservation. The aim of this study was to analyze the response of the antioxidative enzymes superoxide dismutase and catalase in honey bees related to the presence of toxic metals in different habitats. Three locations were selected: (i) Tunovo on the mountain Golija, as control area, without industry and large human impact, (ii) Belgrade as urban area, and (iii) Zajača, as mining and industrial zone. Our results showed that the concentrations of lead (Pb) in whole body of bees vary according to habitat, but there was very significant increase of Pb in bees from investigated industrial area. Bees from urban and industrial area had increased expression of both Sod1 and Cat genes, suggesting adaptation to increased oxidative stress. However, in spite increased gene expression, the enzyme activity of catalase was lower in bees from industrial area suggesting inhibitory effect of Pb on catalase. PMID:26314562

  7. Enzymatic exploration of catalase from a nanoparticle producing and biodecolorizing algae Shewanella xiamenensis BC01.

    PubMed

    Ng, I-Son; Xu, Fangxin; Zhang, Xia; Ye, Chiming

    2015-05-01

    Shewanella xiamenensis (SXM) was found to produce nanoparticles (NPs) under aerobic condition. The oxidoreductase enzymatic activities including of catalase, manganese peroxidase, laccase, NADH dehydrogenase, flavin reductase, azoreductase and Fe reductase are first investigated. Catalase showed the greatest enzymatic activity among all oxidoreductases in SXM, which with strong activities in multiple substrates of ABTS, guaiacol and 2,6-DMP. The optimum temperature, pH, concentrations of H2O2 and 2,6-DMP for this enzyme were found to be 65 °C, pH 4.0, 128.7 mM and 10 mM, respectively. Finally, from the kinetic parameters and structure simulation of catalase, implied that SXM would potentially apply in bioremediation, microbe fuel cells (MFCs) and nano-biotechnology based on its distinguished enzymatic system. PMID:25306444

  8. Layer-by-layer assembled multilayers using catalase-encapsulated gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Kim, Sungwoo; Park, Jeongju; Cho, Jinhan

    2010-09-01

    We introduce a novel and versatile approach for the preparation of multilayers, based on catalase-encapsulated gold nanoparticles (CAT-AuNP), allowing electrostatic charge reversal and structural transformation through pH adjustment. CAT-AuNP, which are synthesized directly from CAT stabilizer, can be electrostatically assembled with anionic and cationic PEs as a result of the charge reversal of the catalase stabilizers through pH control. In particular, at pH 5.2, near the pI of catalase, dispersed CAT-AuNP are structurally transformed into colloidal or network CAT-AuNP nanocomposites. Furthermore, we demonstrate that the layer-by-layer assembled multilayers composed of PEs and CAT-AuNP induce an effective electron transfer between CAT and the electrode as well as a high loading of CAT and AuNP, and resultantly exhibit a highly catalytic activity toward H2O2.

  9. A Salt-Inducible Mn-Catalase (KatB) Protects Cyanobacterium from Oxidative Stress.

    PubMed

    Chakravarty, Dhiman; Banerjee, Manisha; Bihani, Subhash C; Ballal, Anand

    2016-02-01

    Catalases, enzymes that detoxify H2O2, are widely distributed in all phyla, including cyanobacteria. Unlike the heme-containing catalases, the physiological roles of Mn-catalases remain inadequately characterized. In the cyanobacterium Anabaena, pretreatment of cells with NaCl resulted in unusually enhanced tolerance to oxidative stress. On exposure to H2O2, the NaCl-treated Anabaena showed reduced formation of reactive oxygen species, peroxides, and oxidized proteins than the control cells (i.e. not treated with NaCl) exposed to H2O2. This protective effect correlated well with the substantial increase in production of KatB, a Mn-catalase. Addition of NaCl did not safeguard the katB mutant from H2O2, suggesting that KatB was indeed responsible for detoxifying the externally added H2O2. Moreover, Anabaena deficient in KatB was susceptible to oxidative effects of salinity stress. The katB gene was strongly induced in response to osmotic stress or desiccation. Promoter-gfp analysis showed katB to be expressed only in the vegetative cells but not in heterocysts. Biochemically, KatB was an efficient, robust catalase that remained active in the presence of high concentrations of NaCl. Our findings unravel the role of Mn-catalase in acclimatization to salt/oxidative stress and demonstrate that the oxidative stress resistance of an organism can be enhanced by a simple compound such as NaCl. PMID:26645454

  10. Binding of Cimetidine to Balb/C Mouse Liver Catalase; Kinetics and Conformational Studies.

    PubMed

    Jahangirvand, Mahboubeh; Minai-Tehrani, Dariush; Yazdi, Fatemeh; Minai-Tehrani, Arash; Razmi, Nematollah

    2016-01-01

    Catalase is responsible for converting hydrogen peroxide (H2O2) into water and oxygen in cells. This enzyme has high affinity for hydrogen peroxide and can protect the cells from oxidative stress damage. Catalase is a tetramer protein and each monomer contains a heme group. Cimetidine is a histamine H2 receptor blocker which inhibits acid release from stomach and is used for gasterointestinal diseases. In this research, effect of cimetidine on the activity of liver catalase was studied and the kinetic parameters of this enzyme and its conformational changes were investigated. Cell free extract of mouse liver was used for the catalase assay. The activity of the catalase was detected in the absence and presence of cimetidine by monitoring hydrogen peroxide reduction absorbance at 240 nm. The purified enzyme was used for conformational studies by Fluorescence spectrophotometry. The data showed that cimetidine could inhibit the enzyme in a non-competitive manner. Ki and IC50 values of the drug were determined to be about 0.75 and 0.85 uM, respectively. The Arrhenius plot showed that activation energy was 6.68 and 4.77 kJ/mol in the presence and absence of the drug, respectively. Fluorescence spectrophotometry revealed that the binding of cimetidine to the purified enzyme induced hyperchromicity and red shift which determined the conformational change on the enzyme. Cimetidine could non-competitively inhibit the liver catalase with high affinity. Binding of cimetidine to the enzyme induced conformational alteration in the enzyme. PMID:26794506

  11. Catalase Therapy Corrects Oxidative Stress-Induced Pathophysiology in Incipient Diabetic Retinopathy

    PubMed Central

    Giordano, Courtney R.; Roberts, Robin; Krentz, Kendra A.; Bissig, David; Talreja, Deepa; Kumar, Ashok; Terlecky, Stanley R.; Berkowitz, Bruce A.

    2015-01-01

    Purpose. Preclinical studies have highlighted retinal oxidative stress in the pathogenesis of diabetic retinopathy. We evaluated whether a treatment designed to enhance cellular catalase reduces oxidative stress in retinal cells cultured in high glucose and in diabetic mice corrects an imaging biomarker responsive to antioxidant therapy (manganese-enhanced magnetic resonance imaging [MEMRI]). Methods. Human retinal Mller and pigment epithelial cells were chronically exposed to normal or high glucose levels and treated with a cell-penetrating derivative of the peroxisomal enzyme catalase (called CAT-SKL). Hydrogen peroxide (H2O2) levels were measured using a quantitative fluorescence-based assay. For in vivo studies, streptozotocin (STZ)-induced diabetic C57Bl/6 mice were treated subcutaneously once a week for 3 to 4 months with CAT-SKL; untreated age-matched nondiabetic controls and untreated diabetic mice also were studied. MEMRI was used to analytically assess the efficacy of CAT-SKL treatment on diabetes-evoked oxidative stress-related pathophysiology in vivo. Similar analyses were performed with difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase. Results. After catalase transduction, high glucose-induced peroxide production was significantly lowered in both human retinal cell lines. In diabetic mice in vivo, subnormal intraretinal uptake of manganese was significantly improved by catalase supplementation. In addition, in the peroxisome-rich liver of treated mice catalase enzyme activity increased and oxidative damage (as measured by lipid peroxidation) declined. On the other hand, DFMO was largely without effect in these in vitro or in vivo assays. Conclusions. This proof-of-concept study raises the possibility that augmentation of catalase is a therapy for treating the retinal oxidative stress associated with diabetic retinopathy. PMID:25813998

  12. Diminution of mouse epidermal superoxide dismutase and catalase activities by tumor promotors

    SciTech Connect

    Solanki, V.; Rana, R.S.; Slaga, T.J.

    1981-01-01

    The effects of phorbol ester tumor promoters and related compounds on superoxide dismutase (SOD) and catalase were examined. The treatment of adult mouse skin with 2 ..mu..g 12-0-tetradecanoylphorbol-13-acetate (TPA) resulted in a sustained decrease in the basal levels of both SOD and catalase activities in the epidermis. A decline in SOD activity occurred within 2 h after application and the maximum effect was seen at 16-17 h. The decrease in SOD activity was always accompanied by a similar decline in the epidermal catalase activity. The alterations in both enzymes occurred against a high background of enhanced protein synthesis which indicates that the effect of TPA is selective for SOD and catalase. Other tumor promoters such as phorbol 12,13-dibutyrate and the non-phorbol tumor promoter anthraline also lowered the activities of both the enzymes. Mezerein, a resiniferonol derivative with weak promoting activity but a potent stage-II promoter, appeared to be more potent than TPA in lowering the basal levels. These results indicate that damage which favors neoplastic progression would occur in TPA-treated mouse skin due to the accumulation of free radicals resulting from low levels of SOD and catalase activity. In addition, the TPA-caused decrease in the levels of SOD and catalase was not prevented by either retinoic acid, fluocinolone acetonide, tosyl amino-2-phenylethyl chloromethyl ketone, or butylated hydroxytoluene, suggesting that inhibition of tumor promotion by these agents is not mediated through alterations in the levels of enzymatic activities which decrease free radical concentrations.

  13. Catalase activity as a potential indicator of the reducer component of small closed ecosystems

    NASA Astrophysics Data System (ADS)

    Sarangova, A. B.; Somova, L. A.; Pisman, T. I.

    1997-01-01

    Dynamics of catalase activity has been shown to reflect the growth curve of microorganisms in batch cultivation (celluloselythic bacteria Bacillus acidocaldarius and bacteria of the associated microflora Chlorella vulgaris). Gas and substrate closure of the three component ecosystems with spatially separated components ``producer-consumer-reducer'' (Chl. vulgaris-Paramecium caudatum-B. acidocaldarius, two bacterial strains isolated from the associated microflora Chl. vulgaris) demonstrated that the functioning of the reducer component can be estimated by the catalase activity of microorganisms of this component.

  14. Data supporting the spectrophotometric method for the estimation of catalase activity.

    PubMed

    Hadwan, Mahmoud Hussein; Abed, Hussein Najm

    2016-03-01

    Here we provide raw and processed data and methods for the estimation of catalase activities. The method for presenting a simple and accurate colorimetric assay for catalase activities is described. This method is based on the reaction of undecomposed hydrogen peroxide with ammonium molybdate to produce a yellowish color, which has a maximum absorbance at 374nm. The method is characterized by adding a correction factor to exclude the interference that arises from the presence of amino acids and proteins in serum. The assay acts to keep out the interferences that arose from measurement of absorbance at unsuitable wavelengths. PMID:26862558

  15. Data supporting the spectrophotometric method for the estimation of catalase activity

    PubMed Central

    Hadwan, Mahmoud Hussein; Abed, Hussein Najm

    2015-01-01

    Here we provide raw and processed data and methods for the estimation of catalase activities. The method for presenting a simple and accurate colorimetric assay for catalase activities is described. This method is based on the reaction of undecomposed hydrogen peroxide with ammonium molybdate to produce a yellowish color, which has a maximum absorbance at 374 nm. The method is characterized by adding a correction factor to exclude the interference that arises from the presence of amino acids and proteins in serum. The assay acts to keep out the interferences that arose from measurement of absorbance at unsuitable wavelengths. PMID:26862558

  16. Tumour suppressor PTEN enhanced enzyme activity of GPx, SOD and catalase by suppression of PI3K/AKT pathway in non-small cell lung cancer cell lines.

    PubMed

    Akca, Hakan; Demiray, Aydin; Aslan, Mutay; Acikbas, Ibrahim; Tokgun, Onur

    2013-06-01

    Phosphates and tensin homologue deleted on chromosome 10 (PTEN) is a tumour suppressor gene which dephosphorilates phosphoinositol 3,4,5 triphosphates. Therefore PTEN can regulate PI3K/AKT pathway in cells. Because of promoter methylation or gene deletion, PTEN expression is commonly decreased or lost in non-small cell lung cancer (NSCLC) cell lines. Therefore, we hypothesized that PTEN could regulate the activity of superoxide dismutase (CuZnSOD), glutathione peroxidase (GPx) and catalase. We first recreated PTENwt, G129R and G129E expressions in lung cell lines, in which endogenous PTEN expression was not detected. Then, we showed that PTEN could suppress AKT activity by its lipid phosphatase domain. We then examined the effect of recreated PTEN expressions in NSCLC cells. While PTENwt expression caused enhanced activity of SOD, GPx and catalase in transfected cells lines, neither G129R nor G129E expression effected enzyme activities. These results suggest that PTEN can up-regulate SOD, GPx and catalase activity by inhibition of PI3K/AKT pathway in NSCLC cell lines. PMID:22299584

  17. KatB, a cyanobacterial Mn-catalase with unique active site configuration: Implications for enzyme function.

    PubMed

    Bihani, Subhash C; Chakravarty, Dhiman; Ballal, Anand

    2016-04-01

    Manganese catalases (Mn-catalases), a class of H2O2 detoxifying proteins, are structurally and mechanistically distinct from the commonly occurring catalases, which contain heme. Active site of Mn-catalases can serve as template for the synthesis of catalase mimetics for therapeutic intervention in oxidative stress related disorders. However, unlike the heme catalases, structural aspects of Mn-catalases remain inadequately explored. The genome of the ancient cyanobacterium Anabaena PCC7120, shows the presence of two Mn-catalases, KatA and KatB. Here, we report the biochemical and structural characterization of KatB. The KatB protein (with a C-terminal his-tag) was over-expressed in Escherichia coli and purified by affinity chromatography. On the addition of Mn(2+) to the E. coli growth medium, a substantial increase in production of the soluble KatB protein was observed. The purified KatB protein was an efficient catalase, which was relatively insensitive to inhibition by azide. Crystal structure of KatB showed a hexameric assembly with four-helix bundle fold, characteristic of the Ferritin-like superfamily. With canonical Glu4His2 coordination geometry and two terminal water ligands, the KatB active site was distinctly different from that of other Mn-catalases. Interestingly, the KatB active site closely resembled the active sites of ruberythrin/bacterioferritin, bi-iron members of the Ferritin-like superfamily. The KatB crystal structure provided fundamental insights into the evolutionary relationship within the Ferritin-like superfamily and further showed that Mn-catalases can be sub-divided into two groups, each with a distinct active site configuration. PMID:26826576

  18. Low dose X -ray effects on catalase activity in animal tissue

    NASA Astrophysics Data System (ADS)

    Focea, R.; Nadejde, C.; Creanga, D.; Luchian, T.

    2012-12-01

    This study was intended to investigate the effect of low-dose X ray-irradiation upon the activity of catalase (CAT) in freshly excised chicken tissues (liver, kidney, brain, muscle). The tissue samples were irradiated with 0.5Gy and 2Gy respectively, in a 6 MV photon beam produced by a clinical linear accelerator (VARIAN CLINAC 2100SC). The dose rate was of 260.88cGy/min. at 100 cm source to sample distance. The catalase level was assayed spectrophotometrically, based on reaction kinetics, using a catalase UV assay kit (SIGMA). Catalase increased activity in various tissue samples exposed to the studied X ray doses (for example with 24 % in the liver cells, p<0.05) suggested the stimulation of the antioxidant enzyme biosynthesis within several hours after exposure at doses of 0.5 Gy and 2 Gy; the putative enzyme inactivation could also occur (due to the injuries on the hydrogen bonds that ensure the specificity of CAT active site) but the resulted balance of the two concurrent processes indicates the cell ability of decomposing the hydrogen peroxide-with benefits for the cell physiology restoration for the chosen low dose radiation.

  19. Hydrogen peroxide homeostasis: activation of plant catalase by calcium/calmodulin

    NASA Technical Reports Server (NTRS)

    Yang, T.; Poovaiah, B. W.

    2002-01-01

    Environmental stimuli such as UV, pathogen attack, and gravity can induce rapid changes in hydrogen peroxide (H(2)O(2)) levels, leading to a variety of physiological responses in plants. Catalase, which is involved in the degradation of H(2)O(2) into water and oxygen, is the major H(2)O(2)-scavenging enzyme in all aerobic organisms. A close interaction exists between intracellular H(2)O(2) and cytosolic calcium in response to biotic and abiotic stresses. Studies indicate that an increase in cytosolic calcium boosts the generation of H(2)O(2). Here we report that calmodulin (CaM), a ubiquitous calcium-binding protein, binds to and activates some plant catalases in the presence of calcium, but calcium/CaM does not have any effect on bacterial, fungal, bovine, or human catalase. These results document that calcium/CaM can down-regulate H(2)O(2) levels in plants by stimulating the catalytic activity of plant catalase. Furthermore, these results provide evidence indicating that calcium has dual functions in regulating H(2)O(2) homeostasis, which in turn influences redox signaling in response to environmental signals in plants.

  20. A study of the inhibition of catalase by dipotassium trioxohydroxytetrafluorotriborate K?[B?O?F?OH].

    PubMed

    Islamovic, Safija; Galic, Borivoj; Milos, Mladen

    2014-10-01

    In the development of boronic acid-based enzyme inhibitors as potential pharmaceutical drugs, dipotassium trioxohydroxytetrafluorotriborate K2[B3O3F4OH] was listed as a promising new therapeutic for treatment of these diseases. The catalase-mediated conversion of hydrogen peroxide, in the presence and absence of K2[B3O3F4OH] was studied. The kinetics conformed to the Michaelis-Menten model. Lineweaver-Burk plots were linear and plotted the family of straight lines intersected on the abscissa indicating non-competitive inhibition of the catalase. It appears that in the absence of inhibitor, catalase operates the best at conditions around pH 7.1 and in the presence of K2[B3O3F4OH] the optimum is around pH 6.2. The uncatalyzed reaction of hydrogen peroxide decomposition generally has a value of activation energy of 75?kJ?mole(-1), whereas catalase, in the absence of inhibitor, lowers the value to 11.2?kJ?mole(-1), while in the presence 69?mmoles?L(-1) of K2[B3O3F4OH] it was 37.8?kJ?mole(-1). PMID:24506205

  1. Protective role of extracellular catalase (KatA) against UVA radiation in Pseudomonas aeruginosa biofilms.

    PubMed

    Pezzoni, Magdalena; Pizarro, Ramón A; Costa, Cristina S

    2014-02-01

    One of the more stressful factors that Pseudomonas aeruginosa must face in nature is solar UVA radiation. In this study, the protective role of KatA catalase in both planktonic cells and biofilms of P. aeruginosa against UVA radiation was determined by using the wild-type (PAO1) and an isogenic catalase deficient strain (katA). The katA strain was more sensitive than the wild-type, especially in the case of biofilms. Moreover, the wild-type biofilm was more resistant than its planktonic counterpart, but this was not observed in the katA strain. Striking KatA activity was detected in the matrix of katA(+) strains, and to our knowledge, this is the first report of this activity in the matrix of P. aeruginosa biofilms. Provision of bovine catalase or KatA to the matrix of a katA biofilm significantly increased its UVA tolerance, demonstrating that extracellular KatA is essential to optimal defense against UVA in P. aeruginosa biofilms. Efficiency of photocatalytic treatments using TiO2 and UVA was lower in biofilms than in planktonic cells, but KatA and KatB catalases seem not to be responsible for the higher resistance of the sessile cells to this treatment. PMID:24491420

  2. Structural and functional alterations of catalase induced by acriflavine, a compound causing apoptosis and necrosis.

    PubMed

    Attar, Farnoosh; Khavari-Nejad, Sarah; Keyhani, Jacqueline; Keyhani, Ezzatollah

    2009-08-01

    Acriflavine is an antiseptic agent causing both apoptosis and necrosis in yeast. In this work, its effect on the structure and function of catalase, a vital enzyme actively involved in protection against oxidative stress, was investigated. In vitro kinetic studies showed that acriflavine inhibited the enzymatic activity in a competitive manner. The residual activity detectable after preincubation of catalase (1.5 nmol/L) with various concentrations of acriflavine went from 50% to 20% of the control value as the acriflavine concentration increased from 30 to 90 micromol/L. Correlatively with the decrease in activity, alterations in the enzyme's conformation were observed as indicated by fluorescence spectroscopy, circular dichroism spectroscopy, and electronic absorption spectroscopy. The enzyme's intrinsic fluorescence obtained upon excitation at either 297 nm (tryptophan residues) or 280 nm (tyrosine and tryptophan residues) decreased as a function of acriflavine concentration. Circular dichroism studies showed alterations of the protein structure by acriflavine with up to 13% decrease in alpha helix, 16% increase in beta-sheet content, 17% increase in random coil, and 4% increase in beta turns. Spectrophotometric studies showed a blueshift and modifications in the chromicity of catalase at 405 nm, corresponding to an absorbance band due to the enzyme's prosthetic group. Thus, acriflavine induced in vitro a profound change in the structure of catalase so that the enzyme could no longer function. Our results showed that acriflavine, a compound producing apoptosis and necrosis, can have a direct effect on vital functions in cells by disabling key enzymes. PMID:19723068

  3. Methanol and acriflavine resistance in Dictyostelium are caused by loss of catalase.

    PubMed

    Garcia, Ma Xenia U; Roberts, Catherine; Alexander, Hannah; Stewart, A Michael; Harwood, Adrian; Alexander, Stephen; Insall, Robert H

    2002-01-01

    Various chemicals with harmful effects are not themselves toxic, but are metabolized in vivo to produce toxic products. One example is methanol in Dictyostelium, which is lethal to cells containing the acrA gene, but relatively harmless to acrA mutants. This makes methanol resistance one of the tightest genetic selections in DICTYOSTELIUM: Loss of acrA also confers cross-resistance to unrelated compounds such as acriflavine and thiabendazole. We have used insertional mutagenesis to demonstrate that the acrA locus encodes the peroxisomal catalase A enzyme. Disruption of the catA gene results in parallel resistance to acriflavine. Molecular and biochemical studies of several previously characterized methanol-resistant strains reveal that each lacks catalase activity. One allele, acrA2, contains a 13 bp deletion which introduces a frameshift in the middle of the gene. The involvement of catalase in methanol resistance in Dictyostelium compares with its role in methanol metabolism in yeast and rodents. However, this is the first study to show that catalase is required for the toxicity of acriflavine. Our results imply that acriflavine and thiabendazole are precursors which must be oxidized to generate biologically active species. The catA/acrA gene is also a potentially invaluable negative selectable marker for Dictyostelium molecular genetics. PMID:11782526

  4. Do Superoxide Dismutase (SOD) and Catalase (CAT) protect Cells from DNA Damage Induced by Active Arsenicals?

    EPA Science Inventory

    Superoxide dismutase (SOD) catalyzes the conversion of superoxide to hydrogen peroxide, which can be converted to water and oxygen through the action of catalase. Heterozygous mice of strain B6: 129S7-SodltmlLeb/J were obtained from Jackson Laboratories and bred to produce offspr...

  5. Catalase and glutathione peroxidase are equally active in detoxification of hydrogen peroxide in human erythrocytes

    SciTech Connect

    Gaetani, G.F.; Galiano, S.; Canepa, L.; Ferraris, A.M.; Kirkman, H.N.

    1989-01-01

    Genetic deficiencies of glucose-6-phosphate dehydrogenase (G6PD) and NADPH predispose affected erythrocytes to destruction from peroxides. Conversely, genetic deficiencies of catalase do not predispose affected erythrocytes to peroxide-induced destruction. These observations have served to strengthen the assumption that the NADPH/glutathione/glutathione peroxidase pathway is the principal means for disposal of H/sub 2/O/sub 2/ in human erythrocytes. Recently, however, mammalian catalase was found to have tightly bound NADPH and to require NADPH for the prevention and reversal of inactivation by its toxic substrate (H/sub 2/O/sub 2/). Since both catalase and the glutathione pathway are dependent on NADPH for function, this finding raises the possibility that both mechanisms destroy H/sub 2/O/sub 2/ in human erythrocytes. A comparison of normal and acatalasemic erythrocytes in the present study indicated that catalase accounts for more than half of the destruction of H/sub 2/O/sub 2/ when H/sub 2/O/sub 2/ is generated at a rate comparable to that which leads to hemolysis in G6PD- deficient erythrocytes.

  6. Induction and inactivation of catalase and superoxide dismutase of Escherichia coli by ozone

    SciTech Connect

    Whiteside, C.; Hassan, H.M.

    1987-09-01

    Oxyradicals have been implicated in ozone (O/sub 3/) toxicity and in other oxidant stress. In this study, we investigated the effects of O/sub 3/ on the biosynthesis of the antioxidant enzymes catalase and superoxide dismutase in Escherichia coli to determine their role in the defense against ozone toxicity. Inhibition of growth and loss of viability were observed in cultures exposed to ozone. Results also showed an increase in the activities of catalase and superoxide dismutase in cultures exposed to ozone, which was shown to be due to true induction rather than activation of preexisting apoproteins. Cessation of O/sub 3/ exposure resulted in 30 min of continual high rate of catalase biosynthesis followed by a gradual decrease in the level of the enzyme approaching that of control cultures. This decrease was attributed to a concomitant cessation of de novo enzyme synthesis and dilution of preexisting enzyme by cellular growth. Ozonation of cell-free extracts showed that superoxide dismutase and catalase are subject to oxidative inactivation by ozone. In vivo induction of these enzymes may represent an adaptive response evolved to protect cells against ozone toxicity.

  7. Bioefficacy of Graviola leaf extracts in scavenging free radicals and upregulating antioxidant genes.

    PubMed

    Son, Yu-Ra; Choi, Eun-Hye; Kim, Goon-Tae; Park, Tae-Sik; Shim, Soon-Mi

    2016-02-17

    The aims of this study were to determine bioactive components of Graviola leaf extracts and to examine the radical scavenging capacity, gene expression and transcription factors of antioxidant enzymes. Rutin, kaempferol-rutinoside, and vitamin U were identified from the steaming and 50% EtOH extracts of Graviola leaves. Graviola leaf extracts effectively scavenged peroxy and nitrogen radicals. 50% EtOH of Graviola leaves provided a 1-2.9 times higher trolox equivalent than the steaming extract. It also had a higher VCEAC. Graviola leaf extracts reduced the generation of reactive oxygen species (ROS) induced by H2O2 in a dose-dependent manner. The 50% EtOH extract of Graviola leaves upregulated SOD1 and Nrf2, but catalase and HMOX1 were not altered by the 50% EtOH extract of Graviola leaves. PMID:26674326

  8. Photosynthetic electron flow affects H2O2 signaling by inactivation of catalase in Chlamydomonas reinhardtii.

    PubMed

    Shao, Ning; Beck, Christoph F; Lemaire, Stphane D; Krieger-Liszkay, Anja

    2008-11-01

    A specific signaling role for H(2)O(2) in Chlamydomonas reinhardtii was demonstrated by the definition of a promoter that specifically responded to this ROS. Expression of a nuclear-encoded reporter gene driven by this promoter was shown to depend not only on the level of exogenously added H(2)O(2) but also on light. In the dark, the induction of the reporter gene by H(2)O(2) was much lower than in the light. This lower induction was correlated with an accelerated disappearance of H(2)O(2) from the culture medium in the dark. Due to a light-induced reduction in catalase activity, H(2)O(2) levels in the light remained higher. Photosynthetic electron transport mediated the light-controlled down-regulation of the catalase activity since it was prevented by 3-(3'4'-dichlorophenyl)-1,1-dimethylurea (DCMU), an inhibitor of photosystem II. In the presence of light and DCMU, expression of the reporter gene was low while the addition of aminotriazole, a catalase inhibitor, led to a higher induction of the reporter gene by H(2)O(2) in the dark. The role of photosynthetic electron transport and thioredoxin in this regulation was investigated by using mutants deficient in photosynthetic electron flow and by studying the correlation between NADP-malate dehydrogenase and catalase activities. It is proposed that, contrary to expectations, a controlled down-regulation of catalase activity occurs upon a shift of cells from dark to light. This down-regulation apparently is necessary to maintain a certain level of H(2)O(2) required to activate H(2)O(2)-dependent signaling pathways. PMID:18781324

  9. The effect of superoxide dismutase mimetic and catalase on the quality of postthawed goat semen.

    PubMed

    Shafiei, Mojtaba; Forouzanfar, Mohsen; Hosseini, Sayyed Morteza; Esfahani, Mohammad Hossein Nasr

    2015-05-01

    Manganese(III) meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin chloride (MnTE) is a cell-permeable superoxide dismutase mimetic agent which can convert superoxide to hydrogen peroxide (H2O2). Supplementation of MnTE to a commercial semen extender can protect sperm from superoxide but not H2O2. Therefore, we proposed that addition of catalase (0.0, 200, or 400 IU/mL) in combination with MnTE (0.1 ?M) may further improve the cryopreservation efficiency of goat semen in commercially optimized freezing media such as Andromed. Therefore, ejaculates were obtained from three adult bucks twice a week during the breeding season and diluted with Andromed supplemented with or without MnTE and catalase and were frozen in liquid nitrogen. Sperm parameters and reactive oxygen species contents were evaluated 2 hours after dilution (before freezing) and after freezing/thawing. The results revealed that all the treatments significantly (P ? 0.05) improved sperm motility, viability, and membrane integrity after freezing and reduced reactive oxygen species content compared with the control group, but maximum improvement was obtained in MnTE + 400 IU/mL catalase. In addition, supplementation with these antioxidants significantly (P ? 0.05) increases the cleavage rate after IVF. In conclusion, the results of present study suggest that addition of antioxidant MnTE or catalase to commercial optimized media, such as Andromed, improves total motility, membrane integrity, and viability of goat semen samples after thawing. But the degree of improvement for these parameters significantly (P ? 0.05) higher when MnTE and catalase were simultaneously added to the cryopreservation media. PMID:25698161

  10. Catalase and superoxide dismutase in alfalfa root nodules. [Medicago sativa L

    SciTech Connect

    Becana, M.; Aparicio-Tejo, P.M.; Sanchez-Diaz, M.

    1986-04-01

    Catalase and superoxide dismutase (SOD), in scavenging H/sub 2/ O/sub 2/ and O/sub 2/, respectively, have been recently proposed to play a role in leghemoglobin protection. The occurrence of catalase and SOD activities in alfalfa (Medicago sativa L.) nodule cytosol is reported here. Enzymes were extracted at 0-4/sup 0/C from 0.5 g fresh nodules with 12 ml of a medium containing K-phosphate buffer 50 mM, pH 7.8 and Na/sub 2/EDTA 0.1 mM. The homogenate was filtered and centrifuged at 18,000 xg for 10 min, and the resulting supernatant was used for catalase assay. A further precipitation of leghemoglobin was required to avoid interferences with SOD determination. Catalase was determined by back-titration with KMnO/sub 4/. SOD was assayed by measuring the inhibition of nitro blue tetrazolium reduction. The sensitivity of SOD activity to CN/sup -/ was tested by including 1 mM KCN in the reaction mixture. Catalase activity of alfalfa nodule cytosol was 237 +/- 1 units/mg protein, decreasing very significantly (P < 0.01, Duncan's multiple range test) at 20 mM NO/sub 3//sup -/. Typical specific SOD activities were 94 +/- 5 and 65 +/- 4 units/mg protein, without CN/sup -/ and with CN/sup -/, respectively. Both activities increased very significantly at 20 mM NO/sub 3//sup -/. SOD activities with CN/sup -/ were 70-80% those without CN/sup -/ within the range of NO/sub 3//sup -/ investigated (0-20 mM).

  11. Catalase and superoxide dismutase activities as biomarkers of oxidative stress in workers exposed to mercury vapors

    SciTech Connect

    Perrin-Nadif, R.; Dusch, M.; Mur, J.M.; Koch, C.; Schmitt, P.

    1996-06-07

    We investigated the role of three blood antioxidant enzyme activities and total antioxidant status (TAS) as biological markers of oxidative stress in workers exposed to mercury (Hg{degrees}) vapors. Twenty-two female workers took part in the study. Blood and urine sampling for biological analyses was performed. The workers were classified into three subgroups according to their creatinine-corrected Hg concentration in urine. Blood antioxidant enzyme activities and TAS were compared between groups with nonparametric distribution-free methods. A significant difference existed in catalase activity and a slight, but not significant, difference existed in Cu{sup 2+}/Zn{sup 2+} superoxide dismutase (Cu{sup 2+}/Zn{sup 2+} SOD) activity between the three groups. No differences were observed in either the glutathione peroxidase activity or the TAS between these groups. Catalase and Cu{sup 2+}/Zn{sup 2+} SOD activities were increased in the groups of workers with higher creatinine-corrected urinary Hg concentrations when compared with the group of lower creatinine-corrected urinary Hg concentrations. Catalase activity was positively correlated with the creatinine-corrected concentration of Hg in urine, and Cu{sup 2+}/Zn{sup 2+} SOD activity was slightly correlated with the creatinine-corrected concentration of Hg in urine. The role of erythrocyte catalase and Cu{sup 2}/Zn{sup 2+} SOD activities we have measured is in agreement with the hypothesis of the involvement of reactive oxygen species production as an important event in chronic exposure to Hg{degrees} vapors in humans. In spite of the small sample size, results indicate that erythrocyte catalase and Cu{sup 2+}/Zn{sup 2+} SOD activities could be considered as markers of biological effect in workers exposed to Hg{degrees} vapors. 24 refs., 3 figs., 2 tabs.

  12. A Catalase-related Hemoprotein in Coral Is Specialized for Synthesis of Short-chain Aldehydes: DISCOVERY OF P450-TYPE HYDROPEROXIDE LYASE ACTIVITY IN A CATALASE.

    PubMed

    Teder, Tarvi; Lhelaid, Helike; Boeglin, William E; Calcutt, Wade M; Brash, Alan R; Samel, Nigulas

    2015-08-01

    In corals a catalase-lipoxygenase fusion protein transforms arachidonic acid to the allene oxide 8R,9-epoxy-5,9,11,14-eicosatetraenoic acid from which arise cyclopentenones such as the prostanoid-related clavulones. Recently we cloned two catalase-lipoxygenase fusion protein genes (a and b) from the coral Capnella imbricata, form a being an allene oxide synthase and form b giving uncharacterized polar products (Lhelaid, H., Teder, T., Tldsepp, K., Ekins, M., and Samel, N. (2014) PloS ONE 9, e89215). Here, using HPLC-UV, LC-MS, and NMR methods, we identify a novel activity of fusion protein b, establishing its role in cleaving the lipoxygenase product 8R-hydroperoxy-eicosatetraenoic acid into the short-chain aldehydes (5Z)-8-oxo-octenoic acid and (3Z,6Z)-dodecadienal; these primary products readily isomerize in an aqueous medium to the corresponding 6E- and 2E,6Z derivatives. This type of enzymatic cleavage, splitting the carbon chain within the conjugated diene of the hydroperoxide substrate, is known only in plant cytochrome P450 hydroperoxide lyases. In mechanistic studies using (18)O-labeled substrate and incubations in H2(18)O, we established synthesis of the C8-oxo acid and C12 aldehyde with the retention of the hydroperoxy oxygens, consistent with synthesis of a short-lived hemiacetal intermediate that breaks down spontaneously into the two aldehydes. Taken together with our initial studies indicating differing gene regulation of the allene oxide synthase and the newly identified catalase-related hydroperoxide lyase and given the role of aldehydes in plant defense, this work uncovers a potential pathway in coral stress signaling and a novel enzymatic activity in the animal kingdom. PMID:26100625

  13. Molecular cloning, characterization, and the response of Cu/Zn superoxide dismutase and catalase to PBDE-47 and -209 from the freshwater bivalve Anodonta woodiana.

    PubMed

    Xia, Xichao; Huang, Chuanfeng; Zhang, Dongxian; Zhang, Yi; Xue, Shipeng; Wang, Xiying; Zhang, Qingyuan; Guo, Lianghong

    2016-04-01

    Polybrominated diphenyl ethers-47 (PBDE-47) and -209 are significant components of total PBDEs in water and can catalyze the production of reactive oxygen species (ROS) in the organisms. Anti-oxidant enzymes play an important role in scavenging the high level of ROS. In the current study, two full-length cDNAs of Cu/Zn superoxide dismutase (CuZnSODs) and catalase (CAT) were isolated from freshwater bivalve Anodonta woodiana by rapid amplification of cDNA ends approach and respectively named as AwSOD and AwCAT. The nucleotide sequence of AwSOD cDNA had an open reading frame (ORF) of 465 bp encoding a polypeptide of 155 amino acids in which signature 1 GKHGFHVHEFGDNT and signature 2 GNAGARSACGVI of SODs were observed. Deduced amino acid sequence of AwSOD showed a significant similarity with that of CuZnSODs. AwCAT had an ORF 1536 bp encoding a polypeptide of 512 amino acids which contains a conserved catalytic site motif, and a proximal heme-ligand signature motif of CATs. The time-course expressions of AwSOD and AwCAT in hepatopancreas were measured by quantitative real-time PCR. Expressions of AwSOD and AwCAT showed a significant up-regulation in groups at a low concentration treatment of PBDE-47, a biphasic pattern in groups with a high concentration treatment. Administration of PBDE-209 could result in an up-regulation of AwSOD and AwCAT expressions with time- and dose-dependent matter. These results indicate that up-regulations of AwSOD and AwCAT expression of hepatopancreas of freshwater bivalve A. woodiana contribute to eliminate oxidative stress derived from PBDE-47 and -209 treated. PMID:26915310

  14. Purification, crystallization and preliminary crystallographic analysis of KatB, a manganese catalase from Anabaena PCC 7120.

    PubMed

    Bihani, Subhash Chandra; Chakravarty, Dhiman; Ballal, Anand

    2013-11-01

    Catalases are enzymes that play an important role in the detoxification of hydrogen peroxide (H2O2) in aerobic organisms. Among catalases, haem-containing catalases are ubiquitously distributed and their enzymatic mechanism is very well understood. On the other hand, manganese catalases that contain a bimanganese core in the active site have been less well characterized and their mode of action is not fully understood. The genome of Anabaena PCC 7120 does not show the presence of a haem catalase-like gene; instead, two ORFs encoding manganese catalases (Mn-catalases) are present. Here, the crystallization and preliminary X-ray crystallographic analysis of KatB, one of the two Mn-catalases from Anabaena, are reported. KatB was crystallized using the hanging-drop vapour-diffusion method with PEG 400 as a precipitant and calcium acetate as an additive. Diffraction data were collected in-house on an Agilent SuperNova system using a microfocus sealed-tube X-ray source. The crystal diffracted to 2.2 Å resolution at 100 K. The tetragonal crystal belonged to space group P4(1)2(1)2 (or enantiomer), with unit-cell parameters a = b = 101.87, c = 138.86 Å. Preliminary X-ray diffraction analysis using the Matthews coefficient and self-rotation function suggests the presence of a trimer in the asymmetric unit. PMID:24192374

  15. Endothelin-1 upregulates MCAM in melanocytes.

    PubMed

    Mangahas, Catherine R; dela Cruz, Gelo V; Schneider, Robert J; Jamal, Sumayah

    2004-12-01

    Melanoma cell adhesion molecule (MCAM) is a cell-surface adhesion molecule expressed on over 70% of metastatic melanoma cells but not expressed in normal melanocytes invivo. Protein levels of MCAM correlate with aggressive invasive behavior of melanoma cells in vitro and invivo. Here we demonstrate that endothelin-1 (ET-1) upregulates MCAM protein in primary human melanocytes. MCAM upregulation by ET-1 occurs irrespective of degree of melanocyte pigmentation and is dose-responsive. The drug BQ788 is an endothelin-B (ET(B)) receptor antagonist and inhibits upregulation of MCAM by ET-1. In addition, endothelin-3 (ET-3) and N-succinyl-[Glu9, Ala11, 15]-ET-1-1620, both selective ET(B) agonists, are potent upregulators of MCAM. These demonstrate a critical role for the ET(B) receptor in the upregulation of MCAM by ET-1 and related isoforms. MCAM mRNA abundance is also increased by ET-1 stimulation, thus the mechanism of MCAM protein upregulation may occur at the level of transcription. Our previous studies have demonstrated that ET-1 downregulates E-cadherin in melanocytes and melanoma cells. Since E-cadherin is a melanoma invasion suppressor, and MCAM is a melanoma invasion promoter, ET-1 may promote melanoma invasion and metastasis through the regulation of adhesion molecule expression. PMID:15610525

  16. Protective effects of catalase on retinal ischemia/reperfusion injury in rats.

    PubMed

    Chen, Baihua; Tang, Luosheng

    2011-11-01

    Retinal ischemia/reperfusion (I/R) injury causes profound tissue damage, especially retinal ganglion cell (RGC) death. The aims of the study were to investigate whether catalase (CAT) has a neuroprotective effect on RGC after I/R injury in rats, and to determine the possible antioxidant mechanism. Wistar female rats were randonmized into four groups: normal control group (Control group), retinal I/R with vehicle group (I/R with vehicle group), retinal I/R with AAV-CAT group (I/R with AAV-CAT group), and normal retina with AAV-CAT group (normal with AAV-CAT group). One eye of each rat was pretreated with recombinant adeno-associated virus containing catalase gene (I/R with AAV-CAT group or normal with AAV-CAT group) and recombinant adeno-associated virus containing GFP gene (I/R with vehicle group) by intravitreal injection 21 days before initiation of I/R injury. Retinal I/R injury was induced by elevating intraocular pressure to 100mmHg for 1h. The number of RGC and inner plexiform layer (IPL) thickness were measured by fluorogold retrograde labeling and hematoxylin and eosin staining at 6h, 24h, 72 h and 5d after injury. Hydrogen peroxide (H(2)O(2)), the number of RGC, IPL thickness, malondialdehyde(MDA), 8-hydroxy-2-deoxyguanosine (8-OHdG), CAT activity and nitrotyrosine were measured by fluorescence staining, immunohistochemistry and enzyme-linked immunosorbent assay analysis at 5 days after injury. Electroretinographic (ERG) evaluation was also used. Pretreatment of AAV-CAT significantly decreased the levels of H(2)O(2), MDA, 8-OHdG and nitrotyrosine, increased the catalase activity, and prevented the reduction of a- and b- waves in the I/R with AAV-CAT group compare with the I/R with vehicle group (p<0.01). Catalase attenuated the I/R-induced damage of RGC and IPL and retinal function. Therefore, catalase can protect the rat retina from I/R-induced injury by enhancing the antioxidative ability and reducing oxidative stress, which suggests that catalase may be relevant for the neuroprotection of inner retina from I/R-related diseases. PMID:21824472

  17. A Laboratory Experiment Investigating Different Aspects of Catalase Activity in an Inquiry - Based Approach

    NASA Astrophysics Data System (ADS)

    Kimbrough, Doris R.; Magoun, Mary Ann; Langfur, Meg

    1997-02-01

    The action of the enzyme catalase on aqueous hydrogen peroxide to generate oxygen gas is a well-established demonstration (1-3). Catalase is typically obtained by aqueous extraction of a potato, and the potato extract is mixed together with 3% hydrogen peroxide. The oxygen that is produced can be collected over water. Variations on the procedure can demonstrate the dependence of catalytic activity on temperature or the presence of inhibitors (1, 2). The University of Colorado at Denver has used a version of this procedure as a laboratory in its second-semester course for nonmajors. Recently, students have been allowed to expand upon the procedures prescribed in the laboratory handout in an open-ended project format. We explored some of these variations in detail, and the results provided here offer ideas, centered around this laboratory, for open-ended projects that can be used in an inquiry-based approach.

  18. Hydrogen peroxide determination in pharmaceutical formulations and cosmetics using a new catalase biosensor.

    PubMed

    Campanella, L; Roversi, R; Sammartino, M P; Tomassetti, M

    1998-10-01

    The possibility of evaluating the content of hydrogen peroxide in several authentic matrices, such as cosmetic and pharmaceutical formulations, was studied. A new catalase biosensor fabricated using an amperometric gas-diffusion oxygen sensor as electrochemical transducer and the catalase enzyme immobilized in kappa-carrageenan gel and capable of operating in both aqueous and non aqueous solvents was developed and tested for this purpose. Creams, emulsions and disinfectant solutions were analysed. To this end, a preliminary check was needed to establish the best conditions to analyse these matrices; the choice of solvent was one of the most important points studied. The solvents considered included dioxane, water-dioxane mixtures, water saturated chloroform and aqueous solutions. The different solubility properties of the matrices analysed were taken into account. PMID:9863948

  19. Catalase and epoxidation activity of manganese salen complexes bearing two xanthene scaffolds.

    PubMed

    Yang, Jenny Y; Nocera, Daniel G

    2007-07-01

    A series of manganese Hangman salen ligand platforms functionalized by tert-butyl groups in the 3 and 3' positions using the Suzuki cross-coupling methodology are presented. The Hangman platforms support multielectron chemistry mediated by proton-coupled electron transfer (PCET), as demonstrated by their ability to promote the catalytic disproportionation of hydrogen peroxide to oxygen and water via a high-valent metal oxo. The addition of the steric groups to the salen macrocycle leads to enhanced catalase activity by circumventing side reactions that sequester the catalyst off pathway. The stereochemistry imposed by the cyclohexanediamine backbone of the salen platform is revealed by the epoxidation of 1,2-dihydronapthalene by a variety of oxidants. Improved enantiomeric excess and catalase activity as compared to sterically unmodified counterparts establishes the efficacy of the tert-butyl groups in promoting PCET catalysis on the Hangman platform. PMID:17552520

  20. Changes in the activity of amylase, peroxidase and catalase in beech (Fagus orientalis Lipsky) during dormancy and growth.

    PubMed

    Zolfaghari, Roghoyeh; Korori, Soudabeh A A; Etemad, V

    2005-01-01

    Activities of peroxidase, amylase and catalase were analyzed on beech (Fagus orientalis Lipsky) during one year to determine relationship between these enzymes with the period of dormancy and growing season. Results showed that amylase activity was high but catalase and peroxidase activities were low during the growing season. Peroxidase and catalase activities increased from July to November whereas amylase activity started to decrease at the same time, which means that the plants were prepared themselves to be dormant and the hardening was happened. The peroxidase maximum activity was in November, which is an important sign of dormancy and completing hardening in plant. The dormancy released from February along with decrease of catalase activity. At the beginning of growing season, correlation between amylase and catalase was increased. Amylase activity also increased gradually. No significant correlation between amylase-catalase and amylase-peroxidase activities was found at the period of dormancy. In our study, we found that the seasonal activity of enzymes such as peroxidase, catalase, and amylase, also correlation between these enzymes could be an important factor for the detection the period of dormancy and growing season. PMID:16196205

  1. Differential activation of catalase expression and activity by PPAR agonists: implications for astrocyte protection in anti-glioma therapy.

    PubMed

    Khoo, Nicholas K H; Hebbar, Sachin; Zhao, Weiling; Moore, Steven A; Domann, Frederick E; Robbins, Mike E

    2013-01-01

    Glioma survival is dismal, in part, due to an imbalance in antioxidant expression and activity. Peroxisome proliferator-activated receptor (PPAR) agonists have antineoplastic properties which present new redox-dependent targets for glioma anticancer therapies. Herein, we demonstrate that treatment of primary cultures of normal rat astrocytes with PPAR agonists increased the expression of catalase mRNA protein, and enzymatic activity. In contrast, these same agonists had no effect on catalase expression and activity in malignant rat glioma cells. The increase in steady-state catalase mRNA observed in normal rat astrocytes was due, in part, to de novo mRNA synthesis as opposed to increased catalase mRNA stability. Moreover, pioglitazone-mediated induction of catalase activity in normal rat astrocytes was completely blocked by transfection with a PPAR?-dominant negative plasmid. These data suggest that defects in PPAR-mediated signaling and gene expression may represent a block to normal catalase expression and induction in malignant glioma. The ability of PPAR agonists to differentially increase catalase expression and activity in normal astrocytes but not glioma cells suggests that these compounds might represent novel adjuvant therapeutic agents for the treatment of gliomas. PMID:24024139

  2. Differential activation of catalase expression and activity by PPAR agonists: Implications for astrocyte protection in anti-glioma therapy?

    PubMed Central

    Khoo, Nicholas K.H.; Hebbar, Sachin; Zhao, Weiling; Moore, Steven A.; Domann, Frederick E.; Robbins, Mike E.

    2013-01-01

    Glioma survival is dismal, in part, due to an imbalance in antioxidant expression and activity. Peroxisome proliferator-activated receptor (PPAR) agonists have antineoplastic properties which present new redox-dependent targets for glioma anticancer therapies. Herein, we demonstrate that treatment of primary cultures of normal rat astrocytes with PPAR agonists increased the expression of catalase mRNA protein, and enzymatic activity. In contrast, these same agonists had no effect on catalase expression and activity in malignant rat glioma cells. The increase in steady-state catalase mRNA observed in normal rat astrocytes was due, in part, to de novo mRNA synthesis as opposed to increased catalase mRNA stability. Moreover, pioglitazone-mediated induction of catalase activity in normal rat astrocytes was completely blocked by transfection with a PPAR?-dominant negative plasmid. These data suggest that defects in PPAR-mediated signaling and gene expression may represent a block to normal catalase expression and induction in malignant glioma. The ability of PPAR agonists to differentially increase catalase expression and activity in normal astrocytes but not glioma cells suggests that these compounds might represent novel adjuvant therapeutic agents for the treatment of gliomas. PMID:24024139

  3. Immunodetection of a brown planthopper (Nilaparvata lugens Stl) salivary catalase-like protein into tissues of rice, Oryza sativa.

    PubMed

    Petrova, A; Smith, C M

    2014-02-01

    Saliva plays an important role in host plant-phloem-feeding insect molecular interactions. To better elucidate the role of insect saliva, a series of experiments were conducted to establish if catalase from the salivary glands of the brown planthopper (BPH; Nilaparvata lugens Stl) was secreted into rice host plant tissue during feeding. Catalase is the main enzyme that decomposes hydrogen peroxide (H2O2) at high concentrations. H2O2 is a part of the free radicals system that mediates important physiological roles including signalling and defence. Previous studies have suggested that H2O2 is involved in the rice endogenous response to BPH feeding. If, the BPH secretes catalase into host plant tissue this will counter the effects of H2O2, from detoxification to interfering with plant signalling and defence mechanisms. When BPHs were fed on a hopper-resistant rice variety for 24 h, catalase activity in the salivary glands increased 3.5-fold compared with hoppers fed on a susceptible rice variety. Further supporting evidence of the effects of BPH catalase was demonstrated by immunodetection analyses where results from two independent sources: BPH-infested rice tissue and BPH-probed artificial diets, suggest that the BPH secretes catalase-like protein during feeding. The possible physiological roles of BPH-secreted catalase are discussed. PMID:24164290

  4. The study of ascorbate peroxidase, catalase and peroxidase during in vitro regeneration of Argyrolobium roseum.

    PubMed

    Habib, Darima; Chaudhary, Muhammad Fayyaz; Zia, Muhammad

    2014-01-01

    Here, we demonstrate the micropropagation protocol of Argyrolobium roseum (Camb.), an endangered herb exhibiting anti-diabetic and immune-suppressant properties, and antioxidant enzymes pattern is evaluated. Maximum callogenic response (60 %) was observed from leaf explant at 1.0 mg L(-1) 1-nephthalene acetic acid (NAA) and 0.5 mg L(-1) 6-benzyl aminopurine (BA) in Murashige and Skoog (MS) medium using hypocotyl and root explants (48 % each). Addition of AgNO3 and PVP in the culture medium led to an increase in callogenic response up to 86 % from leaf explant and 72 % from hypocotyl and root explants. The best shooting response was observed in the presence of NAA, while maximum shoot length and number of shoots were achieved based on BA-supplemented MS medium. The regenerated shoots were rooted and successfully acclimatized under greenhouse conditions. Catalase and peroxidase enzymes showed ascending pattern during in vitro plant development from seed while ascorbate peroxidase showed descending pattern. Totally reverse response of these enzymes was observed during callus induction from three different explants. During shoot induction, catalase and peroxidase increased at high rate while there was a mild reduction in ascorbate peroxidase activity. Catalase and peroxidase continuously increased; on the other hand, ascorbate peroxidase activity decreased during root development and acclimatization states. The protocol described here can be employed for the mass propagation and genetic transformation of this rare herb. This study also highlights the importance and role of ascorbate peroxidase, catalase, and peroxidase in the establishment of A. roseum in vitro culture through callogenesis and organogenesis. PMID:24142360

  5. Cytotoxicity of lawsone and cytoprotective activity of antioxidants in catalase mutant Escherichia coli.

    PubMed

    Sauriasari, Rani; Wang, Da-Hong; Takemura, Yoko; Tsutsui, Ken; Masuoka, Noriyoshi; Sano, Kuniaki; Horita, Masako; Wang, Bing-Ling; Ogino, Keiki

    2007-06-01

    Lawsone is an active naphthoquinone derivative isolated from henna (Lawsonia inermis L.), a widely used hair dye. Previous study on the toxicity of lawsone remains unclear since the involvement of oxidative stress and the kind of ROS (reactive oxygen species) involved have not been fully resolved yet. This present study reports the cytotoxic effects of lawsone and henna. We carried out CAT assay (a zone of inhibition test of bacterial growth and colony-forming efficiency test of transformant Escherichia coli strains that express mammalian catalase gene derived from normal catalase mice (Cs(a)) and catalase-deficient mutant mice (Cs(b))), Ames mutagenicity assay and H(2)O(2) generation assay. Lawsone generated H(2)O(2) slightly in phosphate buffer system and was not mutagenic in Ames assay using TA 98, TA 100 and TA 102, both in the absence and presence of metabolic activation. Lawsone exposure inhibited the growth of both Cs(a) and Cs(b) strains in a dose-dependent manner. Mean zone diameter for Cs(a) was 9.75+/-0.96 mm and 12.75+/-1.5 mm for Cs(b). Natural henna leaves did not show toxic effects, whereas two out of four samples of marketed henna products were shown toxicity effects. Catalase abolished zone of inhibition (ZOI) of marketed henna products, eliminated ZOI of lawsone in a dose-dependent manner and low concentration of exogenous MnSOD and Cu/ZnSOD eliminated the toxicity. Histidine and DTPA, the metal chelator; BHA and low concentration of capsaicin, the inducer of NADH-quinone reductase, effectively protected Cs(a) and Cs(b) against lawsone in this study. We suggest that lawsone cytotoxicity is probably mediated, at least in part, by the release of O(2)(-), H(2)O(2) and OH(-). PMID:17442476

  6. The roles of CATALASE2 in abscisic acid signaling in Arabidopsis guard cells.

    PubMed

    Jannat, Rayhanur; Uraji, Misugi; Morofuji, Miho; Hossain, Mohammad Anowar; Islam, Mohammad Muzahidul; Nakamura, Yoshimasa; Mori, Izumi C; Murata, Yoshiyuki

    2011-01-01

    We investigated the roles of catalase (CAT) in abscisic acid (ABA)-induced stomatal closure using a cat2 mutant and an inhibitor of CAT, 3-aminotriazole (AT). Constitutive reactive oxygen species (ROS) accumulation due to the CAT2 mutation and AT treatment did not affect stomatal aperture in the absence of ABA, whereas ABA-induced stomatal closure, ROS production, and [Ca(2+)](cyt) oscillation were enhanced. PMID:21979081

  7. Post-Transcriptional Regulation of Catalase Isozyme Expression in Cotton Seeds.

    PubMed Central

    Ni, W; Trelease, RN

    1991-01-01

    We reported previously that expression of the five tetrameric catalase isozymes during postgerminative growth of cotton seedings was a consequence of interactions between two subunits (SU 1 and SU 2) temporally synthesized from two distinct catalase genes. In this study, we focused on the regulation of the expression of these two catalase subunits during the changeover from glyoxysomal to leaf-type peroxisomal metabolism. The steady-state level of glyoxysomal SU 1 protein (present in 12-hour-old seeds) increased through day 3 and then declined linearly through day 6, whereas SU 2 protein (first detected in 24-hour-old seeds) increased continuously through day 6. The time courses for steady-state levels of the mRNAs encoding these two subunits revealed two clearly separated peaks: the first at day 1 (SU 1) and the other at day 4 (SU 2). Accumulation of these mRNAs preceded the accumulation of their corresponding proteins by at least 24 hours, suggesting temporal, pretranslational regulation of synthesis of both subunits. Results from run-on transcriptional assays with isolated nuclei, however, revealed that transcripts encoding both subunits were synthesized together on days 1 through 5. Hence, it appears that the accumulations of SU 1 and SU 2 mRNAs are controlled primarily at the post-transcriptional level, which has not been reported for catalase or any other eukaryotic peroxisomal enzymes. The accumulation of SU 1 mRNA is not light dependent, whereas the accumulation of SU 2 mRNA, which directs synthesis of the predominant subunit comprising the leaf-type peroxisomal isozyme, occurs only after exposure of seedlings to light. PMID:12324611

  8. Spectroscopy, calorimetry and molecular simulation studies on the interaction of catalase with copper ion.

    PubMed

    Hao, Fang; Jing, Mingyang; Zhao, Xingchen; Liu, Rutao

    2015-02-01

    In this research, the binding mechanism of Cu(2+) to bovine liver catalase (BLC) was studied by fluorescence spectroscopy, ultraviolet-visible (UV-vis) absorption spectroscopy, circular dichroism (CD) spectroscopy, isothermal titration calorimetry (ITC) and molecular docking methods. The cellar experiment was firstly carried out to investigate the inhibition effect of catalase. During the fluorescence quenching study, after correcting the inner filter effect (IFE), the fluorescence of BLC was found to be quenched by Cu(2+). The quenching mechanism was determined by fluorescence lifetime measurement, and was confirmed to be the dynamic mode. The secondary structure content of BLC was changed by the addition of Cu(2+), as revealed by UV-vis absorption and CD spectra, which further induces the decrease in BLC activity. Molecular simulation study indicates that Cu(2+) is located between two ?-sheets and two random coils of BLC near to the heme group, and interacts with His 74 and Ser 113 residues near a hydrophilic area. The decrease of ?-helix and the binding of His 74 are considered to be the major reason for the inhibition of BLC activity caused by Cu(2+). The ITC results indicate that the binding stoichiometry of Cu(2+) to catalase is 11.4. Moreover, the binding of Cu(2+) to BLC destroyed H-bonds, which was confirmed by the CD result. PMID:25618814

  9. katGI and katGII encode two different catalases-peroxidases in Mycobacterium fortuitum.

    PubMed Central

    Menndez, M C; Ainsa, J A; Martn, C; Garca, M J

    1997-01-01

    It has been suggested that catalase-peroxidase plays an important role in several aspects of mycobacterial metabolism and is a virulence factor in the main pathogenic mycobacteria. In this investigation, we studied genes encoding for this protein in the fast-growing opportunistic pathogen Mycobacterium fortuitum. Nucleotide sequences of two different catalase-peroxidase genes (katGI and katGII) of M. fortuitum are described. They show only 64% homology at the nucleotide level and 55% identity at the amino acid level, and they are more similar to catalases-peroxidases from different bacteria, including mycobacteria, than to each other. Both proteins were found to be expressed in actively growing M. fortuitum, and both could also be expressed when transformed into Escherichia coli and M. aurum. We detected the presence of a copy of IS6100 in the neighboring region of a katG gene in the M. fortuitum strain in which this element was identified (strain FC1). The influence of each katG gene on isoniazid (isonicotinic acid hydrazide; INH) susceptibility of mycobacteria was checked by using the INH-sensitive M. aurum as the host. Resistance to INH was induced when katGI was transformed into INH-sensitive M. aurum, suggesting that this enzyme contributes to the natural resistance of M. fortuitum to the drug. This is the first report showing two different genes encoding same enzyme activity which are actively expressed within the same mycobacterial strain. PMID:9371430

  10. Optimization of permeabilization process of yeast cells for catalase activity using response surface methodology

    PubMed Central

    Trawczy?ska, Ilona; Wjcik, Marek

    2015-01-01

    Biotransformation processes accompanied by whole yeast cells as biocatalyst are a promising area of food industry. Among the chemical sanitizers currently used in food technology, hydrogen peroxide is a very effective microbicidal and bleaching agent. In this paper, permeabilization has been applied to Saccharomyces cerevisiae yeast cells aiming at increased intracellular catalase activity for decomposed H2O2. Ethanol, which is non-toxic, biodegradable and easily available, has been used as permeabilization factor. Response surface methodology (RSM) has been applied in determining the influence of different parameters on permeabilization process. The aim of the study was to find such values of the process parameters that would yield maximum activity of catalase during decomposition of hydrogen peroxide. The optimum operating conditions for permeabilization process obtained by RSM were as follows: 53% (v/v) of ethanol concentration, temperature of 14.8C and treatment time of 40min. After permeabilization, the activity of catalase increased ca. 40times and its maximum value equalled to 4711U/g. PMID:26019618

  11. Prevalence of Catalase (-21 A/T) Gene Variant in South Indian (Tamil) Population

    PubMed Central

    Lourdhu Mary, A.; Nithya, K.; Isabel, W.

    2014-01-01

    Catalase, an endogenous antioxidant enzyme, is responsible for regulating reactive species levels. Several epidemiologic studies have suggested that single nucleotide polymorphism in catalase gene may be associated with many diseases. The genotype of CAT (-21 A/T) point mutation in promoter region of catalase gene was determined by polymerase chain based restriction fragment length polymorphism analysis in the DNA of 100 healthy volunteers. The frequency of CAT (-21 A/T) gene polymorphism AA, AT, and TT genotypes was found to be 7, 23, and 70 percent, respectively. The mutant “T” allele frequency was found to be 0.82 among the south Indian (Tamil) population. Chi square analysis showed that the study population lies within the Hardy-Weinberg equilibrium. The wild type genotype (AA) was found to be very low (7%) and the mutant genotype (AT/TT) was found to be more prevalent (93%) among the south Indian population. This suggests that the high prevalence of mutant genotype may increase the susceptibility to oxidative stress associated diseases. PMID:25057503

  12. How catalase recognizes H?O? in a sea of water.

    PubMed

    Domnguez, Laura; Sosa-Peinado, Alejandro; Hansberg, Wilhelm

    2014-01-01

    Monofunctional heme-catalases have been studied for many decades but there is still an incomplete understanding of why such a large tetrameric protein with deeply buried active sites is required to accomplish such a simple reaction as H2 O2 dismutation. Catalase accomplishes this reaction at a high rate although water at 55 M is expected to compete with H2 O2 for the enzyme's active site. Using molecular dynamics simulations we addressed the question as to how catalase selects H2 O2 in water. Selection is accomplished through different mechanisms: higher residence time of H2 O2 in the vicinity of certain prevalent amino acid residues at the protein surface and substrate channel, coordinated motion of the main passage amino acids that is increased in the presence of H2 O2 , a gate valve mechanism consisting of the motion of two contiguous phenylalanine residues that drive water molecules out of the final section of the substrate channel, a hydrophobic barrier before the active site that was crossed more easily by H2 O2 which kept most of its hydrogen bonds while passing, and finally an increased residence time for H2 O2 at the active site. These mechanisms, based on the physicochemical differences between H2 O2 and water, provide an explanation as to why such a large tetrameric protein with deeply buried active sites is required to accomplish efficient H2 O2 dismutation. PMID:23818262

  13. Amperometric biosensor for the detection of hydrogen peroxide using catalase modified electrodes in polyacrylamide.

    PubMed

    Varma, Shailly; Mattiasson, Bo

    2005-09-23

    A simple biosensor for the detection of hydrogen peroxide in organic solvents has been developed and coupled to a flow injection analysis (FIA) system. Catalase was entrapped in polyacrylamide gel and placed on the surface of platinum (working electrode) fixed in a Teflon holder with Ag-wire (auxiliary electrode), followed by addition of filter paper soaked in KCl. The entrapped catalase gel was held on the electrode using membranes. The effects of cellulose and polytetrafluroethylene (PTFE) membranes on the electrode response towards hydrogen peroxide have been studied. The modified electrode has been used to study the detection of hydrogen peroxide in solvents like water, dimethyl sulfoxide (DMSO), and 1,4-dioxane using amperometric techniques like cyclic voltammetry (CV) and FIA. The CV of modified catalase electrode showed a broad oxidation peak at -150 mV and a clear reduction peak at -212 mV in the presence of hydrogen peroxide. Comparison of CV with hydrogen peroxide in various solvents has been carried out. The electrode showed an irreversible kinetics with DMSO as the solvent. A flow cell has been designed in order to carry on FIA studies to obtain calibration plots for hydrogen peroxide with the modified electrode. The calibration plots in several solvents such as water, dimethyl sulfoxide, 1,4-dioxane have been obtained. The throughput of the enzyme electrode was 10 injections per hour. Due to the presence of membrane the response time of the electrode is concentration dependent. PMID:16099064

  14. Murine and human b locus pigmentation genes encode a glycoprotein (gp75) with catalase activity.

    PubMed Central

    Halaban, R; Moellmann, G

    1990-01-01

    Melanogenesis is regulated in large part by tyrosinase (monophenol monooxygenase; monophenol, L-dopa:oxygen oxidoreductase, EC 1.14.18.1), and defective tyrosinase leads to albinism. The mechanisms for other pigmentation determinants (e.g., those operative in tyrosinase-positive albinism and in murine coat-color mutants) are not yet known. One murine pigmentation gene, the brown (b) locus, when mutated leads to a brown (b/b) or hypopigmented (Blt/Blt) coat versus the wild-type black (B/B). We show that the b locus codes for a glycoprotein with the activity of a catalase (hydrogen-peroxide:hydrogen-peroxide oxidoreductase, EC 1.11.1.6) (catalase B). Only the c locus protein is a tyrosinase. Because peroxides may be by-products of melanogenic activity and hydrogen peroxide in particular is known to destroy melanin precursors and melanin, we conclude that pigmentation is controlled not only by tyrosinase but also by a hydroperoxidase. Our studies indicate that catalase B is identical with gp75, a known human melanosomal glycoprotein; that the b mutation is in a heme-associated domain; and that the Blt mutation renders the protein susceptible to rapid proteolytic degradation. Images PMID:1693779

  15. Cytoplasmic superoxide dismutase and catalase activity and resistance to radiation lethality in murine tumor cells

    SciTech Connect

    Davy, C.A.; Tesfay, Z.; Jones, J.; Rosenberg, R.C.; McCarthy, C.; Rosenberg, S.O.

    1986-05-01

    Reduced species of molecular oxygen are produced by the interaction of ionizing radiation with aqueous solutions containing molecular oxygen. The enzymes catalase and superoxide dismutase (SOD) are thought to function in vivo as scavengers of metabolically produced peroxide and superoxide respectively. SOD has been shown to protect against the lethal effects of ionizing radiation in vitro and in vivo. The authors have investigated the relationship between the cytosolic SOD catalase content and the sensitivity to radiation lethality of a number of murine cell lines (402AX, EL-4, MB-2T3, MB-4, MEL, P-815, SAI, SP-2, and SV-3T3). K/sub i/(CN/sup -/) for murine Cu-Zn-SOD was determined to be 6.8 x 10/sup -6/ M. No cytosolic Mn-SOD activity was found in any of the cell lines studied. No correlation was found between the cytosolic Cu-Zn-SOD or cytosolic catalase activity and the resistance to radiation lethality or the murine cell lines studied.

  16. Turning points in the evolution of peroxidase-catalase superfamily: molecular phylogeny of hybrid heme peroxidases.

    PubMed

    Zmock, Marcel; Gasselhuber, Bernhard; Furtmller, Paul G; Obinger, Christian

    2014-12-01

    Heme peroxidases and catalases are key enzymes of hydrogen peroxide metabolism and signaling. Here, the reconstruction of the molecular evolution of the peroxidase-catalase superfamily (annotated in pfam as PF00141) based on experimentally verified as well as numerous newly available genomic sequences is presented. The robust phylogenetic tree of this large enzyme superfamily was obtained from 490 full-length protein sequences. Besides already well-known families of heme b peroxidases arranged in three main structural classes, completely new (hybrid type) peroxidase families are described being located at the border of these classes as well as forming (so far missing) links between them. Hybrid-type A peroxidases represent a minor eukaryotic subfamily from Excavates, Stramenopiles and Rhizaria sharing enzymatic and structural features of ascorbate and cytochrome c peroxidases. Hybrid-type B peroxidases are shown to be spread exclusively among various fungi and evolved in parallel with peroxidases in land plants. In some ascomycetous hybrid-type B peroxidases, the peroxidase domain is fused to a carbohydrate binding (WSC) domain. Both here described hybrid-type peroxidase families represent important turning points in the complex evolution of the whole peroxidase-catalase superfamily. We present and discuss their phylogeny, sequence signatures and putative biological function. PMID:24846396

  17. On the role of catalase in the oxidation of tissue fatty acids

    SciTech Connect

    Crane, D.; Masters, C.

    1984-02-15

    The role of catalase in lipid metabolism has been studied by means of a comparison of the turnover characteristics of the major lipid classes in the normal mouse with those of animals in which the catalase activity had been inhibited and blocked by aminotriazole and allylisopropylacetamide. Double isotope ratios were determined in the lipid fractions of several tissues following the injection of labeled glycerol, and a number of significant differences were identified between these treatments. Since catalase is recognized as an integral component of the peroxisomal pathway of fatty acid oxidation, these results may be taken as indicating that interruption of the process of peroxisomal beta-oxidation in this manner cause extensive perturbations of lipid metabolism in the living animal, and these perturbations extend well beyond those tissues where the predominant localization of these organelles occurs. The concept which derives from these data--that of a significant regulatory role of peroxisomes in relation to the overall balance of lipid metabolism in the animal body--is described and discussed.

  18. Superoxide dismutase and catalase conjugated to polyethylene glycol increases endothelial enzyme activity and oxidant resistance

    SciTech Connect

    Beckman, J.S.; Minor, R.L. Jr.; White, C.W.; Repine, J.E.; Rosen, G.M.; Freeman, B.A.

    1988-05-15

    Covalent conjugation of superoxide dismutase and catalase with polyethylene glycol (PEG) increases the circulatory half-lives of these enzymes from <10 min to 40 h, reduced immunogenicity, and decreases sensitivity to proteolysis. Because PEG has surface active properties and can induce cell fusion, the authors hypothesized that PEG conjugation could enhance cell binding and association of normally membrane-impermeable enzymes. Incubation of cultured porcine aortic endothelial cells with /sup 125/I-PEG-catalase or /sup 125/I-PEG-superoxide dismutase produced a linear, concentration-dependent increase in cellular enzyme activity and radioactivity. Fluorescently labeled PEG-superoxide dismutase incubated with endothelial cells showed a vesicular localization. Mechanical injury to cell monolayers, which is known to stimulate endocytosis, further increased the uptake of fluorescent PEG-superoxide dismutase. Addition of PEG and PEG-conjugated enzymes perturbed the spin-label binding environment, indicative of producing an increase in plasma membrane fluidity. Thus, PEG conjugation to superoxide dismutase and catalase enhances cell association of these enzymes in a manner which increases cellular enzyme activities and provides prolonged protection from partially reduced oxygen species.

  19. Probing the two-domain structure of homodimeric prokaryotic and eukaryotic catalase-peroxidases.

    PubMed

    Banerjee, Srijib; Zamocky, Marcel; Furtmüller, Paul G; Obinger, Christian

    2010-11-01

    Catalase-peroxidases (KatGs) are ancestral bifunctional heme peroxidases found in archaeons, bacteria and lower eukaryotes. In contrast to homologous cytochrome c peroxidase (CcP) and ascorbate peroxidase (APx) homodimeric KatGs have a two-domain monomeric structure with a catalytic N-terminal heme domain and a C-terminal domain of high sequence and structural similarity but without obvious function. Nevertheless, without its C-terminal counterpart the N-terminal domain exhibits neither catalase nor peroxidase activity. Except some hybrid-type proteins all other members of the peroxidase-catalase superfamily lack this C-terminal domain. In order to probe the role of the two-domain monomeric structure for conformational and thermal stability urea and temperature-dependent unfolding experiments were performed by using UV-Vis-, electronic circular dichroism- and fluorescence spectroscopy, as well as differential scanning calorimetry. Recombinant prokaryotic (cyanobacterial KatG from Synechocystis sp. PCC6803) and eukaryotic (fungal KatG from Magnaporthe grisea) were investigated. The obtained data demonstrate that the conformational and thermal stability of bifunctional KatGs is significantly lower compared to homologous monofunctional peroxidases. The N- and C-terminal domains do not unfold independently. Differences between the cyanobacterial and the fungal enzyme are relatively small. Data will be discussed with respect to known structure and function of KatG, CcP and APx. PMID:20654740

  20. Murine and human b locus pigmentation genes encode a glycoprotein (gp75) with catalase activity

    SciTech Connect

    Halaban, R.; Moellmann, G. )

    1990-06-01

    Melanogenesis is regulated in large part by tyrosinase, and defective tyrosinase leads to albinism. The mechanisms for other pigmentation determinants (e.g., those operative in tyrosinase-positive albinism and in murine coat-color mutants) are not yet known. One murine pigmentation gene, the brown (b) locus, when mutated leads to a brown (b/b) or hypopigmentated (B{sup lt}/B{sup lt}) coat versus the wild-type black (B/B). The authors show that the b locus codes for a glycoprotein with the activity of a catalase (catalase B). Only the c locus protein is a tyrosinase. Because peroxides may be by-products of melanogenic activity and hydrogen peroxide in particular is known to destroy melanin precursors and melanin, they conclude that pigmentation is controlled not only by tyrosinase but also by a hydroperoxidase. The studies indicate that catalase B is identical with gp75, a known human melanosomal glycoprotein; that the b mutation is in a heme-associated domain; and that the B{sup lt} mutation renders the protein susceptible to rapid proteolytic degradation.

  1. Understanding the role of the catalase/peroxide genes in H2O2 resistance of E. coli serotype O157:H7 biofilms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Escherichia coli serotype O157:H7 defenses against H2O2 include the peroxiredoxin AhpC and three catalases: KatG (catalase-peroxidase), KatE (catalase), and the plasmid-encoded KatP (catalase/peroxidase). AhpC, KatG, and KatP are induced by OxyR in exponential phase, while KatE is indu...

  2. Different behaviour of normal and neoplastic cells cultured in vitro in the presence of catalase and superoxide dismutase.

    PubMed

    Liotti, F S; Bodo, M; Menghini, A R; Guerrieri, P; Mariucci, G; Bruschelli, G

    1987-09-15

    Chicken embryo fibroblasts and hepatocytes were studied in the presence of catalase and superoxide dismutase in order to establish whether these enzymes had the capacity to favour cell multiplication as previously shown for in vitro tumour ascites cells (ATP C+). The results indicate that, unlike ATP C+ cells, both fibroblasts and hepatocytes are inhibited in their multiplication by superoxide dismutase. Similar effects are exerted on hepatocytes by catalase, whereas the multiplication of fibroblasts is favoured by high doses of this enzyme. Enzyme determinations revealed high levels of catalase and superoxide dismutase in hepatocytes, whereas both enzymes were poor in fibroblasts and ATP C+. PMID:3040600

  3. Role of. pi. -cation radicals in the enzymatic cycles of peroxidases, catalases, and nitrite and sulfite reductases

    SciTech Connect

    Hanson, L K; Chang, C K; Davis, M S; Fajer, J

    1980-01-01

    Charge iterative extended Hueckel calculations, and magnetic and optical results on porphyrins, chlorins, and isobacteriochlorins (1) suggest that the catalytic cycles of the enzymes horseradish peroxidase, catalase, Neurospora crassa catalase, and nitrite and sulfite reductases proceed via ..pi..-cation radicals of their prosthetic groups; (2) offer distinguishing features for the optical and magnetic spectra of these radicals, pertinent to their detection as enzymatic intermediates; (3) reconcile the seemingly contradictory optical and NMR data on Compounds I of horseradish peroxidase; and (4) predict that the axial ligation of the heme differs for horseradish peroxidase and catalase.

  4. Homocysteine enhances endothelial apoptosis via upregulation of Fas-mediated pathways.

    PubMed

    Suhara, Toshimitsu; Fukuo, Keisuke; Yasuda, Osamu; Tsubakimoto, Maki; Takemura, Yukihiro; Kawamoto, Hidenobu; Yokoi, Toyohiko; Mogi, Masaki; Kaimoto, Taeko; Ogihara, Toshio

    2004-06-01

    Hyperhomocysteinemia is an independent risk factor for the development of atherosclerosis. However, the underlying mechanism of endothelial cell injury in hyperhomocysteinemia has not been elucidated. In this study, we examined the effect of homocysteine (Hcy) on Fas-mediated apoptosis in endothelial cells. Hcy-induced upregulation of Fas in endothelial cells (ECs) in a dose-dependent manner. At the same time, Hcy increased intracellular peroxide in ECs. Hcy-induced Fas expression was inhibited by the treatment with catalase. Hcy increased NF-kappaB DNA binding activity, and adenovirus-mediated transfection of a Ikappa-B mutant (Ikappa-B mt) gene inhibited Hcy-induced Fas expression. ECs were sensitive to Fas-mediated apoptosis when exposed to Hcy. Under these condition, Ikappa-B mt protected ECs from Fas-mediated apoptosis. In addition, Hcy inhibited expression of the caspase-8 inhibitor FLICE-inhibitory protein (FLIP). Adenovirus-mediated transfection of constitutively active Akt gene abolished the Hcy-mediated downregulation of FLIP. These data suggest that upregulation of Fas expression and downregulation of FLIP is a mechanism through which Hcy induces EC apoptosis. PMID:15117910

  5. Structure of catalase HPII from Escherichia coli at 1.9 A resolution.

    PubMed

    Bravo, J; Mate, M J; Schneider, T; Switala, J; Wilson, K; Loewen, P C; Fita, I

    1999-02-01

    Catalase HPII from Escherichia coli, a homotetramer of subunits with 753 residues, is the largest known catalase. The structure of native HPII has been refined at 1.9 A resolution using X-ray synchrotron data collected from crystals flash-cooled with liquid nitrogen. The crystallographic agreement factors R and R(free) are respectively 16.6% and 21.0%. The asymmetric unit of the crystal contains a whole molecule that shows accurate 222-point group symmetry. The structure of the central part of the HPII subunit gives a root mean square deviation of 1.5 A for 477 equivalencies with beef liver catalase. Most of the additional 276 residues of HPII are located in either an extended N-terminal arm or in a C-terminal domain organized with a flavodoxin-like topology. A small number of mostly hydrophilic interactions stabilize the relative orientation between the C-terminal domain and the core of the enzyme. The heme component of HPII is a cis-hydroxychlorin gamma-spirolactone in an orientation that is flipped 180 degrees with respect to the orientation of the heme found in beef liver catalase. The proximal ligand of the heme is Tyr415 which is joined by a covalent bond between its Cbeta atom and the Ndelta atom of His392. Over 2,700 well-defined solvent molecules have been identified filling a complex network of cavities and channels formed inside the molecule. Two channels lead close to the distal side heme pocket of each subunit suggesting separate inlet and exhaust functions. The longest channel, that begins in an adjacent subunit, is over 50 A in length, and the second channel is about 30 A in length. A third channel reaching the heme proximal side may provide access for the substrate needed to catalyze the heme modification and His-Tyr bond formation. HPII does not bind NADPH and the equivalent region to the NADPH binding pocket of bovine catalase, partially occluded in HPII by residues 585-590, corresponds to the entrance to the second channel. The heme distal pocket contains two solvent molecules, and the one closer to the iron atom appears to exhibit high mobility or low occupancy compatible with weak coordination. PMID:10022351

  6. Specific Function of the Met-Tyr-Trp Adduct Radical and Residues Arg-418 and Asp-137 in the Atypical Catalase Reaction of Catalase-Peroxidase KatG*

    PubMed Central

    Zhao, Xiangbo; Khajo, Abdelahad; Jarrett, Sanchez; Suarez, Javier; Levitsky, Yan; Burger, Richard M.; Jarzecki, Andrzej A.; Magliozzo, Richard S.

    2012-01-01

    Catalase activity of the dual-function heme enzyme catalase-peroxidase (KatG) depends on several structural elements, including a unique adduct formed from covalently linked side chains of three conserved amino acids (Met-255, Tyr-229, and Trp-107, Mycobacterium tuberculosis KatG numbering) (MYW). Mutagenesis, electron paramagnetic resonance, and optical stopped-flow experiments, along with calculations using density functional theory (DFT) methods revealed the basis of the requirement for a radical on the MYW-adduct, for oxyferrous heme, and for conserved residues Arg-418 and Asp-137 in the rapid catalase reaction. The participation of an oxyferrous heme intermediate (dioxyheme) throughout the pH range of catalase activity is suggested from our finding that carbon monoxide inhibits the activity at both acidic and alkaline pH. In the presence of H2O2, the MYW-adduct radical is formed normally in KatG[D137S] but this mutant is defective in forming dioxyheme and lacks catalase activity. KatG[R418L] is also catalase deficient but exhibits normal formation of the adduct radical and dioxyheme. Both mutants exhibit a coincidence between MYW-adduct radical persistence and H2O2 consumption as a function of time, and enhanced subunit oligomerization during turnover, suggesting that the two mutations disrupting catalase turnover allow increased migration of the MYW-adduct radical to protein surface residues. DFT calculations showed that an interaction between the side chain of residue Arg-418 and Tyr-229 in the MYW-adduct radical favors reaction of the radical with the adjacent dioxyheme intermediate present throughout turnover in WT KatG. Release of molecular oxygen and regeneration of resting enzyme are thereby catalyzed in the last step of a proposed catalase reaction. PMID:22918833

  7. Unprecedented access of phenolic substrates to the heme active site of a catalase: substrate binding and peroxidase-like reactivity of Bacillus pumilus catalase monitored by X-ray crystallography and EPR spectroscopy.

    PubMed

    Loewen, Peter C; Villanueva, Jacylyn; Switala, Jacek; Donald, Lynda J; Ivancich, Anabella

    2015-05-01

    Heme-containing catalases and catalase-peroxidases catalyze the dismutation of hydrogen peroxide as their predominant catalytic activity, but in addition, individual enzymes support low levels of peroxidase and oxidase activities, produce superoxide, and activate isoniazid as an antitubercular drug. The recent report of a heme enzyme with catalase, peroxidase and penicillin oxidase activities in Bacillus pumilus and its categorization as an unusual catalase-peroxidase led us to investigate the enzyme for comparison with other catalase-peroxidases, catalases, and peroxidases. Characterization revealed a typical homotetrameric catalase with one pentacoordinated heme b per subunit (Tyr340 being the axial ligand), albeit in two orientations, and a very fast catalatic turnover rate (kcat ?=?339,000 s(-1) ). In addition, the enzyme supported a much slower (kcat ?=?20 s(-1) ) peroxidatic activity utilizing substrates as diverse as ABTS and polyphenols, but no oxidase activity. Two binding sites, one in the main access channel and the other on the protein surface, accommodating pyrogallol, catechol, resorcinol, guaiacol, hydroquinone, and 2-chlorophenol were identified in crystal structures at 1.65-1.95 . A third site, in the heme distal side, accommodating only pyrogallol and catechol, interacting with the heme iron and the catalytic His and Arg residues, was also identified. This site was confirmed in solution by EPR spectroscopy characterization, which also showed that the phenolic oxygen was not directly coordinated to the heme iron (no low-spin conversion of the Fe(III) high-spin EPR signal upon substrate binding). This is the first demonstration of phenolic substrates directly accessing the heme distal side of a catalase. PMID:25663126

  8. Catalase in fluvial biofilms: a comparison between different extraction methods and example of application in a metal-polluted river.

    PubMed

    Bonnineau, Chlo; Bonet, Berta; Corcoll, Natlia; Guasch, Helena

    2011-01-01

    Antioxidant enzymes are involved in important processes of cell detoxification during oxidative stress and have, therefore, been used as biomarkers in algae. Nevertheless, their limited use in fluvial biofilms may be due to the complexity of such communities. Here, a comparison between different extraction methods was performed to obtain a reliable method for catalase extraction from fluvial biofilms. Homogenization followed by glass bead disruption appeared to be the best compromise for catalase extraction. This method was then applied to a field study in a metal-polluted stream (Riou Mort, France). The most polluted sites were characterized by a catalase activity 4-6 times lower than in the low-polluted site. Results of the comparison process and its application are promising for the use of catalase activity as an early warning biomarker of toxicity using biofilms in the laboratory and in the field. PMID:21080224

  9. Increasing the endogenous NO level causes catalase inactivation and reactivation of intercellular apoptosis signaling specifically in tumor cells

    PubMed Central

    Bauer, Georg

    2015-01-01

    Tumor cells generate extracellular superoxide anions and are protected against intercellular apoptosis-inducing HOCl- and NO/peroxynitrite signaling through the expression of membrane-associated catalase. This enzyme decomposes H2O2 and thus prevents HOCl synthesis. It efficiently interferes with NO/peroxynitrite signaling through oxidation of NO and decomposition of peroxynitrite. The regulatory potential of catalase at the crosspoint of ROS and RNS chemical biology, as well as its high local concentration on the outside of the cell membrane of tumor cells, establish tight control of intercellular signaling and thus prevent tumor cell apoptosis. Therefore, inhibition of catalase or its inactivation by singlet oxygen reactivate intercellular apoptosis-inducing signaling. Nitric oxide and peroxynitrite are connected with catalase in multiple and meaningful ways, as (i) NO can be oxidated by compound I of catalase, (ii) NO can reversibly inhibit catalase, (iii) peroxynitrite can be decomposed by catalase and (iv) the interaction between peroxynitrite and H2O2 leads to the generation of singlet oxygen that inactivates catalase. Therefore, modulation of the concentration of free NO through addition of arginine, inhibition of arginase, induction of NOS expression or inhibition of NO dioxygenase triggers an autoamplificatory biochemical cascade that is based on initial formation of singlet oxygen, amplification of superoxide anion/H2O2 and NO generation through singlet oxygen dependent stimulation of the FAS receptor and caspase-8. Finally, singlet oxygen is generated at sufficiently high concentration to inactivate protective catalase and to reactivate intercellular apoptosis-inducing ROS signaling. This regulatory network allows to establish several pathways for synergistic interactions, like the combination of modulators of NO metabolism with enhancers of superoxide anion generation, modulators of NO metabolism that act at different targets and between modulators of NO metabolism and direct catalase inhibitors. The latter aspect is explicitely studied for the interaction between catalase inhibiting acetylsalicylic acid and an NO donor. It is also shown that hybrid molecules like NO-aspirin utilize this synergistic potential. Our data open novel approaches for rational tumor therapy based on specific ROS signaling and its control in tumor cells. PMID:26342455

  10. Purification, cloning, expression, and biochemical characterization of a monofunctional catalase, KatP, from Pigmentiphaga sp. DL-8.

    PubMed

    Dong, Weiliang; Hou, Ying; Li, Shuhuan; Wang, Fei; Zhou, Jie; Li, Zhoukun; Wang, Yicheng; Huang, Fei; Fu, Lei; Huang, Yan; Cui, Zhongli

    2015-04-01

    Catalases are essential components of the cellular equipment used to cope with oxidative stress. The monofunctional catalase KatP was purified from Pigmentiphaga sp. using ammonium sulfate precipitation (ASP), diethylaminoethyl ion exchange chromatography (IEC), and hydrophobic interaction chromatography (HIC). The purified catalase formed polymer with an estimated monomer molecular mass of 54kDa, which were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and zymogram analysis. KatP exhibited a specific catalytic activity of 73,000U/mg, which was higher than that of catalase-1 of Comamonas terrigena N3H (55,900U/mg). Seven short tryptic fragments of this catalase were obtained by electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Q-TOF MS/MS), and the gene, katP, was cloned by PCR amplification and overexpressed in Escherichia coli BL21 (DE3). Based on the complete amino acid sequence, KatP was identified as a clade 3 monofunctional catalase. The specific activities of recombinant KatP for hydrogen peroxide (690,000U/mg) increased 9-fold over that of the parent strain. The Km and Vmax of recombinant KatP were 9.48mM and 81.2mol/minmg, respectively. The optimal pH and temperature for KatP were 7.0 and 37C, respectively, and the enzyme displayed abroad pH-stable range of 4.0-11.0. The enzyme was inhibited by Zn(2+), Cu(2+), Cr(2+), and Mn(2+), whereas Fe(3+) and Mg(2+) stimulated KatP enzymatic activity. Interestingly, the catalase activity of recombinant KatP displayed high stability under different temperature and pH conditions, suggesting that KatP is a potential candidate for the production of catalase. PMID:25665507

  11. A comprehensive evaluation of catalase-like activity of different classes of redox-active therapeutics.

    PubMed

    Tovmasyan, Artak; Maia, Clarissa G C; Weitner, Tin; Carballal, Sebastin; Sampaio, Romulo S; Lieb, Dominik; Ghazaryan, Robert; Ivanovic-Burmazovic, Ivana; Ferrer-Sueta, Gerardo; Radi, Rafael; Reboucas, Julio S; Spasojevic, Ivan; Benov, Ludmil; Batinic-Haberle, Ines

    2015-09-01

    Because of the increased insight into the biological role of hydrogen peroxide (H2O2) under physiological and pathological conditions and the role it presumably plays in the action of natural and synthetic redox-active drugs, there is a need to accurately define the type and magnitude of reactions that may occur with this intriguing and key species of redoxome. Historically, and frequently incorrectly, the impact of catalase-like activity has been assigned to play a major role in the action of many redox-active drugs, mostly SOD mimics and peroxynitrite scavengers, and in particular MnTBAP(3-) and Mn salen derivatives. The advantage of one redox-active compound over another has often been assigned to the differences in catalase-like activity. Our studies provide substantial evidence that Mn(III) N-alkylpyridylporphyrins couple with H2O2 in actions other than catalase-related. Herein we have assessed the catalase-like activities of different classes of compounds: Mn porphyrins (MnPs), Fe porphyrins (FePs), Mn(III) salen (EUK-8), and Mn(II) cyclic polyamines (SOD-active M40403 and SOD-inactive M40404). Nitroxide (tempol), nitrone (NXY-059), ebselen, and MnCl2, which have not been reported as catalase mimics, were used as negative controls, while catalase enzyme was a positive control. The dismutation of H2O2 to O2 and H2O was followed via measuring oxygen evolved with a Clark oxygen electrode at 25C. The catalase enzyme was found to have kcat(H2O2)=1.510(6)M(-1) s(-1). The yield of dismutation, i.e., the maximal amount of O2 evolved, was assessed also. The magnitude of the yield reflects an interplay between the kcat(H2O2) and the stability of compounds toward H2O2-driven oxidative degradation, and is thus an accurate measure of the efficacy of a catalyst. The kcat(H2O2) values for 12 cationic Mn(III) N-substituted (alkyl and alkoxyalkyl) pyridylporphyrin-based SOD mimics and Mn(III) N,N'-dialkylimidazolium porphyrin, MnTDE-2-ImP(5+), ranged from 23 to 88M(-1) s(-1). The analogous Fe(III) N-alkylpyridylporphyrins showed ~10-fold higher activity than the corresponding MnPs, but the values of kcat(H2O2) are still ~4 orders of magnitude lower than that of the enzyme. While the kcat(H2O2) values for Fe ethyl and n-octyl analogs were 803.5 and 368.4M(-1) s(-1), respectively, the FePs are more prone to H2O2-driven oxidative degradation, therefore allowing for similar yields in H2O2 dismutation as analogous MnPs. The kcat(H2O2) values are dependent on the electron deficiency of the metal site as it controls the peroxide binding in the first step of the dismutation process. SOD-like activities depend on electron deficiency of the metal site also, as it controls the first step of O2(?-) dismutation. In turn, the kcat(O2(?-)) parallels the kcat(H2O2). Therefore, the electron-rich anionic non-SOD mimic MnTBAP(3-) has essentially very low catalase-like activity, kcat(H2O2)=5.8M(-1) s(-1). The catalase-like activities of Mn(III) and Fe(III) porphyrins are at most, 0.0004 and 0.05% of the enzyme activity, respectively. The kcat(H2O2) values of 8.2 and 6.5M(-1) s(-1) were determined for electron-rich Mn(II) cyclic polyamine-based compounds, M40403 and M40404, respectively. The EUK-8, with modest SOD-like activity, has only slightly higher kcat(H2O2)=13.5M(-1) s(-1). The biological relevance of kcat(H2O2) of MnTE-2-PyP(5+), MnTDE-2-ImP(5+), MnTBAP(3-), FeTE-2-PyP(5+), M40403, M40404, and Mn salen was evaluated in wild-type and peroxidase/catalase-deficient E. coli. PMID:26026699

  12. Catalase and superoxide dismutase-2 enhance survival and protect ovaries during overwintering diapause in the mosquito Culex pipiens

    PubMed Central

    Sim, Cheolho; Denlinger, David L.

    2011-01-01

    Lifespan extension and stress resistance are two important features of diapause that are essential for successful overwintering. We present several lines of evidence suggesting that genes encoding two antioxidant enzymes, catalase and superoxide dismutase-2, are critical in generating these characteristics during diapause in overwintering adults of the mosquito Culex pipiens. Expression of both catalase and sod-2 was dramatically higher in young diapausing females than in their nondiapausing counterparts at the same age. Suppression of catalase, but not sod-2, resulted in increased damage to the ovaries, as evidenced by signs of apoptosis in ovarian follicle cells. Adult survival time was shortened when levels of either catalase or sod-2 were suppressed using RNAi. Together these results imply that these two antioxidants are particularly important in promoting survival in diapausing females, while elevation of catalase also contributes to protection of the ovaries. In addition, RNAi directed against forkhead transcription factor (foxo), a gene thought to be upstream of the genes encoding these antioxidants, resulted in suppression of both catalase and sod-2. The linkage with FOXO suggests that the genes encoding these two antioxidants are components of an important gene network regulated by this transcription factor. PMID:21277308

  13. Layer-by-layer immobilized catalase on electrospun nanofibrous mats protects against oxidative stress induced by hydrogen peroxide.

    PubMed

    Huang, Rong; Deng, Hongbing; Cai, Tongjian; Zhan, Yingfei; Wang, Xiankai; Chen, Xuanxuan; Ji, Ailing; Lil, Xueyong

    2014-07-01

    Catalase, a kind of redox enzyme and generally recognized as an efficient agent for protecting cells against hydrogen peroxide (H2O2)-induced cytotoxicity. The immobilization of catalase was accomplished by depositing the positively charged chitosan and the negatively charged catalase on electrospun cellulose nanofibrous mats through electrospining and layer-by-layer (LBL) techniques. The morphology obtained from Field emission scanning electron microscopy (FE-SEM) indicated that more orderly arranged three-dimension (3D) structure and roughness formed with increasing the number of coating bilayers. Besides, the enzyme-immobilized nanofibrous mats were found with high enzyme loading and activity, moreover, X-ray photoelectron spectroscopy (XPS) results further demonstrated the successful immobilization of chitosan and catalase on cellulose nanofibers support. Furthermore, we evaluated the cytotoxicity induced by hydrogen peroxide in the Human umbilical vascular endothelial cells with or without pretreatment of nanofibrous mats by MTT assay, LDH activity and Flow cytometric evaluation, and confirmed the pronounced hydrogen peroxide-induced toxicity, but pretreatment of immobilized catalase reduced the cytotoxicity and protected cells against hydrogen peroxide-induced cytotoxic effects which were further demonstrated by scanning electron microscopy (SEM) and Transmission Electron Microscopy (TEM) images. The data pointed toward a role of catalase-immobilized nanofibrous mats in protecting cells against hydrogen peroxide-induced cellular damage and their potential application in biomedical field. PMID:24804555

  14. NADPH binding and control of catalase compound II formation: comparison of bovine, yeast, and Escherichia coli enzymes.

    PubMed Central

    Hillar, A; Nicholls, P; Switala, J; Loewen, P C

    1994-01-01

    1. NADPH binds to bovine catalase and to yeast catalases A and T, but not to Escherichia coli catalase HPII. The association was demonstrated using chromatography and fluorimetry. Bound NADPH fluoresces in a similar way to NADPH in solution. 2. Bound NADPH protects bovine and yeast catalases against forming inactive peroxide compound II either via endogenous reductant action or by ferrocyanide reduction during catalytic activity in the presence of slowly generated peroxide. 3. Bound NADPH reduces neither compound I nor compound II of catalase. It apparently reacts with an intermediate formed during the decay of compound I to compound II; this postulated intermediate is an immediate precursor of stable compound II either when the latter is formed by endogenous reductants or when ferrocyanide is used. It represents therefore a new type of hydrogen donor that is not included in the original classification of Keilin and Nicholls [Keilin, D. and Nicholls, P. (1958) Biochim. Biophys. Acta 29, 302-307] 4. A model for NADPH action is presented in which concerted reduction of the ferryl iron and of a neighbouring protein free radical is responsible for the observed NADPH effects. The roles of migrant radical species in mammalian and yeast catalases are compared with similar events in metmyoglobin and cytochrome c peroxidase reactions with peroxides. Images Figure 1 PMID:8002960

  15. Catalase activity in macro- and microorganisms as an indicator of biotic stress in coastal waters of the eastern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Angel, D. L.; Fiedler, U.; Eden, N.; Kress, N.; Adelung, D.; Herut, B.

    In this study we examined the activity of catalase in the water column (mainly attributed to planktonic microorganisms) and the activity of catalase and superoxide dismutase (SOD), as well as lipid peroxidation in the midgut gland of the benthic bivalve Donax trunculus as possible indicators of biotic stress. The measurements were performed at stations situated at known contaminated and clean sites in the coastal waters and shores along the Israeli coast (eastern Mediterranean Sea). In the water column, we found that catalase activity was higher in polluted coastal waters than in nearby unpolluted or less-polluted stations. Moreover, there was diurnal periodicity in catalase activity rates which matched the diurnal changes in hydrogen peroxide levels in seawater. Consistent evidence of extracellular catalase activity was found in the seawater sampled. Catalase activity rates in the midgut gland of D. trunculus did not exhibit clear patterns with respect to site (polluted or clean) or season. However, SOD activity and lipid peroxidation measured in the same tissues were good indicators of organic pollution in the coastal waters examined and, among the three stations examined in Haifa Bay, Qiriat Haim was the most polluted.

  16. Susceptibility of Treponema pallidum to the toxic products of oxygen reduction and the non-treponemal nature of its catalase.

    PubMed Central

    Steiner, B; Wong, G H; Graves, S

    1984-01-01

    We examined the sensitivity of Treponema pallidum (Nichols strain) to toxic products of oxygen reduction. T pallidum was sensitive to hydrogen peroxide at concentrations similar to those to which obligate anaerobes are sensitive. Accelerated death of T pallidum occurred at hydrogen peroxide concentrations below 50 mumol/l. Agents protective against hydrogen peroxide and the hydroxyl free radical (catalase, peroxidase, and mannitol) significantly enhanced treponemal survival in vitro under all three conditions of aerobiosis tested--that is, air, 3% oxygen, and 3% oxygen in conjunction with a reduced medium. Superoxide dismutase (which provides protection against superoxide radicals) did not enhance treponemal survival in normal media. When superoxide radicals were generated in the medium by means of a xanthine and xanthine oxidase system, however, the enzyme did protect T pallidum. A possible toxic involvement of singlet oxygen was also indicated by enhanced treponemal survival in air in the presence of histidine. Extracts of T pallidum from infected rabbit testes showed catalase activity which, on polyacrylamide gel electrophoresis, had the same relative mobility as purified rabbit catalase. The treponemal catalase activity was neutralised by anti rabbit catalase antiserum (raised in guinea pigs). This confirmed that the catalase was of rabbit origin and not an endogenous enzyme of T pallidum. We discuss the relation of these results to the obligate parasitism of T pallidum. Images PMID:6421449

  17. Changes in the Activity of Catalase (EC 1.11.1.6) in Relation to the Dormancy of Grapevine (Vitis vinifera L.) Buds.

    PubMed

    Nir, G; Shulman, Y; Fanberstein, L; Lavee, S

    1986-08-01

    Catalase activity in grapevine (Vitis vinifera L.) buds cv. ;Perlette.' increased to a maximum in October and thereafter decreased within 3 months to less than half its maximal rate. The decrease in catalase activity coincided with the decline in temperature during winter. The rate of sprouting of buds forced at 23 degrees C was negatively related to the activity of catalase. Artificial chilling of grapevine canes at 5 degrees C resulted in a 25% decrease of catalase activity in the buds after 3 days and 31% after 17 days. The activity of catalase increased to the control level only 96 hours after removing canes from 5 degrees C to room temperature. Efficient buddormancy breaking agents, such as thiourea and cyanamide decreased catalase activity to 64 and 50% of the controls respectively, while the activity of peroxidase remained the same under those conditions. A less efficient dormancy breaking agent dinitro-ortho-cresol, did not decrease catalase activity. PMID:16664957

  18. Genome-wide Screening of Regulators of Catalase Expression: ROLE OF A TRANSCRIPTION COMPLEX AND HISTONE AND tRNA MODIFICATION COMPLEXES ON ADAPTATION TO STRESS.

    PubMed

    Garca, Patricia; Encinar Del Dedo, Javier; Ayt, Jos; Hidalgo, Elena

    2016-01-01

    In response to environmental cues, the mitogen-activated protein kinase Sty1-driven signaling cascade activates hundreds of genes to induce a robust anti-stress cellular response in fission yeast. Thus, upon stress imposition Sty1 transiently accumulates in the nucleus where it up-regulates transcription through the Atf1 transcription factor. Several regulators of transcription and translation have been identified as important to mount an integral response to oxidative stress, such as the Spt-Ada-Gcn5-acetyl transferase or Elongator complexes, respectively. With the aim of identifying new regulators of this massive gene expression program, we have used a GFP-based protein reporter and screened a fission yeast deletion collection using flow cytometry. We find that the levels of catalase fused to GFP, both before and after a threat of peroxides, are altered in hundreds of strains lacking components of chromatin modifiers, transcription complexes, and modulators of translation. Thus, the transcription elongation complex Paf1, the histone methylase Set1-COMPASS, and the translation-related Trm112 dimers are all involved in full expression of Ctt1-GFP and in wild-type tolerance to peroxides. PMID:26567340

  19. Respiration triggers heme transfer from cytochrome c peroxidase to catalase in yeast mitochondria

    PubMed Central

    Kathiresan, Meena; Martins, Dorival; English, Ann M.

    2014-01-01

    In exponentially growing yeast, the heme enzyme, cytochrome c peroxidase (Ccp1) is targeted to the mitochondrial intermembrane space. When the fermentable source (glucose) is depleted, cells switch to respiration and mitochondrial H2O2 levels rise. It has long been assumed that CCP activity detoxifies mitochondrial H2O2 because of the efficiency of this activity in vitro. However, we find that a large pool of Ccp1 exits the mitochondria of respiring cells. We detect no extramitochondrial CCP activity because Ccp1 crosses the outer mitochondrial membrane as the heme-free protein. In parallel with apoCcp1 export, cells exhibit increased activity of catalase A (Cta1), the mitochondrial and peroxisomal catalase isoform in yeast. This identifies Cta1 as a likely recipient of Ccp1 heme, which is supported by low Cta1 activity in ccp1? cells and the accumulation of holoCcp1 in cta1? mitochondria. We hypothesized that Ccp1s heme is labilized by hyperoxidation of the protein during the burst in H2O2 production as cells begin to respire. To test this hypothesis, recombinant Ccp1 was hyperoxidized with excess H2O2 in vitro, which accelerated heme transfer to apomyoglobin added as a surrogate heme acceptor. Furthermore, the proximal heme Fe ligand, His175, was found to be ?85% oxidized to oxo-histidine in extramitochondrial Ccp1 isolated from 7-d cells, indicating that heme labilization results from oxidation of this ligand. We conclude that Ccp1 responds to respiration-derived H2O2 via a previously unidentified mechanism involving H2O2-activated heme transfer to apoCta1. Subsequently, the catalase activity of Cta1, not CCP activity, contributes to mitochondrial H2O2 detoxification. PMID:25422453

  20. A Single Nucleotide Polymorphism in Catalase Is Strongly Associated with Ovarian Cancer Survival

    PubMed Central

    Saed, Mohammed G.; Abusamaan, Mohammed S.; Dyson, Gregory; Diamond, Michael P.; Saed, Ghassan M.

    2015-01-01

    Ovarian cancer is the deadliest of all gynecologic cancers. Recent evidence demonstrates an association between enzymatic activity altering single nucleotide polymorphisms (SNP) with human cancer susceptibility. We sought to evaluate the association of SNPs in key oxidant and antioxidant enzymes with increased risk and survival in epithelial ovarian cancer. Individuals (n = 143) recruited were divided into controls, (n = 94): healthy volunteers, (n = 18), high-risk BRCA1/2 negative (n = 53), high-risk BRCA1/2 positive (n = 23) and ovarian cancer cases (n = 49). DNA was subjected to TaqMan SNP genotype analysis for selected oxidant and antioxidant enzymes. Of the seven selected SNP studied, no association with ovarian cancer risk (Pearson Chi-square) was found. However, a catalase SNP was identified as a predictor of ovarian cancer survival by the Cox regression model. The presence of this SNP was associated with a higher likelihood of death (hazard ratio (HR) of 3.68 (95% confidence interval (CI): 1.149–11.836)) for ovarian cancer patients. Kaplan-Meier survival analysis demonstrated a significant median overall survival difference (108 versus 60 months, p<0.05) for those without the catalase SNP as compared to those with the SNP. Additionally, age at diagnosis greater than the median was found to be a significant predictor of death (HR of 2.78 (95% CI: 1.022–7.578)). This study indicates a strong association with the catalase SNP and survival of ovarian cancer patients, and thus may serve as a prognosticator. PMID:26301412

  1. Catalase activity of cytochrome C oxidase assayed with hydrogen peroxide-sensitive electrode microsensor.

    PubMed

    Bolshakov, I A; Vygodina, T V; Gennis, R; Karyakin, A A; Konstantinov, A A

    2010-11-01

    An iron-hexacyanide-covered microelectrode sensor has been used to continuously monitor the kinetics of hydrogen peroxide decomposition catalyzed by oxidized cytochrome oxidase. At cytochrome oxidase concentration ~1 M, the catalase activity behaves as a first order process with respect to peroxide at concentrations up to ~300-400 M and is fully blocked by heat inactivation of the enzyme. The catalase (or, rather, pseudocatalase) activity of bovine cytochrome oxidase is characterized by a second order rate constant of ~210(2) M(-1)sec(-1) at pH 7.0 and room temperature, which, when divided by the number of H2O2 molecules disappearing in one catalytic turnover (between 2 and 3), agrees reasonably well with the second order rate constant for H2O2-dependent conversion of the oxidase intermediate F(I)-607 to F(II)-580. Accordingly, the catalase activity of bovine oxidase may be explained by H2O2 procession in the oxygen-reducing center of the enzyme yielding superoxide radicals. Much higher specific rates of H2O2 decomposition are observed with preparations of the bacterial cytochrome c oxidase from Rhodobacter sphaeroides. The observed second order rate constants (up to ~3000 M(-1)sec(-1)) exceed the rate constant of peroxide binding with the oxygen-reducing center of the oxidized enzyme (~500 M(-1)sec(-1)) several-fold and therefore cannot be explained by catalytic reaction in the a(3)/Cu(B) site of the enzyme. It is proposed that in the bacterial oxidase, H2O2 can be decomposed by reacting with the adventitious transition metal ions bound by the polyhistidine-tag present in the enzyme, or by virtue of reaction with the tightly-bound Mn2+, which in the bacterial enzyme substitutes for Mg2+ present in the mitochondrial oxidase. PMID:21314602

  2. Targeted Overexpression of Mitochondrial Catalase Prevents Radiation-Induced Cognitive Dysfunction

    PubMed Central

    Parihar, Vipan K.; Allen, Barrett D.; Tran, Katherine K.; Chmielewski, Nicole N.; Craver, Brianna M.; Martirosian, Vahan; Morganti, Josh M.; Rosi, Susanna; Vlkolinsky, Roman; Acharya, Munjal M.; Nelson, Gregory A.; Allen, Antiño R.

    2015-01-01

    Abstract Aims: Radiation-induced disruption of mitochondrial function can elevate oxidative stress and contribute to the metabolic perturbations believed to compromise the functionality of the central nervous system. To clarify the role of mitochondrial oxidative stress in mediating the adverse effects of radiation in the brain, we analyzed transgenic (mitochondrial catalase [MCAT]) mice that overexpress human catalase localized to the mitochondria. Results: Compared with wild-type (WT) controls, overexpression of the MCAT transgene significantly decreased cognitive dysfunction after proton irradiation. Significant improvements in behavioral performance found on novel object recognition and object recognition in place tasks were associated with a preservation of neuronal morphology. While the architecture of hippocampal CA1 neurons was significantly compromised in irradiated WT mice, the same neurons in MCAT mice did not exhibit extensive and significant radiation-induced reductions in dendritic complexity. Irradiated neurons from MCAT mice maintained dendritic branching and length compared with WT mice. Protected neuronal morphology in irradiated MCAT mice was also associated with a stabilization of radiation-induced variations in long-term potentiation. Stabilized synaptic activity in MCAT mice coincided with an altered composition of the synaptic AMPA receptor subunits GluR1/2. Innovation: Our findings provide the first evidence that neurocognitive sequelae associated with radiation exposure can be reduced by overexpression of MCAT, operating through a mechanism involving the preservation of neuronal morphology. Conclusion: Our article documents the neuroprotective properties of reducing mitochondrial reactive oxygen species through the targeted overexpression of catalase and how this ameliorates the adverse effects of proton irradiation in the brain. Antioxid. Redox Signal. 22, 78–91. PMID:24949841

  3. Two temporally synthesized charge subunits interact to form the five isoforms of cottonseed (Gossypium hirsutum) catalase.

    PubMed Central

    Ni, W; Trelease, R N; Eising, R

    1990-01-01

    Five charge isoforms of tetrameric catalase were isolated from cotyledons of germinated cotton (Gossypium hirsutum L.) seedlings. Denaturing isoelectric focusing of the individual isoforms in polyacrylamide gels indicated that isoforms A (most anodic) and E (most cathodic) consisted of one subunit of different charge, whereas isoforms B, C and D each consisted of a mixture of these two subunits. Thus the five isoforms apparently were formed through combinations of two subunits in different ratios. Labelling cotyledons in vivo with [35S]methionine at three daily intervals in the dark, and translation in vivo of polyadenylated RNA isolated from cotyledons at the same ages, revealed synthesis of two different subunits. One of the subunits was synthesized in cotyledons at all ages studied (days 1-3), whereas the other subunit was detected only at days 2 and 3. This differential expression of two catalase subunits helped explain previous results from this laboratory showing that the two anodic forms (A and B) found in maturing seeds were supplemented with three cathodic forms (C-E) after the seeds germinated. These subunit data also helped clarify our new findings that proteins of isoforms A, B and C (most active isoforms) accumulated in cotyledons of plants kept in the dark for 3 days, then gradually disappeared during the next several days, whereas isoforms D and E (least active isoforms) remained in the cells. This shift in isoform pattern occurred whether seedlings were kept in the dark or exposed to continuous light after day 3, although exposure to light enhanced this process. These sequential molecular events were responsible for the characteristic developmental changes (rise and fall) in total catalase activity. We believe that the isoform changeover is physiologically related to the changeover in glyoxysome to leaf-type-peroxisome metabolism. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. PMID:1695843

  4. Pharmacokinetics and stability properties of catalase modified with water-soluble polysaccharides.

    PubMed

    Valdivia, Aymara; Prez, Yunel; Gmez, Leissy; Ramrez, Hector L; Schacht, Etienne H; Villalonga, Reynaldo

    2006-07-01

    Bovine liver catalase (EC 1.11.1.6) was chemically modified with mannan, carboxymethylcellulose, and carboxymethylchitin. The enzyme retained about 48-97% of the initial specific activity after glycosidation with the polysaccharides. The prepared neoglycoenzyme was 1.9-5.7 fold more stable against the thermal inactivation processes at 55 degrees C, in comparison with the native counterpart. Also, the modified enzyme was more resistant to proteolytic degradation with trypsin. Pharmacokinetics studies revealed higher plasma half-life time for all the enzyme-polymer preparations, but better results were achieved for the enzyme modified with the anionic macromolecules. PMID:16838281

  5. X-ray diffraction study of Penicillium Vitale catalase in the complex with aminotriazole

    SciTech Connect

    Borovik, A. A.; Grebenko, A. I.; Melik-Adamyan, V. R.

    2011-07-15

    The three-dimensional structure of the enzyme catalase from Penicillium vitale in a complex with the inhibitor aminotriazole was solved and refined by protein X-ray crystallography methods. An analysis of the three-dimensional structure of the complex showed that the inhibition of the enzyme occurs as a result of the covalent binding of aminotriazole to the amino-acid residue His64 in the active site of the enzyme. An investigation of the three-dimensional structure of the complex resulted in the amino-acid residues being more precisely identified. The binding sites of saccharide residues and calcium ions in the protein molecule were found.

  6. X-ray diffraction study of Penicillium Vitale catalase in the complex with aminotriazole

    NASA Astrophysics Data System (ADS)

    Borovik, A. A.; Grebenko, A. I.; Melik-Adamyan, V. R.

    2011-07-01

    The three-dimensional structure of the enzyme catalase from Penicillium vitale in a complex with the inhibitor aminotriazole was solved and refined by protein X-ray crystallography methods. An analysis of the three-dimensional structure of the complex showed that the inhibition of the enzyme occurs as a result of the covalent binding of aminotriazole to the amino-acid residue His64 in the active site of the enzyme. An investigation of the three-dimensional structure of the complex resulted in the amino-acid residues being more precisely identified. The binding sites of saccharide residues and calcium ions in the protein molecule were found.

  7. Temperature dependence of oxygen evolution through catalase-like activity of horseradish peroxidase

    NASA Astrophysics Data System (ADS)

    Popovi?-Bijeli?, A.; Bijeli?, G.; Kolar-Ani?, Lj.; Vukojevi?, V.

    2007-09-01

    By experimental investigations of the temperature dependence of catalase-like activity of horseradish peroxidase in the temperature range 278 328 K, different kinetic profiles for oxygen evolution were found below and above 298 K. Extension of the model is proposed to account for these observations. By numeric simulations of the reaction kinetics at different temperatures, it was found that enhanced evaporation of molecular oxygen from the reaction solution is the main root through which oxygen is lost at elevated temperatures in laboratory conditions.

  8. Biomimetic Mn-Catalases Based on Dimeric Manganese Complexes in Mesoporous Silica for Potential Antioxidant Agent.

    PubMed

    Escriche-Tur, Luis; Corbella, Montserrat; Font-Bardia, Mercè; Castro, Isabel; Bonneviot, Laurent; Albela, Belén

    2015-11-01

    Two new structural and functional models of the Mn-catalase with formula [{Mn(III)(bpy)(H2O)}(μ-2-MeOC6H4CO2)2(μ-O){Mn(III)(bpy)(X)}]X, where X = NO3 (1) and ClO4 (2) and bpy = 2,2'-bipyridine, were synthesized and characterized by X-ray diffraction. In both cases, a water molecule and an X ion occupy the monodentate positions. The magnetic properties of these compounds reveal a weak antiferromagnetic behavior (2J = -2.2 cm(-1) for 1 and -0.7 cm(-1) for 2, using the spin Hamiltonian H = -2J S1·S2) and negative zero-field splitting parameter DMn (-4.6 cm(-1) and -3.0 cm(-1) for 1 and 2, respectively). This fact, together with the nearly orthogonal orientation of the Jahn-Teller axes of the Mn(III) ions explain the unusual shape of χMT versus T plot at low temperature. Compound 1 presents a better catalase activity than 2 in CH3CN-H2O media, probably due to a beneficial interaction of the NO3(-) ion with the Mn complex in solution. These compounds were successfully inserted inside two-dimensional hexagonal mesoporous silica (MCM-41 type) leading to the same hybrid material ([Mn2O]@SiO2), without the X group. The manganese complex occupies approximately half of the available pore volume, keeping the silica's hexagonal array intact. Magnetic measurements of [Mn2O]@SiO2 suggest that most of the dinuclear unit is preserved, as a non-negligible interaction between Mn ions is still observed. The X-ray photoelectron spectroscopy analysis of the Mn 3s peak confirms that Mn remains as Mn(III) inside the silica. The catalase activity study of material [Mn2O]@SiO2 reveals that the complex is more active inside the porous silica, probably due to the surface silanolate groups of the pore wall. Moreover, the new material shows catalase activity in water media, while the coordination compounds are not active. PMID:26484833

  9. Epigenetic Silencing of the Key Antioxidant Enzyme Catalase in Karyotypically Abnormal Human Pluripotent Stem Cells

    PubMed Central

    Konki, Mikko; Pasumarthy, Kalyan; Malonzo, Maia; Sainio, Annele; Valensisi, Cristina; Söderström, Mirva; Emani, Maheswara Reddy; Stubb, Aki; Närvä, Elisa; Ghimire, Bishwa; Laiho, Asta; Järveläinen, Hannu; Lahesmaa, Riitta; Lähdesmäki, Harri; Hawkins, R. David; Lund, Riikka J.

    2016-01-01

    Epigenomic regulation is likely to be important in the maintenance of genomic integrity of human pluripotent stem cells, however, the mechanisms are unknown. We explored the epigenomes and transcriptomes of human pluripotent stem cells before and after spontaneous transformation to abnormal karyotypes and in correlation to cancer cells. Our results reveal epigenetic silencing of Catalase, a key regulator of oxidative stress and DNA damage control in abnormal cells. Our findings provide novel insight into the mechanisms associated with spontaneous transformation of human pluripotent stem cells towards malignant fate. The same mechanisms may control the genomic stability of cells in somatic tissues. PMID:26911679

  10. Dynamics of the reaction glucose-catalase-glucose oxidase-hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    ?p, M.; Schreiberov, L.; Schreiber, I.

    2011-12-01

    Glucose-catalase-glucose oxidase-hydrogen peroxide reaction is one of the few known enzymatic systems studied in vitro in the field of nonlinear chemical dynamics. This reaction belongs to the family of oscillatory enzymatic reactions, which form a natural basis of oscillations in biological systems. A parametric study of dependence on mixing, temperature and initial concentrations of components in a batch stirred reactor was carried out. A newly proposed mathematical model of the reaction conforms to the obtained experimental data. Results of our experiments and simulations hint at further directions of research of non-linear dynamics in this reaction.

  11. Epigenetic Silencing of the Key Antioxidant Enzyme Catalase in Karyotypically Abnormal Human Pluripotent Stem Cells.

    PubMed

    Konki, Mikko; Pasumarthy, Kalyan; Malonzo, Maia; Sainio, Annele; Valensisi, Cristina; Sderstrm, Mirva; Emani, Maheswara Reddy; Stubb, Aki; Nrv, Elisa; Ghimire, Bishwa; Laiho, Asta; Jrvelinen, Hannu; Lahesmaa, Riitta; Lhdesmki, Harri; Hawkins, R David; Lund, Riikka J

    2016-01-01

    Epigenomic regulation is likely to be important in the maintenance of genomic integrity of human pluripotent stem cells, however, the mechanisms are unknown. We explored the epigenomes and transcriptomes of human pluripotent stem cells before and after spontaneous transformation to abnormal karyotypes and in correlation to cancer cells. Our results reveal epigenetic silencing of Catalase, a key regulator of oxidative stress and DNA damage control in abnormal cells. Our findings provide novel insight into the mechanisms associated with spontaneous transformation of human pluripotent stem cells towards malignant fate. The same mechanisms may control the genomic stability of cells in somatic tissues. PMID:26911679

  12. Catalase, carbonic anhydrase and xanthine oxidase activities in patients with mycosis fungoides.

    PubMed

    Cengiz, Fatma Pelin; Beyaztas, Serap; Gokce, Basak; Arslan, Oktay; Guler, Ozen Ozensoy

    2015-04-01

    Mycosis fungoides (MF) is the most common form of cutaneous T-cell lymphoma. In several studies the relationship between catalase (CAT), human cytosolic carbonic anhydrases (CA; hCA-I and hCA-II) and xanthine oxidase (XO) enzyme activities have been investigated in various types of cancers but carbonic anhydrase, catalase and xanthine oxidase activities in patients with MF have not been previously reported. Therefore, in this preliminary study we aim to investigate CAT, CA and XO activities in patients with MF. This study enrolled 32 patients with MF and 26 healthy controls. According to the results, CA and CAT activities were significantly lower in patients with mycosis fungoides than controls (p?

  13. Isonicotinic Acid Hydrazide Conversion to Isonicotinyl-NAD by Catalase-peroxidases*

    PubMed Central

    Wiseman, Ben; Carpena, Xavi; Feliz, Miguel; Donald, Lynda J.; Pons, Miquel; Fita, Ignacio; Loewen, Peter C.

    2010-01-01

    Activation of the pro-drug isoniazid (INH) as an anti-tubercular drug in Mycobacterium tuberculosis involves its conversion to isonicotinyl-NAD, a reaction that requires the catalase-peroxidase KatG. This report shows that the reaction proceeds in the absence of KatG at a slow rate in a mixture of INH, NAD+, Mn2+, and O2, and that the inclusion of KatG increases the rate by >7 times. Superoxide, generated by either Mn2+- or KatG-catalyzed reduction of O2, is an essential intermediate in the reaction. Elimination of the peroxidatic process by mutation slows the rate of reaction by 60% revealing that the peroxidatic process enhances, but is not essential for isonicotinyl-NAD formation. The isonicotinyl-NAD•+ radical is identified as a reaction intermediate, and its reduction by superoxide is proposed. Binding sites for INH and its co-substrate, NAD+, are identified for the first time in crystal complexes of Burkholderia pseudomallei catalase-peroxidase with INH and NAD+ grown by co-crystallization. The best defined INH binding sites were identified, one in each subunit, on the opposite side of the protein from the entrance to the heme cavity in a funnel-shaped channel. The NAD+ binding site is ∼20 Å from the entrance to the heme cavity and involves interactions primarily with the AMP portion of the molecule in agreement with the NMR saturation transfer difference results. PMID:20554537

  14. One-step purification and properties of catalase from leaves of Zantedeschia aethiopica.

    PubMed

    Trindade, H; Karmali, A; Pais, M S

    1988-12-01

    Catalase (E.C 1.11.1.6) was purified from leaves of Zandedeschia aethiopica to apparent homogeneity by a one-step hydrophobic interaction chromatography on a phenyl Sepharose CL-4B column. The purified enzyme preparation was obtained with a final recovery of enzyme activity of about 61% and a specific activity of 146 U/mg protein. The purified enzyme ran as a single protein band when analyzed both by native PAGE and SDS-PAGE corresponding to an Mr of 220,000 Da, which consists of 4 subunits with identical Mr of 54,000 Da. The pI of purified enzyme was found to be 5.2 by isoelectric focusing on ultrathin polyacrylamide gels. The purified catalase has an optimum temperature of activity at 40 degrees C, whereas it is stable between 0 degrees and 50 degrees C. As regards pH, the enzyme has an optimum activity at pH 7.0 and it is stable in the range pH 6-8. The absorption spectrum of the purified enzyme exhibited 2 peaks at 280 nm and 405 nm. PMID:3150680

  15. Influence of added catalase on chromosome stability and neoplastic transformation of mouse cells in culture.

    PubMed Central

    Jones, G. M.; Sanford, K. K.; Parshad, R.; Gantt, R.; Price, F. M.; Tarone, R. E.

    1985-01-01

    The generation of hydrogen peroxide (H2O2) and the derivative free hydroxyl radical (. OH) in cultures of mouse cells grown in the presence of visible light and ambient oxygen was shown previously to be implicated in chromatid damage. Furthermore, chromosome alterations appear to be associated with the spontaneous neoplastic transformation of mouse cells in culture. An attempt was made in this study to reduce the incidence of chromosomal aberrations and delay or prevent the onset of spontaneous neoplastic transformation of freshly isolated mouse cells, both fibroblasts and epidermal keratinocytes, by adding catalase to the culture medium, shielding the cultures from wavelengths less than 500 nm and providing a gas phase of 0-1% O2. These conditions significantly decreased the incidence of chromosomal aberrations in both cell types, and in fibroblasts prevented tumourigenicity in non-irradiated syngeneic mice, and increased latent periods for tumour development in X-irradiated mice. The epidermal keratinocytes were particularly resistant to spontaneous neoplastic transformation under all conditions tested. These observations on the protective effect of extracellular catalase suggest that H2O2, a normal metabolite, and/or the derivative .OH can directly or indirectly produce genetic damage and neoplastic transformation in mouse fibroblasts. PMID:2415146

  16. Catalase-like activity studies of the manganese(II) adsorbed zeolites

    NASA Astrophysics Data System (ADS)

    Ćiçek, Ekrem; Dede, Bülent

    2013-12-01

    Preparation of manganese(II) adsorbed on zeolite 3A, 4A, 5A. AW-300, ammonium Y zeolite, organophilic, molecular sieve and catalase-like enzyme activity of manganese(II) adsorbed zeolites are reported herein. Firstly zeolites are activated at 873 K for two hours before contact manganese(II) ions. In order to observe amount of adsorption, filtration process applied for the solution. The pure zeolites and manganese(II) adsorbed zeolites were analysed by FT-IR. As a result according to the FT-IR spectra, the incorporation of manganese(II) cation into the zeolite structure causes changes in the spectra. These changes are expected particularly in the pseudolattice bands connected with the presence of alumino and silicooxygen tetrahedral rings in the zeolite structure. Furthermore, the catalytic activities of the Mn(II) adsorbed zeolites for the disproportionation of hydrogen peroxide were investigated in the presence of imidazole. The Mn(II) adsorbed zeolites display efficiency in the disproportion reactions of hydrogen peroxide, producing water and dioxygen in catalase-like activity.

  17. A bifunctional enzyme from Rhodococcus erythropolis exhibiting secondary alcohol dehydrogenase-catalase activities.

    PubMed

    Martinez-Rojas, Enriqueta; Kurt, Tutku; Schmidt, Udo; Meyer, Vera; Garbe, Leif-Alexander

    2014-11-01

    Alcohol dehydrogenases have long been recognized as potential biocatalyst for production of chiral fine and bulk chemicals. They are relevant for industry in enantiospecific production of chiral compounds. In this study, we identified and purified a nicotinamide adenine dinucleotide (NAD)-dependent secondary alcohol dehydrogenase (SdcA) from Rhodococcus erythropolis oxidizing γ-lactols into γ-lactones. SdcA showed broad substrate specificity on γ-lactols; secondary aliphatic alcohols with 8 and 10 carbon atoms were also substrates and oxidized with (2S)-stereospecificity. The enzyme exhibited moderate stability with a half-life of 5 h at 40 °C and 20 days at 4 °C. Mass spectrometric identification revealed high sequence coverage of SdcA amino acid sequence to a highly conserved catalase from R. erythropolis. The corresponding encoding gene was isolated from genomic DNA and subsequently overexpressed in Escherichia coli BL21 DE3 cells. In addition, the recombinant SdcA was purified and characterized in order to confirm that the secondary alcohol dehydrogenase and catalase activity correspond to the same enzyme. PMID:24846734

  18. Modulation of reactive oxygen species by Rac1 or catalase prevents asbestos-induced pulmonary fibrosis

    PubMed Central

    Murthy, Shubha; Adamcakova-Dodd, Andrea; Perry, Sarah S.; Tephly, Linda A.; Keller, Richard M.; Metwali, Nervana; Meyerholz, David K.; Wang, Yongqiang; Glogauer, Michael; Thorne, Peter S.

    2009-01-01

    The release of reactive oxygen species (ROS) and cytokines by alveolar macrophages has been demonstrated in asbestos-induced pulmonary fibrosis, but the mechanism linking alveolar macrophages to the pathogenesis is not known. The GTPase Rac1 is a second messenger that plays an important role in host defense. In this study, we demonstrate that Rac1 null mice are protected from asbestos-induced pulmonary fibrosis, as determined by histological and biochemical analysis. We hypothesized that Rac1 induced pulmonary fibrosis via generation of ROS. Asbestos increased TNF-? and ROS in a Rac1-dependent manner. TNF-? was elevated only 1 day after exposure, whereas ROS generation progressively increased in bronchoalveolar lavage cells obtained from wild-type (WT) mice. To determine whether ROS generation contributed to pulmonary fibrosis, we overexpressed catalase in WT monocytes and observed a decrease in ROS generation in vitro. More importantly, administration of catalase to WT mice attenuated the development of fibrosis in vivo. For the first time, these results demonstrate that Rac1 plays a crucial role in asbestos-induced pulmonary fibrosis. Moreover, it suggests that a simple intervention may be useful to prevent progression of the disease. PMID:19684199

  19. Catalytic activity of catalase under strong magnetic fields of up to 8 T

    NASA Astrophysics Data System (ADS)

    Ueno, S.; Iwasaka, M.

    1996-04-01

    The question of whether or not magnetic fields affect enzymatic activity is of considerable interest in biomagnetics and biochemistry. This study focuses on whether magnetically related enzymatic activities can be affected by magnetic fields. We examined the effect of magnetic fields of up to 8 T on catalytic decomposition of hydrogen peroxide (H2O2). We observed changes in absorbance of reaction mixture of hydrogen peroxide and catalase at 240 nm, during and after magnetic field exposures. When the reaction mixture was not treated with nitrogen-gas bubbling, it was observed that the initial reaction rate of the reaction which was exposed to magnetic fields of up to 8 T was 50%-85% lower than the control data. This magnetic field effect was not observed, however, when the reaction mixture was bubbled with nitrogen gas to remove the dissolved oxygen molecules which were produced in the solution. We also measured concentration of dissolved oxygen which was produced by the decomposition of hydrogen peroxide. Dissolved oxygen concentration in the reaction mixture which was exposed to magnetic fields increased 20%-25% compared to the control solution. The results of the present study indicate that magnetic fields affect dynamic movement of oxygen bubbles which are produced in the reaction mixture by the decomposition of hydrogen peroxide, but not the catalytic activity of catalase itself.

  20. Isonicotinic acid hydrazide conversion to Isonicotinyl-NAD by catalase-peroxidases.

    PubMed

    Wiseman, Ben; Carpena, Xavi; Feliz, Miguel; Donald, Lynda J; Pons, Miquel; Fita, Ignacio; Loewen, Peter C

    2010-08-20

    Activation of the pro-drug isoniazid (INH) as an anti-tubercular drug in Mycobacterium tuberculosis involves its conversion to isonicotinyl-NAD, a reaction that requires the catalase-peroxidase KatG. This report shows that the reaction proceeds in the absence of KatG at a slow rate in a mixture of INH, NAD(+), Mn(2+), and O(2), and that the inclusion of KatG increases the rate by >7 times. Superoxide, generated by either Mn(2+)- or KatG-catalyzed reduction of O(2), is an essential intermediate in the reaction. Elimination of the peroxidatic process by mutation slows the rate of reaction by 60% revealing that the peroxidatic process enhances, but is not essential for isonicotinyl-NAD formation. The isonicotinyl-NAD(*+) radical is identified as a reaction intermediate, and its reduction by superoxide is proposed. Binding sites for INH and its co-substrate, NAD(+), are identified for the first time in crystal complexes of Burkholderia pseudomallei catalase-peroxidase with INH and NAD(+) grown by co-crystallization. The best defined INH binding sites were identified, one in each subunit, on the opposite side of the protein from the entrance to the heme cavity in a funnel-shaped channel. The NAD(+) binding site is approximately 20 A from the entrance to the heme cavity and involves interactions primarily with the AMP portion of the molecule in agreement with the NMR saturation transfer difference results. PMID:20554537

  1. Copper suppresses abscisic acid catabolism and catalase activity, and inhibits seed germination of rice.

    PubMed

    Ye, Nenghui; Li, Haoxuan; Zhu, Guohui; Liu, Yinggao; Liu, Rui; Xu, Weifeng; Jing, Yu; Peng, Xinxiang; Zhang, Jianhua

    2014-11-01

    Although copper (Cu) is an essential micronutrient for plants, a slight excess of Cu in soil can be harmful to plants. Unfortunately, Cu contamination is a growing problem all over the world due to human activities, and poses a soil stress to plant development. As one of the most important biological processes, seed germination is sensitive to Cu stress. However, little is known about the mechanism of Cu-induced inhibition of seed germination. In the present study, we investigated the relationship between Cu and ABA which is the predominant regulator of seed germination. Cu at a concentration of 30 M effectively inhibited germination of rice caryopsis. ABA content in germinating seeds under copper stress was also higher than that under control conditions. Quantitative real-time PCR (qRT-PCR) revealed that Cu treatment reduced the expression of OsABA8ox2, a key gene of ABA catabolism in rice seeds. In addition, both malondialdehyde (MDA) and H2O2 contents were increased by Cu stress in the germinating seeds. Antioxidant enzyme assays revealed that only catalase activity was reduced by excess Cu, which was consistent with the mRNA profile of OsCATa during seed germination under Cu stress. Together, our results demonstrate that suppression of ABA catabolism and catalase (CAT) activity by excess Cu leads to the inhibition of seed germination of rice. PMID:25273891

  2. Cysteine-independent Catalase-like Activity of Vertebrate Peroxiredoxin 1 (Prx1).

    PubMed

    Sun, Cen-Cen; Dong, Wei-Ren; Zhao, Jing; Nie, Li; Xiang, Li-Xin; Zhu, Guan; Shao, Jian-Zhong

    2015-08-01

    Peroxiredoxins (Prxs) are a ubiquitous family of antioxidant proteins that are known as thioredoxin peroxidases. Here we report that Prx1 proteins from Tetraodon nigroviridis and humans also possess a previously unknown catalase-like activity that is independent of Cys residues and reductants but dependent on iron. We identified that the GVL motif was essential to the catalase (CAT)-like activity of Prx1 but not to the Cys-dependent thioredoxin peroxidase (POX) activity, and we generated mutants lacking POX and/or CAT activities for individually delineating their functional features. We discovered that the TnPrx1 POX and CAT activities possessed different kinetic features in reducing H2O2. The overexpression of wild-type TnPrx1 and mutants differentially regulated the intracellular levels of reactive oxygen species and p38 phosphorylation in HEK-293T cells treated with H2O2. These observations suggest that the dual antioxidant activities of Prx1 may be crucial for organisms to mediate intracellular redox homeostasis. PMID:26088136

  3. Catalase Overexpression Reduces Lactic Acid-Induced Oxidative Stress in Saccharomyces cerevisiae?

    PubMed Central

    Abbott, Derek A.; Suir, Erwin; Duong, Giang-Huong; de Hulster, Erik; Pronk, Jack T.; van Maris, Antonius J. A.

    2009-01-01

    Industrial production of lactic acid with the current pyruvate decarboxylase-negative Saccharomyces cerevisiae strains requires aeration to allow for respiratory generation of ATP to facilitate growth and, even under nongrowing conditions, cellular maintenance. In the current study, we observed an inhibition of aerobic growth in the presence of lactic acid. Unexpectedly, the cyb2? reference strain, used to avoid aerobic consumption of lactic acid, had a specific growth rate of 0.25 h?1 in anaerobic batch cultures containing lactic acid but only 0.16 h?1 in identical aerobic cultures. Measurements of aerobic cultures of S. cerevisiae showed that the addition of lactic acid to the growth medium resulted in elevated levels of reactive oxygen species (ROS). To reduce the accumulation of lactic acid-induced ROS, cytosolic catalase (CTT1) was overexpressed by replacing the native promoter with the strong constitutive TPI1 promoter. Increased activity of catalase was confirmed and later correlated with decreased levels of ROS and increased specific growth rates in the presence of high lactic acid concentrations. The increased fitness of this genetically modified strain demonstrates the successful attenuation of additional stress that is derived from aerobic metabolism and may provide the basis for enhanced (micro)aerobic production of organic acids in S. cerevisiae. PMID:19251894

  4. Molecular Cloning and Expression Analysis of a Catalase Gene (NnCAT) from Nelumbo nucifera.

    PubMed

    Dong, Chen; Zheng, Xingfei; Diao, Ying; Wang, Youwei; Zhou, Mingquan; Hu, Zhongli

    2015-11-01

    Rapid amplification cDNA end (RACE) assay was established to achieve the complete cDNA sequence of a catalase gene (NnCAT) from Nelumbo nucifera. The obtained full-length cDNA was 1666 bp in size and contained a 1476-bp open reading frame. The 3D structural model of NnCAT was constructed by homology modeling. The putative NnCAT possessed all the main characteristic amino acid residues and motifs of catalase (CAT) protein family, and the phylogenetic analysis revealed that NnCAT grouped together with high plants. Moreover, recombinant NnCAT showed the CAT activity (758 U/mg) at room temperature, holding high activity during temperature range of 20-50 °C, then the optimal pH of recombinant protein was assessed from pH 4 to pH 11. Additionally, real-time PCR assay demonstrated that NnCAT mRNA was expressed in various tissues of N. nucifera, with the highest expression in young leaf and lowest level in the root, and mRNA level of NnCAT was significantly augmented in response to short-time mechanical wounding. Different expression pattern of NnCAT gene suggested that NnCAT probably played a defensive role in the initial stages of oxidative stress, regulating the level of reactive oxygen species (ROS) by extracellular stimuli such as short-time mechanical wounding. PMID:26299377

  5. Superoxide dismutase, catalase, and. alpha. -tocopherol content of stored potato tubers. [Solanum tuberosum L

    SciTech Connect

    Spychalla, J.P.; Desborough, S.L. )

    1990-11-01

    Activated oxygen or oxygen free radical mediated damage to plants has been established or implicated in many plant stress situations. The extent of activated oxygen damage to potato (Solanum tuberosum L.) tubers during low temperature storage and long-term storage is not known. Quantitation of oxygen free radical mediated damage in plant tissues is difficult. However, it is comparatively easy to quantitate endogenous antioxidants, which detoxify potentially damaging forms of activated oxygen. Three tuber antioxidants, superoxide dismutase, catalase, and {alpha}-tocopherol were assayed from four potato cultivars stored at 3{degree}C and 9{degree}C for 40 weeks. Tubers stored at 3{degree}C demonstrated increased superoxide dismutase activities (up to 72%) compared to tubers stored at 9{degree}C. Time dependent increases in the levels of superoxide dismutase, catalase, and {alpha}-tocopherol occurred during the course of the 40 week storage. The possible relationship between these increases in antioxidants and the rate of activated oxygen production in the tubers is discussed.

  6. Salicylic acid and salicylic acid sensitive and insensitive catalases in different genotypes of chickpea against Fusarium oxysporum f. sp. ciceri.

    PubMed

    Gayatridevi, S; Jayalakshmi, S K; Mulimani, V H; Sreeramulu, K

    2013-10-01

    Differential expression of catalase isozymes in different genotypes of chickpea resistant genotypes- A1, JG-315, JG-11, WR-315, R1-315, Vijaya, ICCV-15017, GBS-964, GBM-10, and susceptible genotypes- JG-62, MNK, ICCV-08321, ICCV-08311, KW-104, ICCV-08123, ICC-4951, ICC-11322, ICC-08116 for wilt disease caused by Fusarium oxysporum. f. sp. ciceri (Foc) was analyzed. Salicylic acid (SA) and H2O2 concentrations were determined in control as well as in plants infected with F. ciceri and found that the high and low levels of salicylic acid and H2O2 in resistant and susceptible genotypes of chickpea respectively. Catalase isozyme activities were detected in the gel and found that no induction of new catalases was observed in all the resistant genotypes and their some of the native catalase isozymes were inhibited; whereas, induction of multiple catalase isozymes was observed in all the screened susceptible genotypes and their activities were not inhibited upon Foc or SA treatments. The above results support the possible role of these isozymes as a marker to identify which genotype of chickpea is expressing systemic acquired resistance. PMID:24431522

  7. Important role of catalase in the cellular response of the budding yeast Saccharomyces cerevisiae exposed to ionizing radiation.

    PubMed

    Nishimoto, Takuto; Furuta, Masakazu; Kataoka, Michihiko; Kishida, Masao

    2015-03-01

    Ionizing radiation indirectly causes oxidative stress in cells via reactive oxygen species (ROS), such as hydroxyl radicals (OH(-)) generated by the radiolysis of water. We investigated how the catalase function was affected by ionizing radiation and analyzed the phenotype of mutants with a disrupted catalase gene in Saccharomyces cerevisiae exposed to radiation. The wild-type yeast strain and isogenic mutants with disrupted catalase genes were exposed to various doses of (60)Co gamma-rays. There was no difference between the wild-type strain and the cta1 disruption mutant following exposure to gamma-ray irradiation. In contrast, there was a significant decrease in the ctt1 disruption mutant, suggesting that this strain exhibited decreased survival on gamma-ray exposure compared with other strains. In all three strains, stationary phase cells were more tolerant to the exposure of gamma-rays than exponential phase cells, whereas the catalase activity in the wild-type strain and cta1 disruption mutant was higher in the stationary phase than in the exponential phase. These data suggest a correlation between catalase activity and survival following gamma-ray exposure. However, this correlation was not clear in the ctt1 disruption mutant, suggesting that other factors are involved in the tolerance to ROS induced by irradiation. PMID:25416226

  8. Evidence for separate substrate binding sites for hydrogen peroxide and cumene hydroperoxide (CHP) in the oxidation of ethanol by catalase

    SciTech Connect

    DeMaster, E.G.; Nagasawa,ss H.T.

    1986-03-01

    The oxidation of ethanol by purified bovine liver catalase (Sigma, C-40) can be supported by H/sub 2/O/sub 2/ or by CHP. The time course of the H/sub 2/O/sub 2/ supported reaction (using glucose/glucose oxidase as the H/sub 2/O/sub 2/ source) was linear for at least one hr, whereas the rate of acetaldehyde formation in the CHP (4.2 mM) supported reaction decreased with time. When catalase was exposed o CHP for 5 min before the addition of ethanol, the rate of CHP supported ethanol oxidation was reduced by more than 90% compared to incubations where the addition of ethanol preceded that of CHP. In the CHP inhibited state, the peroxidative activity of catalase was not restored by further addition of CHP or ethanol; however, addition of fresh catalase yielded its expected activity. Significantly, the CHP inhibited enzyme was equally effective as the untreated enzyme in catalyzing (a) the oxidation of ethanol in the presence H/sub 2/O/sub 2/ supported peroxidative activity as well as catalytic activity by CHP inhibited catalase points to separate binding sites for H/sub 2/O/sub 2/ and CHP in this reaction. Alternatively, CHP may bind adjacent to a common peroxide active site, thereby sterically impeding the binding of CHP - but not of H/sub 2/O/sub 2/ - to this active site.

  9. Ultraviolet Light B-Mediated Inhibition of Skin Catalase Activity Promotes Gr-1+CD11b+ Myeloid Cell Expansion

    PubMed Central

    Sullivan, Nicholas J.; Tober, Kathleen L.; Burns, Erin M.; Schick, Jonathan S.; Riggenbach, Judith A.; Mace, Thomas A.; Bill, Matthew A.; Young, Gregory S.; Oberyszyn, Tatiana M.; Lesinski, Gregory B.

    2011-01-01

    Skin cancer incidence and mortality are higher in men compared to women, but the causes of this sex discrepancy remain largely unknown. Ultraviolet light exposure induces cutaneous inflammation and neutralizes cutaneous antioxidants. Gr-1+CD11b+ myeloid cells are heterogeneous bone marrow-derived cells that promote inflammation-associated carcinogenesis. Reduced activity of catalase, an antioxidant present within skin, has been associated with skin carcinogenesis. We utilized the outbred, immune competent Skh-1 hairless mouse model of ultraviolet light B (UVB)-induced inflammation and non-melanoma skin cancer to further define sex discrepancies in UVB-induced inflammation. Our results demonstrated that male skin had relatively lower baseline catalase activity, which was inhibited following acute UVB exposure in both sexes. Further analysis revealed that skin catalase activity inversely correlated with splenic Gr-1+CD11b+ myeloid cell percentage. Acute UVB exposure induced Gr-1+CD11b+ myeloid cell skin infiltration, which was inhibited to a greater extent in males by topical catalase treatment. In chronic UVB studies, we demonstrated that the percentage of splenic Gr-1+CD11b+ myeloid cells was 55% higher in male tumor-bearing mice compared to their female counterparts. Together, our findings indicate that lower skin catalase activity in male mice may at least in part contribute to increased UVB-induced Gr-1+CD11b+ myeloid cells and subsequent skin carcinogenesis. PMID:22030957

  10. Uncaria tomentosa extracts protect human erythrocyte catalase against damage induced by 2,4-D-Na and its metabolites.

    PubMed

    Bukowska, Bo?ena; Bors, Milena; Gulewicz, Krzysztof; Koter-Michalak, Maria

    2012-06-01

    The effect of ethanolic and aqueous extracts from leaves and bark of Uncaria tomentosa was studied, with particular attention to catalase activity (CAT - EC. 1.11.1.6). We observed that all tested extracts, at a concentration of 250 ?g/mL were not toxic to erythrocyte catalase because they did not decreased its activity. Additionally, we investigated the protective effect of extracts on changes in CAT activity in the erythrocytes incubated with sodium salt of 2,4-dichlorophenoxyacetic acid (2,4-D-Na) and its metabolites i.e., 2,4-dichlorophenol (2,4-DCP) and catechol. Previous investigations showed that these chemicals decreased activity of erythrocyte catalase (Bukowska et al., 2000; Bukowska and Kowalska, 2004). The erythrocytes were divided into two portions. The first portion was incubated for 1 and 5h at 37C with 2,4-D-Na, 2,4-DCP and catechol, and second portion was preincubated with extracts for 10 min and then incubated with xenobiotics for 1 and 5h. CAT activity was measured in the first and second portion of the erythrocytes. We found a protective effect of the extracts from U. tomentosa on the activity of catalase incubated with xenobiotics studied. Probably, phenolic compounds contained in U. tomentosa scavenged free radicals, and therefore protected active center (containing -SH groups) of catalase. PMID:22426356

  11. Protective effects of PEP-1-Catalase on stress-induced cellular toxicity and MPTP-induced Parkinsons disease

    PubMed Central

    Eom, Seon Ae; Kim, Dae Won; Shin, Min Jea; Ahn, Eun Hee; Chung, Seok Young; Sohn, Eun Jeong; Jo, Hyo Sang; Jeon, Su-Jeong; Kim, Duk-Soo; Kwon, Hyeok Yil; Cho, Sung-Woo; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Choi, Soo Young

    2015-01-01

    Parkinsons disease (PD) is a neurodegenerative disability caused by a decrease of dopaminergic neurons in the substantia nigra (SN). Although the etiology of PD is not clear, oxidative stress is believed to lead to PD. Catalase is antioxidant enzyme which plays an active role in cells as a reactive oxygen species (ROS) scavenger. Thus, we investigated whether PEP-1-Catalase protects against 1-methyl-4-phenylpyridinium (MPP+) induced SH-SY5Y neuronal cell death and in a 1-methyl-4-phenyl-1,2,3,6-trtrahydropyridine (MPTP) induced PD animal model. PEP-1-Catalase transduced into SH-SY5Y cells significantly protecting them against MPP+-induced death by decreasing ROS and regulating cellular survival signals including Akt, Bax, Bcl-2, and p38. Immunohistochemical analysis showed that transduced PEP-1-Catalase markedly protected against neuronal cell death in the SN in the PD animal model. Our results indicate that PEP-1-Catalase may have potential as a therapeutic agent for PD and other oxidative stress related diseases. [BMB Reports 2015; 48(7): 395-400] PMID:25322954

  12. A factor converting viable but nonculturable Vibrio cholerae to a culturable state in eukaryotic cells is a human catalase

    PubMed Central

    Senoh, Mitsutoshi; Hamabata, Takashi; Takeda, Yoshifumi

    2015-01-01

    In our previous work, we demonstrated that viable but nonculturable (VBNC) Vibrio cholerae O1 and O139 were converted to culturable by coculture with eukaryotic cells. Furthermore, we isolated a factor converting VBNC V. cholerae to culturable (FCVC) from a eukaryotic cell line, HT-29. In this study, we purified FCVC by successive column chromatographies comprising UNO Q-6 anion exchange, Bio-Scale CHT2-1 hydroxyapatite, and Superdex 200 10/300 GL. Homogeneity of the purified FCVC was demonstrated by SDS-PAGE. Nano-LC MS/MS analysis showed that the purified FCVC was a human catalase. An experiment of RNAi knockdown of catalase mRNA from HT-29 cells and treatment of the purified FCVC with a catalase inhibitor, 3-amino-1,2,4-triazole confirmed that the FCVC was a catalase. A possible role of the catalase in converting a VBNC V. cholerae to a culturable state in the human intestine is discussed. PMID:25974870

  13. Crystallization and preliminary X-ray diffraction analysis of a cold-adapted catalase from Vibrio salmonicida

    SciTech Connect

    Riise, Ellen Kristin; Lorentzen, Marit Sjo; Helland, Ronny; Willassen, Nils Peder

    2006-01-01

    Monoclinic (P2{sub 1}) crystals of a His-tagged form of V. salmonicida catalase without cofactor diffract X-rays to 1.96 Å. Catalase (EC 1.11.1.6) catalyses the breakdown of hydrogen peroxide to water and molecular oxygen. Recombinant Vibrio salmonicida catalase (VSC) possesses typical cold-adapted features, with higher catalytic efficiency, lower thermal stability and a lower temperature optimum than its mesophilic counterpart from Proteus mirabilis. Crystals of VSC were produced by the hanging-drop vapour-diffusion method using ammonium sulfate as precipitant. The crystals belong to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 98.15, b = 217.76, c = 99.28 Å, β = 110.48°. Data were collected to 1.96 Å and a molecular-replacement solution was found with eight molecules in the asymmetric unit.

  14. Fluoxetin Upregulates Connexin 43 Expression in Astrocyte

    PubMed Central

    Mostafavi, Hossein; Khaksarian, Mojtaba; Joghataei, Mohammad Taghi; Hassanzadeh, Gholamreza; Soleimani, Masoud; Eftekhari, Sanaz; Soleimani, Mansooreh; Mousavizadeh, Kazem; Hadjighassem, Mahmoud Reza

    2014-01-01

    Introduction Recent studies have shown that astrocytes play major roles in normal and disease condition of the central nervous system including multiple sclerosis (MS). Molecular target therapy studies in MS have revealed that connexin-43 (Cx43) and Aquaporin-4 (AQP4) contents of astrocytes undergo expression alteration. Fluoxetine had some effects in MS patients unrelated to its known antidepressant effects. Some of fluoxetine effects were attributed to its capability of cAMP signaling pathway stimulation. This study aimed to investigate possible acute effects of fluoxetine on Cx43 and AQP4 expression in astrocyte. Methods Astrocytoma cells were treated for 24 hours with fluoxetine (10 and 20 g/ml) with or without adenyl cyclase (AC) and protein kinase A (PKA) inhibition. Cx43 expression at both mRNA and protein levels and AQP4 expression at mRNA level were evaluated. Results Acquired results showed that fluoxetine with and without AC and PKA inhibition resulted in Cx43 up-regulation both in mRNA and protein levels, whereas AQP4 expression have not changed. Discussion In conclusion, data showed that fluoxetine alone and in the absence of serotonin acutely up-regulated Cx43 expression in astrocytes that can be assumed in molecular target therapy of MS patients. It seems that cAMP involvement in fluoxetine effects need more researches. PMID:25436087

  15. The catalase C-262T gene polymorphism and cancer risk: a systematic review and meta-analysis.

    PubMed

    Shen, Yongchun; Li, Diandian; Tian, Panwen; Shen, Konglong; Zhu, Jing; Feng, Mei; Wan, Chun; Yang, Ting; Chen, Lei; Wen, Fuqiang

    2015-04-01

    Many studies suggest that catalase C-262T gene polymorphism is associated with cancer risk, but with inconsistent results. This study aimed to summarize the overall association between catalase C-262T polymorphism and cancer risk. Literature search was performed in PubMed, Embase, and other databases, studies regarding the association between catalase C-262T polymorphism and cancer risk were identified, and data were retrieved and analyzed by using Review Manager 5.0.24 and STATA 12.0. A total of 18 publications with 22 case-control studies, including 9777 cancer patients and 12,223 controls, met the inclusion criteria. Meta-analysis results showed significant association between catalase C-262 T polymorphism and cancer risk (TT vs CT?+?CC: odds ratio [OR]?=?1.17, 95% confidence interval [CI]?=?1.03-1.31, P?=?0.01). Subgroup analyses stratified by cancer types suggested the catalase C-262T polymorphism was significantly associated with an increased prostate cancer risk (TT vs CT?+?CC: OR?=?1.61, 95% CI?=?1.17-2.22, P?=?0.004); for subgroup analyses stratified by ethnicity, no associations between this polymorphism and Asians or whites were identified (CT?+?TT vs CC: OR?=?1.11, 95% CI?=?0.98-1.26, P?=?0.09 for whites; OR?=?1.19, 95% CI?=?0.78-1.80, P?=?0.42 for Asians). In summary, the catalase C-262T polymorphism may be a risk factor for cancer with cancer type-specific effects. Further studies should be performed to confirm these findings. PMID:25837760

  16. Improved membrane filtration method incorporating catalase and sodium pyruvate for detection of chlorine-stressed coliform bacteria.

    PubMed Central

    Calabrese, J P; Bissonnette, G K

    1990-01-01

    In vitro pure culture studies were conducted on three different strains of Escherichia coli (K-12, EPA 00244, and SWEI) to determine the effect of chlorination on catalase activity. In each case, stationary-phase cells exhibited significant (P less than 0.001) reductions in enzyme activity following exposure to chlorine. Mean differences in activity between control and chlorine-stressed cells ranged from 8.8 to 20.3 U/mg of protein for E. coli SWEI and EPA 00244, respectively. Following initial enzyme studies, resuscitation experiments utilizing the membrane filtration technique were conducted on chlorinated sewage effluent. Five different amendments, including catalase (1,000 U per plate), heat-inactivated catalase (1,000-U per plate), sodium pyruvate (0.05%), a catalase-sodium pyruvate combination (1,500 U/0.01%), and acetic acid (0.05%), were tested for the ability to enhance detection of chlorine-stressed cells on M-fecal coliform (M-FC), mT7, M-Endo, and tryptone-glucose-yeast extract (TGY) media. Significant (P less than 0.001) increases in recovery of fecal coliforms on M-FC, total coliforms on mT7 and M-Endo, and total heterotrophs on TGY were obtained on plates containing catalase, pyruvate, or the combination of these compounds. Supplementation with heat-inactivated catalase and acetic acid did not improve recovery of chlorine-stressed cells compared with recovery on nonamended media. Subsequent analysis of colonies from plates containing compounds which enhanced recovery indicated coliform verification percentages of greater than 80% on M-FC, greater than 90% on mT7, and greater than 94% on M-Endo media. These data suggest that the addition of peroxide-degrading compounds to various standard recovery media may improve detection of both coliform and heterotrophic bacteria in chlorinated waters. PMID:2268162

  17. Predominant Catalase-negative Soil Bacteria. II. Occurrence and Characterization of Actinomyces humiferus, sp. N1

    PubMed Central

    Gledhill, William E.; Casida, L. E.

    1969-01-01

    A microorganism resembling an Actinomyces species was found to be a numerically predominant inhabitant of various organically rich soils. This organism forms a hyphal-like structure with true branching that fragments into gram-positive diphtheroid and coccoid elements. Its cells ferment carbohydrates and contain both lysine and ornithine as the major basic amino acids of the cell wall. It is catalase-negative, microaerophilic to aerobic, and sensitive to lysozyme, and it is dependent on an organic nitrogen source and incubation at 30 C for optimum growth. Based on these characteristics, a new species, Actinomyces humiferus, is proposed. The ecological and medical implications of a large soil population of this microorganism are discussed. Images PMID:5803624

  18. Sixty years from discovery to solution: crystal structure of bovine liver catalase form III

    SciTech Connect

    Foroughi, Leila M.; Kang, You-Na; Matzger, Adam J.

    2012-03-27

    The crystallization and structural characterization of bovine liver catalase (BLC) has been intensively studied for decades. Forms I and II of BLC have previously been fully characterized using single-crystal X-ray diffraction. Form III has previously been analyzed by electron microscopy, but owing to the thinness of this crystal form an X-ray crystal structure had not been determined. Here, the crystal structure of form III of BLC is presented in space group P212121, with unit-cell parameters a = 68.7, b = 173.7, c = 186.3 {angstrom}. The asymmetric unit is composed of the biological tetramer, which is packed in a tetrahedron motif with three other BLC tetramers. This higher resolution structure has allowed an assessment of the previously published electron-microscopy studies.

  19. Catalase HPI influences membrane permeability in Escherichia coli following near-UV stress

    SciTech Connect

    Leven, S.; Heimberger, A.; Eisenstark, A. )

    1990-09-28

    The katG gene in Escherichia coli encodes catalase HPI, which is involved in membrane transport and protects the cell during oxidative stress. Hydrogen peroxide (H2O2) induces synthesis of HPI. We examined the role of HPI in membrane permeability (proline uptake) following exposure to near-ultraviolet radiation (NUV). We found that NUV resulted in the same type of induction as H2O2. KatG::Tn10 cells experienced a large drop in uptake after NUV exposure, and levels remained low following incubation. A strain carrying a katG+ plasmid, however, showed considerably less decrease in uptake after NUV, and uptake quickly resumed upon incubation. Further, in an srd mutant which lacks 4-thiouracil, NUV resulted in only a small drop in proline uptake, which was immediately resumed.

  20. Short arm of chromosome 11 and sporadic Alzheimer's disease: catalase and cathepsin D gene polymorphisms.

    PubMed

    Capurso, Cristiano; Solfrizzi, Vincenzo; D'Introno, Alessia; Colacicco, Anna M; Capurso, Sabrina A; Bifaro, Luigia; Menga, Roberta; Santamato, Andrea; Seripa, Davide; Pilotto, Alberto; Capurso, Antonio; Panza, Francesco

    2008-02-27

    Catalase (CAT) -262 C/T promoter (rs1001179), cathepsin D (CTSD) exon 2 (rs17571), and apolipoprotein E (APOE) gene polymorphisms were studied in 242 patients with sporadic Alzheimer's disease (AD) and 421 unrelated age-, sex-, and ethnically matched control subjects from Apulia (Southern Italy). No statistically significant differences in CAT rs1001179 and CTSD rs17571 genotype and allele distribution between AD cases and healthy controls were observed for the whole AD sample, and when AD group was categorized by age at onset in early- and late-onset AD subsets. Furthermore, we did not find any statistically significant differences in rates between CAT rs1001179 and CTSD rs17571 genotypes and AD controlling for APOE e4 allele status. Our data, at present, do not support a role of two gene polymorphisms of the short arm of the chromosome 11, the CAT rs1001179 and CTSD rs17571, as a possible susceptibility factors for sporadic AD. PMID:18248894

  1. Molecular mechanism on cadmium-induced activity changes of catalase and superoxide dismutase.

    PubMed

    Wang, Jing; Zhang, Hao; Zhang, Tong; Zhang, Rui; Liu, Rutao; Chen, Yadong

    2015-01-01

    Cadmium contributes to adverse effects of organisms probably because of its ability to induce oxidative stress via alterations in activities of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD), but their molecular mechanisms remain unclear. We investigated the molecular mechanism of CAT and SOD response under Cd-induced oxidative stress in the liver of zebrafish. The enzyme activity changes observed in vitro were consistent with those seen in vivo, indicating the direct interaction of CAT and SOD with Cd contributes to their activity change in vivo. Further experiments utilizing multiple spectroscopic methods, isothermal titration calorimetry and a molecular docking study were performed to explore the mechanism of molecular interaction of CAT and SOD with Cd. Different interaction patterns were found that resulted in misfolding and changed the enzyme activities. Taken together, we suggest the misfolding of CAT and SOD contributes to their activity change under Cd-induced oxidative stress in vivo. PMID:25795390

  2. Molecular interaction of 2-mercaptobenzimidazole with catalase reveals a potentially toxic mechanism of the inhibitor.

    PubMed

    Teng, Yue; Zou, Luyi; Huang, Ming; Zong, Wansong

    2014-12-01

    2-Mercaptobenzimidazole (MBI) is widely utilized as a corrosion inhibitor, copper-plating brightener and rubber accelerator. The residue of MBI in the environment possesses a potential risk to human health. In this work, the toxic interaction of MBI with the important antioxidant enzyme catalase (CAT) was investigated using spectroscopic and molecular docking methods under physiological conditions. MBI can spontaneously bind with CAT with one binding site through hydrogen bonds and van der Waals forces to form MBI-CAT complex. The molecular docking study revealed that MBI bound into the CAT interface of chains B and C, which led to some conformational and microenvironmental changes of CAT and further resulted in the inhibition of CAT activity. This present study provides direct evidence at a molecular level to show that exposure to MBI could induce changes in the structure and function of the enzyme CAT. PMID:25463673

  3. Effect of occupational exposure to ammonia on enzymatic activities of catalase and mono amine oxidase.

    PubMed

    Hamid, H A; El-Gazzar, R M

    1996-01-01

    The study was carried out to investigate the effect of ammonia inhalation on a total number of 60 male subjects from an urea production plant located in Alexandria. Laboratory investigations were carried out for 30 exposed and 30 controlled subjects. The results showed statistically significant inhibition (p<0.01) in the activity of catalase enzyme among the exposed than the control subjects. The inhibition could lead to deleterious effects on electrical stability, permeability and fluidity of membranes, which could affect the liver and brain to be more susceptible to hepatotoxic and neurotoxic alterations. The present work showed a significant inhibition (p<0.01) of monoamine oxidase (MAO) activities and significant increase (p<0.05, 0.01) in liver function activities among exposed subjects than the control subjects. PMID:17214191

  4. Catalase-positive microperoxisomes in rat soleus and extensor digitorum longus muscle fiber types

    NASA Technical Reports Server (NTRS)

    Riley, Danny A.; Bain, James L. W.; Ellis, Stanley

    1988-01-01

    The size, distribution, and content of catalase-reactive microperoxisomes were investigated cytochemically in three types of muscle fibers from the soleus and the extensor digitorum longus (EDL) of male rats. Muscle fibers were classified on the basis of the mitochondrial content and distribution, the Z-band widths, and the size and shape of myofibrils as the slow-twitch oxidative (SO), the fast-twitch oxidative glycolytic (FOG), and the fast-twitch glycolytic (FG) fibers. It was found that both the EDL and soleus SO fibers possessed the largest microperoxisomes. A comparison of microperoxisome number per muscle fiber area or the microperoxisome area per fiber area revealed following ranking, starting from the largest number and the area-ratio values: soleus SO, EDL SO, EDL FOG, and EDL FG.

  5. Catalase and superoxide dismutase activities after heat injury of listeria monocytogenes

    SciTech Connect

    Dallmier, A.W.; Martin, S.E.

    1988-02-01

    Four strains of Listeria monocytogenes were examined for catalase (CA) and superoxide dismutase (SOD) activities. The two strains having the highest CA activities (LCDC and Scott A) also possessed the highest SOD activities. The CA activity of heated cell extracts of all four strains examined decreased sharply between 55 and 60/sup 0/C. SOD was more heat labile than CA. Two L. monocytogenes strains demonstrated a decline in SOD activity after heat treatment at 45/sup 0/C, whereas the other two strains demonstrated a decline at 50/sup 0/C. Sublethal heating of the cells at 55/sup 0/C resulted in increased sensitivity to 5.5% NaCl. Exogenous hydrogen peroxide was added to suspensions of L. monocytogenes; strains producing the highest CA levels showed the greatest H/sub 2/O/sub 2/ resistance.

  6. Lack of effect of deferoxamine, dimethyl sulfoxide, and catalase on monocrotaline pyrrole pulmonary injury

    SciTech Connect

    Bruner, L.H.; Johnson, K.; Carpenter, L.J.; Roth, R.A.

    1987-01-01

    Monocrotaline pyrrole (MCTP) is a reactive metabolite of the pyrrolizidine alkaloid monocrotaline. MCTP given intravenously to rats causes pulmonary hypertension and right ventricular hypertrophy. Lesions in lungs after MCTP treatment contain macrophages and neutrophils, which may contribute to the damage by generation of reactive oxygen metabolites. Rats were treated with MCTP and agents known to protect against oxygen radical-mediated damage in acute models of neutrophil-dependent lung injury. Rats received MCTP and deferoxamine mesylate (DF), dimethyl sulfoxide (DMSO), or polyethylene glycol-coupled catalase (PEG-CAT). MCTP/vehicle-treated controls developed lung injury manifested as increased lung weight, release of lactate dehydrogenase into the airway, and sequestration of SVI-labeled bovine serum albumin in the lungs. Cotreatment of rats with DF, DMSO, or PEG-CAT did not protect against the injury due to MCTP. These results suggest that toxic oxygen metabolites do not play an important role in the pathogenesis of MCTP-induced pulmonary injury.

  7. A gas-phase amplified quartz crystal microbalance immunosensor based on catalase modified immunoparticles.

    PubMed

    Liu, Wei; Huang, Renliang; Qi, Wei; Wang, Mengfan; Su, Rongxin; He, Zhimin

    2015-02-21

    A novel signal amplification strategy for quartz crystal microbalance (QCM) based on catalytic gas generation was developed to construct an ultrasensitive immunosensor for the detection of proteins (immunoglobulin G, IgG, used as a model). A catalase modified immunoparticle was prepared to form a sandwich-type immunocomplex with the IgG and anti-IgG antibodies that were immobilized on the QCM sensor. The amount of immunoparticles on the sensor surface was thus controlled by the IgG concentration. Then H2O2 was added and catalyzed by catalase for oxygen generation. The generated oxygen replaced some of the liquid on the sensor surface, leading to the change in the shear modulus of the immunocomplex layer and the apparent viscosity and density of the liquid layer. Due to the ultrasensitive response of QCM to these changes, a significant frequency shift related to the IgG concentration was achieved. Different parameters, including the flow cell structure, operation temperature, immunoparticle concentration, and H2O2 concentration were optimized to achieve steady and efficient frequency shifts. Under the optimal conditions, the proposed gas-phase amplified QCM sensor could achieve up to 72 times improvement of detection sensitivity compared to the label-free sensor as a control, in the concentration range of 0.1-3.0 ?g mL(-1). The detection limit was also reduced from 236 ng mL(-1) to 51.0 ng mL(-1) at the 3Sblank level. PMID:25519742

  8. Role of Catalase in Inducing Chilling Tolerance in Pre-Emergent Maize Seedlings.

    PubMed Central

    Prasad, T. K.

    1997-01-01

    The mechanisms of chilling acclimation and the role of antioxidant enzymes, catalase in particular, in inducing chilling tolerance in pre-emergent maize (Zea mays L.) seedlings have been investigated. Seedlings were acclimated to chilling stress in two different ways. Three-day-old seedlings did not survive 7 d of 4[deg]C stress unless acclimated by exposure to either 14[deg]C for 1 d or 4[deg]C for 1 d followed by recovery at 27[deg]C for 1 d. Although no changes in superoxide dismutase and ascorbate peroxidase activities were observed, both kinds of acclimated seedlings had higher catalase (CAT), glutathione reductase, and guaiacol peroxidase activities compared with nonacclimated seedlings during low-temperature stress and recovery conditions. To study the role of CAT in chilling tolerance, aminotriazole (AT) was used as a tool to artificially inhibit CAT activity and to initiate oxidative stress in the seedlings. Treatment of acclimating seedlings with 3 mM AT for 18 h abolished the acclimation phenomenon. AT treatment was found to be specific to CAT inhibition, because the total activities or isozyme profiles of the other investigated antioxidant enzymes were not altered in AT-treated seedlings. Protein carbonyl content, an indication of oxidative damage, was increased 2-fold in nonacclimated and AT-treated acclimated seedlings. These results collectively indicate that acclimation to prolonged chilling stress can be achieved by briefly pre-exposing the seedlings to 4[deg]C chilling stress and that acclimation-induced (oxidative stress-induced) CAT seems to play a major role, probably along with other antioxidant enzymes, in inducing chilling tolerance in pre-emergent maize seedlings. PMID:12223775

  9. Evidence of catalase mimetic activity in Ce(3+)/Ce(4+) doped bioactive glasses.

    PubMed

    Nicolini, Valentina; Gambuzzi, Elisa; Malavasi, Gianluca; Menabue, Ledi; Menziani, Maria Cristina; Lusvardi, Gigliola; Pedone, Alfonso; Benedetti, Francesco; Luches, Paola; D'Addato, Sergio; Valeri, Sergio

    2015-03-12

    The ability of Ce-containing bioactive glasses to inhibit oxidative stress in terms of reduction of hydrogen peroxide, by mimicking the catalase enzyme activity is demonstrated here for the first time. The antioxidant properties of three bioactive glasses containing an increasing amount of CeO2 have been evaluated by following the degradation of hydrogen peroxide with time after immersion in H2O2 aqueous solutions with different concentration. XPS and UV-vis measurements allowed us to determine the Ce(3+)/Ce(4+) ratio in the bulk and on the glass surface, and to correlate it with the ability of the samples to show catalase mimetic activity. Interestingly, we have found that the bioactive glass with composition 23.2Na2O-25.7CaO-43.4SiO2-2.4P2O5-5.3CeO2 immersed in 0.1 M H2O2 aqueous solution is able to degrade 90% of it in 1 week. The reduction in bioactivity of the glasses with increasing CeO2 content is here rationalized in terms of a lower amount of phosphate groups available for the hydroxyapatite layer formation, after binding with cerium ions. In fact, classical molecular dynamics simulations revealed that the addition of CeO2 leads to the formation of cerium phosphate rich regions. The formation of an insoluble CePO4 crystalline phase is also observed by XRD analysis after thermal treatment of the glass samples. PMID:25710332

  10. Probing the function of Mycobacterium tuberculosis catalase-peroxidase by site-directed mutagenesis.

    PubMed

    Eady, Nigel A J; Jesmin, Nigel A J; Servos, Spiros; Cass, Anthony E G; Nagy, Judit M; Brown, Katherine A

    2005-11-01

    Catalase-peroxidase is a multi-functional heme-dependent enzyme which is well known for its ability to carry out both catalatic and peroxidatic reactions. Catalase-peroxidase from Mycobacterium tuberculosis(mtCP) is of particular interest because this enzyme activates the pro-antitubercular drug isoniazid. It is estimated that 2 billion people are infected with M. tuberculosis, the principal causative agent of tuberculosis, and that 2 million people die from the disease each year. The rise of drug-resistant strains continues to be of critical concern and it is well documented that mutations which reduce activity or inactivate mtCP lead to increased levels of isoniazid resistance in M. tuberculosis. The recent determination of the crystal structure for M. tuberculosis mtCP has aided the understanding of how the enzyme functions and provides a three-dimensional framework for testing hypotheses about the roles of various residues in the active site. Here we report site-directed mutagenesis studies of three conserved residues located near the heme of mtCP, His-108, Trp-107 and Trp-321 including the construction of the double mutant W107F-W321F. Resulting mutants have been purified and their catalatic and peroxidatic activities have been determined. Data are compared in the context of related studies aimed at dissecting the roles of these residues in the different activities of the enzyme. Analyses of single and double mutants studied here emphasise that the hydrogen bonding network surrounding the heme in the active site appears more important for maintenance of catalatic rather than peroxidatic activity in CP enzymes. PMID:16315359

  11. Francisella tularensis Catalase Restricts Immune Function by Impairing TRPM2 Channel Activity.

    PubMed

    Shakerley, Nicole L; Chandrasekaran, Akshaya; Trebak, Mohamed; Miller, Barbara A; Melendez, J Andrs

    2016-02-19

    As an innate defense mechanism, macrophages produce reactive oxygen species that weaken pathogens and serve as secondary messengers involved in immune function. The Gram-negative bacterium Francisella tularensis utilizes its antioxidant armature to limit the host immune response, but the mechanism behind this suppression is not defined. Here we establish that F. tularensis limits Ca(2+) entry in macrophages, thereby limiting actin reorganization and IL-6 production in a redox-dependent fashion. Wild type (live vaccine strain) or catalase-deficient F. tularensis (?katG) show distinct profiles in their H2O2 scavenging rates, 1 and 0.015 pm/s, respectively. Murine alveolar macrophages infected with ?katG display abnormally high basal intracellular Ca(2+) concentration that did not increase further in response to H2O2. Additionally, ?katG-infected macrophages displayed limited Ca(2+) influx in response to ionomycin, as a result of ionophore H2O2 sensitivity. Exogenously added H2O2 or H2O2 generated by ?katG likely oxidizes ionomycin and alters its ability to transport Ca(2+). Basal increases in cytosolic Ca(2+) and insensitivity to H2O2-mediated Ca(2+) entry in ?katG-infected cells are reversed by the Ca(2+) channel inhibitors 2-aminoethyl diphenylborinate and SKF-96365. 2-Aminoethyl diphenylborinate but not SKF-96365 abrogated ?katG-dependent increases in macrophage actin remodeling and IL-6 secretion, suggesting a role for H2O2-mediated Ca(2+) entry through the transient receptor potential melastatin 2 (TRPM2) channel in macrophages. Indeed, increases in basal Ca(2+), actin polymerization, and IL-6 production are reversed in TRPM2-null macrophages infected with ?katG. Together, our findings provide compelling evidence that F. tularensis catalase restricts reactive oxygen species to temper macrophage TRPM2-mediated Ca(2+) signaling and limit host immune function. PMID:26679996

  12. Elimination of hydrogen peroxide by Haemophilus somnus, a catalase-negative pathogen of cattle.

    PubMed Central

    Sample, A K; Czuprynski, C J

    1991-01-01

    Haemophilus somnus is a catalase-negative, gram-negative pathogen of cattle which is refractory to killing by bovine neutrophils. In this report, we showed that H. somnus rapidly inhibited Luminol-dependent chemiluminescence of bovine neutrophils costimulated with opsonized zymosan or phorbol myristate acetate. We have postulated that this inhibition resulted in part from H. somnus preventing the accumulation of hydrogen peroxide (H2O2) during the oxidative burst. In support of this hypothesis, we have demonstrated that when stimulated with viable H. somnus, bovine neutrophils accumulate lower levels of H2O2 than did neutrophils stimulated with heat-killed H. somnus or opsonized zymosan. We have presented evidence that four separate strains of H. somnus, despite being catalase negative by conventional criteria, removed H2O2 from solution. Viable cells of H. somnus were required for the removal of H2O2 from solution; little or no activity was observed when suspensions of heat-killed, formalin-killed, or sonicated cells of H. somnus were incubated with H2O2. In addition, the elimination of H2O2 occurred only in the presence of carbon sources that could be utilized by H. somnus, indicating that elimination of H2O2 was an energy-dependent process. The amount of H2O2 that could be eliminated by 10(7) cells of H. somnus was greater than 10 nmol, an amount comparable to that produced by a similar number of stimulated bovine neutrophils. Thus, we suggest that the ability of H. somnus to remove H2O2 from solution may be an important virulence mechanism that contributes to the survival of the organism following ingestion by bovine neutrophils. PMID:1646767

  13. Data regarding M1 muscarinic receptor-mediated modulation of hepatic catalase activity in response to oxidative stress.

    PubMed

    Jadeja, Ravirajsinh N; Urrunaga, Nathalie H; Ahmad, Daniel; Khurana, Sandeep

    2016-03-01

    We recently demonstrated the role of M1 muscarinic receptors (M1R) in modulating oxidative stress in liver and hepatocytes (Urrunaga et al., 2015) [1]. Here we provide data regarding the effect of a novel M1R agonist, VU0357017 (Lebois et al., 2010) [2], on H2O2-mediated hepatocyte injury, the effect of an M1R antagonist VU0255035 (Sheffler et al., 2009) [3] on catalase and super oxide dismutase (SOD) activities in H2O2-treated hepatocytes in vitro, and finally, the effect of M1R ablation on hepatic catalase activity in acetaminophen (APAP)-treated mice. PMID:26862589

  14. Data regarding M1 muscarinic receptor-mediated modulation of hepatic catalase activity in response to oxidative stress

    PubMed Central

    Jadeja, Ravirajsinh N.; Urrunaga, Nathalie H.; Ahmad, Daniel; Khurana, Sandeep

    2015-01-01

    We recently demonstrated the role of M1 muscarinic receptors (M1R) in modulating oxidative stress in liver and hepatocytes (Urrunaga et al., 2015) [1]. Here we provide data regarding the effect of a novel M1R agonist, VU0357017 (Lebois et al., 2010) [2], on H2O2-mediated hepatocyte injury, the effect of an M1R antagonist VU0255035 (Sheffler et al., 2009) [3] on catalase and super oxide dismutase (SOD) activities in H2O2treated hepatocytes in vitro, and finally, the effect of M1R ablation on hepatic catalase activity in acetaminophen (APAP)-treated mice.

  15. Proteomic analysis of upregulated proteins in Helicobacter pylori under oxidative stress induced byhydrogen peroxide.

    PubMed

    Huang, Chun-Hao; Chiou, Shyh-Horng

    2011-12-01

    The development of gastric cancer was suggested to be associated with chronic inflammation as a consequence of Helicobacter pylori infection. Such inflammation-related oxidative stress induced by reactive oxygen species (ROS) invivo may exert bidirectional effects on both hosts and H pylori. In this study, ROS-induced oxidative stress was mimicked by coculture of gastric epithelial cells with H pylori treated with hydrogen peroxide (H(2)O(2)). To investigate the effect of H(2)O(2) on the proteome of H pylori, we performed two-dimensional polyacrylamide gel electrophoresis followed by liquid chromatography coupled with nano-electrospray ionization-tandem mass spectrometry (liquid chromatography mass spectrometry) and bioinformatics database analysis. The nine most overexpressed proteins consisted of three virulence factors, including cytotoxin-associated protein A (CagA), vacuolating cytotoxin (VacA), adherence-associated protein (AlpA), and two antioxidant enzymes alkylhydroperoxide reductase (AhpC) and catalase (KatA), plus one serine protease (HtrA), aconitate hydratase, and fumarate reductase. We have also confirmed the upregulation of virulence factors and antioxidant proteins in several H pylori strains isolated from patients of different clinical outcomes. Furthermore, it is noted that Hpylori was found to decrease in infection rate and increase in proliferation after being exposed to H(2)O(2). We also found that gastric epithelial cells can be protected from oxidative damage by H(2)O(2) in the presence of H pylori. In conclusion, this study lends support to the supposition that ROS containing H(2)O(2) as one of the major oxidative species can induce upregulation of virulence factors and antioxidant enzymes in H pylori, which may aid in the elucidation of inflammation leading to the development of gastric cancer from H pylori infection. PMID:22208537

  16. Intracellular antioxidant enzymes are not globally upregulated during hibernation in the major oxidative tissues of the 13-lined ground squirrel Spermophilus tridecemlineatus.

    PubMed

    Page, Melissa M; Peters, Craig W; Staples, James F; Stuart, Jeffrey A

    2009-01-01

    Hibernating mammals exhibit oxidative stress resistance in brain, liver and other tissues. In many animals, cellular oxidative stress resistance is associated with enhanced expression of intracellular antioxidant enzymes. Intracellular antioxidant capacity may be upregulated during hibernation to protect against oxidative damage associated with the ischemia-reperfusion that occurs during transitions between torpor and arousal. We tested the hypothesis that the 13-lined ground squirrel (Spermophilus tridecemlineatus), upregulates intracellular antioxidant enzymes in major oxidative tissues during hibernation. The two major intracellular isoforms of superoxide dismutase (MnSOD and CuZnSOD), which catalyze the first step in superoxide detoxification, were quantified in heart, brain and liver tissue using immunodetection and an in-gel activity assay. However, no differences in SOD protein expression or activity were found between active and hibernating squirrels. Measurements of glutathione peroxidase and glutathione reductase, which catalyze hydrogen peroxide removal, were not broadly upregulated during hibernation. The activity of catalase, which catalyzes an alternative hydrogen peroxide detoxification pathway, was higher in heart and brain of torpid squirrels, but lower in liver. Taken together, these data do not support the hypothesis that hibernation is associated with enhanced oxidative stress resistance due to an upregulation of intracellular antioxidant enzymes in the major oxidative tissues. PMID:18948223

  17. Toward "stable-on-the-table" enzymes: improving key properties of catalase by covalent conjugation with poly(acrylic acid).

    PubMed

    Riccardi, Caterina M; Cole, Kyle S; Benson, Kyle R; Ward, Jessamyn R; Bassett, Kayla M; Zhang, Yiren; Zore, Omkar V; Stromer, Bobbi; Kasi, Rajeswari M; Kumar, Challa V

    2014-08-20

    Several key properties of catalase such as thermal stability, resistance to protease degradation, and resistance to ascorbate inhibition were improved, while retaining its structure and activity, by conjugation to poly(acrylic acid) (PAA, Mw 8000) via carbodiimide chemistry where the amine groups on the protein are appended to the carboxyl groups of the polymer. Catalase conjugation was examined at three different pH values (pH 5.0, 6.0, and 7.0) and at three distinct mole ratios (1:100, 1:500, and 1:1000) of catalase to PAA at each reaction pH. The corresponding products are labeled as Cat-PAA(x)-y, where x is the protein to polymer mole ratio and y is the pH used for the synthesis. The coupling reaction consumed about 60-70% of the primary amines on the catalase; all samples were completely water-soluble and formed nanogels, as evidenced by gel electrophoresis and electron microscopy. The UV circular dichroism (CD) spectra indicated substantial retention of protein secondary structure for all samples, which increased to 100% with increasing pH of the synthesis and polymer mole fraction. Soret CD bands of all samples indicated loss of ∼50% of band intensities, independent of the reaction pH. Catalytic activities of the conjugates increased with increasing synthesis pH, where 55-80% and 90-100% activity was retained for all samples synthesized at pH 5.0 and pH 7.0, respectively, and the Km or Vmax values of Cat-PAA(100)-7 did not differ significantly from those of the free enzyme. All conjugates synthesized at pH 7.0 were thermally stable even when heated to ∼85-90 °C, while native catalase denatured between 55 and 65 °C. All conjugates retained 40-90% of their original activities even after storing for 10 weeks at 8 °C, while unmodified catalase lost all of its activity within 2 weeks, under similar storage conditions. Interestingly, PAA surrounding catalase limited access to the enzyme from large molecules like proteases and significantly increased resistance to trypsin digestion compared to unmodified catalase. Similarly, negatively charged PAA surrounding the catalase in these conjugates protected the enzyme against inhibition by negatively charged inhibitors such as ascorbate. While Cat-PAA(100)-7 did not show any inhibition by ascorbate in the presence of 270 μM ascorbate, unmodified catalase lost ∼70% of its activity under similar conditions. This simple, facile, and rational methodology produced thermostable, storable catalase that is also protected from protease digestion and ascorbate inhibition and most likely prevented the dissociation of the multimer. Using synthetic polymers to protect and improve enzyme properties could be an attractive approach for making "Stable-on-the-Table" enzymes, as a viable alternative to protein engineering. PMID:25046001

  18. Hypoxia Up-Regulates Galectin-3 in Mammary Tumor Progression and Metastasis

    PubMed Central

    Barros, Rita; Gomes, Catarina; de Matos, Augusto J.; Reis, Celso A.; Rutteman, Gerard R.; Gärtner, Fátima

    2015-01-01

    The tumor microenvironment encompasses several stressful conditions for cancer cells such as hypoxia, oxidative stress and pH alterations. Galectin-3, a well-studied member of the beta-galactoside-binding animal family of lectins has been implicated in multiple steps of metastasis as cell-cell and cell-ECM adhesion, promotion of angiogenesis, cell proliferation and resistance to apoptosis. However, both its aberrantly up- and down-regulated expression was observed in several types of cancer. Thus, the mechanisms that regulate galectin-3 expression in neoplastic settings are not clear. In order to demonstrate the putative role of hypoxia in regulating galectin-3 expression in canine mammary tumors (CMT), in vitro and in vivo studies were performed. In malignant CMT cells, hypoxia was observed to induce expression of galectin-3, a phenomenon that was almost completely prevented by catalase treatment of CMT-U27 cells. Increased galectin-3 expression was confirmed at the mRNA level. Under hypoxic conditions the expression of galectin-3 shifts from a predominant nuclear location to cytoplasmic and membrane expressions. In in vivo studies, galectin-3 was overexpressed in hypoxic areas of primary tumors and well-established metastases. Tumor hypoxia thus up-regulates the expression of galectin-3, which may in turn increase tumor aggressiveness. PMID:26222311

  19. Horizontal gene transfer confers adaptive advantages to phytopathogenic fungi: a case study of catalase-peroxidase in Fusarium verticillioides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Horizontal gene transfer (HGT), the exchange and stable integration of genetic material between different evolutionary lineages, is widely observed in fungi. We hypothesize that successful stabilization of HGT elements provides adaptive advantages (e.g., virulence). Catalase/peroxidases (KatGs) are ...

  20. The induction of human superoxide dismutase and catalase in vivo: a fundamentally new approach to antioxidant therapy.

    PubMed

    Nelson, Sally K; Bose, Swapan K; Grunwald, Gary K; Myhill, Paul; McCord, Joe M

    2006-01-15

    A composition consisting of extracts of five widely studied medicinal plants (Protandim) was administered to healthy human subjects ranging in age from 20 to 78 years. Individual ingredients were selected on the basis of published findings of induction of superoxide dismutase (SOD) and/or catalase in rodents in vivo, combined with evidence of decreasing lipid peroxidation. Each ingredient was present at a dosage sufficiently low to avoid any accompanying unwanted pharmacological effects. Blood was analyzed before supplementation and after 30 and 120 days of supplementation (675 mg/day). Erythrocytes were assayed for SOD and catalase, and plasma was assayed for lipid peroxidation products as thiobarbituric acid-reacting substances (TBARS), as well as uric acid, C-reactive protein, and cholesterol (total, LDL, and HDL). Before supplementation, TBARS showed a strong age-dependent increase. After 30 days of supplementation, TBARS declined by an average of 40% (p = 0.0001) and the age-dependent increase was eliminated. By 120 days, erythrocyte SOD increased by 30% (p < 0.01) and catalase by 54% (p < 0.002). We conclude that modest induction of the catalytic antioxidants SOD and catalase may be a much more effective approach than supplementation with antioxidants (such as vitamins C and E) that can, at best, stoichiometrically scavenge a very small fraction of total oxidant production. PMID:16413416

  1. A catalase-peroxidase from a newly isolated thermoalkaliphilic Bacillus sp. with potential for the treatment of textile bleaching effluents.

    PubMed

    Gudelj, M; Fruhwirth, G O; Paar, A; Lottspeich, F; Robra, K H; Cavaco-Paulo, A; Gbitz, G M

    2001-12-01

    A new thermoalkaliphilic bacterium was isolated from a textile wastewater drain and identified as a new Bacillus sp. (Bacillus SF). Because of its high pH stability and thermostability, a catalase-peroxidase (CP) from this strain has potential for the treatment of textile bleaching effluents. The CP from Bacillus SF was purified to more than 70.3-fold homogeneity using fractionated ammonium sulfate precipitation, hydrophobic interaction, and anion-exchange and gel-filtration chromatography. The native CP had a molecular mass of 165 kDa and was composed of two identical subunits. The isoelectric point of the protein was at pH 6.0. Peptide mass mapping using matrix-assisted laser desorption ionization-mass spectrometry showed a homology between the CP from Bacillus SF and the CP from Bacillus stearothermophilus. The apparent Km value of the catalase activity for H2O2 was 2.6 mM and the k(cat) value was 11,475 s(-1). The enzyme showed high catalase activity and an appreciable peroxidase activity with guaiacol and o-dianisidine. The enzyme was stable at high pH, with a half-life of 104 h at pH 10 and 25 degrees C and 14 h at 50 degrees C. The enzyme was inhibited by azide and cyanide, in a competitive manner, but not by the catalase-specific inhibitor 3-amino-1,2,4-triazole. PMID:11778844

  2. Novel immobilization process of a thermophilic catalase: efficient purification by heat treatment and subsequent immobilization at high temperature.

    PubMed

    Xu, Juan; Luo, Hui; Lpez, Claudia; Xiao, Jing; Chang, Yanhong

    2015-10-01

    The main goal of the present work is to investigate a novel process of purification and immobilization of a thermophilic catalase at high temperatures. The catalase, originated from Bacillus sp., was overexpressed in a recombinant Escherichia coli BL21(DE3)/pET28-CATHis and efficiently purified by heat treatment, achieving a threefold purification. The purified catalase was then immobilized onto an epoxy support at different temperatures (25, 40, and 55C). The immobilizate obtained at higher temperatures reached its maximum activity in a shorter time than that obtained at lower temperatures. Furthermore, immobilization at higher temperatures required a lower ionic strength than immobilization at lower temperatures. The characteristics of immobilized enzymes prepared at different temperatures were investigated. The high-temperature immobilizate (55C) showed the highest thermal stability, followed by the 40C immobilizate. And the high-temperature immobilizate (55C) had slightly higher operational stability than the 25C immobilizate. All of the immobilized catalase preparations showed higher stability than the free enzyme at alkaline pH 10.0, while the alkali resistance of the 25C immobilizate was slightly better than that of the 40 and 55C immobilizates. PMID:26205324

  3. Erythrocyte Catalase Activity in More Frequent Microcytic Hypochromic Anemia: Beta-Thalassemia Trait and Iron Deficiency Anemia

    PubMed Central

    Lazarte, Sandra Stella; Mnaco, Mara Eugenia; Jimenez, Cecilia Laura; Ledesma Achem, Miryam Emilse; Tern, Magdalena Mara; Iss, Blanca Alicia

    2015-01-01

    Most common microcytic hypochromic anemias are iron deficiency anemia (IDA) and ?-thalassemia trait (BTT), in which oxidative stress (OxS) has an essential role. Catalase causes detoxification of H2O2 in cells, and it is an indispensable antioxidant enzyme. The study was designed to measure erythrocyte catalase activity (ECAT) in patients with IDA (10) or BTT (21), to relate it with thalassemia mutation type (?0 or ?+) and to compare it with normal subjects (67). Ninety-eight individuals were analyzed since September 2013 to June 2014 in Tucumn, Argentina. Total blood count, hemoglobin electrophoresis at alkaline pH, HbA2, catalase, and iron status were performed. ?-thalassemic mutations were determined by real-time PCR. Normal range for ECAT was 70,0130,0?MU/L. ECAT was increased in 14% (3/21) of BTT subjects and decreased in 40% (4/10) of those with IDA. No significant difference (p = 0,245) was shown between normal and BTT groups, while between IDA and normal groups the difference was proved to be significant (p = 0,000). In ?0 and ?+ groups, no significant difference (p = 0,359) was observed. An altered ECAT was detected in IDA and BTT. These results will help to clarify how the catalase activity works in these anemia types. PMID:26527217

  4. Thermo-alkali-stable catalases from newly isolated Bacillus sp. for the treatment and recycling of textile bleaching effluents.

    PubMed

    Paar, A; Costa, S; Tzanov, T; Gudelj, M; Robra, K H; Cavaco-Paulo, A; Gbitz, G M

    2001-08-23

    Three thermoalkaliphilic bacteria, which were grown at pH 9.3-10 and 60-65 degrees C were isolated out of a textile wastewater drain. The unknown micro-organisms were identified as thermoalkaliphilic Bacillus sp. Growth conditions were studied and catalase activities and stabilities compared. Catalases from Bacillus SF showed high stabilities at 60 degrees C and pH 9 (t1/2=38 h) and thus this strain was chosen for further investigations, such as electron microscopy, immobilization of catalase and hydrogen peroxide degradation studies. Degradation of hydrogen peroxide with an immobilized catalase from Bacillus SF enabled the reuse of the water for the dyeing process. In contrast, application of the free enzyme for treatment of bleaching effluents, caused interaction between the denaturated protein and the dye, resulting in reduced dye uptake, and a higher color difference of 1.3DeltaE* of dyed fabrics compared to 0.9DeltaE* when using the immobilized enzyme. PMID:11500208

  5. Function and stationary-phase induction of periplasmic copper-zinc superoxide dismutase and catalase/peroxidase in Caulobacter crescentus.

    PubMed Central

    Schnell, S; Steinman, H M

    1995-01-01

    Although cytosolic superoxide dismutases (SODs) are widely distributed among bacteria, only a small number of species contain a periplasmic SOD. One of these is Caulobacter crescentus, which has a copper-zinc SOD (CuZnSOD) in the periplasm and an iron SOD (FeSOD) in the cytosol. The function of periplasmic CuZnSOD was studied by characterizing a mutant of C. crescentus with an insertionally inactivated CuZnSOD gene. Wild-type and mutant strains showed identical tolerance to intracellular superoxide. However, in response to extracellular superoxide, the presence of periplasmic CuZnSOD increased survival by as much as 20-fold. This is the first demonstration that periplasmic SOD defends against external superoxide of environmental origin. This result has implications for those bacterial pathogens that contain a CuZnSOD. C. crescentus was shown to contain a single catalase/peroxidase which, like Escherichia coli KatG catalase/peroxidase, is present in both the periplasmic and cytoplasmic fractions. The growth stage dependence of C. crescentus catalase/peroxidase and SOD activity was studied. Although FeSOD activity was identical in exponential- and stationary-phase cultures, CuZnSOD was induced nearly 4-fold in stationary phase and the catalase/peroxidase was induced nearly 100-fold. Induction of antioxidant enzymes in the periplasm of C. crescentus appears to be an important attribute of the stationary-phase response and may be a useful tool for studying its regulation. PMID:7592345

  6. Parthenolide-induced apoptosis in multiple myeloma cells involves reactive oxygen species generation and cell sensitivity depends on catalase activity.

    PubMed

    Wang, Wei; Adachi, Masaaki; Kawamura, Rina; Sakamoto, Hiroki; Hayashi, Toshiaki; Ishida, Tadao; Imai, Kohzoh; Shinomura, Yasuhisa

    2006-12-01

    The sesquiterpene lactone, parthenolide (PTL), possesses strong anticancer activity against various cancer cells. We report that PTL strongly induced apoptosis in 4 multiple myeloma (MM) cell lines and primary MM cells (CD38(+) high), but barely induced death in normal lymphocytes (CD38(-/+)low). PTL-mediated apoptosis correlated well with ROS generation and was almost completely inhibited by L-N-acetylcysteine (L-NAC), indicating the crucial role of oxidative stress in the mechanism. Among 4 MM cell lines, there is considerable difference in susceptibility to PTL. KMM-1 and MM1S cells sensitive to PTL possess less catalase activity than the less sensitive KMS-5 and NCI-H929 cells as well as normal lymphocytes. A catalase inhibitor 3-amino-1,2,4-triazole enhanced their PTL-mediated ROS generation and cell death. The siRNA-mediated knockdown of catalase in KMS-5 cells decreased its activity and sensitized them to PTL. Our findings indicate that PTL induced apoptosis in MM cells depends on increased ROS and intracellular catalase activity is a crucial determinant of their sensitivity to PTL. PMID:17051330

  7. Multiple abiotic stress tolerance of the transformants yeast cells and the transgenic Arabidopsis plants expressing a novel durum wheat catalase.

    PubMed

    Feki, Kaouthar; Kamoun, Yosra; Ben Mahmoud, Rihem; Farhat-Khemakhem, Ameny; Gargouri, Ali; Brini, Faial

    2015-12-01

    Catalases are reactive oxygen species scavenging enzymes involved in response to abiotic and biotic stresses. In this study, we described the isolation and functional characterization of a novel catalase from durum wheat, designed TdCAT1. Molecular Phylogeny analyses showed that wheat TdCAT1 exhibited high amino acids sequence identity to other plant catalases. Sequence homology analysis showed that TdCAT1 protein contained the putative calmodulin binding domain and a putative conserved internal peroxisomal targeting signal PTS1 motif around its C-terminus. Predicted three-dimensional structural model revealed the presence of four putative distinct structural regions which are the N-terminal arm, the ?-barrel, the wrapping and the ?-helical domains. TdCAT1 protein had the heme pocket that was composed by five essential residues. TdCAT1 gene expression analysis showed that this gene was induced by various abiotic stresses in durum wheat. The expression of TdCAT1 in yeast cells and Arabidopsis plants conferred tolerance to several abiotic stresses. Compared with the non-transformed plants, the transgenic lines maintained their growth and accumulated more proline under stress treatments. Furthermore, the amount of H2O2 was lower in transgenic lines, which was due to the high CAT and POD activities. Taken together, these data provide the evidence for the involvement of durum wheat catalase TdCAT1 in tolerance to multiple abiotic stresses in crop plants. PMID:26555900

  8. AGEs-Induced IL-6 Synthesis Precedes RAGE Up-Regulation in HEK 293 Cells: An Alternative Inflammatory Mechanism?

    PubMed

    Serban, Andreea Iren; Stanca, Loredana; Geicu, Ovidiu Ionut; Dinischiotu, Anca

    2015-01-01

    Advanced glycation end products (AGEs) can activate the inflammatory pathways involved in diabetic nephropathy. Understanding these molecular pathways could contribute to therapeutic strategies for diabetes complications. We evaluated the modulation of inflammatory and oxidative markers, as well as the protective mechanisms employed by human embryonic kidney cells (HEK 293) upon exposure to 200 ?g/mL bovine serum albumine (BSA) or AGEs-BSA for 12, 24 and 48 h. The mRNA and protein expression levels of AGEs receptor (RAGE) and heat shock proteins (HSPs) 27, 60 and 70, the activity of antioxidant enzymes and the expression levels of eight cytokines were analysed. Cell damage via oxidative mechanisms was evaluated by glutathione and malondialdehyde levels. The data revealed two different time scale responses. First, the up-regulation of interleukin-6 (IL-6), HSP 27 and high catalase activity were detected as early as 12 h after exposure to AGEs-BSA, while the second response, after 24 h, consisted of NF-?B p65, RAGE, HSP 70 and inflammatory cytokine up-regulation, glutathione depletion, malondialdehyde increase and the activation of antioxidant enzymes. IL-6 might be important in the early ignition of inflammatory responses, while the cellular redox imbalance, RAGE activation and NF-?B p65 increased expression further enhance inflammatory signals in HEK 293 cells. PMID:26307981

  9. AGEs-Induced IL-6 Synthesis Precedes RAGE Up-Regulation in HEK 293 Cells: An Alternative Inflammatory Mechanism?

    PubMed Central

    Serban, Andreea Iren; Stanca, Loredana; Geicu, Ovidiu Ionut; Dinischiotu, Anca

    2015-01-01

    Advanced glycation end products (AGEs) can activate the inflammatory pathways involved in diabetic nephropathy. Understanding these molecular pathways could contribute to therapeutic strategies for diabetes complications. We evaluated the modulation of inflammatory and oxidative markers, as well as the protective mechanisms employed by human embryonic kidney cells (HEK 293) upon exposure to 200 μg/mL bovine serum albumine (BSA) or AGEs–BSA for 12, 24 and 48 h. The mRNA and protein expression levels of AGEs receptor (RAGE) and heat shock proteins (HSPs) 27, 60 and 70, the activity of antioxidant enzymes and the expression levels of eight cytokines were analysed. Cell damage via oxidative mechanisms was evaluated by glutathione and malondialdehyde levels. The data revealed two different time scale responses. First, the up-regulation of interleukin-6 (IL-6), HSP 27 and high catalase activity were detected as early as 12 h after exposure to AGEs–BSA, while the second response, after 24 h, consisted of NF-κB p65, RAGE, HSP 70 and inflammatory cytokine up-regulation, glutathione depletion, malondialdehyde increase and the activation of antioxidant enzymes. IL-6 might be important in the early ignition of inflammatory responses, while the cellular redox imbalance, RAGE activation and NF-κB p65 increased expression further enhance inflammatory signals in HEK 293 cells. PMID:26307981

  10. Isolation of a Novel Peroxisomal Catalase Gene from Sugarcane, Which Is Responsive to Biotic and Abiotic Stresses

    PubMed Central

    Ling, Hui; Chen, Shanshan; Wang, Shanshan; Xu, Liping; Allan, Andrew C.; Que, Youxiong

    2014-01-01

    Catalase is an iron porphyrin enzyme, which serves as an efficient scavenger of reactive oxygen species (ROS) to avoid oxidative damage. In sugarcane, the enzymatic activity of catalase in a variety (Yacheng05–179) resistant to the smut pathogen Sporisorium scitamineum was always higher than that of the susceptible variety (Liucheng03–182), suggesting that catalase activity may have a positive correlation with smut resistance in sugarcane. To understand the function of catalase at the molecular level, a cDNA sequence of ScCAT1 (GenBank Accession No. KF664183), was isolated from sugarcane infected by S. scitamineum. ScCAT1 was predicted to encode 492 amino acid residues, and its deduced amino acid sequence shared a high degree of homology with other plant catalases. Enhanced growth of ScCAT1 in recombinant Escherichia coli Rosetta cells under the stresses of CuCl2, CdCl2 and NaCl indicated its high tolerance. Q-PCR results showed that ScCAT1 was expressed at relatively high levels in the bud, whereas expression was moderate in stem epidermis and stem pith. Different kinds of stresses, including S. scitamineum challenge, plant hormones (SA, MeJA and ABA) treatments, oxidative (H2O2) stress, heavy metal (CuCl2) and hyper-osmotic (PEG and NaCl) stresses, triggered a significant induction of ScCAT1. The ScCAT1 protein appeared to localize in plasma membrane and cytoplasm. Furthermore, histochemical assays using DAB and trypan blue staining, as well as conductivity measurement, indicated that ScCAT1 may confer the sugarcane immunity. In conclusion, the positive response of ScCAT1 to biotic and abiotic stresses suggests that ScCAT1 is involved in protection of sugarcane against reactive oxidant-related environmental stimuli. PMID:24392135

  11. The Effects of Vitamins E and D Supplementation on Erythrocyte Superoxide Dismutase and Catalase in Atopic Dermatitis

    PubMed Central

    Javanbakht, MH; Keshavarz, SA; Mirshafiey, A; Djalali, M; Siassi, F; Eshraghian, MR; Firooz, AR; Seirafi, H; Ehsani, AH; Chamari, M

    2010-01-01

    Background: Atopic dermatitis is a public health problem worldwide. Increment of reactive oxygen species (ROS) production may be one of the contributing factors of tissue damage in atopic dermatitis. The present study was designed to determine the effect of vitamins E and/or D on erythrocyte superoxide dismutase and catalase activities in patients with atopic dermatitis. Methods: In a randomized, double blind, placebo controlled clinical trial 45 atopic dermatitis patients were divided into four groups. Each group received one of the following supplements for 60 days: group A (n=11) vitamins E and D placebos; group B (n= 12) 1600 international unit (IU) vitamin D3 plus vitamin E placebo; group C (n=11) 600 IU synthetic all-rac-? tocopherol plus vitamin D placebo; group D (n=11) 1600 IU vitamin D3 plus 600 IU synthetic all-rac-? tocopherol. Erythrocyte superoxide dismutase (SOD) and catalase activities, serum 25 (OH) D, plasma ?-tocopherol were determined. The data were analyzed by analysis of variance (ANOVA) and paired t-test. Results: After 60 days vitamin D and E supplementation, erythrocyte SOD activities increased in groups B, C and D (P= 0.002, P= 0.016 and P= 0.015, respectively). Erythrocyte catalase activities increased in groups B and D (P= 0.026 and P= 0.004, respectively). The increment of erythrocyte catalase activity was not significant in group C. There was a positive significant correlation between SOD activity and serum 25 (OH) D (r= 0.378, P= 0.01). Conclusions: It is concluded that vitamin D is as potent as vitamin E in increasing the activities of erythrocyte SOD and catalase in atopic dermatitis patients. PMID:23112990

  12. Low erythrocyte catalase enzyme activity is correlated with high serum total homocysteine levels in tunisian patients with acute myocardial infarction

    PubMed Central

    2013-01-01

    Background An imbalance between pro-oxidants and antioxidant systems has been suggested to be implicated in the physiopathology of acute myocardial infarction (AMI). We aimed to evaluate the antioxidant capacity in Tunisian patients and to assess the possible relationship between erythrocyte catalase enzyme activity and hyperhomocysteinaemia. Methods 108 patients with AMI and 81 healthy subjects were enrolled in this study. Catalase erythrocyte enzyme activity was determined spectrophotometrically whereas total antioxidant status (TAS) concentration was measured by a commercially available method. Serum total homocysteine (tHcy) level was determined by a fluorescence polarization immunoassay (FPIA). Lipid peroxidation was measured with a fluorimetric method as thiobarbituric acid reactive substances (TBARS). Results Compared with healthy subjects, patients with AMI had significantly lower catalase activity (P<0.001), TAS concentrations (P<0.001), and significantly higher serum tHcy (P<0.001) and TBARS levels (P<0.001). Erythrocyte catalase enzyme activity was negatively correlated with serum tHcy and TBARS while serum tHcy and TBARS were in positive correlation. Furthermore, the unbalance between pro-oxidants and antioxidants seems to be more aggravated in patients with Q wave AMI compared to patients with non-Q wave AMI. Conclusion Our results suggest the involvement of hyperhomocysteinaemia in the drop of erythrocyte catalase activity related to myocardial ischemia reperfusion. Hyperhomocysteinaemia may increase the myocardial wall dysfunction under ischemia reperfusion by excessive production of reactive oxygen species which is made evident by increased lipid peroxidation. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1623509866881834 PMID:23631751

  13. Catalase-conjugated liposomes encapsulating glucose oxidase for controlled oxidation of glucose with decomposition of hydrogen peroxide produced.

    PubMed

    Yoshimoto, Makoto; Takaki, Noriyuki; Yamasaki, Miku

    2010-09-01

    The catalase-conjugated liposome encapsulating glucose oxidase (CLG) was prepared for developing a novel liposomal system for glucose oxidation with controllable enzyme activities. The catalase molecules were conjugated to the surface of liposome with 100 nm in mean diameter through coupling with the membrane-incorporated 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(glutaryl) (NGPE) at its mole fraction f(G) of 0.05 or 0.15. The average number of enzyme molecules per CLG with f(G) of 0.15 was 8.7 for glucose oxidase and 6.5 for catalase. The CLG-catalyzed oxidation of glucose was performed at 40 degrees C for prolonged period up to 99 h. The CLG with f(G) of 0.15 gave larger oxidation rate than that with f(G) of 0.05. In the fed-batch oxidation of glucose catalyzed by the former CLG, the stable oxidation rate was observed for 75 h with negligible accumulation of H(2)O(2) produced because of the durable catalytic actions of the liposomal enzymes. The oxidation rate of the CLG reaction increased to 1.1 mM-glucose/(hmM-lipid) at the acidic pH in the internal phase of liposome and the neutral pH in the external one corresponding to the optimal pH conditions for the activities of glucose oxidase and catalase, respectively. The oxidation rate catalyzed by the CLG could be controlled by adding sublytic concentrations of cholate to increase permeability of the liposome membrane to glucose. The catalase-conjugated liposomal system is potentially utilized for controlling the rate of reactions catalyzed by a variety of oxidases. PMID:20537512

  14. Isolation of a novel peroxisomal catalase gene from sugarcane, which is responsive to biotic and abiotic stresses.

    PubMed

    Su, Yachun; Guo, Jinlong; Ling, Hui; Chen, Shanshan; Wang, Shanshan; Xu, Liping; Allan, Andrew C; Que, Youxiong

    2014-01-01

    Catalase is an iron porphyrin enzyme, which serves as an efficient scavenger of reactive oxygen species (ROS) to avoid oxidative damage. In sugarcane, the enzymatic activity of catalase in a variety (Yacheng05-179) resistant to the smut pathogen Sporisorium scitamineum was always higher than that of the susceptible variety (Liucheng03-182), suggesting that catalase activity may have a positive correlation with smut resistance in sugarcane. To understand the function of catalase at the molecular level, a cDNA sequence of ScCAT1 (GenBank Accession No. KF664183), was isolated from sugarcane infected by S. scitamineum. ScCAT1 was predicted to encode 492 amino acid residues, and its deduced amino acid sequence shared a high degree of homology with other plant catalases. Enhanced growth of ScCAT1 in recombinant Escherichia coli Rosetta cells under the stresses of CuCl2, CdCl2 and NaCl indicated its high tolerance. Q-PCR results showed that ScCAT1 was expressed at relatively high levels in the bud, whereas expression was moderate in stem epidermis and stem pith. Different kinds of stresses, including S. scitamineum challenge, plant hormones (SA, MeJA and ABA) treatments, oxidative (H2O2) stress, heavy metal (CuCl2) and hyper-osmotic (PEG and NaCl) stresses, triggered a significant induction of ScCAT1. The ScCAT1 protein appeared to localize in plasma membrane and cytoplasm. Furthermore, histochemical assays using DAB and trypan blue staining, as well as conductivity measurement, indicated that ScCAT1 may confer the sugarcane immunity. In conclusion, the positive response of ScCAT1 to biotic and abiotic stresses suggests that ScCAT1 is involved in protection of sugarcane against reactive oxidant-related environmental stimuli. PMID:24392135

  15. Further studies on O sub 2 -resistant photosynthesis and photorespiration in a tobacco mutant with enhanced catalase activity

    SciTech Connect

    Zelitch, I. )

    1990-02-01

    The increase in net photosynthesis in M{sub 4} progeny of an O{sub 2}-resistant tobacco (Nicotiana tabacum) mutant relative to wild-type plants at 21 and 42% O{sub 2} has been confirmed and further investigated. Self-pollination of an M{sub 3} mutant produced M{sub 4} progeny segregating high catalase phenotypes (average 40% greater than wild type) at a frequency of about 60%. The high catalase phenotype cosegregated precisely with O{sub 2}-resistant photosynthesis. About 25% of the F{sub 1} progeny of reciprocal crosses between the same M{sub 3} mutant and wild type had high catalase activity, whether the mutant was used as the maternal or paternal parent, indicating nuclear inheritance. In high-catalase mutants the activity of NADH-hydroxypyruvate reductase, another peroxisomal enzyme, was the same as wild type. The mutants released 15% less photorespiratory CO{sub 2} as a percent of net photosynthesis in CO{sub 2}-free 21% O{sub 2} and 36% less in CO{sub 2}-free 42% O{sub 2} compared with wild type. The mutant leaf tissue also released less {sup 14}CO{sub 2} per (1-{sup 14}C)glycolate metabolized than wild type in normal air, consistent with less photorespiration in the mutant. The O{sub 2}-resistant photosynthesis appears to be caused by a decrease in photorespiration especially under conditions of high O{sub 2} where the stoichiometry of CO{sub 2} release per glycolate metabolized is expected to be enhanced. The higher catalase activity in the mutant may decrease the nonenzymatic peroxidation of keto-acids such as hydroxypyruvate and glyoxylate by photorespiratory H{sub 2}O{sub 2}.

  16. Failure of catalase to protect against aflatoxin B{sub 1}-induced mouse lung tumorigenicity

    SciTech Connect

    Guindon, Katherine A.; Foley, Julie F.; Maronpot, Robert R.; Massey, Thomas E.

    2008-03-01

    The carcinogenic mycotoxin aflatoxin B{sub 1} (AFB{sub 1}) induces 8-hydroxy-2'-deoxyguanosine (8-OHdG) formation in mouse lung, an effect that can be prevented by treatment with polyethylene glycol-conjugated catalase (PEG-CAT). G {yields} T transversion mutation in K-ras, an early event in AFB{sub 1}-induced mouse lung carcinogenesis, is thought to result from AFB{sub 1}-8,9-exo-epoxide binding to DNA to form AFB{sub 1}-N{sup 7}-guanine, but may also result from formation of 8-OHdG. Therefore, oxidative DNA damage may be important in AFB{sub 1} carcinogenicity. The objective of this study was to determine whether PEG-CAT would prevent AFB{sub 1} tumorigenicity. Mouse lung tumorigenesis was assessed following treatment of female A/J mice with 300 kU/kg PEG-CAT ip and/or 50 mg/kg AFB{sub 1}. Mice were killed 7 months post-treatment and tumors greater than 1 mm in diameter were excised. Unexpectedly, the mean number of tumors per mouse in the PEG-CAT + AFB{sub 1} group (8.81 {+-} 3.64, n = 47) was greater than that of the group treated with AFB{sub 1} alone (7.05 {+-} 3.45, n = 42) (P < 0.05). The tumors obtained from mice treated with PEG-CAT + AFB{sub 1} were larger than those from mice treated with AFB{sub 1} alone (P < 0.05). There was no difference in K-ras exon 1 mutation spectrum or in the histological diagnosis of tumors between AFB{sub 1} and PEG-CAT + AFB{sub 1} groups (P > 0.05). In vitro incubation with mouse liver catalase (CAT) resulted in conversion of [{sup 3}H]AFB{sub 1} into a DNA-binding species, a possible explanation for the results observed in vivo. These results demonstrate that PEG-CAT is not protective against AFB{sub 1} carcinogenicity in mouse lung despite preventing DNA oxidation.

  17. Catalasic activity in fish liver: improvement of the UV to visible analytic method.

    PubMed

    Paris-Palacios, Sverine; Delahaut, Laurence; Carreras, Alexis; Thomas, Marielle; Biagianti-Risbourg, Sylvie

    2013-08-01

    Antioxidative defenses and more especially catalasic activity (CAT) are studied in a large range of scientific research thematics. In environmental sciences, the problematic of oxidative stress is of great interest as pollutants can induce perturbations of redox homeostasis. Consequently, changes in antioxidative defenses levels in fish tissues and particularly in liver are used as potential biomarkers of pollution. In most studies, the CAT was assayed by following during 5 min the consumption of H2O2 in cytosolic buffered extracts at 240 nm (UV-method). This study proposed a development of this method in the visible, using permanganate and a 525-nm detection, which was more accurate, sensitive, and rapid. Moreover, the hepatic CAT of six different fish species [a cyclidae (Nimbochromis linni), 3 cyprinidae (Brachydanio rerio, Rutilus rutilus, Cyprinus carpio), an anguillidae (Anguilla anguilla), and a percidae (Perca fluviatilus)] was evaluated with the two protocols (UV- and KMnO4-method). The results but also the thermal optimum of the reaction and the interest of CAT as biomarker in ecotoxicology were discussed. PMID:23224832

  18. Kinetic properties and storage stability of catalase immobilized on to florisil.

    PubMed

    Ozyilmaz, Gul; Tukel, S Seyhan; Alptekin, Ozlem

    2007-02-01

    The covalent immobilization of bovine liver catalase (CAT) on to florisil via glutaraldehyde was investigated. Optimum immobilization pH and temperature were determined as pH 6.0, 10 degrees C respectively, while the amount of initial CAT per g of carrier and immobilization time was determined as 5 mg g(-1) and 120 min, respectively. The Vmax values for free and immobilized CAT were found to be 1.7 x 10(5) and 2.0 x 10(4) micromol H2O2 min(-1) mg protein(-1), respectively, whereas KM values were 33.3 mM and 1722.0 mM respectively. Operational stability was determined by using a stirred batch-type column reactor. Immobilized CAT retained about 40% of its initial activity after 50 uses. It showed higher storage stability than free CAT at 4 degrees C and 25 degrees C. Its storage stability increased with increasing relative humidity (RH) from 0 to 20% of the medium. The highest storage stability was obtained in 20% RH, however, further increase in RH from 40 to 100% significantly decreased the storage stability. PMID:17385339

  19. Flavonoid-induced conversion of catalase to its inactive form--Compound II.

    PubMed

    Krych, J; Gebicki, J L; Gebicka, L

    2014-11-01

    Flavonoids (FlaOHs), plant polyphenols, are ubiquitous components of human diet and are known as antioxidants. However, their prooxidant activity has also been reported. We have recently found that FlaOHs inhibit catalase, the heme enzyme which catalyzes the decomposition of hydrogen peroxide (H2O2) into water and molecular oxygen. The catalytic cycle proceeds with the formation of the intermediate, Compound I (Cpd I), an oxoferryl porphyrin π-cation radical, the two-electron oxidation product of a heme group. Under conditions of low H2O2 fluxes and in the presence of an appropriate substrate, Cpd I can undergo one-electron reduction to inactive Compound II (Cpd II), oxoferryl derivative without radical site. Here we show that in vitro, under low fluxes of H2O2, FlaOHs reduce Cpd I to inactive Cpd II. Measurable amounts of Cpd II can be formed even in the presence of reduced nicotinamide adenine dinucleotide phosphate (NADPH) at concentration comparable with the investigated FlaOHs. Possible mechanisms of electron transfer from FlaOH molecule to the heme are discussed. PMID:25111015

  20. Selenium affects the expression of GPx4 and catalase in the liver of chicken.

    PubMed

    Zoidis, E; Pappas, A C; Georgiou, C A; Komaitis, Epsilon; Feggeros, K

    2010-03-01

    A total of 128 chickens (Gallus gallus, broilers) were used to investigate the effect of organic selenium (Se) in expression of catalase (CAT) and phospholipid hydroperoxidase 4 (GPx4) genes. There were 4 replicates of 4 dietary treatments: T1 (basal diet with no added Se), T2 (T1 with 0.15 ppm Se added), T3 (T1 with 0.3 ppm Se) and T4 (T1 with 3.0 ppm Se). At 4th and 6th week, 2 chickens per replicate pen were sacrificed for whole blood and liver sample collections. Samples were analyzed for total Se by ICP-MS and gene expression by RT-PCR. Dietary supplementation with organic Se (Se-yeast) readily elevated its concentration in the tissues. GPx4 mRNA levels, pooled for both ages, of chickens fed T3 and T4 diets were significantly reduced compared to those fed diet T1 by 47% and 77% respectively, while that of T2 did not differ. Liver CAT mRNA levels at 4th week were significantly decreased as Se supplementation increased, while at 6th week, were not significantly affected by Se. The study showed that liver GPx4 mRNA levels could be down-regulated by excess of Se. It is possible that reserves built by excess of Se meet antioxidant requirements and no additional GPx4 transcription is necessary. PMID:19961950

  1. Structure and heme environment of beef liver catalase at 2.5 A resolution.

    PubMed Central

    Reid, T J; Murthy, M R; Sicignano, A; Tanaka, N; Musick, W D; Rossmann, M G

    1981-01-01

    Most of the amino acid side chains of beef liver catalase were clearly identifiable in the 2.5 A resolution electron-density map, and the results are in good agreement with the sequence [Schroeder, W. A., Shelton, J. R., Shelton, J. B., Roberson, B. & Apell, G. (1969) Arch. Biochem. Biophys. 131, 653-655]. The tertiary structure of one subunit consists of a large antiparallel beta-pleated sheet domain with helical insertions, followed by a smaller domain containing four alpha-helices. The heme group is buried at least 20 A below the molecular surface and is accessible by a channel lined with hydrophobic residues. The proximal ligand is tyrosine-357, while histidine-74 and asparagine-147 re the important residues on the distal side of the heme. The inhibitor 3-amino-1,2,4-triazole, which has been shown to covalently bond to histidine-74, can be built into the heme cavity with its N(2) atom coordinated to the heme iron. PMID:6946424

  2. Bioaccumulation of fullerene (C60) and corresponding catalase elevation in Lumbriculus variegatus.

    PubMed

    Wang, Jiafan; Wages, Mike; Yu, Shuangying; Maul, Jonathan D; Mayer, Greg; Hope-Weeks, Louisa; Cobb, George P

    2014-05-01

    Fullerene (C(60)), with its unique physical properties and nanometer size, has been mass-produced for many applications in recent decades. The increased likelihood of direct release into the environment has raised interest in understanding both the environmental fate and corresponding biological effects of fullerenes to living organisms. Because few studies have emphasized fullerene uptake and resulting biochemical responses by living organisms, a toxicity screening test and a 28-d bioaccumulation test for Lumbriculus variegatus were performed. No mortality was observed in the range of 0.05?mg?C(60) /kg dry sediment to 11.33?mg?C(60) /kg dry sediment. A biota-sediment accumulation factor of micron-sized fullerene agglomerates (-C(60)) was 0.032??0.008 at day 28, which is relatively low compared with pyrene (1.62??0.22). Catalase (CAT) activity, an oxidative stress indicator, was elevated significantly on day 14 for L. variegatus exposed to -C(60) (p?=?0.034). This peak CAT activity corresponded to the highest body residues observed in the present study, 199??80?g?C(60) /kg dry weight sediment. Additionally, smaller C(60) agglomerate size increased bioaccumulation potential in L. variegatus. The relationship between C(60) body residue and the increased CAT activity followed a linear regression. All results suggest that C(60) has a lower bioaccumulation potential than pyrene but a higher potential to induce oxidative stress in L. variegatus. PMID:24477927

  3. Antioxidant effects of black rice extract through the induction of superoxide dismutase and catalase activities.

    PubMed

    Chiang, An-Na; Wu, Hua-Lin; Yeh, Hung-I; Chu, Chi-Shuen; Lin, Hui-Chiao; Lee, Wei-Chin

    2006-08-01

    Our ex vivo study revealed that BRE had significantly stronger ability to inhibit LDL oxidation than white rice extract (WRE). The purpose of this study was to investigate whether black rice extract (BRE) supplementation might ameliorate oxidative stress and enhance antioxidant enzyme activities in HepG2 cells and in C57BL/6 mice. In the cellular study, superoxide anions (O2*-) and reactive oxygen species (ROS) in the BRE group were significantly suppressed. The BRE group also showed significant increases in superoxide dismutase (SOD) and catalase (CAT) activities by 161.6% and 73.4%, respectively. The major components responsible for the free-radical-scavenging and antioxidative properties might be cyanidin-3-O-glucoside chloride and peonidin-3-O-glucuside chloride. In the animal study, male C57BL/6 mice were divided into three groups (control, BRE, and WRE). Plasma HDL-cholesterol was significantly higher, and thiobarbituric, acid-reactive substances were significantly lower in the BRE group, whereas plasma levels of total cholesterol and triglyceride were not affected by BRE supplementation. Increased hepatic SOD and CAT activities were observed in BRE-treated mice as compared to the control mice. However, no changes were detected for the protein expression of antioxidant enzymes by Western blot analysis. Our data suggest that antioxidative effects exerted by BRE are mediated through decreases in free-radical generation as well as increases in SOD and CAT activities both in vitro and in vivo. PMID:17120934

  4. Nanospherical Brush as Catalase Container for Enhancing the Detection Sensitivity of Competitive Plasmonic ELISA.

    PubMed

    Huang, Xiaolin; Chen, Rui; Xu, Hengyi; Lai, Weihua; Xiong, Yonghua

    2016-02-01

    Plasmonic enzyme-linked immunosorbent assay (pELISA) based on catalase (CAT)-mediated gold nanoparticle growth shows great potential for the determination of disease-related biomarkers at ultralow concentrations by using sandwich formats. However, the relatively low sensitivity of this strategy using competitive formats limits its adoption for hapten detection. Herein, we present an improved competitive pELISA for ultrasensitive detection of ochratoxin A (OTA), where silica nanoparticles carrying poly(acrylic acid) brushes (SiO2@PAA) were used to decrease the affinity of competing antigens to anti-OTA monoclonal antibodies and amplify the signal as a "CAT container" (SiO2@PAA@CAT). The developed competitive pELISA exhibits extremely high sensitivity for OTA with detection limits of 10(-18) and 5 × 10(-20) g/mL by the naked eye and microplate reader, respectively. These values are at least 7 orders of magnitude lower than that of competitive CAT-based pELISA (10(-11) g/mL by the naked eye) and 8 orders of magnitude lower than that of horseradish peroxidase-based conventional ELISA (10(-11) g/mL by the microplate reader), respectively. Reliability and robustness of the proposed method were evaluated using actual agricultural products and human serum samples. This study demonstrated the potential of this modified method in practical applications involving the ultrasensitive detection of mycotoxins or other haptens. PMID:26719076

  5. Endothelial targeting of liposomes encapsulating SOD/catalase mimetic EUK-134 alleviates acute pulmonary inflammation.

    PubMed

    Howard, Melissa D; Greineder, Colin F; Hood, Elizabeth D; Muzykantov, Vladimir R

    2014-03-10

    Production of excessive levels of reactive oxygen species (ROS) in the vascular endothelium is a common pathogenic pathway in many dangerous conditions, including acute lung injury, ischemia-reperfusion, and inflammation. Ineffective delivery of antioxidants to the endothelium limits their utility for management of these conditions. In this study, we devised a novel translational antioxidant intervention targeted to the vascular endothelium using PEG-liposomes loaded with EUK-134 (EUK), a potent superoxide dismutase/catalase mimetic. EUK loaded into antibody-coated liposomes (size 197.8±4.5 nm diameter, PDI 0.179±0.066) exerted partial activity in the intact carrier, while full activity was recovered upon liposome disruption. For targeting we used antibodies (Abs) to platelet-endothelial cell adhesion molecule (PECAM-1). Both streptavidin-biotin and SATA/SMCC conjugation chemistries provided binding of 125-150 Ab molecules per liposome. Ab/EUK/liposomes, but not IgG/EUK/liposomes: i) bound to endothelial cells and inhibited cytokine-induced inflammatory activation in vitro; and, ii) accumulated in lungs after intravascular injection, providing >60% protection against pulmonary edema in endotoxin-challenged mice (vs <6% protection afforded by IgG/liposome/EUK counterpart). Since the design elements of this drug delivery system are already in clinical use (PEG-liposomes, antibodies, SATA/SMCC conjugation), it is an attractive candidate for translational interventions using antioxidant molecules such as EUK and other clinically acceptable drugs. PMID:24412573

  6. A simple method to measure effective catalase activities: optimization, validation, and application in green coffee.

    PubMed

    Montavon, Philippe; Kukic, Koraljka Rade; Bortlik, Karlheinz

    2007-01-15

    Oxidative metabolism in coffee cherries during maturation appears to be regulated by the timely expression of redox enzymes such as catalase (CAT), peroxidase (POD), and polyphenoloxidase (PPO). Among these enzymes, CAT is suspected to contribute significantly in setting the redox status of the healthy cherry and the processed bean. The initial redox status of the green bean might further control the nature and dynamics of reactions induced by roasting and eventually quality aspects of the end product. In this respect, Arabica (Coffea arabica) and Robusta (Coffea canephora) typically differ by their cup coffee flavor profiles. We developed an assay that allowed us to screen numerous green coffee samples for effective CAT activities. The proposed assay, which monitors CAT activities by online oxygen sensing in green coffee crude suspensions incubated with H2O2, seeks to integrate potential effects of endogenous inhibitors and activators. After optimization and validation of the assay, 23 Arabicas, 23 Robustas, and 8 Arabustas were analyzed. Nearly all Arabicas (22 of 23) harbored high CAT activity levels, whereas all Robustas harbored low ones. Arabustas performed like Arabicas of the lower CAT activity range. The traditional spectrophotometric assay did not reveal these specificities. Because of its simplicity, our assay might be valuable for assessing effective CAT activities in various plant tissues. PMID:17141173

  7. Influence of catalase gene silencing on the survivability of Sitobion avenae.

    PubMed

    Deng, Fei; Zhao, Zhangwu

    2014-05-01

    Reactive oxygen species (ROS), such as superoxide anions and hydrogen peroxide produced in cell metabolism, result in the disruption of cellular function and structure. Catalase (CAT), an enzyme which exists in almost all organisms including plants, invertebrates and vertebrates, acts in scavenging ROS. In this study, a sequence fragment encoding a CAT-like protein from wheat aphids (?Sitobion avenae) was cloned. Amino acid sequence alignment showed this CAT shared relatively high conservation with CAT sequences from other insects. We detected cat mRNA levels at nymphs of different stages and adults and results showed that cat expression in adults was significantly higher compared to juvenile stages. At the third instar stage, ingestion of dsCAT significantly knocked down CAT expression. Continuous feeding of dsCAT mixed in an artificial diet led to reduced survival rate and ecdysis index. This study indicates that cat, a potential target gene for management of insect pests, is important for maintaining the survival of ?S. avenae. PMID:24719312

  8. Effect of covalent attachment of neomycin on conformational and aggregation properties of catalase.

    PubMed

    Hashemnia, S; Mokhtari, Z; Tashkhourian, J; Moosavi-Movahedi, A A

    2015-04-01

    The carboxylic groups of glutamic acid and aspartic acid residues of catalase (CAT) were chemically modified using the treatment of the enzyme with 1-ethyl-3-(3'-dimethylamino) carbodiimide hydrochloride (EDC) and neomycin. The effect of covalent attachment of neomycin on the enzymatic activity, conformational and aggregation properties of CAT was investigated. The modification of CAT with different concentrations of neomycin showed two different types of behavior, depending up on the concentration range of neomycin. In the concentration range from 0.0 to 5.2 mM, neomycin-modified CAT, compared to the native enzyme exhibited higher a-helix content, reduced surface hydrophobicity, little enhancement in CAT activity and a better protection against thermal aggregation, whereas at concentrations greater than 5.2 mM, the modified enzyme exhibited a significant decrease in CAT activity and an increase in random coil content which may result in disorder in the protein structure and increase in thermal aggregation. This modification is a rapid and simple approach to investigate the role of aspartate and glutamate residues in the structure, function and folding of CAT. PMID:26118131

  9. Effect of cyprodinil and fludioxonil pesticides on bovine liver catalase activity

    PubMed Central

    Karadag, Hasan; Ozhan, Fadil

    2015-01-01

    This study investigated if the use of the pesticides cyprodinil and fludioxonil produced an inhibitory effect on the bovine liver catalase (CAT) activity. It was documented that the activity of the enzyme decreased with increasing concentrations of cyprodinil and fludioxonil from 0 to 500 ppm. At pesticide concentrations of 250 and 500 ppm, the activity of CAT remained unchanged and passed to a steady state. The exposure to cyprodinil in concentrations of 10, 50, 100, 250 and 500 ppm, led to a decrease in the per cent of the CAT enzyme activity calculated as 45.4, 68.0, 73.0, 77.8 and 77.4, respectively. Similarly, the exposure to fludioxonil in concentrations of 10, 50, 100, 250 and 500 ppm, produced the following percentage decrease in the CAT enzyme activity: 20.0, 30.8, 42.8, 46.3 and 45.9, respectively. Cyprodinil inhibited CAT competitively, whereas the mechanism of fludioxonil inhibition over the enzyme was non-competitive. PMID:26740786

  10. Study on the interaction of catalase with pesticides by flow injection chemiluminescence and molecular docking.

    PubMed

    Tan, Xijuan; Wang, Zhuming; Chen, Donghua; Luo, Kai; Xiong, Xunyu; Song, Zhenghua

    2014-08-01

    The interaction mechanisms of catalase (CAT) with pesticides (including organophosphates: disulfoton, isofenphos-methyl, malathion, isocarbophos, dimethoate, dipterex, methamidophos and acephate; carbamates: carbaryl and methomyl; pyrethroids: fenvalerate and deltamethrin) were first investigated by flow injection (FI) chemiluminescence (CL) analysis and molecular docking. By homemade FI-CL model of lg[(I0-I)/I]=lgK+nlg[D], it was found that the binding processes of pesticides to CAT were spontaneous with the apparent binding constants K of 10(3)-10(5) L mol(-1) and the numbers of binding sites about 1.0. The binding abilities of pesticides to CAT followed the order: fenvalerate>deltamethrin>disulfoton>isofenphos-methyl>carbaryl>malathion>isocarbophos>dimethoate>dipterex>acephate>methomyl>methamidophos, which was generally similar to the order of determination sensitivity of pesticides. The thermodynamic parameters revealed that CAT bound with hydrophobic pesticides by hydrophobic interaction force, and with hydrophilic pesticides by hydrogen bond and van der Waals force. The pesticides to CAT molecular docking study showed that pesticides could enter into the cavity locating among the four subdomains of CAT, giving the specific amino acid residues and hydrogen bonds involved in CAT-pesticides interaction. It was also found that the lgK values of pesticides to CAT increased regularly with increasing lgP, Mr, MR and MV, suggesting that the hydrophobicity and steric property of pesticide played essential roles in its binding to CAT. PMID:24875908

  11. Effects of humic acid-metal complexes on hepatic carnitine palmitoyltransferase, carnitine acetyltransferase and catalase activities

    SciTech Connect

    Fungjou Lu; Youngshin Chen . Dept. of Biochemistry); Tienshang Huang . Dept. of Medicine)

    1994-03-01

    A significant increase in activities of hepatic carnitine palmitoyltransferase and carnitine acetyltransferase was observed in male Balb/c mice intraperitoneally injected for 40 d with 0.125 mg/0.1 ml/d humic acid-metal complexes. Among these complexes, the humic acid-As complex was relatively effective, whereas humic acid-25 metal complex was more effective, and humic acid-26 metal complex was most effective. However, humic acid or metal mixtures, or metal such as As alone, was not effective. Humic acid-metal complexes also significantly decreased hepatic catalase activity. A marked decrease of 60-kDa polypeptide in liver cytoplasm was also observed on SDS-polyacrylamide gel electrophoresis after the mice had been injected with the complexes. Morphological analysis of a histopathological biopsy of such treated mice revealed several changes in hepatocytes, including focal necrosis and cell infiltration, mild fatty changes, reactive nuclei, and hypertrophy. Humic acid-metal complexes affect activities of metabolic enzymes of fatty acids, and this results in accumulation of hydrogen peroxide and increase of the lipid peroxidation. The products of lipid peroxidation may be responsible for liver damage and possible carcinogenesis. Previous studies in this laboratory had shown that humic acid-metal complex altered the coagulation system and that humic acid, per se, caused vasculopathy. Therefore, humic acid-metal complexes may be main causal factors of not only so-called blackfoot disease, but also the liver cancer prevailing on the southwestern coast of Taiwan.

  12. Analysis of Oxidative Stress Status, Catalase and Catechol-O-Methyltransferase Polymorphisms in Egyptian Vitiligo Patients

    PubMed Central

    Mehaney, Dina A.; Darwish, Hebatallah A.; Hegazy, Rehab A.; Nooh, Mohammed M.; Tawdy, Amira M.; Gawdat, Heba I.; El-Sawalhi, Maha M.

    2014-01-01

    Vitiligo is the most common depigmentation disorder of the skin. Oxidative stress is implicated as one of the probable events involved in vitiligo pathogenesis possibly contributing to melanocyte destruction. Evidence indicates that certain genes including those involved in oxidative stress and melanin synthesis are crucial for development of vitiligo. This study evaluates the oxidative stress status, the role of catalase (CAT) and catechol-O-Methyltransferase (COMT) gene polymorphisms in the etiology of generalized vitiligo in Egyptians. Total antioxidant capacity (TAC) and malondialdehyde (MDA) levels as well as CAT exon 9 T/C and COMT 158 G/A polymorphisms were determined in 89 patients and 90 age and sex-matched controls. Our results showed significantly lower TAC along with higher MDA levels in vitiligo patients compared with controls. Meanwhile, genotype and allele distributions of CAT and COMT polymorphisms in cases were not significantly different from those of controls. Moreover, we found no association between both polymorphisms and vitiligo susceptibility. In conclusion, the enhanced oxidative stress with the lack of association between CAT and COMT polymorphisms and susceptibility to vitiligo in our patients suggest that mutations in other genes related to the oxidative pathway might contribute to the etiology of generalized vitiligo in Egyptian population. PMID:24915010

  13. Multifrequency EPR Studies of Manganese Catalases Provide a Complete Description of Proteinaceous Nitrogen Coordination

    PubMed Central

    Stich, Troy A.; Whittaker, James W.; Britt, R. David

    2012-01-01

    Pulse electron paramagnetic resonance (EPR) spectroscopy is employed at two very different excitation frequencies, 9.77 and 30.67 GHz, in the study of the nitrogen coordination environment of the Mn(III)Mn(IV) state of the dimanganese-containing catalases from Lactobacillus plantarum and Thermus thermophilus. Consistent with previous studies, the lower-frequency results reveal one unique histidine nitrogen-Mn cluster interaction. For the first time, a second, more strongly hyperfine-coupled 14N atom is unambiguously observed through the use of higher frequency/higher field EPR spectroscopy. The low excitation frequency spectral features are rationalized as arising from the interaction of a histidine nitrogen that is bound to the Mn(IV) ion, while the higher excitation frequency features are attributed to the histidine nitrogen bound to the Mn(III) ion. These results allow for the computation of intrinsic hyperfine coupling constants, which range from 2.2 to 2.9 MHz, for sp2-hybridized nitrogens coordinating equatorially to high-valent Mn ions. The relevance of these findings is discussed in the context of recent results from analogous higher frequency EPR studies of the Mn cluster in photosystem II and other exchange-coupled transition metal-containing systems. PMID:20055466

  14. Potential toxicity of sarafloxacin to catalase: Spectroscopic, ITC and molecular docking descriptions

    NASA Astrophysics Data System (ADS)

    Cao, Zhaozhen; Liu, Rutao; Yang, Bingjun

    2013-11-01

    The interaction between sarafloxacin and catalase (CAT) was studied by fluorescence spectroscopy, UV-visible absorption spectroscopy, circular dichroism (CD) spectroscopy, isothermal titration microcalorimetry (ITC) and molecular docking method. After deducting the inner filter effect, the fluorescence of CAT was quenched regularly by different concentrations of sarafloxacin. The quenching mechanism was studied by lifetime measurement, and it was proved to be mostly due to static quenching. The formation of sarafloxacin-CAT complex alters the micro-environment of amide moieties and tryptophan (Trp) residues, reduces the α-helix content of the enzyme, changes the peripheral substituents on the porphyrin ring of heme and leads to the inhibition of the enzyme activity. Molecular docking study reveals that sarafloxacin is located between two α-helix of CAT near to Trp 182 and Trp 185 residues, which supports the experimental results and helps to have a more clear understanding about the interaction mechanism. The change in the relative position of His 74 to heme induced by the variation of secondary structure is considered to be the major reason for the reduction of CAT activity. Moreover, sarafloxacin binds into a hydrophobic area of CAT mainly through hydrophobic interactions, which is consistent with the ITC analysis.

  15. Touch automatically upregulates motor readiness in humans.

    PubMed

    van Ede, Freek; Winner, Tobias; Maris, Eric

    2015-12-01

    Goal-directed movements require effective integration of tactile input with ongoing movement. Here we investigated the functional consequences of such integration in healthy humans by probing the influence of spatially congruent and incongruent tactile stimuli on performance in a speeded button-press task. In addition, using magnetoencephalography (MEG), we evaluated whether the modulation of somato-motor beta (13-30 Hz) oscillations following tactile input-which has been shown to propagate to motor areas-could underlie this influence. We demonstrate that congruent tactile stimuli, despite being irrelevant to the motor task, lead to both faster and more accurate responses. We further show that this automatic upregulation of lateralized motor readiness 1) is specific to tactile input, 2) is independent of the spatial separation of the hands in peripersonal space, and 3) lasts (and remains facilitatory) for up to a second after the tactile input. This pattern of behavioral results is in line with recent physiological investigations showing that somatosensory and motor areas directly influence each other's processing capacity through joint changes in brain state. At the same time, however, the tactile-induced modulation of beta oscillations (one particular index of such a somato-motor state change) could not account for the observed movement facilitation, because it had a different time course. PMID:26400256

  16. Cytoophidium assembly reflects upregulation of IMPDH activity

    PubMed Central

    Chang, Chia-Chun; Lin, Wei-Cheng; Pai, Li-Mei; Lee, Hsuan-Shu; Wu, Shinn-Chih; Ding, Shih-Torng; Liu, Ji-Long; Sung, Li-Ying

    2015-01-01

    ABSTRACT Cytidine triphosphate synthase (CTPS) and inosine monophosphate dehydrogenase (IMPDH) (both of which have two isoforms) can form fiber-like subcellular structures termed cytoophidia under certain circumstances in mammalian cells. Although it has been shown that filamentation of CTPS downregulates its activity by disturbing conformational changes, the activity of IMPDH within cytoophidia is still unclear. Most previous IMPDH cytoophidium studies were performed under conditions involving inhibitors that impair GTP synthesis. Here, we show that IMPDH forms cytoophidia without inhibition of GTP synthesis. First, we find that an elevated intracellular CTP concentration or treatment with 3?-deazauridine, a CTPS inhibitor, promotes IMPDH cytoophidium formation and increases the intracellular GTP pool size. Moreover, restriction of cell growth triggers the disassembly of IMPDH cytoophidia, implying that their presence is correlated with active cell metabolism. Finally, we show that the presence of IMPDH cytoophidia in mouse pancreatic islet cells might correlate with nutrient uptake in the animal. Collectively, our findings reveal that formation of IMPDH cytoophidia reflects upregulation of purine nucleotide synthesis, suggesting that the IMPDH cytoophidium plays a role distinct from that of the CTPS cytoophidium in controlling intracellular nucleotide homeostasis. PMID:26303200

  17. Caloric restriction or catalase inactivation extends yeast chronological lifespan by inducing H2O2 and superoxide dismutase activity

    PubMed Central

    Mesquita, Ana; Weinberger, Martin; Silva, Alexandra; Sampaio-Marques, Belém; Almeida, Bruno; Leão, Cecília; Costa, Vítor; Rodrigues, Fernando; Burhans, William C.; Ludovico, Paula

    2010-01-01

    The free radical theory of aging posits oxidative damage to macromolecules as a primary determinant of lifespan. Recent studies challenge this theory by demonstrating that in some cases, longevity is enhanced by inactivation of oxidative stress defenses or is correlated with increased, rather than decreased reactive oxygen species and oxidative damage. Here we show that, in Saccharomyces cerevisiae, caloric restriction or inactivation of catalases extends chronological lifespan by inducing elevated levels of the reactive oxygen species hydrogen peroxide, which activate superoxide dismutases that inhibit the accumulation of superoxide anions. Increased hydrogen peroxide in catalase-deficient cells extends chronological lifespan despite parallel increases in oxidative damage. These findings establish a role for hormesis effects of hydrogen peroxide in promoting longevity that have broad implications for understanding aging and age-related diseases. PMID:20696905

  18. Dynamics of erythrocyte count, hemoglobin, and catalase activity in rat blood in hypokinesia, muscular activity and restoration

    NASA Technical Reports Server (NTRS)

    Taneyeva, G. V.; Potapovich, G. M.; Voloshko, N. A.; Uteshev, A. B.

    1980-01-01

    Tests were conducted to prove that muscular exertion (in this instance swimming) of different duration and intensity, as well as hypodynamia, result in an increase of hemoglobin and number of red blood cells in peripheral blood rats. Catalase activity increased with an increase in the duration of swimming, but only up to 6 hr; with 7-9 hr of swimming as well as in hypodynamia, catalase activity decreased. It was also observed that under hypodynamia as well as in 3, 5 and 6 hr exertion (swimming) the color index of blood decreased. Pressure chamber treatment (for 8 min each day for one week), alternating a 2 min negative pressure up to 35 mm Hg with 1 min positive pressure, increased the erythrocyte count and hemoglobin content.

  19. EUK-134, a synthetic superoxide dismutase and catalase mimetic, prevents oxidative stress and attenuates kainate-induced neuropathology

    PubMed Central

    Rong, Yongqi; Doctrow, Susan R.; Tocco, Georges; Baudry, Michel

    1999-01-01

    The present study tested the effects of EUK-134, a synthetic superoxide dismutase/catalase mimetic, on several indices of oxidative stress and neuropathology produced in the rat limbic system as a result of seizure activity elicited by systemic kainic acid (KA) administration. Pretreatment of rats with EUK-134 did not modify the latency for or duration of KA-induced seizure activity. It did produce a highly significant reduction in increased protein nitration, activator protein-1- and NF-?B-binding activity, and spectrin proteolysis as well as in neuronal damage resulting from seizure activity in limbic structures. These results support the hypothesis that kainate-induced excitotoxicity is caused, at least in part, by the action of reactive oxygen species. Furthermore, they suggest that synthetic superoxide dismutase/catalase mimetics such as EUK-134 might be used to prevent excitotoxic neuronal injury. PMID:10449791

  20. Simultaneous and sequential co-immobilization of glucose oxidase and catalase onto florisil.

    PubMed

    Ozyilmaz, Gul; Tukel, S Seyhan

    2007-06-01

    The co-immobilization of Aspergillus niger glucose oxidase (GOD) with bovine liver catalase (CAT) onto florisil (magnesium silicate-based porous carrier) was investigated to improve the catalytic efficiency of GOD against H2O2 inactivation. The effect of the amount of bound CAT on the GOD activity was also studied for 12 different initial combinations of GOD and CAT, using simultaneous and sequential coupling. The sequentially co-immobilized GOD-CAT showed a higher efficiency than the simultaneously co-immobilized GOD-CAT in terms of the GOD activity and economic costs. The highest activity was shown by the sequentially co-immobilized GOD-CAT when the initial amounts of GOD and CAT were 10 mg and 5 mg per gram of carrier. The optimum pH, buffer concentration, and temperature for GOD activity for the same co-immobilized GOD-CAT sample were then determined as pH 6.5, 50 mM, and 30 degrees C, respectively. When compared with the individually immobilized GOD, the catalytic activity of the co-immobilized GOD-CAT was 70% higher, plus the reusability was more than two-fold. The storage stability of the co-immobilized GOD-CAT was also found to be higher than that of the free form at both 5 degrees C and 25 degrees C. The increased GOD activity and reusability resulting from the co-immobilization process may have been due to CAT protecting GOD from inactivation by H2O2 and supplying additional O2 to the reaction system. PMID:18050914

  1. Transcriptional inhibition of the Catalase gene in phosphine-induced oxidative stress in Drosophila melanogaster.

    PubMed

    Liu, Tao; Li, Li; Zhang, Fanhua; Wang, Yuejin

    2015-10-01

    Phosphine (PH3) is a toxic substance to pest insects and is therefore commonly used in pest control. The oxidative damage induced by PH3 is considered to be one of the primary mechanisms of its toxicity in pest insects; however, the precise mode of PH3 action in this process is still unclear. In this study, we evaluated the responses of several oxidative biomarkers and two of the main antioxidant enzymes, catalase (CAT) and superoxide dismutase (SOD), after fumigation treatment with PH3 in Drosophila melanogaster as a model system. The results showed that larvae exposed to sub-lethal levels of PH3 (0.028 mg/L) exhibited lower aerobic respiration rates and higher levels of hydrogen peroxide (H2O2) and lipid peroxidation (LPO). Furthermore, unlike SOD, the activity and expression of CAT and its encoding gene were downregulated by PH3 in a time- and dose-dependent manner. Finally, the responses of six potential transcription factors of PH3 were determined by real-time polymerase chain reaction to explore the regulation mechanism of DmCAT by PH3. There were no significant effects of PH3 on three nuclear factor-kappa B homologs (DORSAL, DIF, and RELISH) or two activator protein-1 genes (JUN and FOS), while dramatic inhibition of DNA replication-related element factor (DREF) expression was observed after fumigation with PH3, suggesting that PH3 could inhibit the expression of DmCAT via the DRE/DREF system. These results confirmed that PH3 induces oxidative stress and targets CAT by downregulating its encoding gene in Drosophila. Our results provide new insight into the signal transduction mechanism between PH3 and its target genes. PMID:26453223

  2. Application of different molecular techniques for characterization of catalase-positive cocci isolated from sucuk.

    PubMed

    Kesmen, Zlal; Yarimcam, Burcu; Aslan, Hakiye; Ozbekar, Esra; Yetim, Hasan

    2014-02-01

    This study was carried out for the characterization and discrimination of the indigenous Gram positive, catalase-positive cocci (GCC) population in sucuk, a traditional Turkish dry-fermented sausage. Sucuk samples, produced by the traditional method without starter culture were collected from 8 local producers in Kayseri/Turkey and a total of 116 GCC isolates were identified by using different molecular techniques. Two different molecular fingerprinting methods; namely, randomly amplified polymorphic DNA-PCR (RAPD-PCR) and repetitive extragenic palindrome-PCR (rep-PCR), were used for the clustering of isolates and identification at species level was carried out by full length sequencing of 16S rDNA. Combining the results obtained from molecular fingerprinting and 16S rDNA sequencing showed that the dominant GCC species isolated from the sucuk samples was Staphylococcus saprophyticus followed by Staphylococcus succinus and Staphylococcus equorum belonging to the Staphylococcus genus. Real-time PCR DNA melting curve analysis and high-resolution melting (HRM) analysis targeting the V1 + V3 regions of 16S rDNA were also applied for the discrimination of isolates belonging to different species. It was observed statistically different Tm values and species-specific HRM profiles for all except 2 species (S. saprophyticus and Staphylococcus xylosus) that have high 16S rDNA sequence similarity. The combination of rep-PCR and/or PCR-RAPD with 16S rRNA gene sequencing was an efficient approach for the characterization and identification of the GCC population in spontaneously fermented sucuk. On the other hand, intercalating dye assays were found to be a simple and very promising technique for the differentiation of the GCC population at species level. PMID:24410408

  3. Combined effects of water temperature and copper ion concentration on catalase activity in Crassostrea ariakensis

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Yang, Hongshuai; Liu, Jiahui; Li, Yanhong; Liu, Zhigang

    2015-07-01

    A central composite experimental design and response surface method were used to investigate the combined effects of water temperature (18-34°C) and copper ion concentration (0.1-1.5 mg/L) on the catalase (CAT) activity in the digestive gland of Crassostrea ariakensis. The results showed that the linear effects of temperature were significant ( P<0.01), the quadratic effects of temperature were significant ( P<0.05), the linear effects of copper ion concentration were not significant ( P>0.05), and the quadratic effects of copper ion concentration were significant ( P<0.05). Additionally, the synergistic effects of temperature and copper ion concentration were not significant ( P>0.05), and the effect of temperature was greater than that of copper ion concentration. A model equation of CAT enzyme activity in the digestive gland of C. ariakensis toward the two factors of interest was established, with R 2, Adj. R 2 and Pred. R 2 values as high as 0.943 7, 0.887 3 and 0.838 5, respectively. These findings suggested that the goodness of fit to experimental data and predictive capability of the model were satisfactory, and could be practically applied for prediction under the conditions of the study. Overall, the results suggest that the simultaneous variation of temperature and copper ion concentration alters the activity of the antioxidant enzyme CAT by modulating active oxygen species metabolism, which may be utilized as a biomarker to detect the effects of copper pollution.

  4. Evaluation of a rapid method for measurement of catalase activity in cooked beef and sausage.

    PubMed

    Davis, C E; Cyrus, S

    1998-02-01

    Catalase (CAT) activity in ground beef and pork was determined on samples cooked from 60 to 71.1 degrees C. One-gram samples of ground round (4% fat), hamburger (24% fat), and commercial pork sausage (38%fat) were cooked in a controlled-temperature waterbath at 65, 68.3 and 71 degrees C. Chilled samples were immersed in direct contact with the cooking water; the test samples were removed every 15 s and immediately immersed in an ice-water bath (O to 1 degrees C) to quick-chill the samples to prevent temperature over-run. Samples retained high (HMB value 20+, over range) CAT activity through 90, 60, and 45 s at 65, 68.3, and 71 degrees C, respectively, before showing rapid activity decreases. Four USDA-FSIS approved meat patty heating processes (66.1 degrees C, 41 s; 67.2 degrees C, 26 s; 68.3 degrees C, 16 s; and 69.4 degrees C, 10 s) were analyzed for CAT activity in meat frozen prior to cooking was slightly lower (P < 0.05) than in degrees C meat. CAT activity decreased (P < 0.05) among meat treated at 66.1 degrees C for 41 s, at 67.2 degrees C for 26 s, and at 68.3 degrees C for 16 s, but the treatment at 68.3 degrees C for 16 s was not different (P < 0.05) from that at 69.4 degrees C for 10 s. These results show this rapid (20 to 25 min) CAT activity test could be used to establish activity values at specific end-point temperatures for model heat-processed ground beef or sausage products and may be useful to USDA FSIS process inspectors and food processors in quality assurance and HACCP (hazard analysis critical control points) programs for thermal input verification. PMID:9708292

  5. Combination of heterogeneous catalase and superoxide dismutase protects Bifidobacterium longum strain NCC2705 from oxidative stress.

    PubMed

    Zuo, Fanglei; Yu, Rui; Feng, Xiujuan; Khaskheli, Gul Bahar; Chen, Lili; Ma, Huiqin; Chen, Shangwu

    2014-09-01

    Bifidobacteria are generally sensitive to oxidative stress caused by reactive oxygen species (ROS). To improve oxidative-stress tolerance, the superoxide dismutase (SOD) gene from Streptococcus thermophilus (StSodA) and the heme-dependent catalase (KAT) gene from Lactobacillus plantarum (LpKatL) were heterologously expressed in Bifidobacterium longum strain NCC2705. Three types of strain NCC2705 transformants were obtained: with transgenic SOD expression, with transgenic KAT expression, and with coexpression of the two genes. Intracellular expression of the genes and their functional role in oxidative-stress resistance were evaluated. In response to oxidative stress, B. longum NCC2705/pDP401-LpKatL (expressing LpKatL) and NCC2705/pDP-Kat-Sod (coexpressing LpKatL and StSodA) rapidly degraded exogenous H2O2 and the peroxides generated as a byproduct of aerobic cultivation, preventing oxidative damage to DNA and RNA. Individual expression of StSodA or LpKatL both improved B. longum NCC2705 cell viability. Survival rate of strain NCC2705 was further improved by combining SOD and KAT expression. The two enzymes played complementary roles in ROS-scavenging pathways, and coexpression led to a synergistic beneficial effect under conditions of intensified oxidative stress. Our results illustrate that heterogeneous expression of heme-dependent KAT and Mn(2+)-dependent SOD is functional in the B. longum oxidative-stress response, and synergistic protection is achieved when their expressions are combined. PMID:24903816

  6. Manganese superoxide dismutase, glutathione peroxidase and catalase gene polymorphisms and clinical outcomes in acute kidney injury.

    PubMed

    Kidir, Veysel; Uz, Efkan; Yigit, Ayse; Altuntas, Atila; Yigit, Barbaros; Inal, Salih; Uz, Ebru; Sezer, Mehmet Tugrul; Yilmaz, H Ramazan

    2016-04-01

    Introduction The aim of this study was to evaluate the potential association of single gene polymorphisms of manganese superoxide dismutase (MnSOD), glutathione peroxidase 1 (GPX1) and catalase (CAT) with clinical outcomes of acute kidney injury (AKI). Materials and methods Ninety AKI patients and 101 healthy volunteers were included in the study. Determination of MnSOD rs4880, GPX1 rs1050450 and CAT rs769217 polymorphisms was performed using real-time polymerase chain reaction amplification. The duration of hospitalization of AKI patients, dialysis and intensive care requirements, sepsis, oliguria and in-hospital mortality rates were assessed. Results The MnSOD, GPX1 and CAT genotypes and allele frequencies of AKI patients did not differ significantly from those of healthy controls. In patients with a T allele in the ninth exon of the CAT gene, intensive care requirements were greater than those of patients with the CC genotype (p = 0.04). In addition, sepsis and in-hospital mortality were observed significantly more frequently in patients with a T allele in the ninth exon of the CAT gene (p = 0.03). Logistic regression analysis determined that bearing a T allele was the primary determinant of intensive care requirements and in-hospital mortality, independent of patient age, gender, presence of diabetes and dialysis requirements (OR 6.10, 95% CI 1.34-27.81, p = 0.02 and OR 10.25, 95% CI 1.13-92.80, p = 0.04, respectively). Conclusion Among AKI patients in the Turkish population, hospital morbidity and mortality were found to be more frequent in patients bearing a T allele of the rs769217 polymorphism of the CAT gene. PMID:26787049

  7. Improving of catalase stability properties by encapsulation in alginate/Fe3O4 magnetic composite beads for enzymatic removal of H2O2.

    PubMed

    Do?a, Yasemin Ispirli; inar, Mrvet; Teke, Mustafa

    2015-01-01

    The aim of this study was enhancing of stability properties of catalase enzyme by encapsulation in alginate/nanomagnetic beads. Amounts of carrier (10-100mg) and enzyme concentrations (0.25-1.5mg/mL) were analyzed to optimize immobilization conditions. Also, the optimum temperature (25-50C), optimum pH (3.0-8.0), kinetic parameters, thermal stability (20-70C), pH stability (4.0-9.0) operational stability (0-390min), and reusability were investigated for characterization of the immobilized catalase system. The optimum pH levels of both free and immobilized catalase were 7.0. At the thermal stability studies, the magnetic catalase beads protected 90% activity, while free catalase maintained only 10% activity at 70C. The thermal profile of magnetic catalase beads was spread over a large area. Similarly, this system indicated the improving of the pH stability. The reusability, which is especially important for industrial applications, was also determined. Thus, the activity analysis was done 50 times in succession. Catalase encapsulated magnetic alginate beads protected 83% activity after 50cycles. PMID:24679144

  8. Characterizing dose-responses of catalase to nitrofurazone exposure in model ciliated protozoan Euplotes vannus for ecotoxicity assessment: enzyme activity and mRNA expression.

    PubMed

    Li, Jiqiu; Zhou, Liang; Lin, Xiaofeng; Yi, Zhenzhen; Al-Rasheid, Khaled A S

    2014-02-01

    In environmental studies, some biological responses, known as biomarkers, have been used as a powerful bioassay tool for more than four decades. Disparity between enzyme activity and mRNA abundance leads to correlation equivocality, which makes the application of biomarkers for environmental risk assessment more complicated. This study investigates this disparity in the case of catalase when used as a biomarker for detecting ecotoxicity induced by antibiotics in aquatic ecosystems. In particular, dose-responses for catalase activity and mRNA expression abundance were investigated in Euplotes vannus which were exposed to graded doses of nitrofurazone for several discrete durations, and dose-response models were developed to characterize the dose-response dynamics. Significant differences were found in both catalase activity and mRNA expression abundance among the E. vannus treated with nitrofurazone. Catalase activity showed a hormetic-like effect in terms of dose-response, characterized by a biphasic relationship which was more clearly evident after a longer exposure period, while mRNA expression abundance increased linearly with the exposure duration. Additionally, the correlation between catalase activity and mRNA expression abundance reversed along with the duration of exposure to nitrofurazone. Taken together, our results demonstrate that catalase mRNA expression offers a more straightforward dose-response model than enzyme activity. Our findings suggest that both catalase enzyme activity and mRNA expression abundance can be used jointly as bioassay tools for detecting ecotoxicity induced by nitrofurazone in aquatic ecosystems. PMID:24075098

  9. Two-dimensional HYSCORE spectroscopy of superoxidized manganese catalase: a model for the oxygen-evolving complex of photosystem II.

    PubMed

    Coates, Christopher S; Milikisiyants, Sergey; Chatterjee, Ruchira; Whittaker, Mei M; Whittaker, James W; Lakshmi, K V

    2015-04-16

    The solar water-splitting protein complex, photosystem II (PSII), catalyzes one of the most energetically demanding reactions in Nature by using light energy to drive a catalyst capable of oxidizing water. The water oxidation reaction takes place at the tetra-nuclear manganese calcium-oxo (Mn4Ca-oxo) cluster at the heart of the oxygen-evolving complex (OEC) of PSII. Previous studies have determined the magnetic interactions between the paramagnetic Mn4Ca-oxo cluster and its environment in the S2 state of the OEC. The assignments for the electron-nuclear magnetic interactions that were observed in these studies were facilitated by the use of synthetic dimanganese di-?-oxo complexes. However, there is an immense need to understand the effects of the protein environment on the coordination geometry of the Mn4Ca-oxo cluster in the OEC of PSII. In the present study, we use a proteinaceous model system to examine the protein ligands that are coordinated to the dimanganese catalytic center of manganese catalase from Lactobacillus plantarum. We utilize two-dimensional hyperfine sublevel correlation (2D HYSCORE) spectroscopy to detect the weak magnetic interactions of the paramagnetic dinuclear manganese catalytic center of superoxidized manganese catalase with the nitrogen and proton atoms of the surrounding protein environment. We obtain a complete set of hyperfine interaction parameters for the protons of a water molecule that is directly coordinated to the dinuclear manganese center. We also obtain a complete set of hyperfine and quadrupolar interaction parameters for two histidine ligands as well as a coordinated azide ligand, in azide-treated superoxidized manganese catalase. On the basis of the values of the hyperfine interaction parameters of the dimanganese model, manganese catalase, and those of the S2 state of the OEC of PSII, for the first time, we discuss the impact of a proteinaceous environment on the coordination geometry of multinuclear manganese clusters. PMID:25731604

  10. recA and catalase in H sub 2 O sub 2 -mediated toxicity in Neisseria gonorrhoeae

    SciTech Connect

    Hassett, D.J.; Charniga, L.; Cohen, M.S. )

    1990-12-01

    Neisseria gonorrhoeae cells defective in the biosynthesis of the recA gene product are no more sensitive to hydrogen peroxide than wild-type cells. Although gonococci possess nearly 100-fold-greater catalase levels than Escherichia coli, they are more susceptible to hydrogen peroxide than this organism. The natural niche of gonococci undoubtedly results in exposure to oxidant stress; however, they do not demonstrate particularly efficient antioxidant defense systems.

  11. Catalase Expression Is Modulated by Vancomycin and Ciprofloxacin and Influences the Formation of Free Radicals in Staphylococcus aureus Cultures

    PubMed Central

    Wang, Ying; Hougaard, Anni B.; Paulander, Wilhelm; Skibsted, Leif H.

    2015-01-01

    Detection of free radicals in biological systems is challenging due to their short half-lives. We have applied electron spin resonance (ESR) spectroscopy combined with spin traps using the probes PBN (N-tert-butyl-α-phenylnitrone) and DMPO (5,5-dimethyl-1-pyrroline N-oxide) to assess free radical formation in the human pathogen Staphylococcus aureus treated with a bactericidal antibiotic, vancomycin or ciprofloxacin. While we were unable to detect ESR signals in bacterial cells, hydroxyl radicals were observed in the supernatant of bacterial cell cultures. Surprisingly, the strongest signal was detected in broth medium without bacterial cells present and it was mitigated by iron chelation or by addition of catalase, which catalyzes the decomposition of hydrogen peroxide to water and oxygen. This suggests that the signal originates from hydroxyl radicals formed by the Fenton reaction, in which iron is oxidized by hydrogen peroxide. Previously, hydroxyl radicals have been proposed to be generated within bacterial cells in response to bactericidal antibiotics. We found that when S. aureus was exposed to vancomycin or ciprofloxacin, hydroxyl radical formation in the broth was indeed increased compared to the level seen with untreated bacterial cells. However, S. aureus cells express catalase, and the antibiotic-mediated increase in hydroxyl radical formation was correlated with reduced katA expression and catalase activity in the presence of either antibiotic. Therefore, our results show that in S. aureus, bactericidal antibiotics modulate catalase expression, which in turn influences the formation of free radicals in the surrounding broth medium. If similar regulation is found in other bacterial species, it might explain why bactericidal antibiotics are perceived as inducing formation of free radicals. PMID:26150471

  12. Cj1386 is an ankyrin-containing protein involved in heme trafficking to catalase in Campylobacter jejuni.

    PubMed

    Flint, Annika; Sun, Yi-Qian; Stintzi, Alain

    2012-01-01

    Campylobacter jejuni, a microaerophilic bacterium, is the most frequent cause of human bacterial gastroenteritis. C. jejuni is exposed to harmful reactive oxygen species (ROS) produced during its own normal metabolic processes and during infection from the host immune system and from host intestinal microbiota. These ROS will damage DNA and proteins and cause peroxidation of lipids. Consequently, identifying ROS defense mechanisms is important for understanding how Campylobacter survives this environmental stress during infection. Construction of a ΔCj1386 isogenic deletion mutant and phenotypic assays led to its discovery as a novel oxidative stress defense gene. The ΔCj1386 mutant has an increased sensitivity toward hydrogen peroxide. The Cj1386 gene is located directly downstream from katA (catalase) in the C. jejuni genome. A ΔkatAΔ Cj1386 double deletion mutant was constructed and exhibited a sensitivity to hydrogen peroxide similar to that seen in the ΔCj1386 and ΔkatA single deletion mutants. This observation suggests that Cj1386 may be involved in the same detoxification pathway as catalase. Despite identical KatA abundances, catalase activity assays showed that the ΔCj1386 mutant had a reduced catalase activity relative to that of wild-type C. jejuni. Heme quantification of KatA protein from the ΔCj1386 mutant revealed a significant decrease in heme concentration. This indicates an important role for Cj1386 in heme trafficking to KatA within C. jejuni. Interestingly, the ΔCj1386 mutant had a reduced ability to colonize the ceca of chicks and was outcompeted by the wild-type strain for colonization of the gastrointestinal tract of neonate piglets. These results indicate an important role for Cj1386 in Campylobacter colonization and pathogenesis. PMID:22081390

  13. Nox1 upregulates the function of vascular T-type calcium channels following chronic nitric oxide deficit.

    PubMed

    Howitt, Lauren; Matthaei, Klaus I; Drummond, Grant R; Hill, Caryl E

    2015-04-01

    Cardiovascular disease is characterised by reduced nitric oxide bioavailability resulting from oxidative stress. Our previous studies have shown that nitric oxide deficit per se increases the contribution of T-type calcium channels to vascular tone through increased superoxide from NADPH oxidase (Nox). The aim of the present study was therefore to identify the Nox isoform responsible for modulating T-type channel function, as T-type channels are implicated in several pathophysiological conditions involving oxidative stress. We evaluated T-channel function in skeletal muscle arterioles in vivo, using a novel T-channel blocker, TTA-A2 (3 ?mol/L), which demonstrated no cross reactivity with L-type channels. Wild-type and Nox2 knockout (Nox2ko) mice were treated with the nitric oxide synthase inhibitor L-NAME (40 mg/kg/day) for 2 weeks. L-NAME treatment significantly increased systolic blood pressure and the contribution of T-type calcium channels to arteriolar tone in wild-type mice, and this was not prevented by Nox2 deletion. In Nox2ko mice, pharmacological inhibition of Nox1 (10 ?mol/L ML171), Nox4 (10 ?mol/L VAS2870) and Nox4-derived hydrogen peroxide (500 U/mL catalase) significantly reduced the effect of chronic nitric oxide inhibition on T-type channel function. In contrast, in wild-type mice, ML171 and VAS2870, but not catalase, reduced the contribution of T-type channels to vascular tone, suggesting a role for Nox1 and non-selective actions of VAS2870. We conclude that Nox1, but not Nox2 or Nox4, is responsible for the upregulation of T-type calcium channels elicited by chronic nitric oxide deficit. These data point to an important role for this isoform in increasing T-type channel function during oxidative stress. PMID:24923576

  14. The 2.2? resolution structure of the catalase-peroxidase KatG from Synechococcus elongatus PCC7942

    PubMed Central

    Kamachi, Saori; Wada, Kei; Tamoi, Masahiro; Shigeoka, Shigeru; Tada, Toshiji

    2014-01-01

    The crystal structure of catalase-peroxidase from Synechococcus elongatus PCC7942 (SeKatG) was solved by molecular replacement and refined to an R work of 16.8% and an R free of 20.6% at 2.2? resolution. The asymmetric unit consisted of only one subunit of the catalase-peroxidase molecule, including a protoporphyrin IX haem moiety and two sodium ions. A typical KatG covalent adduct was formed, Met248Tyr222Trp94, which is a key structural element for catalase activity. The crystallographic equivalent subunit was created by a twofold symmetry operation to form the functional dimer. The overall structure of the dimer was quite similar to other KatGs. One sodium ion was located close to the proximal Trp314. The location and configuration of the proximal cation site were very similar to those of typical peroxidases such as ascorbate peroxidase. These features may provide a structural basis for the behaviour of the radical localization/delocalization during the course of the enzymatic reaction. PMID:24598912

  15. Probing hydrogen peroxide oxidation kinetics of wild-type Synechocystis catalase-peroxidase (KatG) and selected variants.

    PubMed

    Vlasits, Jutta; Furtmller, Paul G; Jakopitsch, Christa; Zamocky, Marcel; Obinger, Christian

    2010-04-01

    Catalase-peroxidases (KatGs) are unique bifunctional heme peroxidases that exhibit peroxidase and substantial catalase activities. Nevertheless, the reaction pathway of hydrogen peroxide dismutation, including the electronic structure of the redox intermediate that actually oxidizes H(2)O(2), is not clearly defined. Several mutant proteins with diminished overall catalase but wild-type-like peroxidase activity have been described in the last years. However, understanding of decrease in overall catalatic activity needs discrimination between reduction and oxidation reactions of hydrogen peroxide. Here, by using sequential-mixing stopped-flow spectroscopy, we have investigated the kinetics of the transition of KatG compound I (produced by peroxoacetic acid) to its ferric state by trapping the latter as cyanide complex. Apparent bimolecular rate constants (pH 6.5, 20 degrees C) for wild-type KatG and the variants Trp122Phe (lacks KatG-typical distal adduct), Asp152Ser (controls substrate access to the heme cavity) and Glu253Gln (channel entrance) are reported to be 1.2x10(4)M(-1)s(-1), 30M(-1)s(-1), 3.4x10(3)M(-1)s(-1), and 8.6x10(3)M(-1)s(-1), respectively. These findings are discussed with respect to steady-state kinetic data and proposed reaction mechanism(s) for KatG. Assets and drawbacks of the presented method are discussed. PMID:20026288

  16. Enhanced hippocampus-dependent memory and reduced anxiety in mice over-expressing human catalase in mitochondria.

    PubMed

    Olsen, Reid H J; Johnson, Lance A; Zuloaga, Damian G; Limoli, Charles L; Raber, Jacob

    2013-04-01

    Oxidative stress (OS) and reactive oxygen species (ROS) play a modulatory role in synaptic plasticity and signaling pathways. Mitochondria (MT), a major source of ROS because of their involvement in energy metabolism, are important for brain function. MT-generated ROS are proposed to be responsible for a significant proportion of OS and are associated with developmental abnormalities and aspects of cellular aging. The role of ROS and MT function in cognition of healthy individuals is relatively understudied. In this study, we characterized behavioral and cognitive performance of 5- to 6-month-old mice over-expressing mitochondrial catalase (MCAT). MCAT mice showed enhancements in hippocampus-dependent spatial learning and memory in the water maze and contextual fear conditioning, and reduced measures of anxiety in the elevated zero maze. Catalase activity was elevated in MCAT mice in all brain regions examined. Measures of oxidative stress (glutathione, protein carbonyl content, lipid peroxidation, and 8-hydroxyguanine) did not significantly differ between the groups. The lack of differences in these markers of oxidative stress suggests that the differences observed in this study may be due to altered redox signaling. Catalase over-expression might be sufficient to enhance cognition and reduce measures of anxiety even in the absence of alteration in levels of OS. PMID:23383735

  17. Manganese L-edge X-ray absorption spectroscopy of manganese catalase from Lactobacillus plantarum and mixed valence manganese complexes

    SciTech Connect

    Grush, M.M.; Chen, J.; George, S.J.

    1996-01-10

    The first Mn L-edge absorption spectra of a Mn metalloprotein are presented in this paper. Both reduced and superoxidized Mn catalase have been examined by fluorescence-detected soft X-ray absorption spectroscopy, and their Mn L-edge spectra are dramatically different. The spectrum of reduced Mn(II)Mn(II) catalase has been interpreted by ligand field atomic multiplet calculations and by comparison to model compound spectra. The analysis finds a 10 Dq value of nearly 1.1 eV, consistent with coordination by predominately nitrogen and oxygen donor ligands. For interpretation of mixed valence Mn spectra, an empirical simulation procedure based on the addition of homovalent model compound spectra has been developed and was tested on a variety of Mn complexes and superoxidized Mn catalase. This routine was also used to determine the oxidation state composition of the Mn in [Ba{sub 8}Na{sub 2}ClMn{sub 16}(OH){sub 8}(CO{sub 3}){sub 4}L{sub 8}] .53 H{sub 2}O (L=1,3-diamino-2-hydroxypropane-N,N,N`N`-tetraacetic acid). 27 refs., 6 figs.

  18. Effect of Adenoviral Catalase Gene Transfer on Renal Ischemia/Reperfusion Injury in Rats.

    PubMed

    Yang, Chih-Ching; Hsu, Ship-Ping; Chen, Kuo-Hsin; Chien, Chiang-Ting

    2015-12-31

    Ischemia/reperfusion (I/R) may through overt H?O?-induced pathophysiologic mechanisms lead to renal dysfunction. We explore whether catalase (CAT) protein overexpression by adenoviral CAT gene (Adv-CAT) transfection may improve ischemia/reperfusion-induced renal dysfunction. We augmented renal CAT expression by intrarenal arterial Adv-CAT administration with renal venous clamping in avertin-anesthetized female Wistar rats. After Adv-CAT transfection, we examined the CAT expression, location and effects on blood urea nitrogen (BUN) and urinary tubular injury biomarkers by biochemical assays, microcirculation by a laser perfusion imager, renal H?O? amount by a chemiluminescent analyzer and molecular mechanisms including cytosolic cytochrome C leakage, apoptosis, autophagy and phospho- Akt (p-Akt)/phospho-endothelial nitric oxide (p-eNOS)/nitric oxide (NO) signaling by western blotting, immunohistochemistry and immunofluorescence. Adv-CAT enhanced 2.6-fold renal CAT protein expression primarily located in the proximal and distal tubules and renal vessels. Ischemia/reperfusion increased cytosolic cytochrome C leakage, renal H?O?-dependent level, autophagic Beclin-1/Atg5-Atg12/LC3 II expression, apoptotic Bax/Bcl-2/caspase 3/poly-(ADP-ribose)-polymerase fragments (PARP) expression and terminal deoxynucleotidyl transferasemediated nick-end labeling (TUNEL) stains and BUN and urinary glutathione S-transferase (GST) levels leading to proximal tubular injury. Ischemia/reperfusion also decreased renal microvascular blood flow associated with the inhibited renal expression of p-Akt and p-eNOS and NO production. Adv-CAT significantly improved the reduction in renal microvascular blood flow, reduced ischemia/reperfusion-enhanced oxidative stress, Beclin-1/Atg5-Atg12/LC3 II-meidated autophagy, Bax/Bcl-2/caspase 3/PARP-mediated apoptotic signaling, TUNEL stains, urinary GST level, and restored the p-Akt/p-eNOS/NO signaling in the kidney. Treatment of phosphatidylinositol 3-kinase inhibitors, wortmannin and LY294002, deleted Adv-CAT-induced p-Akt/p-eNOS/NO protective signaling. In conclusion, our results suggest Adv-CAT gene transfer counteracts H?O?-induced ischemia/reperfusion injury through preserving p-Akt/p-eNOS/NO pathway in the rat kidney. PMID:26717921

  19. Catalase (KatA) Plays a Role in Protection against Anaerobic Nitric Oxide in Pseudomonas aeruginosa

    PubMed Central

    Su, Shengchang; Panmanee, Warunya; Wilson, Jeffrey J.; Mahtani, Harry K.; Li, Qian; VanderWielen, Bradley D.; Makris, Thomas M.; Rogers, Melanie; McDaniel, Cameron; Lipscomb, John D.; Irvin, Randall T.; Schurr, Michael J.; Lancaster, Jack R.; Kovall, Rhett A.; Hassett, Daniel J.

    2014-01-01

    Pseudomonas aeruginosa (PA) is a common bacterial pathogen, responsible for a high incidence of nosocomial and respiratory infections. KatA is the major catalase of PA that detoxifies hydrogen peroxide (H2O2), a reactive oxygen intermediate generated during aerobic respiration. Paradoxically, PA displays elevated KatA activity under anaerobic growth conditions where the substrate of KatA, H2O2, is not produced. The aim of the present study is to elucidate the mechanism underlying this phenomenon and define the role of KatA in PA during anaerobiosis using genetic, biochemical and biophysical approaches. We demonstrated that anaerobic wild-type PAO1 cells yielded higher levels of katA transcription and expression than aerobic cells, whereas a nitrite reductase mutant ?nirS produced ?50% the KatA activity of PAO1, suggesting that a basal NO level was required for the increased KatA activity. We also found that transcription of the katA gene was controlled, in part, by the master anaerobic regulator, ANR. A ?katA mutant and a mucoid mucA22 ?katA bacteria demonstrated increased sensitivity to acidified nitrite (an NO generator) in anaerobic planktonic and biofilm cultures. EPR spectra of anaerobic bacteria showed that levels of dinitrosyl iron complexes (DNIC), indicators of NO stress, were increased significantly in the ?katA mutant, and dramatically in a ?norCB mutant compared to basal levels of DNIC in PAO1 and ?nirS mutant. Expression of KatA dramatically reduced the DNIC levels in ?norCB mutant. We further revealed direct NO-KatA interactions in vitro using EPR, optical spectroscopy and X-ray crystallography. KatA has a 5-coordinate high spin ferric heme that binds NO without prior reduction of the heme iron (Kd ?6 ?M). Collectively, we conclude that KatA is expressed to protect PA against NO generated during anaerobic respiration. We proposed that such protective effects of KatA may involve buffering of free NO when potentially toxic concentrations of NO are approached. PMID:24663218

  20. Androgen Receptor Upregulation Mediates Radioresistance after Ionizing Radiation.

    PubMed

    Spratt, Daniel E; Evans, Michael J; Davis, Brian J; Doran, Michael G; Lee, Man Xia; Shah, Neel; Wongvipat, John; Carnazza, Kathryn E; Klee, George G; Polkinghorn, William; Tindall, Donald J; Lewis, Jason S; Sawyers, Charles L

    2015-11-15

    Clinical trials have established the benefit of androgen deprivation therapy (ADT) combined with radiotherapy in prostate cancer. ADT sensitizes prostate cancer to radiotherapy-induced death at least in part through inhibition of DNA repair machinery, but for unknown reasons, adjuvant ADT provides further survival benefits. Here, we show that androgen receptor (AR) expression and activity are durably upregulated following radiotherapy in multiple human prostate cancer models in vitro and in vivo. Moreover, the degree of AR upregulation correlates with survival in vitro and time to tumor progression in animal models. We also provide evidence of AR pathway upregulation, measured by a rise in serum levels of AR-regulated hK2 protein, in nearly 20% of patients after radiotherapy. Furthermore, these men were three-fold more likely to experience subsequent biochemical failure. Collectively, these data demonstrate that radiotherapy can upregulate AR signaling after therapy to an extent that negatively affects disease progression and/or survival. PMID:26432404

  1. Mitochondrial mutations contribute to HIF1? accumulation via increased reactive oxygen species and upregulated PDK2 in head and neck squamous cell carcinoma

    PubMed Central

    Sun, Wenyue; Zhou, Shaoyu; Chang, Steven S.; McFate, Thomas; Verma, Ajay; Califano, Joseph A.

    2008-01-01

    Purpose Mitochondrial mutations have been identified in head and neck squamous cell carcinoma (HNSCC), but the pathways by which phenotypic effects of these mutations are exerted remain unclear. Previously, we found that mitochondrial ND2 mutations in primary HNSCC increased reactive oxygen species (ROS) and conferred an aerobic, glycolytic phenotype with HIF1? accumulation and increased cell growth. The purpose of present study was to examine the pathways relating these alterations. Experimental Design Mitochondrial mutant and wild-type ND2 constructs were transfected into oral keratinocyte immortal cell line OKF6 and head and neck cancer cell line JHU-O19 and established transfectants. The protein levels of HIF1?, pyruvate dehydrogenease (PDH), phospho-PDH, and pyruvate dehydrogenease kinase (PDK) 2, together with ROS generation, were compared between the mutant and wild type. Meanwhile, the effects of small molecule inhibitors targeting PDK2, and mitochondrial targeted catalase, were evaluated on the ND2 mutant transfectants. Results We determined that ND2 mutant downregulated PDH expression via upregulated PDK2, with an increase in phospho-PDH. Inhibition of PDK2 with dichloroacetate decreased HIF1? accumulation and reduced cell growth. Extracellular treatment with hydrogen peroxide, a ROS mimic, increased PDK2 expression and HIF1? expression, and introduction of mitochondrial targeted catalase decreased mitochondrial mutation mediated PDK2 and HIF1? expression and suppressed cell growth. Conclusions Our findings suggest that mitochondrial ND2 mutation contributes to HIF1? accumulation via increased ROS production, upregulation of PDK2, attenuating PDH activity, thereby increasing pyruvate, resulting in HIF1? stabilization. This may provide insight into a potential mechanism by which mitochondrial mutations contribute to HNSCC development. PMID:19147752

  2. Cardiac-specific overexpression of catalase prevents diabetes-induced pathological changes by inhibiting NF-?B signaling activation in the heart.

    PubMed

    Cong, Weitao; Ruan, Dandan; Xuan, Yuanhu; Niu, Chao; Tao, Youli; Wang, Yang; Zhan, Kungao; Cai, Lu; Jin, Litai; Tan, Yi

    2015-12-01

    Catalase is an antioxidant enzyme that specifically catabolizes hydrogen peroxide (H2O2). Overexpression of catalase via a heart-specific promoter (CAT-TG) was reported to reduce diabetes-induced accumulation of reactive oxygen species (ROS) and further prevent diabetes-induced pathological abnormalities, including cardiac structural derangement and left ventricular abnormity in mice. However, the mechanism by which catalase overexpression protects heart function remains unclear. This study found that activation of a ROS-dependent NF-?B signaling pathway was downregulated in hearts of diabetic mice overexpressing catalase. In addition, catalase overexpression inhibited the significant increase in nitration levels of key enzymes involved in energy metabolism, including ?-oxoglutarate dehydrogenase E1 component (?-KGD) and ATP synthase ? and ? subunits (ATP-? and ATP-?). To assess the effects of the NF-?B pathway activation on heart function, Bay11-7082, an inhibitor of the NF-?B signaling pathway, was injected into diabetic mice, protecting mice against the development of cardiac damage and increased nitrative modifications of key enzymes involved in energy metabolism. In conclusion, these findings demonstrated that catalase protects mouse hearts against diabetic cardiomyopathy, partially by suppressing NF-?B-dependent inflammatory responses and associated protein nitration. PMID:26456065

  3. Elemental sulfur: toxicity in vivo and in vitro to bacterial luciferase, in vitro yeast alcohol dehydrogenase, and bovine liver catalase.

    PubMed

    Cetkauskaite, Anolda; Pessala, Piia; Sdergren, Anders

    2004-08-01

    The aim of this research was to analyze the effects and the modes of action of elemental sulfur (S(0)) in bioluminescence and respiration of Vibrio fischeri cells and the enzymes crude luciferase, pure catalase, and alcohol dehydrogenase (ADH). Metallic copper removed sulfur and reduced the toxicity of acetone extracts of sediment samples analyzed in the bioluminescence test. The sulfur inhibition of cell bioluminescence was noncompetitive with decanal, the luciferase substrate; reversible, with maximum toxicity after 15 min (EC(50) = 11.8 microg/L); and almost totally recovered after 2 h. In vitro preincubation of crude luciferase extract with sulfur (0.28 ppm) weakly inhibited bioluminescence at 5 min, but at 30 min the inhibition reached 60%. Increasing the concentration of sulfur in the parts per million concentration range in vitro decreased bioluminescence, which was not constant, but depended on exposure time, and no dead-end/total inhibition was observed. The redox state of enzymes in the in vitro system significantly affected inhibition. Hydrogen peroxide restored fully and the reducing agent dithiothreitol, itself toxic, restored only partially luciferase activity in the presence of sulfur. Sulfur (5.5 ppm) slightly inhibited ADH and catalase, and dithiothreitol enhanced sulfur inhibition. High sulfur concentrations (2.2 ppm) inhibited the bioluminescence and enhanced the respiration rate of V. fischeri cells. Elemental sulfur data were interpreted to show that sulfur acted on at least a few V. fischeri cell sites: reversibly modifying luciferase at sites sensitive to/protected by oxidative and reducing agents and by affecting electron transport processes, resulting in enhanced oxygen consumption. Sulfur together with an enzyme reducing agent inhibited the oxidoreductive enzymes ADH and catalase, which have --SH groups, metal ion cofactors, or heme, respectively, in their active centers. PMID:15269910

  4. Cytochrome P450-type Hydroxylation and Epoxidation in a Tyrosine-liganded Hemoprotein, Catalase-related Allene Oxide Synthase*

    PubMed Central

    Boeglin, William E.; Brash, Alan R.

    2012-01-01

    The ability of hemoproteins to catalyze epoxidation or hydroxylation reactions is usually associated with a cysteine as the proximal ligand to the heme, as in cytochrome P450 or nitric oxide synthase. Catalase-related allene oxide synthase (cAOS) from the coral Plexaura homomalla, like catalase itself, has tyrosine as the proximal heme ligand. Its natural reaction is to convert 8R-hydroperoxy-eicosatetraenoic acid (8R-HPETE) to an allene epoxide, a reaction activated by the ferric heme, forming product via the FeIV–OH intermediate, Compound II. Here we oxidized cAOS to Compound I (FeV=O) using the oxygen donor iodosylbenzene and investigated the catalytic competence of the enzyme. 8R-hydroxyeicosatetraenoic acid (8R-HETE), the hydroxy analog of the natural substrate, normally unreactive with cAOS, was thereby epoxidized stereospecifically on the 9,10 double bond to form 8R-hydroxy-9R,10R-trans-epoxy-eicosa-5Z,11Z,14Z-trienoic acid as the predominant product; the turnover was 1/s using 100 μm iodosylbenzene. The enantiomer, 8S-HETE, was epoxidized stereospecifically, although with less regiospecificity, and was hydroxylated on the 13- and 16-carbons. Arachidonic acid was converted to two major products, 8R-HETE and 8R,9S-eicosatrienoic acid (8R,9S-EET), plus other chiral monoepoxides and bis-allylic 10S-HETE. Linoleic acid was epoxidized, whereas stearic acid was not metabolized. We conclude that when cAOS is charged with an oxygen donor, it can act as a stereospecific monooxygenase. Our results indicate that in the tyrosine-liganded cAOS, a catalase-related hemoprotein in which a polyunsaturated fatty acid can enter the active site, the enzyme has the potential to mimic the activities of typical P450 epoxygenases and some capabilities of P450 hydroxylases. PMID:22628547

  5. Cytochrome P450-type hydroxylation and epoxidation in a tyrosine-liganded hemoprotein, catalase-related allene oxide synthase.

    PubMed

    Boeglin, William E; Brash, Alan R

    2012-07-13

    The ability of hemoproteins to catalyze epoxidation or hydroxylation reactions is usually associated with a cysteine as the proximal ligand to the heme, as in cytochrome P450 or nitric oxide synthase. Catalase-related allene oxide synthase (cAOS) from the coral Plexaura homomalla, like catalase itself, has tyrosine as the proximal heme ligand. Its natural reaction is to convert 8R-hydroperoxy-eicosatetraenoic acid (8R-HPETE) to an allene epoxide, a reaction activated by the ferric heme, forming product via the Fe(IV)-OH intermediate, Compound II. Here we oxidized cAOS to Compound I (Fe(V)=O) using the oxygen donor iodosylbenzene and investigated the catalytic competence of the enzyme. 8R-hydroxyeicosatetraenoic acid (8R-HETE), the hydroxy analog of the natural substrate, normally unreactive with cAOS, was thereby epoxidized stereospecifically on the 9,10 double bond to form 8R-hydroxy-9R,10R-trans-epoxy-eicosa-5Z,11Z,14Z-trienoic acid as the predominant product; the turnover was 1/s using 100 ?m iodosylbenzene. The enantiomer, 8S-HETE, was epoxidized stereospecifically, although with less regiospecificity, and was hydroxylated on the 13- and 16-carbons. Arachidonic acid was converted to two major products, 8R-HETE and 8R,9S-eicosatrienoic acid (8R,9S-EET), plus other chiral monoepoxides and bis-allylic 10S-HETE. Linoleic acid was epoxidized, whereas stearic acid was not metabolized. We conclude that when cAOS is charged with an oxygen donor, it can act as a stereospecific monooxygenase. Our results indicate that in the tyrosine-liganded cAOS, a catalase-related hemoprotein in which a polyunsaturated fatty acid can enter the active site, the enzyme has the potential to mimic the activities of typical P450 epoxygenases and some capabilities of P450 hydroxylases. PMID:22628547

  6. Bacterioferritin A Modulates Catalase A (KatA) Activity and Resistance to Hydrogen Peroxide in Pseudomonas aeruginosa

    PubMed Central

    Ma, Ju-Fang; Ochsner, Urs A.; Klotz, Martin G.; Nanayakkara, Vagira K.; Howell, Michael L.; Johnson, Zaiga; Posey, James E.; Vasil, Michael L.; Monaco, John J.; Hassett, Daniel J.

    1999-01-01

    We have cloned a 3.6-kb genomic DNA fragment from Pseudomonas aeruginosa harboring the rpoA, rplQ, katA, and bfrA genes. These loci are predicted to encode, respectively, (i) the ? subunit of RNA polymerase; (ii) the L17 ribosomal protein; (iii) the major catalase, KatA; and (iv) one of two iron storage proteins called bacterioferritin A (BfrA; cytochrome b1 or b557). Our goal was to determine the contributions of KatA and BfrA to the resistance of P. aeruginosa to hydrogen peroxide (H2O2). When provided on a multicopy plasmid, the P. aeruginosa katA gene complemented a catalase-deficient strain of Escherichia coli. The katA gene was found to contain two translational start codons encoding a heteromultimer of ?160 to 170 kDa and having an apparent Km for H2O2 of 44.7 mM. Isogenic katA and bfrA mutants were hypersusceptible to H2O2, while a katA bfrA double mutant demonstrated the greatest sensitivity. The katA and katA bfrA mutants possessed no detectable catalase activity. Interestingly, a bfrA mutant expressed only ?47% the KatA activity of wild-type organisms, despite possessing wild-type katA transcription and translation. Plasmids harboring bfrA genes encoding BfrA altered at critical amino acids essential for ferroxidase activity could not restore wild-type catalase activity in the bfrA mutant. RNase protection assays revealed that katA and bfrA are on different transcripts, the levels of which are increased by both iron and H2O2. Mass spectrometry analysis of whole cells revealed no significant difference in total cellular iron levels in the bfrA, katA, and katA bfrA mutants relative to wild-type bacteria. Our results suggest that P. aeruginosa BfrA may be required as one source of iron for the heme prosthetic group of KatA and thus for protection against H2O2. PMID:10368148

  7. Influence of Foreign DNA Introduction and Periplasmic Expression of Recombinant Human Interleukin-2 on Hydrogen Peroxide Quantity and Catalase Activity in Escherichia coli

    PubMed Central

    Mahmoudi Azar, Lena; Mehdizadeh Aghdam, Elnaz; Karimi, Farrokh; Haghshenas, Babak; Barzegari, Abolfazl; Yaghmaei, Parichehr; Hejazi, Mohammad Saeid

    2013-01-01

    Purpose: Oxidative stress is generated through imbalance between composing and decomposing of reactive oxygen species (ROS). This kind of stress was rarely discussed in connection with foreign protein production in Escherichia coli. Effect of cytoplasmic recombinant protein expression on Hydrogen peroxide concentration and catalase activity was previously reported. In comparison with cytoplasm, periplasmic space has different oxidative environment. Therefore, in present study we describe the effect of periplasmic expression of recombinant human interleukin-2 (hIL-2) on H2O2 concentration and catalase activity in Escherichia coli and their correlation with cell growth. Methods: Having constructed pET2hIL2 vector, periplasmic expression of hIL-2 was confirmed. Then, H2O2 concentration and catalase activity were determined at various ODs. Wild type and empty vector transformed cells were used as negative controls. Results: It was shown that H2O2 concentration in hIL-2 expressing cells was significantly higher than its concentration in wild type and empty vector transformed cells. Catalase activity and growth rate reduced significantly in hIL-2 expressing cells compared to empty vector transformed and wild type cells. Variation of H2O2 concentration and catalase activity is intensive in periplasmic hIL-2 expressing cells than empty vector containing cells. Correlation between H2O2 concentration elevation and catalase activity reduction with cell growth depletion are also demonstrated. Conclusion: Periplasmic expression of recombinant hIL-2 elevates the host cells hydrogen peroxide concentration possibly due to reduced catalase activity which has consequent suppressive effect on growth rate. PMID:24312866

  8. Egg yolk peptides up-regulate glutathione synthesis and antioxidant enzyme activities in a porcine model of intestinal oxidative stress.

    PubMed

    Young, Denise; Fan, Ming Z; Mine, Yoshinori

    2010-07-14

    Long-term oxidative stress in the gastrointestinal tract can lead to the development of chronic intestinal disorders. Many food-derived antioxidants are effective in vitro, but the variable reports of in vivo efficacy and the pro-oxidant nature of some antioxidants necessitate alternative strategies for the reduction of in vivo oxidative stress. Compounds that up-regulate the production of endogenous antioxidants such as glutathione (GSH) and antioxidant enzymes provide novel approaches for the restoration of redox homeostatis. Egg yolk peptides (EYP) prepared from Alcalase and protease N digestion of delipidated egg yolk proteins were found to exhibit antioxidative stress properties. The effect of EYP supplementation was examined in a hydrogen peroxide-induced human colon cell line and in an animal model of intestinal oxidative stress. EYP significantly reduced the pro-inflammatory cytokine, IL-8, in Caco-2 cells. In piglets given intraperitoneal infusions of hydrogen peroxide, EYP treatment increased GSH and gamma-glutamylcysteine synthetase mRNA expression and activity, significantly increased antioxidant enzyme activities, in particular catalase and glutathione S-transferase activities, and reduced protein and lipid oxidation in the duodenum, jejunum, ileum, and colon. Furthermore, EYP boosted the systemic antioxidant status in blood by increasing the GSH concentration in red blood cells. These results suggest that EYP supplementation is a novel strategy for the reduction of intestinal oxidative stress. PMID:20540508

  9. Up-Regulated Expression of AOS-LOXa and Increased Eicosanoid Synthesis in Response to Coral Wounding

    PubMed Central

    Lhelaid, Helike; Teder, Tarvi; Tldsepp, Kadri; Ekins, Merrick; Samel, Nigulas

    2014-01-01

    In octocorals, a catalaselike allene oxide synthase (AOS) and an 8R-lipoxygenase (LOX) gene are fused together encoding for a single AOS-LOX fusion protein. Although the AOS-LOX pathway is central to the arachidonate metabolism in corals, its biological function in coral homeostasis is unclear. Using an acute incision wound model in the soft coral Capnella imbricata, we here test whether LOX pathway, similar to its role in plants, can contribute to the coral damage response and regeneration. Analysis of metabolites formed from exogenous arachidonate before and after fixed time intervals following wounding indicated a significant increase in AOS-LOX activity in response to mechanical injury. Two AOS-LOX isoforms, AOS-LOXa and AOS-LOXb, were cloned and expressed in bacterial expression system as active fusion proteins. Transcription levels of corresponding genes were measured in normal and stressed coral by qPCR. After wounding, AOS-LOXa was markedly up-regulated in both, the tissue adjacent to the incision and distal parts of a coral colony (with the maximum reached at 1 h and 6 h post wounding, respectively), while AOS-LOXb was stable. According to mRNA expression analysis, combined with detection of eicosanoid product formation for the first time, the AOS-LOX was identified as an early stress response gene which is induced by mechanical injury in coral. PMID:24551239

  10. Docosahexaenoic acid inhibits the invasion of MDA-MB-231 breast cancer cells through upregulation of cytokeratin-1.

    PubMed

    Blanckaert, Vincent; Kerviel, Vincent; Lpinay, Alexandra; Joubert-Durigneux, Vanessa; Hondermarck, Hubert; Chnais, Benot

    2015-01-01

    Docosahexaenoic acid (DHA), the main member of the omega-3 essential fatty acid family, has been shown to reduce the invasion of the triple-negative breast cancer cell line MDA-MB-231, but the mechanism involved remains unclear. In the present study, a proteomic approach was used to define changes in protein expression induced by DHA. Proteins from crude membrane preparations of MDA-MB-231 cells treated with 100 M DHA were separated by two-dimensional electrophoresis (2-DE) and differentially expressed proteins were identified using MALDI-TOF mass spectrometry. The main changes observed were the upregulation of Keratin, type ? cytoskeletal 1 (KRT1), catalase and lamin-A/C. Immunocytochemistry analyses confirmed the increase in KRT1 induced by DHA. Furthermore, in vitro invasion assays showed that siRNA against KRT1 was able to reverse the DHA-induced inhibition of breast cancer cell invasion. In conclusion, KRT1 is involved in the anti-invasive activity of DHA in breast cancer cells. PMID:25825023

  11. Effect of compatible and noncompatible osmolytes on the enzymatic activity and thermal stability of bovine liver catalase.

    PubMed

    Sepasi Tehrani, H; Moosavi-Movahedi, A A; Ghourchian, H; Ahmad, F; Kiany, A; Atri, M S; Ariaeenejad, Sh; Kavousi, K; Saboury, A A

    2013-12-01

    Catalase is an important antioxidant enzyme that catalyzes the disproportionation of H2O2 into harmless water and molecular oxygen. Due to various applications of the enzyme in different sectors of industry as well as medicine, the enhancement of stability of the enzyme is important. Effect of various classes of compatible as well as noncompatible osmolytes on the enzymatic activity, disaggregation, and thermal stability of bovine liver catalase have been investigated. Compatible osmolytes, proline, xylitol, and valine destabilize the denatured form of the enzyme and, therefore, increase its disaggregation and thermal stability. The increase in the thermal stability is accompanied with a slight increase of activity in comparison to the native enzyme at 25?C. On the other hand, histidine, a noncompatible osmolyte stabilizes the denatured form of the protein and hence causes an overall decrease in the thermal stability and enzymatic activity of the enzyme. Chemometric results have confirmed the experimental results and have provided insight into the distribution and number of mole fraction components for the intermediates. The increase in melting temperature (Tm) and enzymatic rate could be further amplified by the intrinsic effect of temperature enhancement on the enzymatic activity for the industrial purposes. PMID:23249140

  12. Mechanism of pH-switchable peroxidase and catalase-like activities of gold, silver, platinum and palladium.

    PubMed

    Li, Junnan; Liu, Wenqi; Wu, Xiaochun; Gao, Xingfa

    2015-04-01

    Despite being increasingly used as artificial enzymes, little has been known for the origin of the pH-switchable peroxidase-like and catalase-like activities of metals. Using calculations and experiments, we report the mechanisms for both activities and their pH-switchability for metals Au, Ag, Pd and Pt. The calculations suggest that both activities are intrinsic properties of metals, regardless of the surfaces and intersections of facets exposed to environments. The pre-adsorbed OH groups on the surfaces, which are only favorably formed in basic conditions, trigger the switch between both activities and render the pH-switchability. The adsorption energies between H2O2 and metals can be used as convenient descriptors to predict the relative enzyme-like activities of the metals with similar surface morphologies. The results agree with the enzyme-mimic activities that have been experimentally reported for Au, Ag, Pt and predict that Pd should have the similar properties. The prediction, as well as the predicted activity order for the four metals, has been verified by the experimental tests. The results thus provide an in-depth insight into the peroxidase-like and catalase-like activities of the metals and will guide the de novo design, synthesis and application of artificial enzymes based on inorganic materials. PMID:25701030

  13. Mechanism of catalase activity in aqueous solutions of dimanganese(III,IV) ethylenediamine-N,N prime -diacetate

    SciTech Connect

    Rush, J.D.; Maskos, Z. )

    1990-03-07

    Manganous ions, ligated by ethylenediamine-N,N{prime}-diacetate (edda = L) decompose hydrogen peroxide with a rate law {minus}d(H{sub 2}O{sub 2})/dt = k{sub 17}(Mn(edda))(H{sub 2}O{sub 2}) where k{sub 17} = 5.4 M{sup {minus}1} s{sup {minus}1} at pH 7. The reduction of peroxide to water is initiated by the reaction of Mn{sup II}L with a dinuclear Mn{sup III,IV}L{sub 2}. A subsequent fast reaction between the transient product of this reaction and hydrogen peroxide or tert-butyl hydroperoxide effectively oxidizes Mn(II) to Mn(IV) in a concerted step without formation of the hydroxyl radical. The green mixed-valence complex, which is probably a bis({mu}-oxo)-bridged structure, is stable in neutral aqueous solution and exhibits a 16-line ESR signal in frozen solution. The basis of catalase activity is the autocatalytic formation of this complex when hydrogen peroxide is reduced by manganese(II). The catalase cycle is independent of the formation of oxy radicals. Mononuclear Mn{sup III}edda and Mn{sup II}edda react with superoxide radicals, but the decomposition of peroxide is virtually independent of these reactions. In unbuffered solutions, with a moderate excess of hydrogen peroxide, an oscillation in the concentration of the dinuclear complex is detected. 28 refs., 10 figs., 5 tabs.

  14. Selective peracetic acid determination in the presence of hydrogen peroxide using a label free enzymatic method based on catalase.

    PubMed

    Galbán, Javier; Sanz, Vanesa; de Marcos, Susana

    2010-11-01

    Peracetic acid (PAA) is selectively determined in the presence of hydrogen peroxide (H(2)O(2)) by using the self-indicating UV-Vis molecular absorption properties of catalase. The PAA reacts with the protein giving an intermediate (Cat-I) which is reduced back by the amino acid core surrounding the heme group. Since the original form of the enzyme and the Cat-I have different UV-Vis absorption properties, the absorbance changes can be used for PAA determination. The H(2)O(2)/catalase reaction is extremely fast so that neither Cat-I compound nor kinetic interferences are observed. The method permits PAA determination in the 5 × 10(-7) to 1.5 × 10(-5) M range, the reproducibility being between 1% and 10%. Using this method, PAA has been successfully determined in water samples treated with commercial PAA/H(2)O(2) biocides. A theoretical study has also been carried out for obtaining a mathematical model able to analytically describe the process. PMID:20824427

  15. Engineering of chimeric catalase-Angiopep-2 for intracellular protection of brain endothelial cells against oxidative stress.

    PubMed

    Yainoy, Sakda; Houbloyfa, Patcharaporn; Eiamphungporn, Warawan; Isarankura-Na-Ayudhya, Chartchalerm; Prachayasittikul, Virapong

    2014-07-01

    Blood-brain barrier (BBB) disruption and brain microvascular endothelial cells (BMVECs) death caused by excessive production of hydrogen peroxide (H2O2) have been implicated in several neurological conditions. To overcome this problem, H2O2-degrading enzyme with ability to enter the BMVECs is required. In the present study, genetic fusion of gene encoding human catalase and gene encoding Angiopep-2 (AP2), a brain targeting peptide, was performed. The fusion protein was successfully expressed in Escherichia coli and purified to homogeneity. The protein retained heme content and specific enzymatic activity in the same order of magnitude as that of native enzyme. Study of the BMVECs internalization showed that 0.1?M of the fusion protein can enter the cell within 15min, while internalization of the native protein was not observed at this condition. In addition, treatment of the BMVECs with 20 units of the fusion protein for 30min showed protection against H2O2 up to 5.0mM, whereas this protective effect was not observed from treatment with the native protein. Therefore, construction of chimeric human catalase and AP2 provides an insight into the development of potential therapeutic antioxidant with ability to penetrate the BBB for protection against neurodegenerative disorders. PMID:24769213

  16. Endogenous allergen upregulation: transgenic vs. traditionally bred crops.

    PubMed

    Herman, Rod A; Ladics, Gregory S

    2011-10-01

    The safety assessment for transgenic food crops currently includes an evaluation of the endogenous allergy potential (via serum IgE screening) when the non-transgenic counterpart is a commonly allergenic food. The value of this analysis in the safety assessment of transgenic crops, especially with reference to recent requests to quantify individual allergen concentrations in raw commodities, is examined. We conclude that the likelihood of upregulating an endogenous allergen due to transgenesis is no greater than from traditional breeding which has a history of safety and is largely unregulated. The potential consequences of upregulating an endogenous allergen are also unclear. PMID:21784119

  17. Catalase induces the expression of inducible nitric oxide synthase through activation of NF-kappaB and PI3K signaling pathway in Raw 264.7 cells.

    PubMed

    Jang, Byeong-Churl; Paik, Ji-Hye; Kim, Sang-Pyo; Bae, Jae-Hoon; Mun, Kyo-Chul; Song, Dae-Kyu; Cho, Chi-Heum; Shin, Dong-Hoon; Kwon, Taeg Kyu; Park, Jong-Wook; Park, Jong-Gu; Baek, Won-Ki; Suh, Min-Ho; Lee, Soo Hwan; Baek, Suk-Hwan; Lee, In-Seon; Suh, Seong-Il

    2004-12-01

    It has been reported that macrophages produce substantial amounts of nitrite and nitrate after addition of catalase, but the mechanism associated remains unclear. In present study, we investigated whether catalase modulates the expression of inducible nitric oxide synthase (iNOS), an enzyme that produces nitric oxide. Exposure of Raw 264.7 macrophages (Raw cells) to catalase induced high expression of iNOS mRNA as well as protein with enzymatic activity. Data of mechanical analyses, such as iNOS promoter-driven luciferase assay and actinomycin D chase experiments demonstrated that the induction was due to increased iNOS transcription and post-transcriptional iNOS mRNA stability. Of interest, catalase-induced iNOS protein expression was abrogated through inactivation of NF-kappaB pathway by MG132 or BAY 11-7085 and PI3K pathway by LY294002 or wortmannin, respectively. In particular, blockage of PI3K pathway by LY294002 down-regulated iNOS transcription and steady-state iNOS mRNA levels as well as iNOS mRNA stability induced by catalase, suggesting regulation of PI3K pathway in catalase-induced iNOS expression at the levels of iNOS transcription, steady-state mRNA status, and mRNA stability. Additional cell culture works in different types of cells indicated that iNOS expression by catalase might be cell type-specific, based on the facts that catalase induced iNOS expression in BV2 microglial macrophage-like cells, but not in HT-29 or A549, human colon or lung cancer epithelial-like cells. Together, these results demonstrate for the first time that catalase induces iNOS expression in Raw cells, which seems to be associated with the increase of iNOS transcription and mRNA stability as well as the activation of NF-kappaB and PI3K signaling pathways. PMID:15498507

  18. Lactate Up-Regulates the Expression of Lactate Oxidation Complex-Related Genes in Left Ventricular Cardiac Tissue of Rats

    PubMed Central

    Gabriel-Costa, Daniele; da Cunha, Telma Fatima; Bechara, Luiz Roberto Grassmann; Fortunato, Rodrigo Soares; Bozi, Luiz Henrique Marchesi; Coelho, Marcele de Almeida; Barreto-Chaves, Maria Luiza; Brum, Patricia Chakur

    2015-01-01

    Background Besides its role as a fuel source in intermediary metabolism, lactate has been considered a signaling molecule modulating lactate-sensitive genes involved in the regulation of skeletal muscle metabolism. Even though the flux of lactate is significantly high in the heart, its role on regulation of cardiac genes regulating lactate oxidation has not been clarified yet. We tested the hypothesis that lactate would increase cardiac levels of reactive oxygen species and up-regulate the expression of genes related to lactate oxidation complex. Methods/Principal Findings Isolated hearts from male adult Wistar rats were perfused with control, lactate or acetate (20mM) added Krebs-Henseleit solution during 120 min in modified Langendorff apparatus. Reactive oxygen species (O2●-/H2O2) levels, and NADH and NADPH oxidase activities (in enriched microsomal or plasmatic membranes, respectively) were evaluated by fluorimetry while SOD and catalase activities were evaluated by spectrophotometry. mRNA levels of lactate oxidation complex and energetic enzymes MCT1, MCT4, HK, LDH, PDH, CS, PGC1α and COXIV were quantified by real time RT-PCR. Mitochondrial DNA levels were also evaluated. Hemodynamic parameters were acquired during the experiment. The key findings of this work were that lactate elevated cardiac NADH oxidase activity but not NADPH activity. This response was associated with increased cardiac O2●-/H2O2 levels and up-regulation of MCT1, MCT4, LDH and PGC1α with no changes in HK, PDH, CS, COXIV mRNA levels and mitochondrial DNA levels. Lactate increased NRF-2 nuclear expression and SOD activity probably as counter-regulatory responses to increased O2●-/H2O2. Conclusions Our results provide evidence for lactate-induced up-regulation of lactate oxidation complex associated with increased NADH oxidase activity and cardiac O2●-/H2O2 driving to an anti-oxidant response. These results unveil lactate as an important signaling molecule regulating components of the lactate oxidation complex in cardiac muscle. PMID:25996919

  19. Coordination modes of tyrosinate-ligated catalase-type heme enzymes: magnetic circular dichroism studies of Plexaura homomalla allene oxide synthase, Mycobacterium avium ssp. paratuberculosis protein-2744c, and bovine liver catalase in their ferric and ferrous states.

    PubMed

    Bandara, D M Indika; Sono, Masanori; Bruce, Grant S; Brash, Alan R; Dawson, John H

    2011-12-01

    Bovine liver catalase (BLC), catalase-related allene oxide synthase (cAOS) from Plexaura homomalla, and a recently isolated protein from the cattle pathogen Mycobacterium avium ssp. paratuberculosis (MAP-2744c (MAP)) are all tyrosinate-ligated heme enzymes whose crystal structures have been reported. cAOS and MAP have low (<20%) sequence similarity to, and significantly different catalytic functions from, BLC. cAOS transforms 8R-hydroperoxy-eicosatetraenoic acid to an allene epoxide, whereas the MAP protein is a putative organic peroxide-dependent peroxidase. To elucidate factors influencing the functions of these and related heme proteins, we have investigated the heme iron coordination properties of these tyrosinate-ligated heme enzymes in their ferric and ferrous states using magnetic circular dichroism and UV-visible absorption spectroscopy. The MAP protein shows remarkable spectral similarities to cAOS and BLC in its native Fe(III) state, but clear differences from ferric proximal heme ligand His93Tyr Mb (myoglobin) mutant, which may be attributed to the presence of an Arg(+)-N(?)-HO-Tyr (proximal heme axial ligand) hydrogen bond in the first three heme proteins. Furthermore, the spectra of Fe(III)-CN, Fe(III)-NO, Fe(II)-NO (except for five-coordinate MAP), Fe(II)-CO, and Fe(II)-O(2) states of cAOS and MAP, but not H93Y Mb, are also similar to the corresponding six-coordinate complexes of BLC, suggesting that a tyrosinate (Tyr-O) is the heme axial ligand trans to the bound ligands in these complexes. The Arg(+)-N(?)-H to O-Tyr hydrogen bond would be expected to modulate the donor properties of the proximal tyrosinate oxyanion and, combined with the subtle differences in the catalytic site structures, affect the activities of cAOS, MAP and BLC. PMID:22104301

  20. Piper betle shows antioxidant activities, inhibits MCF-7 cell proliferation and increases activities of catalase and superoxide dismutase

    PubMed Central

    2012-01-01

    Background Breast cancer is the most common form of cancer and the focus on finding chemotherapeutic agents have recently shifted to natural products. Piper betle is a medicinal plant with various biological activities. However, not much data is available on the anti-cancer effects of P. betle on breast cancer. Due to the current interest in the potential effects of antioxidants from natural products in breast cancer treatment, we investigated the antioxidant activities of the leaves of P. betle and its inhibitory effect on the proliferation of the breast cancer cell line, MCF-7. Methods The leaves of P. betle were extracted with solvents of varying polarities (water, methanol, ethyl acetate and hexane) and their phenolic and flavonoid content were determined using colorimetric assays. Phenolic composition was characterized using HPLC. Antioxidant activities were measured using FRAP, DPPH, superoxide anion, nitric oxide and hyroxyl radical scavenging assays. Biological activities of the extracts were analysed using MTT assay and antioxidant enzyme (catalase, superoxide dismutase, glutathione peroxidase) assays in MCF-7 cells. Results Overall, the ethyl acetate extract showed the highest ferric reducing activity and radical scavenging activities against DPPH, superoxide anion and nitric oxide radicals. This extract also contained the highest phenolic content implying the potential contribution of phenolics towards the antioxidant activities. HPLC analyses revealed the presence of catechin, morin and quercetin in the leaves. The ethyl acetate extract also showed the highest inhibitory effect against the proliferation of MCF-7 cells (IC50=65 μg/ml). Treatment of MCF-7 cells with the plant extract increased activities of catalase and superoxide dismutase. Conclusions Ethyl acetate is the optimal solvent for the extraction of compounds with antioxidant and anti-proliferative activities. The increased activities of catalase and superoxide dismutase in the treated cells could alter the antioxidant defense system, potentially contributing towards the anti-proliferative effect. There is great potential for the ethyl acetate extract of P. betle leaf as a source of natural antioxidants and to be developed as therapeutics in cancer treatment. PMID:23153283

  1. Spectroscopic and kinetic investigation of the reactions of peroxyacetic acid with Burkholderia pseudomallei catalase-peroxidase, KatG.

    PubMed

    Ivancich, Anabella; Donald, Lynda J; Villanueva, Jacylyn; Wiseman, Ben; Fita, Ignacio; Loewen, Peter C

    2013-10-15

    Catalase-peroxidases or KatGs can utilize organic peroxyacids and peroxides instead of hydrogen peroxide to generate the high-valent ferryl-oxo intermediates involved in the catalase and peroxidase reactions. In the absence of peroxidatic one-electron donors, the ferryl intermediates generated with a low excess (10-fold) of peroxyacetic acid (PAA) slowly decay to the ferric resting state after several minutes, a reaction that is demonstrated in this work by both stopped-flow UV-vis absorption measurements and EPR spectroscopic characterization of Burkholderia pseudomallei KatG (BpKatG). EPR spectroscopy showed that the [Fe(IV)═O Trp330(•+)], [Fe(IV)═O Trp139(•)], and [Fe(IV)═O Trp153(•)] intermediates of the peroxidase-like cycle of BpKatG ( Colin, J. Wiseman, B. Switala, J. Loewen, P. C. Ivancich, A. ( 2009 ) J. Am. Chem. Soc. 131 , 8557 - 8563 ), formed with a low excess of PAA at low temperature, are also generated with a high excess (1000-fold) of PAA at room temperature. However, under high excess conditions, there is a rapid conversion to a persistent [Fe(IV)═O] intermediate. Analysis of tryptic peptides of BpKatG by mass spectrometry before and after treatment with PAA showed that specific tryptophan (including W330, W139, and W153), methionine (including Met264 of the M-Y-W adduct), and cysteine residues are either modified with one, two, or three oxygen atoms or could not be identified in the spectrum because of other undetermined modifications. It was concluded that these oxidized residues were the source of electrons used to reduce the excess of PAA to acetic acid and return the enzyme to the ferric state. Treatment of BpKatG with PAA also caused a loss of catalase activity towards certain substrates, consistent with oxidative disruption of the M-Y-W adduct, and a loss of peroxidase activity, consistent with accumulation of the [Fe(IV)═O] intermediate and the oxidative modification of the W330, W139, and W153. PAA, but not H2O2 or tert-butyl hydroperoxide, also caused subunit cross-linking. PMID:24044787

  2. Nutraceutical up-regulation of serotonin paradoxically induces compulsive behavior

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The role of diet in either the etiology or treatment of complex mental disorder is highly controversial in psychiatry. However, physiological mechanisms by which diet can influence brain chemistry – particularly that of serotonin – are well established. Here we show that dietary up-regulation of br...

  3. Cyclooxygenase-2 is Upregulated in Copper-Deficient Rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copper deficiency inactivates Cu/Zn-SOD and promotes accumulation of reactive oxygen species. This process likely impairs nitric oxide (NO)-mediated relaxation as well as triggers vascular inflammation. The current study was designed to determine whether COX-2 expression and activity are upregulated...

  4. Three-phase partitioning as a rapid and easy method for the purification and recovery of catalase from sweet potato tubers (Solanum tuberosum).

    PubMed

    Duman, Yonca Avcı; Kaya, Erdem

    2013-07-01

    Three-phase partitioning (TPP) was used to purify and recover catalase from potato crude extract. The method consists of ammonium sulfate saturation, t-butanol addition, and adjustment of pH, respectively. The best catalase recovery (262 %) and 14.1-fold purification were seen in the interfacial phase in the presence of 40 % (w/v) ammonium sulfate saturation with 1.0:1.0 crude extract/t-butanol ratio (v/v) at pH 7 in a single step. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the enzyme showed comparatively purification and protein molecular weight was nearly found to be 56 kDa. This study shows that TPP is a simple, economical, and quick method for the recovering of catalase and can be used for the purification process. PMID:23640263

  5. Purification, biochemical characterization, and implications of an alkali-tolerant catalase from the spacecraft-associated and oxidation-resistant Acinetobacter gyllenbergii 2P01AA.

    PubMed

    Muster, N; Derecho, I; Dallal, F; Alvarez, R; McCoy, K B; Mogul, R

    2015-04-01

    Herein, we report on the purification, characterization, and sequencing of catalase from Acinetobacter gyllenbergii 2P01AA, an extremely oxidation-resistant bacterium that was isolated from the Mars Phoenix spacecraft assembly facility. The Acinetobacter are dominant members of the microbial communities that inhabit spacecraft assembly facilities and consequently may serve as forward contaminants that could impact the integrity of future life-detection missions. Catalase was purified by using a 3-step chromatographic procedure, where mass spectrometry provided respective subunit and intact masses of 57.8 and 234.6?kDa, which were consistent with a small-subunit tetrameric catalase. Kinetics revealed an extreme pH stability with no loss in activity between pH 5 and 11.5 and provided respective kcat/Km and kcat values of ?10(7) s(-1) M(-1) and 10(6) s(-1), which are among the highest reported for bacterial catalases. The amino acid sequence was deduced by in-depth peptide mapping, and structural homology suggested that the catalases from differing strains of A. gyllenbergii differ only at residues near the subunit interfaces, which may impact catalytic stability. Together, the kinetic, alkali-tolerant, and halotolerant properties of the catalase from A. gyllenbergii 2P01AA are significant, as they are consistent with molecular adaptations toward the alkaline, low-humidity, and potentially oxidizing conditions of spacecraft assembly facilities. Therefore, these results support the hypothesis that the selective pressures of the assembly facilities impact the microbial communities at the molecular level, which may have broad implications for future life-detection missions. PMID:25826195

  6. In vitro and in vivo inhibitory effects of some fungicides on catalase produced and purified from white-rot fungus Phanerochaete chrysosporium.

    PubMed

    Kavakçıoğlu, Berna; Tarhan, Leman

    2014-10-01

    In this study, in vitro and in vivo effects of some commonly used fungicides, antibiotics, and various chemicals on isolated and purified catalase from Phanerochaete chrysosporium were investigated. The catalase was purified 129.10-fold by using 60% ammonium sulfate and 60% ethanol precipitations, DEAE-cellulose anion exchange and Sephacryl-S-200 gel filtration chromatographies from P. chrysosporium growth in carbon- and nitrogen-limited medium for 12 days. The molecular weight of native purified catalase from P. chrysosporium was found to be 290 ± 10 kDa, and sodium dodecyl sulfate (SDS)-PAGE results indicated that enzyme consisted of four apparently identical subunits, with a molecular weight of 72.5 ± 2.5 kDa. Kinetic characterization studies showed that optimum pH and temperature, Km and Vmax values of the purified catalase which were stable in basic region and at comparatively high temperatures were 7.5, 30°C, 289.86 mM, and 250,000 U/mg, respectively. The activity of purified catalase from P. chrysosporium was significantly inhibited by dithiothreitol (DTT), 2-mercaptoethanol, iodoacetamide, EDTA, and sodium dodecyl sulfate (SDS). It was found that while antibiotics had no inhibitory effects, 45 ppm benomyl, 144 ppm captan, and 47.5 ppm chlorothalonil caused 14.52, 10.82, and 38.86% inhibition of purified catalase, respectively. The inhibition types of these three fungicides were found to be non-competitive inhibition with the Ki values of 1.158, 0.638, and 0.145 mM and IC50 values of 0.573, 0.158, 0.010 mM, respectively. The results of in vivo experiments also showed that benomyl, captan and chlorothalonil caused 15.25, 1.96, and 36.70% activity decreases after 24-h treatments compared to that of the control. PMID:24079700

  7. A role for catalase-peroxidase large loop 2 revealed by deletion mutagenesis: control of active site water and ferric enzyme reactivity.

    PubMed

    Kudalkar, Shalley N; Njuma, Olive J; Li, Yongjiang; Muldowney, Michelle; Fuanta, N Rene; Goodwin, Douglas C

    2015-03-01

    Catalase-peroxidases (KatGs), the only catalase-active members of their superfamily, all possess a 35-residue interhelical loop called large loop 2 (LL2). It is essential for catalase activity, but little is known about its contribution to KatG function. LL2 shows weak sequence conservation; however, its length is nearly identical across KatGs, and its apex invariably makes contact with the KatG-unique C-terminal domain. We used site-directed and deletion mutagenesis to interrogate the role of LL2 and its interaction with the C-terminal domain in KatG structure and catalysis. Single and double substitutions of the LL2 apex had little impact on the active site heme [by magnetic circular dichroism or electron paramagnetic resonance (EPR)] and activity (catalase or peroxidase). Conversely, deletion of a single amino acid from the LL2 apex reduced catalase activity by 80%. Deletion of two or more apex amino acids or all of LL2 diminished catalase activity by 300-fold. Peroxide-dependent but not electron donor-dependent kcat/KM values for deletion variant peroxidase activity were reduced 20-200-fold, and kon for cyanide binding diminished by 3 orders of magnitude. EPR spectra for deletion variants were all consistent with an increase in the level of pentacoordinate high-spin heme at the expense of hexacoordinate high-spin states. Together, these data suggest a shift in the distribution of active site waters, altering the reactivity of the ferric state, toward, among other things, compound I formation. These results identify the importance of LL2 length conservation for maintaining an intersubunit interaction that is essential for an active site water distribution that facilitates KatG catalytic activity. PMID:25674665

  8. Polymer-Induced Heteronucleation for Protein Single Crystal Growth: Structural Elucidation of Bovine Liver Catalase and Concanavalin A Forms

    SciTech Connect

    Foroughi, Leila M.; Kang, You-Na; Matzger, Adam J.

    2012-05-09

    Obtaining single crystals for X-ray diffraction remains a major bottleneck in structural biology; when existing crystal growth methods fail to yield suitable crystals, often the target rather than the crystallization approach is reconsidered. Here we demonstrate that polymer-induced heteronucleation, a powerful technique that has been used for small molecule crystallization form discovery, can be applied to protein crystallization by optimizing the heteronucleant composition and crystallization formats for crystallizing a wide range of protein targets. Applying these advances to two benchmark proteins resulted in dramatically increased crystal size, enabling structure determination, for a half century old form of bovine liver catalase (BLC) that had previously only been characterized by electron microscopy, and the discovery of two new forms of concanavalin A (conA) from the Jack bean and accompanying structural elucidation of one of these forms.

  9. Hydrogen peroxide-dependent conversion of nitrite to nitrate as a crucial feature of bovine milk catalase.

    PubMed

    Silanikove, Nissim; Shapiro, Fira; Silanikove, Mayan; Merin, Uzi; Leitner, Gabriel

    2009-09-01

    The enzyme catalase is well-known to catalyze the disintegration of hydrogen peroxide to water and oxygen; however, this study shows that its main function in bovine milk is oxidation of nitrite to nitrate. This process depends on hydrogen peroxide, of which the main source appears to be hydrogen peroxide formation that is coupled to the conversion of purines--xanthine in the present study--to uric acid by milk xanthine oxidase. However, additional secondary sources of hydrogen peroxide appear to be important during the relatively long storage of milk in the gland cistern. This paper demonstrates that the oxidation of nitrite to nitrate is necessary to prevent accumulation of free radicals and oxidative products during storage of milk in the gland and during the unavoidable delay between milking and pasteurization in dairy plants. Recommendations for minimizing the deterioration in milk quality during commercial storage are presented. PMID:19722711

  10. Cloning, expression and physiological analysis of broccoli catalase gene and Chinese cabbage ascorbate peroxidase gene under heat stress.

    PubMed

    Lin, Kuan-Hung; Huang, Ho-Chang; Lin, Ching-Yun

    2010-06-01

    The objectives of this work were to clone the catalase (CAT) gene from broccoli (Brassica oleracea) and the ascorbate peroxidase (APX) gene from Chinese cabbage and measure the regulation of CAT and APX gene expressions under heat-stress conditions. Different genotypes responded differently to heat stress according to their various antioxidant enzymes and physiological parameters. CAT and APX gene expression profiles were well matched with the data for CAT and APX enzyme activities in the broccoli and Chinese cabbage plants, respectively. Full-length of the CAT and APX cDNA were 1,768 and 1,070 bp, respectively. A phylogenetic analysis of CAT and APX indicated that plant CATs and APXs diverged into two major clusters. PMID:20352229

  11. Effect of N+ Beam Exposure on Superoxide Dismutase and Catalase Activities and Induction of Mn-SOD in Deinococcus Radiodurans

    NASA Astrophysics Data System (ADS)

    Song, Dao-jun; Chen, Ruo-lei; Shao, Chun-lin; Wu, Li-jun; Yu, Zeng-liang

    2000-10-01

    Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. In this report, the superoxide dismutase (SOD) and catalase (CAT) activities produced by these bacteria were measured, and the change of SOD and CAT activities by 20 keV N+ beam exposure was examined. Their activities were increased by N+ beam exposure from 81014 ions/cm2 to 61015 ions/cm2. The treatment of H2O2 and [CHCl3 +CH3CH2OH] and the measurement of absorption spectrum showed that the increase in SOD activity was resulted from inducible activities of Mn-SOD in D. radiodurans AS1.633 by N+ beam exposure. These results suggested that this bacteria possess inducible defense mechanisms against the deleterious effects of oxidization.

  12. Covalent conjugation of tetrameric bovine liver catalase to liposome membranes for stabilization of the enzyme tertiary and quaternary structures.

    PubMed

    Yoshimoto, Makoto; Sakamoto, Hideyuki; Shirakami, Hiroshi

    2009-03-01

    Tetrameric bovine liver catalase (BLC) is unstable because of its dissociation into subunits at low enzyme concentrations and the conformational change of the subunits at high temperatures. In this work, for stabilization of BLC, the enzyme was covalently conjugated with liposome membranes composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), cholesterol and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-glutaryl (NGPE). The NGPE, which was responsible for the BLC/membrane coupling, was altered from 0.05 to 0.2 in its liposomal mole fraction f(G). The catalase-conjugated liposome (CCL) with f(G) of 0.15 showed the maximum number of the conjugated BLC molecules of 28 per liposome. The reactivity of CCLs to H(2)O(2) was as high as that of free BLC at 25 degrees C in Tris-HCl buffer of pH 7.4. Among the CCLs, the catalyst with f(G) of 0.15 was the most stable at 55 degrees C in its enzyme activity in the buffer because the appropriate number of BLC/liposome covalent bonding prevented the dissociation-induced enzyme deactivation. Furthermore, the CCL showed much higher stability at 55 degrees C than the free BLC/enzyme-free liposome mixture and free BLC at the low BLC concentration of 340ng/mL. This was because BLC in the CCL was located in the vicinity of the host membrane regardless of the catalyst concentration, which could induce the effective stabilization effect of the membrane on the enzyme tertiary structure as indicated by the intrinsic tryptophan fluorescence analysis. The results obtained demonstrate the high structural stability of BLC in the CCL system, which was derived from the covalent bonding and interaction between BLC and liposomes. PMID:19131221

  13. Oxygen-Dependent Regulation of the Expression of the Catalase Gene katA of Lactobacillus sakei LTH677

    PubMed Central

    Hertel, Christian; Schmidt, Gudrun; Fischer, Marc; Oellers, Katja; Hammes, Walter P.

    1998-01-01

    The catalase gene katA of Lactobacillus sakei LTH677 was cloned and expressed in Escherichia coli UM2, Lactobacillus casei LK1, and Lactobacillus curvatus LTH1432. The last host is a catalase-deficient plasmid-cured derivative of a starter organism used in meat fermentation. The regulation of katA expression was found to be the same in L. sakei LTH677 and the recombinant strains. The addition of H2O2 to anaerobic cultures, as well as a switch to aerobic conditions, resulted in a strong increase in KatA activity. The expression was investigated in more detail with L. sakei LTH677 and L. curvatus LTH4002. The recombinant strain LTH4002 did not accumulate H2O2 under glucose-limited aerobic conditions and remained viable in the stationary phase. Under inductive conditions, the katA-specific mRNA and the apoenzyme were synthesized de novo. Deletion derivatives of the katA promoter were produced, and the regulatory response was investigated by fusion to the β-glucuronidase reporter gene gusA and expression in L. sakei LTH677. The fact that gene expression was subject to induction was confirmed at the level of transcription and protein synthesis. A small putative regulatory sequence of at least 25 bp was identified located upstream of the −35 site. Competition experiments performed with L. sakei LTH677 harboring the fusion constructs consisting of the katA promoter and gusA revealed that an activator protein is involved in the transcriptional induction of katA. PMID:9546173

  14. Molecular, technological and safety characterization of Gram-positive catalase-positive cocci from slightly fermented sausages.

    PubMed

    Martín, B; Garriga, M; Hugas, M; Bover-Cid, S; Veciana-Nogués, M T; Aymerich, T

    2006-03-15

    The population of Gram-positive catalase-positive cocci from slightly fermented sausages was characterized at species and strain level by molecular techniques and some technological and hygienic aspects were also considered. Staphylococcus xylosus was the predominant species (80.8%) followed by Staphylococcus warneri (8.3%), Staphylococcus epidermidis (5.8%) Staphylococcus carnosus (4.6%), and Kocuria varians (0.4%). Proteolytic activity was observed in 23% of the isolates. The species with the highest percentage of proteolytic strains was S. warneri. Lipolytic activity was found in 45.8% of the isolates and S. xylosus was the species with the highest percentage of lipolytic isolates. Biogenic amine production was not widely distributed (only 14.6% of the isolates). Tyramine was the most intense amine produced, although by only 4.6% of the isolates. Phenylethylamine was more frequently detected (10.8% of isolates) but at lower levels. Some strains also produced putrescine (3.3%), cadaverine (2.9%), histamine (1.3%) and tryptamine (0.4%). All isolates were susceptible to linezolid and vancomicin and over 70% were resistant to penicillin G, ampicillin and sulphonamides. Most of the mecA+ strains (only 4.6% of isolates) also displayed resistance to multiple antibiotics. A reduced enterotoxigenic potential was found. Only 3.3% of isolates showed staphylococcal enterotoxins genes, all identified as entC gene. The combination of RAPD-PCR and plasmid profiling allowed the discrimination of 208 different profiles among the 240 Gram-positive catalase-positive cocci characterized, indicating a great genetic variability. PMID:16297478

  15. Electron pathways in catalase and peroxidase enzymic catalysis. Metal and macrocycle oxidations of iron porphyrins and chlorins

    SciTech Connect

    Hanson, L.K.; Chang, C.K.; Davis, M.S.; Fajer, J.

    1981-02-11

    Charge iterative extended Hueckel calculations are presented for compound II, the one-electron oxidation intermediate of horseradish peroxidase (HRP), and for compounds I, the two-electron oxidation transients of HRP and catalase (CAT) observed in the catalytic cycles of the hydroperoxidase enzymes. Compound II is described in terms of a ferryl configuration (O = Fe/sup IV/), and compounds I are described as ferrylporphyrin ..pi..-cation radicals. The validity of the iron ..pi..-cation calculations is supported by favorable comparison of parallel computations for porphyrin ..pi.. cations of diamagnetic metals with new and previously reported ESR results for radicals of zinc tetrabenz-, meso-tetramethyl, (/sup 14/N and /sup 15/N) tetraphenyl-, and magnesium (/sup 1/H and /sup 2/H) octaethylporphyrins. The calculated electronic configurations and unpaired spin density profiles for the ferryl ..pi.. cations satisfactorily account for the physical properties reported for compounds I of HRP (in the native protoporphyrin IX form or reconstituted with deuteroporphyrin), chloroperoxidase, and CAT. The ground states of the ..pi.. cations, a/sub 1u/ or a/sub 2u/, are determined by peripheral substitution and axial ligation, and the axial ligand of CAT I is predicted to differ from that of HRP I. The combination of model studies and calculations suggests that /sup 2/H, /sup 13/C, and /sup 15/N NMR studies of isotopically substituted proto and deutero HRP I would confirm the electronic profiles predicted. /sup 15/N NMR in particular would clearly discriminate between a/sub 1u/ and a/sub 2u/ configurations. As an additional test of the ferryl ..pi..-cation hypothesis, calculations are presented for a proposed ferrylchlorin ..pi.. cation of Neurospora crassa catalase, which contains an iron chlorin prosthetic group. Compound I of this unusual heme is predicted to occupy an a/sub 2/ ground state with the spin distribution and optical spectra reported here for synthetic chlorin radicals.

  16. Humic acid effect on catalase activity and the generation of reactive oxygen species in corn (Zea mays).

    PubMed

    Cordeiro, Flvio Couto; Santa-Catarina, Claudete; Silveira, Vanildo; de Souza, Sonia Regina

    2011-01-01

    Humic acids (HAs) have positive effects on plant physiology, but the molecular mechanisms underlying these events are only partially understood. The induction of root growth and emission of lateral roots (LRs) promoted by exogenous auxin is a natural phenomenon. Exogenous auxins are also associated with HA. Gas nitric oxide (NO) is a secondary messenger produced endogenously in plants. It is associated with metabolic events dependent on auxin. With the application of auxin, NO production is significantly increased, resulting in positive effects on plant physiology. Thus it is possible to evaluate the beneficial effects of the application of HA as an effect of auxin. To investigate the effects of HA the parameters of root growth, Zea mays was studied by evaluating the application of 3 mM C L? of HA extracted from Oxisol and 100 M SNP (sodium nitroprusside) and the NO donor, subject to two N-NO??, high dose (5.0 mM N-NO??) and low dose (5.0 mM N-NO??). Treatments with HA and NO were positively increased, regardless of the N-NO?? taken, as assessed by fresh weight and dry root, issue of LRs. The effects were more pronounced in the treatment with a lower dose of N-NO??. Detection of reactive oxygen species (ROS) in vivo and catalase activity were evaluated; these tests were associated with root growth. Under application of the bioactive substances tested, detection of ROS and catalase activity increased, especially in treatments with lower doses of N-NO??. The results of this experiment indicate that the effects of HA are dependent on ROS generation, which act as a messenger that induces root growth and the emission of LRs. PMID:21228492

  17. Electrospun regenerated cellulose nanofibrous membranes surface-grafted with polymer chains/brushes via the atom transfer radical polymerization method for catalase immobilization.

    PubMed

    Feng, Quan; Hou, Dayin; Zhao, Yong; Xu, Tao; Menkhaus, Todd J; Fong, Hao

    2014-12-10

    In this study, an electrospun regenerated cellulose (RC) nanofibrous membrane with fiber diameters of ?200-400 nm was prepared first; subsequently, 2-hydroxyethyl methacrylate (HEMA), 2-dimethylaminoethyl methacrylate (DMAEMA), and acrylic acid (AA) were selected as the monomers for surface grafting of polymer chains/brushes via the atom transfer radical polymerization (ATRP) method. Thereafter, four nanofibrous membranes (i.e., RC, RC-poly(HEMA), RC-poly(DMAEMA), and RC-poly(AA)) were explored as innovative supports for immobilization of an enzyme of bovine liver catalase (CAT). The amount/capacity, activity, stability, and reusability of immobilized catalase were evaluated, and the kinetic parameters (Vmax and Km) for immobilized and free catalase were determined. The results indicated that the respective amounts/capacities of immobilized catalase on RC-poly(HEMA) and RC-poly(DMAEMA) nanofibrous membranes reached 78 3.5 and 67 2.7 mg g(-1), which were considerably higher than the previously reported values. Meanwhile, compared to that of free CAT (i.e., 18 days), the half-life periods of RC-CAT, RC-poly(HEMA)-CAT, RC-poly(DMAEMA)-CAT, and RC-poly(AA)-CAT were 49, 58, 56, and 60 days, respectively, indicating that the storage stability of immobilized catalase was also significantly improved. Furthermore, the immobilized catalase exhibited substantially higher resistance to temperature variation (tested from 5 to 70 C) and lower degree of sensitivity to pH value (tested from 4.0 and 10.0) than the free catalase. In particular, according to the kinetic parameters of Vmax and Km, the nanofibrous membranes of RC-poly(HEMA) (i.e., 5102 ?mol mg(-1) min(-1) and 44.89 mM) and RC-poly(DMAEMA) (i.e., 4651 ?mol mg(-1) min(-1) and 46.98 mM) had the most satisfactory biocompatibility with immobilized catalase. It was therefore concluded that the electrospun RC nanofibrous membranes surface-grafted with 3-dimensional nanolayers of polymer chains/brushes would be suitable/ideal as efficient supports for high-density and reusable enzyme immobilization. PMID:25396286

  18. Oxidative upregulation of Bcl-2 in healthy lymphocytes.

    PubMed

    Cristofanon, Silvia; Nuccitelli, Silvia; D'Alessio, Maria; Radogna, Flavia; De Nicola, Milena; Bergamaschi, Antonio; Cerella, Claudia; Magrini, Andrea; Diederich, Marc; Ghibelli, Lina

    2006-12-01

    In many cell systems, pharmacological glutathione (GSH) depletion with the GSH neosynthesis inhibitor buthionine sulfoximine (BSO) leads to cell death and highly sensitizes tumor cells to apoptosis induced by standard chemotherapeutic agents. However, some tumor cells upregulate Bcl-2 in response to BSO, thus surviving the treatment and failing to be chemosensitized. Cell lines of monocytic and lymphocytic origins respond to BSO treatment in an opposite way, lymphocytes being chemosensitized and unable to transactivate Bcl-2. In this article we investigate the response to BSO of lymphocytes freshly isolated from peripheral blood of healthy donors. After ensuring that standard separation procedures do not alter per se lymphocytes redox equilibrium nor Bcl-2 levels in the first 24 h of culture, we show that BSO treatment promotes the upregulation of Bcl-2, with a mechanism involving the increased radical production consequent to GSH depletion. Thus, BSO treatment may increase the differential cytocidal effect of cytotoxic drugs in tumor versus normal lymphocytes. PMID:17341597

  19. Iron upregulates melanogenesis in cultured retinal pigment epithelial cells

    PubMed Central

    Wolkow, Natalie; Li, Yafeng; Maminishkis, Arvydas; Song, Ying; Alekseev, Oleg; Iacovelli, Jared; Song, Delu; Lee, Jennifer C.; Dunaief, Joshua L.

    2014-01-01

    The purpose of our studies was to examine the relationship between iron and melanogenesis in retinal pigment epithelial cells, as prior observations had suggested that iron may promote melanogenesis. This relationship has potential clinical importance, as both iron overload and hyperpigmentation are associated with age-related macular degeneration (AMD). Human fetal retinal pigment epithelial cells and ARPE-19 cells were treated with iron in the form of ferric ammonium citrate, after which quantitative RT-PCR and electron microscopy were performed. Melanogenesis genes tyrosinase, tyrosinase-related protein 1, Hermansky-Pudlak Syndrome 3, premelanosome protein and dopachrome tautomerase were upregulated, as was the melanogenesis-controlling transcription factor, microphthalmia-associated transcription factor (MITF). Iron-treated cells had increased pigmentation and melanosome number. Multiple transcription factors upstream of MITF were upregulated by iron. PMID:25277027

  20. Upregulating endogenous genes by an RNA-programmable artificial transactivator

    PubMed Central

    Fimiani, Cristina; Goina, Elisa; Mallamaci, Antonello

    2015-01-01

    To promote expression of endogenous genes ad libitum, we developed a novel, programmable transcription factor prototype. Kept together via an MS2 coat protein/RNA interface, it includes a fixed, polypeptidic transactivating domain and a variable RNA domain that recognizes the desired gene. Thanks to this device, we specifically upregulated five genes, in cell lines and primary cultures of murine pallial precursors. Gene upregulation was small, however sufficient to robustly inhibit neuronal differentiation. The transactivator interacted with target gene chromatin via its RNA cofactor. Its activity was restricted to cells in which the target gene is normally transcribed. Our device might be useful for specific applications. However for this purpose, it will require an improvement of its transactivation power as well as a better characterization of its target specificity and mechanism of action. PMID:26152305

  1. Upregulating endogenous genes by an RNA-programmable artificial transactivator.

    PubMed

    Fimiani, Cristina; Goina, Elisa; Mallamaci, Antonello

    2015-09-18

    To promote expression of endogenous genes ad libitum, we developed a novel, programmable transcription factor prototype. Kept together via an MS2 coat protein/RNA interface, it includes a fixed, polypeptidic transactivating domain and a variable RNA domain that recognizes the desired gene. Thanks to this device, we specifically upregulated five genes, in cell lines and primary cultures of murine pallial precursors. Gene upregulation was small, however sufficient to robustly inhibit neuronal differentiation. The transactivator interacted with target gene chromatin via its RNA cofactor. Its activity was restricted to cells in which the target gene is normally transcribed. Our device might be useful for specific applications. However for this purpose, it will require an improvement of its transactivation power as well as a better characterization of its target specificity and mechanism of action. PMID:26152305

  2. Upregulation of ATM in sclerosing adenosis of the breast.

    PubMed Central

    Clarke, R A; Kairouz, R; Watters, D; Lavin, M F; Kearsley, J H; Lee, C S

    1998-01-01

    The gene mutated in ataxia telangiectasia (ATM) has an established tumour suppressor role in breast cancer. ATM appears to be expressed in most normal cells, including breast epithelium, where it has been postulated to have a nuclear role in cell cycle regulation following DNA damage. However, ATM is not upregulated after DNA damage. In this study, we demonstrate an absence of immunohistologically detectable levels of ATM in the normally quiescent myoepithelial cells that line normal breast ducts. This contrasts dramatically with the significant expression of ATM in the proliferative myoepithelium of sclerosing adenosis (n = 7). This upregulation of ATM suggests that ATM expression is coupled to the proliferative status of the myoepithelium. Our results also indicate that there are factors other than ATM gene mutations that can dramatically influence ATM expression in the breast and that these factors should be considered for their possible implications in carcinogenesis. PMID:9893751

  3. Acoustic trauma triggers upregulation of serotonin receptor genes.

    PubMed

    Smith, Adam R; Kwon, Jae Hyun; Navarro, Marco; Hurley, Laura M

    2014-09-01

    Hearing loss induces plasticity in excitatory and inhibitory neurotransmitter systems in auditory brain regions. Excitatory-inhibitory balance is also influenced by a range of neuromodulatory regulatory systems, but less is known about the effects of auditory damage on these networks. In this work, we studied the effects of acoustic trauma on neuromodulatory plasticity in the auditory midbrain of CBA/J mice. Quantitative PCR was used to measure the expression of serotonergic and GABAergic receptor genes in the inferior colliculus (IC) of mice that were unmanipulated, sham controls with no hearing loss, and experimental individuals with hearing loss induced by exposure to a 116dB, 10kHz pure tone for 3h. Acoustic trauma induced substantial hearing loss that was accompanied by selective upregulation of two serotonin receptor genes in the IC. The Htr1B receptor gene was upregulated tenfold following trauma relative to shams, while the Htr1A gene was upregulated threefold. In contrast, no plasticity in serotonin receptor gene expression was found in the hippocampus, a region also innervated by serotonergic projections. Analyses in the IC demonstrated that acoustic trauma also changed the coexpression of genes in relation to each other, leading to an overexpression of Htr1B compared to other genes. These data suggest that acoustic trauma induces serotonergic plasticity in the auditory system, and that this plasticity may involve comodulation of functionally-linked receptor genes. PMID:24997228

  4. Uromodulin Upregulates TRPV5 by Impairing Caveolin-Mediated Endocytosis

    PubMed Central

    Wolf, Matthias T.F.; Wu, Xue-Ru; Huang, Chou-Long

    2013-01-01

    Uromodulin (UMOD) is synthesized in the thick ascending limb and secreted into urine as the most abundant protein. Association studies in humans suggest protective effects of UMOD against calcium-containing kidney stones. Mice carrying mutations of Umod found in human uromodulin-associated kidney disease (UAKD) and Umod deficient mice exhibit hypercalciuria. The mechanism for UMOD regulation of urinary Ca2+ excretion is incompletely understood. We examined if UMOD regulates TRPV5 and TRPV6, channels critical for renal transcellular Ca2+ reabsorption. Coexpression with UMOD increased whole-cell TRPV5 current density in HEK293 cells. In biotinylation studies UMOD increased TRPV5 cell-surface abundance. Extracellular application of purified UMOD upregulated TRPV5 current density within physiological relevant concentration ranges. UMOD exerted a similar effect on TRPV6. TRPV5 undergoes constitutive caveolin-mediated endocytosis. UMOD had no effect on TRPV5 in a caveolin-1 deficient cell line. Expression of recombinant caveolin-1 in these cells restored the ability of UMOD to upregulate TRPV5. Secretion of UAKD-mutant UMOD was markedly reduced and coexpression of mutant UMOD with TRPV5 failed to increase its current. Immunofluorescent studies demonstrated lower TRPV5 expression in Umod−/− mice compared to wild-type. UMOD upregulates TRPV5 by acting from extracellular and by decreasing endocytosis of TRPV5. The stimulation of Ca2+ reabsorption via TRPV5 by UMOD may contribute to protection against kidney stone formation. PMID:23466996

  5. Acoustic trauma triggers upregulation of serotonin receptor genes

    PubMed Central

    Smith, Adam R.; Kwon, Jae Hyun; Navarro, Marco; Hurley, Laura M.

    2014-01-01

    Hearing loss induces plasticity in excitatory and inhibitory neurotransmitter systems in auditory brain regions. Excitatory-inhibitory balance is also influenced by a range of neuromodulatory regulatory systems, but less is known about the effects of auditory damage on these networks. In this work, we studied the effects of acoustic trauma on neuromodulatory plasticity in the auditory midbrain of CBA/J mice. Quantitative PCR was used to measure the expression of serotonergic and GABAergic receptor genes in the inferior colliculus (IC) of mice that were unmanipulated, sham controls with no hearing loss, and experimental individuals with hearing loss induced by exposure to a 116 dB, 10 kHz pure tone for 3 hours. Acoustic trauma induced substantial hearing loss that was accompanied by selective upregulation of two serotonin receptor genes in the IC. The Htr1B receptor gene was upregulated tenfold following trauma relative to shams, while the Htr1A gene was upregulated threefold. In contrast, no plasticity in serotonin receptor gene expression was found in the hippocampus, a region also innervated by serotonergic projections. Analyses in the IC demonstrated that acoustic trauma also changed the coexpression of genes in relation to each other, leading to an overexpression of Htr1B compared to other genes.. These data suggest that acoustic trauma induces serotonergic plasticity in the auditory system, and that this plasticity may involve comodulation of functionally-linked receptor genes. PMID:24997228

  6. Singlet oxygen treatment of tumor cells triggers extracellular singlet oxygen generation, catalase inactivation and reactivation of intercellular apoptosis-inducing signaling☆

    PubMed Central

    Riethmüller, Michaela; Burger, Nils; Bauer, Georg

    2015-01-01

    Intracellular singlet oxygen generation in photofrin-loaded cells caused cell death without discrimination between nonmalignant and malignant cells. In contrast, extracellular singlet oxygen generation caused apoptosis induction selectively in tumor cells through singlet oxygen-mediated inactivation of tumor cell protective catalase and subsequent reactivation of intercellular ROS-mediated apoptosis signaling through the HOCl and the NO/peroxynitrite signaling pathway. Singlet oxygen generation by extracellular photofrin alone was, however, not sufficient for optimal direct inactivation of catalase, but needed to trigger the generation of cell-derived extracellular singlet oxygen through the interaction between H2O2 and peroxynitrite. Thereby, formation of peroxynitrous acid, generation of hydroxyl radicals and formation of perhydroxyl radicals (HO2.) through hydroxyl radical/H2O2 interaction seemed to be required as intermediate steps. This amplificatory mechanism led to the formation of singlet oxygen at a sufficiently high concentration for optimal inactivation of membrane-associated catalase. At low initial concentrations of singlet oxygen, an additional amplification step needed to be activated. It depended on singlet oxygen-dependent activation of the FAS receptor and caspase-8, followed by caspase-8-mediated enhancement of NOX activity. The biochemical mechanisms described here might be considered as promising principle for the development of novel approaches in tumor therapy that specifically direct membrane-associated catalase of tumor cells and thus utilize tumor cell-specific apoptosis-inducing ROS signaling. PMID:26225731

  7. Coexpressed Catalase Protects Chimeric Antigen Receptor–Redirected T Cells as well as Bystander Cells from Oxidative Stress–Induced Loss of Antitumor Activity

    PubMed Central

    Ligtenberg, Maarten A.; Mougiakakos, Dimitrios; Mukhopadhyay, Madhura; Witt, Kristina; Lladser, Alvaro; Chmielewski, Markus; Riet, Tobias; Abken, Hinrich

    2016-01-01

    Treatment of cancer patients by adoptive T cell therapy has yielded promising results. In solid tumors, however, T cells encounter a hostile environment, in particular with increased inflammatory activity as a hallmark of the tumor milieu that goes along with abundant reactive oxygen species (ROS) that substantially impair antitumor activity. We present a strategy to render antitumor T cells more resilient toward ROS by coexpressing catalase along with a tumor specific chimeric Ag receptor (CAR) to increase their antioxidative capacity by metabolizing H2O2. In fact, T cells engineered with a bicistronic vector that concurrently expresses catalase, along with the CAR coexpressing catalase (CAR-CAT), performed superior over CAR T cells as they showed increased levels of intracellular catalase and had a reduced oxidative state with less ROS accumulation in both the basal state and upon activation while maintaining their antitumor activity despite high H2O2 levels. Moreover, CAR-CAT T cells exerted a substantial bystander protection of nontransfected immune effector cells as measured by CD3ζ chain expression in bystander T cells even in the presence of high H2O2 concentrations. Bystander NK cells, otherwise ROS sensitive, efficiently eliminate their K562 target cells under H2O2-induced oxidative stress when admixed with CAR-CAT T cells. This approach represents a novel means for protecting tumor-infiltrating cells from tumor-associated oxidative stress–mediated repression. PMID:26673145

  8. Modulatory effect of pineapple peel extract on lipid peroxidation, catalase activity and hepatic biomarker levels in blood plasma of alcohol-induced oxidative stressed rats

    PubMed Central

    Okafor, OY; Erukainure, OL; Ajiboye, JA; Adejobi, RO; Owolabi, FO; Kosoko, SB

    2011-01-01

    Objective To investigate the ability of the methanolic extract of pineapple peel to modulate alcohol-induced lipid peroxidation, changes in catalase activities and hepatic biochemical marker levels in blood plasma. Methods Oxidative stress was induced by oral administration of ethanol (20% w/v) at a dosage of 5 mL/kg bw in rats. After 28 days of treatment, the rats were fasted overnight and sacrificed by cervical dislocation. Blood was collected with a 2 mL syringe by cardiac puncture and was centrifuged at 3 000 rpm for 10 min. The plasma was analyzed to evaluate malondialdehyde (MDA), catalase activity, aspartate aminotransferase (AST), alkaline phosphatase (ALP) and alanine aminotransferase (ALT) concentrations. Results Administration of alcohol caused a drastic increase (87.74%) in MDA level compared with the control. Pineapple peel extract significantly reduced the MDA level by 60.16% at 2.5 mL/kg bw. Rats fed alcohol only had the highest catalase activity, treatment with pineapple peel extract at 2.5 mL/kg bw however, reduced the activity. Increased AST, ALP and ALT activities were observed in rats fed alcohol only respectively, treatment with pineapple peel extract drastically reduced their activities. Conclusions The positive modulation of lipid peroxidation, catalase activities as well as hepatic biomarker levels of blood plasma by the methanolic extract of pineapple peels under alcohol-induced oxidative stress is an indication of its protective ability in the management of alcohol-induced toxicity. PMID:23569717

  9. Zymogram profiling of superoxide dismutase and catalase activities allows Saccharomyces and non-Saccharomyces species differentiation and correlates to their fermentation performance.

    PubMed

    Gamero-Sandemetrio, Esther; Gmez-Pastor, Roco; Matallana, Emilia

    2013-05-01

    Aerobic organisms have devised several enzymatic and non-enzymatic antioxidant defenses to deal with reactive oxygen species (ROS) produced by cellular metabolism. To combat such stress, cells induce ROS scavenging enzymes such as catalase, peroxidase, superoxide dismutase (SOD) and glutathione reductase. In the present research, we have used a double staining technique of SOD and catalase enzymes in the same polyacrylamide gel to analyze the different antioxidant enzymatic activities and protein isoforms present in Saccharomyces and non-Saccharomyces yeast species. Moreover, we used a technique to differentially detect Sod1p and Sod2p on gel by immersion in NaCN, which specifically inhibits the Sod1p isoform. We observed unique SOD and catalase zymogram profiles for all the analyzed yeasts and we propose this technique as a new approach for Saccharomyces and non-Saccharomyces yeast strains differentiation. In addition, we observed functional correlations between SOD and catalase enzyme activities, accumulation of essential metabolites, such as glutathione and trehalose, and the fermentative performance of different yeasts strains with industrial relevance. PMID:23354444

  10. Coexpressed Catalase Protects Chimeric Antigen Receptor-Redirected T Cells as well as Bystander Cells from Oxidative Stress-Induced Loss of Antitumor Activity.

    PubMed

    Ligtenberg, Maarten A; Mougiakakos, Dimitrios; Mukhopadhyay, Madhura; Witt, Kristina; Lladser, Alvaro; Chmielewski, Markus; Riet, Tobias; Abken, Hinrich; Kiessling, Rolf

    2016-01-15

    Treatment of cancer patients by adoptive T cell therapy has yielded promising results. In solid tumors, however, T cells encounter a hostile environment, in particular with increased inflammatory activity as a hallmark of the tumor milieu that goes along with abundant reactive oxygen species (ROS) that substantially impair antitumor activity. We present a strategy to render antitumor T cells more resilient toward ROS by coexpressing catalase along with a tumor specific chimeric Ag receptor (CAR) to increase their antioxidative capacity by metabolizing H2O2. In fact, T cells engineered with a bicistronic vector that concurrently expresses catalase, along with the CAR coexpressing catalase (CAR-CAT), performed superior over CAR T cells as they showed increased levels of intracellular catalase and had a reduced oxidative state with less ROS accumulation in both the basal state and upon activation while maintaining their antitumor activity despite high H2O2 levels. Moreover, CAR-CAT T cells exerted a substantial bystander protection of nontransfected immune effector cells as measured by CD3? chain expression in bystander T cells even in the presence of high H2O2 concentrations. Bystander NK cells, otherwise ROS sensitive, efficiently eliminate their K562 target cells under H2O2-induced oxidative stress when admixed with CAR-CAT T cells. This approach represents a novel means for protecting tumor-infiltrating cells from tumor-associated oxidative stress-mediated repression. PMID:26673145

  11. 1,25-Dihydroxyvitamin D3 and its analogues increase catalase at the mRNA, protein and activity level in a canine transitional carcinoma cell line.

    PubMed

    Middleton, R P; Nelson, R; Li, Q; Blanton, A; Labuda, J A; Vitt, J; Inpanbutr, N

    2015-12-01

    Antioxidant enzymes, such as catalase, superoxide dismutases (SOD), MnSOD and Cu/ZnSOD, protect cells by scavenging reactive oxygen species (ROS). Numerous studies have reported the anti-cancer effects of 1,25-dihydroxyvitamin D3 (calcitriol) and its related analogues, seocalcitol and analogue V. In this study, canine bladder transitional cell carcinoma (cbTCC) cells were used to determine effects of calcitriol and its related analogues on antioxidant enzyme gene expression, protein expression and activity. Catalase mRNA was increased in response to calcitriol (10(-7) M), and seocalcitol (10(-7) and 10(-9) M). MnSOD mRNA was decreased in response to calcitriol at 10(-7) M. Catalase was significantly increased in response to calcitriol (10(-7) and 10(-9) M), and seocalcitol (10(-9) M). Catalase enzymatic activity increased in response to calcitriol, seocalcitol and analogue V (10(-9) M). In addition, global gene expression analysis identified the involvement of mitogen-activated protein kinase (MAPK) signalling in cbTCC's response to calcitriol and seocalcitol treatment. PMID:26750780

  12. A natural xanthone increases catalase activity but decreases NF-kappa B and lipid peroxidation in U-937 and HepG2 cell lines.

    PubMed

    Sahoo, Binay K; Zaidi, Adeel H; Gupta, Pankaj; Mokhamatam, Raveendra B; Raviprakash, Nune; Mahali, Sidhartha K; Manna, Sunil K

    2015-10-01

    Mangiferin, a C-glycosyl xanthone, has shown anti-inflammatory, antioxidant, and anti-tumorigenic activities. In the present study, we investigated the molecular mechanism for the antioxidant property of mangiferin. Considering the role of nuclear transcription factor kappa B (NF-κB) in inflammation and tumorigenesis, we hypothesized that modulating its activity will be a viable therapeutic target in regulating the redox-sensitive ailments. Our results show that mangiferin blocks several inducers, such as tumor necrosis factor (TNF), lypopolysaccharide (LPS), phorbol-12-myristate-13-acetate (PMA) or hydrogen peroxide (H2O2) mediated NF-κB activation via inhibition of reactive oxygen species generation. In silico docking studies predicted strong binding energy of mangiferin to the active site of catalase (-9.13 kcal/mol), but not with other oxidases such as myeloperoxidase, glutathione peroxidase, or inducible nitric oxide synthase. Mangiferin increased activity of catalase by 44%, but had no effect on myeloperoxidase activity in vitro. Fluorescence spectroscopy further revealed the binding of mangiferin to catalase at the single site with binding constant and binding affinity of 3.1×10(-7) M(-1) and 1.046 respectively. Mangiferin also inhibits TNF-induced lipid peroxidation and thereby protects apoptosis. Hence, mangiferin with its ability to inhibit NF-κB and increase the catalase activity may prove to be a potent therapeutic. PMID:26209362

  13. Role of superoxide dismutase and catalase as determinants of pathogenicity of Nocardia asteroides: importance in resistance to microbicidal activities of human polymorphonuclear neutrophils.

    PubMed

    Beaman, B L; Black, C M; Doughty, F; Beaman, L

    1985-01-01

    The roles of nocardial superoxide dismutase (SOD) and catalase in the resistance of Nocardia asteroides to the microbicidal properties of human polymorphonuclear leukocytes were determined in vitro. The neutrophils killed ca. 80% of the cells of the less virulent N. asteroides 10905 and ca. 50% of the log phase of the more virulent N. asteroides GUH-2 after 180 min of incubation. These phagocytes were not able to kill early-stationary-phase cells of strain GUH-2 that contained 10 times more intracytoplasmic catalase than log-phase cells of the same culture. However, the polymorphonuclear leukocytes were able to kill more than 50% of the cells of early-stationary-phase strain GUH-2 after treatment with purified antibody specific for surface-associated SOD. No killing was observed when the bacteria were treated with normal rabbit immunoglobulin G or with serum obtained from rabbits immunized against whole nocardial cells (containing little or no activity against SOD). These phagocytes killed more than 99% of Listeria monocytogenes used as a control. Chlorpromazine-treated polymorphonuclear leukocytes killed L. monocytogenes (70%) but they were not able to kill antibody-treated cells of N. asteroides GUH-2. Exogenously added SOD partially protected strain 10905, which lacked surface-associated enzyme, but it had no effect on the killing of strain GUH-2, which already possessed significant amounts of surface-bound SOD. In contrast, catalase added to the nocardiae provided almost complete protection to the log-phase cells of strain GUH-2, but strain 10905 was only partially protected. SOD combined with catalase had additive activity which completely protected the cells of strain 10905. A mutant of N. asteroides GUH-2 (SCII-C) is more virulent during the log phase than is the parental strain. This mutant contained at least 7 times more catalase at this stage of growth than did the parent. No other differences between these two strains were observed during the log phase. In sharp contrast to those of the parent, log-phase cells of this high-catalase mutant were not killed by polymorphonuclear phagocytes. These data indicate a role for both SOD and catalase in the resistance of Nocardia spp. to human neutrophils, and they represent at least two factors associated with virulence. PMID:3880721

  14. Identification of a member of the catalase multigene family on wheat chromosome 7A associated with flour b* colour and biological significance of allelic variation.

    PubMed

    Li, Dora A; Walker, Esther; Francki, Michael G

    2015-12-01

    Carotenoids (especially lutein) are known to be the pigment source for flour b* colour in bread wheat. Flour b* colour variation is controlled by a quantitative trait locus (QTL) on wheat chromosome 7AL and one gene from the carotenoid pathway, phytoene synthase, was functionally associated with the QTL on 7AL in some, but not all, wheat genotypes. A SNP marker within a sequence similar to catalase (Cat3-A1snp) derived from full-length (FL) cDNA (AK332460), however, was consistently associated with the QTL on 7AL and implicated in regulating hydrogen peroxide (H2O2) to control carotenoid accumulation affecting flour b* colour. The number of catalase genes on chromosome 7AL was investigated in this study to identify which gene may be implicated in flour b* variation and two were identified through interrogation of the draft wheat genome survey sequence consisting of five exons and a further two members having eight exons identified through comparative analysis with the single catalase gene on rice chromosome 6, PCR amplification and sequencing. It was evident that the catalase genes on chromosome 7A had duplicated and diverged during evolution relative to its counterpart on rice chromosome 6. The detection of transcripts in seeds, the co-location with Cat3-A1snp marker and maximised alignment of FL-cDNA (AK332460) with cognate genomic sequence indicated that TaCat3-A1 was the member of the catalase gene family associated with flour b* colour variation. Re-sequencing identified three alleles from three wheat varieties, TaCat3-A1a, TaCat3-A1b and TaCat3-A1c, and their predicted protein identified differences in peroxisomal targeting signal tri-peptide domain in the carboxyl terminal end providing new insights into their potential role in regulating cellular H2O2 that contribute to flour b* colour variation. PMID:26134858

  15. Changes in catalase and glucose-6-phosphatase distribution patterns within oval cell compartment as possible differentiation markers during viral hepatocarcinogenesis in woodchucks.

    PubMed

    Radaeva, S; Bannasch, P

    1996-06-01

    Cytochemical analysis at the ultrastructural level was performed to characterize expression of catalase and glucose-6-phosphatase (G6Pase) activity as possible differentiation markers in oval cells proliferating during hepatocarcinogenesis induced in woodchucks by chronic infection with the woodchuck hepatitis virus (WHV) and additional treatment with aflatoxin B1 (AFB1). Oval cells from WHV-carriers treated with AFB1 showed two types of catalase-positive organelles: 1) microperoxisomes appearing as small strongly osmiophilic bodies corresponding to those present in biliary cells from control woodchucks, 2) peroxisomes with a hepatic staining pattern resembling those of mature hepatocytes but lacking a nucleoid. While in oval cells penetrating into the parenchyma a catalase-positive reaction product was restricted to rare microperoxisomes, in close vicinity to the portal tract about 30% of the oval cells produced peroxisomes with a hepatic staining pattern, indicating the existence of two different populations within the oval cell compartment. Peroxisomes with a hepatic staining pattern formed clusters and exhibited pleomorphism with marked variation in shape and size, the size sometimes coming up to that of normal hepatocellular peroxisomes. Serial sections revealed the complex organization of these peroxisomes. They consisted of several interconnected segments forming a peroxisomal reticulum. These findings are consistent with the hypothesis that a subpopulation of oval cells represents committed precursor cells capable of differentiating into hepatocytes. Activity of G6Pase was not demonstrable in this subpopulation of oval cells and became positive only in transitional cells. Differential expression of catalase and G6Pase activity in a stepwise fashion within the oval cell compartment appear to mark differentiation of oval cells into hepatocytes. Thus, elevated expression of catalase may be a useful early marker for the distinction of different subpopulations of oval cells committed to hepatic cell lineages before definitely changing their phenotype, whereas expression of G6Pase activity seems to begin later, accompanying morphological changes towards the phenotype of mature hepatocytes. PMID:8766596

  16. Revealing mechanisms of selective, concentration-dependent potentials of 4-hydroxy-2-nonenal to induce apoptosis in cancer cells through inactivation of membrane-associated catalase.

    PubMed

    Bauer, Georg; Zarkovic, Neven

    2015-04-01

    Tumor cells generate extracellular superoxide anions and are protected against superoxide anion-mediated intercellular apoptosis-inducing signaling by the expression of membrane-associated catalase. 4-Hydroxy-2-nonenal (4-HNE), a versatile second messenger generated during lipid peroxidation, has been shown to induce apoptosis selectively in malignant cells. The findings described in this paper reveal the strong, concentration-dependent potential of 4-HNE to specifically inactivate extracellular catalase of tumor cells both indirectly and directly and to consequently trigger apoptosis in malignant cells through superoxide anion-mediated intercellular apoptosis-inducing signaling. Namely, 4-HNE caused apoptosis selectively in NOX1-expressing tumor cells through inactivation of their membrane-associated catalase, thus reactivating subsequent intercellular signaling through the NO/peroxynitrite and HOCl pathways, followed by the mitochondrial pathway of apoptosis. Concentrations of 4-HNE of 1.2 M and higher directly inactivated membrane-associated catalase of tumor cells, whereas at lower concentrations, 4-HNE triggered a complex amplificatory pathway based on initial singlet oxygen formation through H2O2 and peroxynitrite interaction. Singlet-oxygen-dependent activation of the FAS receptor and caspase-8 increased superoxide anion generation by NOX1 and amplification of singlet oxygen generation, which allowed singlet-oxygen-dependent inactivation of catalase. 4-HNE and singlet oxygen cooperate in complex autoamplificatory loops during this process. The finding of these novel anticancer pathways may be useful for understanding the role of 4-HNE in the control of malignant cells and for the optimization of ROS-dependent therapeutic approaches including antioxidant treatments. PMID:25619142

  17. Inhibitory effects of deferasirox on the structure and function of bovine liver catalase: a spectroscopic and theoretical study.

    PubMed

    Moradi, M; Divsalar, A; Saboury, A A; Ghalandari, B; Harifi, A R

    2015-01-01

    Deferasirox (DFX), as an oral chelator, is used for treatment of transfusional iron overload. In this study, we have investigated the effects of DFX as an iron chelator, on the function and structure of bovine liver catalase (BLC) by different spectroscopic methods of UV-visible, fluorescence, and circular dichroism (CD) at two temperatures of 25 and 37C. In vitro kinetic studies showed that DFX can inhibit the enzymatic activity in a competitive manner. KI value was calculated 39nM according to the Lineweaver-Burk plot indicating a high rate of inhibition of the enzyme. Intrinsic fluorescence data showed that increasing the drug concentrations leads to a significant decrease in the intrinsic emission of the enzyme indicating a significant change in the three-dimensional environment around the chromophores of the enzyme structure. By analyzing the fluorescence quenching data, it was found that the BLC has two binding sites for DFX and the values of binding constant at 25 and 37C were calculated 1.7נ10(7) and 3נ10(7)M(-1), respectively. The static type of quenching mechanism is involved in the quenching of intrinsic emission of enzyme. The thermodynamic data suggest that hydrophobic interactions play a major role in the binding reaction. UV-vis spectroscopy results represented the changes in tryptophan (Trp) absorption and Soret band spectra, which indicated changes in Trp and heme group position caused by the drug binding. Also, CD data represented that high concentrations of DFX lead to a significant decreasing in the content of ?-sheet and random coil accompanied an increasing in ?-helical content of the protein. The molecular docking results indicate that docking may be an appropriate method for prediction and confirmation of experimental results and also useful for determining the binding mechanism of proteins and drugs. According to above results, it can be concluded that the DFX can chelate the Fe(III) on the enzyme active site leading to changes in the function and structure of catalase which can be considered as a side effect of this drug and consequently has an important role in hepatic complications and fibrosis. PMID:25586906

  18. Molecular Characterization of KatY (Antigen 5), a Thermoregulated Chromosomally Encoded Catalase-Peroxidase of Yersinia pestis

    PubMed Central

    Garcia, Emilio; Nedialkov, Yuri A.; Elliott, Jeffrey; Motin, Vladimir L.; Brubaker, Robert R.

    1999-01-01

    The first temperature-dependent proteins (expressed at 37C, but not 26C) to be identified in Yersinia pestis were antigens 3 (fraction 1), 4 (pH 6 antigen), and 5 (hereafter termed KatY). Antigens 3 and 4 are now established virulence factors, whereas little is known about KatY, except that it is encoded chromosomally, produced in abundance, possesses modest catalase activity, and is shared by Yersinia pseudotuberculosis, but not Yersinia enterocolitica. We report here an improved chromatographic method (DEAE-cellulose, calcium hydroxylapatite, and Sephadex G-150) that yields enzymatically active KatY (2,423 U/mg of protein). Corresponding mouse monoclonal antibody 1B70.1 detected plasminogen activator-mediated hydrolysis of KatY, and a polyclonal rabbit antiserum raised against outer membranes of Y. pestis was enriched for anti-KatY. A sequenced ?16-kb Y. pestis DNA insert of a positive pLG338 clone indicated that katY encodes an 81.4-kDa protein (pI 6.98) containing a leader sequence of 2.6 kDa; the deduced molecular mass and pI of processed KatY were 78.8 kDa and 6.43, respectively. A minor truncated variant (predicted molecular mass of 53.6 kDa) was also expressed. KatY is similar (39 to 59% identity) to vegetative bacterial catalase-peroxidases (KatG in Escherichia coli) and is closely related to plasmid-encoded KatP of enterohemorrhagic E. coli O157:H7 (75% identity). katY encoded a putative Ca2+-binding site, and its promoter contained three homologues to the consensus recognition sequence of the pCD-encoded transcriptional activator LcrF. rbsA was located upstream of katY, and cybB, cybC, dmsABC, and araD were mapped downstream. These genes are not linked to katG or katP in E. coli. PMID:10322012

  19. In Vitro Effect of Sodium Fluoride on Malondialdehyde Concentration and on Superoxide Dismutase, Catalase, and Glutathione Peroxidase in Human Erythrocytes

    PubMed Central

    Gutirrez-Salinas, Jos; Garca-Ortz, Liliana; Morales Gonzlez, Jos A.; Hernndez-Rodrguez, Sergio; Ramrez-Garca, Sotero; Nez-Ramos, Norma R.; Madrigal-Santilln, Eduardo

    2013-01-01

    The aim of this paper was to describe the in vitro effect of sodium fluoride (NaF) on the specific activity of the major erythrocyte antioxidant enzymes, as well as on the membrane malondialdehyde concentration, as indicators of oxidative stress. For this purpose, human erythrocytes were incubated with NaF (0, 7, 28, 56, and 100??g/mL) or NaF (100??g/mL) + vitamin E (1, 2.5, 5 and 10??g/mL). The malondialdehyde (MDA) concentration on the surface of the erythrocytes was determined, as were the enzymatic activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GlPx). Our results demonstrated that erythrocytes incubated with increasing NaF concentrations had an increased MDA concentration, along with decreased activity of antioxidant enzymes. The presence of vitamin E partially reversed the toxic effects of NaF on erythrocytes. These findings suggest that NaF induces oxidative stress in erythrocytes in vitro, and this stress is partially reversed by the presence of vitamin E. PMID:24223512

  20. Evaluation of the serum catalase and myeloperoxidase activities in chronic arsenic-exposed individuals and concomitant cytogenetic damage

    SciTech Connect

    Banerjee, Mayukh; Banerjee, Nilanjana; Ghosh, Pritha; Das, Jayanta K.; Basu, Santanu; Sarkar, Ajoy K.; States, J. Christopher; Giri, Ashok K.

    2010-11-15

    Chronic arsenic exposure through contaminated drinking water is a major environmental health issue. Chronic arsenic exposure is known to exert its toxic effects by a variety of mechanisms, of which generation of reactive oxygen species (ROS) is one of the most important. A high level of ROS, in turn, leads to DNA damage that might ultimately culminate in cancer. In order to keep the level of ROS in balance, an array of enzymes is present, of which catalase (CAT) and myeloperoxidase (MPO) are important members. Hence, in this study, we determined the activities of these two enzymes in the sera and chromosomal aberrations (CA) in peripheral blood lymphocytes in individuals exposed and unexposed to arsenic in drinking water. Arsenic in drinking water and in urine was used as a measure of exposure. Our results show that individuals chronically exposed to arsenic have significantly higher CAT and MPO activities and higher incidence of CA. We found moderate positive correlations between CAT and MPO activities, induction of CA and arsenic in urine and water. These results indicate that chronic arsenic exposure causes higher CAT and MPO activities in serum that correlates with induction of genetic damage. We conclude that the serum levels of these enzymes might be used as biomarkers of early arsenic exposure induced disease much before the classical dermatological symptoms of arsenicosis begin to appear.

  1. Hexachlorocyclohexane-induced changes in lipid peroxidation, superoxide dismutase and catalase activities and glutathione content in chick liver.

    PubMed

    Samanta, L; Chainy, G B

    1995-02-01

    An elevation in the level of lipid peroxides in nuclear, mitochondrial and microsomal fractions of chick liver was recorded 6 hr after hexachlorocyclohexane (HCH; 50 mg/kg body wt., ip) treatment. The magnitude of increase remained more or less same even 24 hr after the pesticide treatment. Total glutathione content also increased by 6 hr of HCH treatment and did not change even 24 hr after the pesticide treatment. Protein content of crude homogenate and 10000 g supernatant decreased significantly 6 hr after the pesticide treatment. The magnitude of decrease was more or less same even 24 hr after the pesticide treatment. Although cytoplasmic superoxide dismutase and catalase activities (expressed as units/mg protein) did not change 24 hr after HCH treatment, a small but significant increase in superoxide dismutase activity was recorded 6 hr after HCH treatment. On the other hand when activities were expressed as units/mg tissue wt., a significant decrease in the activities of both the enzymes was recorded 6 and 24 hr after HCH treatment. Therefore, the decrease in the activities of both the enzymes in response to HCH in chick liver may be due to decrease in tissue protein content in general rather than specific decrease in the activities of the enzymes. PMID:7538972

  2. Engineering of a novel tri-functional enzyme with MnSOD, catalase and cell-permeable activities.

    PubMed

    Luangwattananun, Piriya; Yainoy, Sakda; Eiamphungporn, Warawan; Songtawee, Napat; Bülow, Leif; Ayudhya, Chartchalerm Isarankura Na; Prachayasittikul, Virapong

    2016-04-01

    Cooperative function of superoxide dismutase (SOD) and catalase (CAT), in protection against oxidative stress, is known to be more effective than the action of either single enzyme. Chemical conjugation of the two enzymes resulted in molecules with higher antioxidant activity and therapeutic efficacy. However, chemical methods holds several drawbacks; e.g., loss of enzymatic activity, low homogeneity, time-consuming, and the need of chemical residues removal. Yet, the conjugated enzymes have never been proven to internalize into target cells. In this study, by employing genetic and protein engineering technologies, we reported designing and production of a bi-functional protein with SOD and CAT activities for the first time. To enable cellular internalization, cell penetrating peptide from HIV-1 Tat (TAT) was incorporated. Co-expression of CAT-MnSOD and MnSOD-TAT fusion genes allowed simultaneous self-assembly of the protein sequences into a large protein complex, which is expected to contained one tetrameric structure of CAT, four tetrameric structures of MnSOD and twelve units of TAT. The protein showed cellular internalization and superior protection against paraquat-induced cell death as compared to either complex bi-functional protein without TAT or to native enzymes fused with TAT. This study not only provided an alternative strategy to produce multifunctional protein complex, but also gained an insight into the development of therapeutic agent against oxidative stress-related conditions. PMID:26778154

  3. Growth rate, catalase and superoxide dismutase activities in rock carp (Procypris rabaudi Tchang) exposed to supersaturated total dissolved gas*

    PubMed Central

    Liu, Xiao-qing; Li, Ke-feng; Du, Jun; Li, Jia; Li, Ran

    2011-01-01

    Total dissolved gas supersaturation (TDGS) appears when the pressures of gases in a solution exceed the barometric pressures. TDGS is often caused by flood discharge at dams. It may lead to gas bubble disease (GBD) for fish and biochemical responses of selected fish and other aquatic organisms. The purpose of this study was to determine the impact of long-term TDGS levels on the growth and biochemical responses of rock carp (Procypris rabaudi Tchang) dwelling in the upper reaches of the Yangtze River. Three-year-old rock carp were exposed to TDGS levels at 100%, 104%, 108%, 112%, and 116% for 42 d. Samples were taken every 7 d after the start of the trial in order to determine catalase (CAT) and superoxide dismutase (SOD) activities in gill and muscle tissues. Samples were taken at Days 0 and 42 of exposure to determine growth rate. Little effect was found on growth rate in all treatment groups. SOD and CAT activities varied in different tissues, according to time of exposure and TDGS levels. The biochemical response of fish exposed to TDGS was more obvious in gill tissue than in muscle tissue. Surveys of SOD and CAT activities in different tissues offer important information about the effect of TDGS on the rare fish in the Yangtze River, and may help evaluate the risk to the aquatic eco-environment and aquatic ecosystem in the downstream of the Yangtze River. PMID:22042655

  4. Growth rate, catalase and superoxide dismutase activities in rock carp (Procypris rabaudi Tchang) exposed to supersaturated total dissolved gas.

    PubMed

    Liu, Xiao-qing; Li, Ke-feng; Du, Jun; Li, Jia; Li, Ran

    2011-11-01

    Total dissolved gas supersaturation (TDGS) appears when the pressures of gases in a solution exceed the barometric pressures. TDGS is often caused by flood discharge at dams. It may lead to gas bubble disease (GBD) for fish and biochemical responses of selected fish and other aquatic organisms. The purpose of this study was to determine the impact of long-term TDGS levels on the growth and biochemical responses of rock carp (Procypris rabaudi Tchang) dwelling in the upper reaches of the Yangtze River. Three-year-old rock carp were exposed to TDGS levels at 100%, 104%, 108%, 112%, and 116% for 42 d. Samples were taken every 7 d after the start of the trial in order to determine catalase (CAT) and superoxide dismutase (SOD) activities in gill and muscle tissues. Samples were taken at Days 0 and 42 of exposure to determine growth rate. Little effect was found on growth rate in all treatment groups. SOD and CAT activities varied in different tissues, according to time of exposure and TDGS levels. The biochemical response of fish exposed to TDGS was more obvious in gill tissue than in muscle tissue. Surveys of SOD and CAT activities in different tissues offer important information about the effect of TDGS on the rare fish in the Yangtze River, and may help evaluate the risk to the aquatic eco-environment and aquatic ecosystem in the downstream of the Yangtze River. PMID:22042655

  5. Changes in Isozyme Profiles of Catalase, Peroxidase, and Glutathione Reductase during Acclimation to Chilling in Mesocotyls of Maize Seedlings.

    PubMed

    Anderson, M. D.; Prasad, T. K.; Stewart, C. R.

    1995-12-01

    The response of antioxidants to acclimation and chilling in various tissues of dark-grown maize (Zea mays L.) seedlings was examined in relation to chilling tolerance and protection from chilling-induced oxidative stress. Chilling caused an accumulation of H2O2 in both the coleoptile + leaf and the mesocotyl (but not roots), and acclimation prevented this accumulation. None of the antioxidant enzymes were significantly affected by acclimation or chilling in the coleoptile + leaf or root. However, elevated levels of glutathione in acclimated seedlings may contribute to an enhanced ability to scavenge H2O2 in the coleoptile + leaf. In the mesocotyl (visibly most susceptible to chilling), catalase3 was elevated in acclimated seedlings and may represent the first line of defense from mitochondria-generated H2O2. Nine of the most prominent peroxidase isozymes were induced by acclimation, two of which were located in the cell wall, suggesting a role in lignification. Lignin content was elevated in mesocotyls of acclimated seedlings, likely improving the mechanical strength of the mesocotyl. One cytosolic glutathione reductase isozyme was greatly decreased in acclimated seedlings, whereas two others were elevated, possibly resulting in improved effectiveness of the enzyme at low temperature. When taken together, these responses to acclimation illustrate the potential ways in which chilling tolerance may be improved in preemergent maize seedlings. PMID:12228666

  6. Ascorbate Peroxidase and Catalase Activities and Their Genetic Regulation in Plants Subjected to Drought and Salinity Stresses.

    PubMed

    Sofo, Adriano; Scopa, Antonio; Nuzzaci, Maria; Vitti, Antonella

    2015-01-01

    Hydrogen peroxide (H2O2), an important relatively stable non-radical reactive oxygen species (ROS) is produced by normal aerobic metabolism in plants. At low concentrations, H2O2 acts as a signal molecule involved in the regulation of specific biological/physiological processes (photosynthetic functions, cell cycle, growth and development, plant responses to biotic and abiotic stresses). Oxidative stress and eventual cell death in plants can be caused by excess H2O2 accumulation. Since stress factors provoke enhanced production of H2O2 in plants, severe damage to biomolecules can be possible due to elevated and non-metabolized cellular H2O2. Plants are endowed with H2O2-metabolizing enzymes such as catalases (CAT), ascorbate peroxidases (APX), some peroxiredoxins, glutathione/thioredoxin peroxidases, and glutathione sulfo-transferases. However, the most notably distinguished enzymes are CAT and APX since the former mainly occurs in peroxisomes and does not require a reductant for catalyzing a dismutation reaction. In particular, APX has a higher affinity for H2O2 and reduces it to H2O in chloroplasts, cytosol, mitochondria and peroxisomes, as well as in the apoplastic space, utilizing ascorbate as specific electron donor. Based on recent reports, this review highlights the role of H2O2 in plants experiencing water deficit and salinity and synthesizes major outcomes of studies on CAT and APX activity and genetic regulation in drought- and salt-stressed plants. PMID:26075872

  7. Physiological analyses indicate superoxide dismutase, catalase, and phytochelatins play important roles in Pb tolerance in Eremochloa ophiuroides.

    PubMed

    Li, Xi; Cen, Huameng; Chen, Youxiang; Xu, Siying; Peng, Lingli; Zhu, Hanmingyue; Li, Yiqiao

    2016-03-01

    Phytoremediation is considered to be a promising approach to restore or stabilize soil contaminated by lead (Pb). Turfgrasses, due to their high biomass yields, are considered to be suitable for use in phytoextraction of soil contaminated with heavy metal. It has been demonstrated that centipedegrass (Eremochloa ophiuroides (Munro) Hack., Poaceae) is a good turfgrass for restore of soil contaminated by Pb. However, the enhanced tolerant mechanisms in metallicolous (M) centipedegrass accessions remain unknown. In this study, we made a comparative study of growth performance, Pb accumulation, antioxidant levels, and phytochelatin concentrations in roots and shoots from M and nonmetallicolous (NM) centipedegrass accessions. Results showed that turf quality and growth rate were less repressed in M accessions than in NM accession. Pb stress caused generation of reactive oxygen species in centipedegrass with relatively lower levels in M accessions. Antioxidant activity analysis indicated that superoxide dismutase and catalase played important roles in Pb tolerance in M accessions. M accessions accumulated more Pb in roots and shoots. Greatly increased phytochelatins and less repressed sulfur contents in roots and shoots of M accessions indicated that they correlated with Pb accumulation and tolerance in centipedegrass. PMID:26368658

  8. Ascorbate Peroxidase and Catalase Activities and Their Genetic Regulation in Plants Subjected to Drought and Salinity Stresses

    PubMed Central

    Sofo, Adriano; Scopa, Antonio; Nuzzaci, Maria; Vitti, Antonella

    2015-01-01

    Hydrogen peroxide (H2O2), an important relatively stable non-radical reactive oxygen species (ROS) is produced by normal aerobic metabolism in plants. At low concentrations, H2O2 acts as a signal molecule involved in the regulation of specific biological/physiological processes (photosynthetic functions, cell cycle, growth and development, plant responses to biotic and abiotic stresses). Oxidative stress and eventual cell death in plants can be caused by excess H2O2 accumulation. Since stress factors provoke enhanced production of H2O2 in plants, severe damage to biomolecules can be possible due to elevated and non-metabolized cellular H2O2. Plants are endowed with H2O2-metabolizing enzymes such as catalases (CAT), ascorbate peroxidases (APX), some peroxiredoxins, glutathione/thioredoxin peroxidases, and glutathione sulfo-transferases. However, the most notably distinguished enzymes are CAT and APX since the former mainly occurs in peroxisomes and does not require a reductant for catalyzing a dismutation reaction. In particular, APX has a higher affinity for H2O2 and reduces it to H2O in chloroplasts, cytosol, mitochondria and peroxisomes, as well as in the apoplastic space, utilizing ascorbate as specific electron donor. Based on recent reports, this review highlights the role of H2O2 in plants experiencing water deficit and salinity and synthesizes major outcomes of studies on CAT and APX activity and genetic regulation in drought- and salt-stressed plants. PMID:26075872

  9. Manganese(II) induces cell division and increases in superoxide dismutase and catalase activities in an aging deinococcal culture

    SciTech Connect

    Chou, F.I.; Tan, S.T. )

    1990-04-01

    Addition of Mn(II) at 2.5 microM or higher to stationary-phase cultures of Deinococcus radiodurans IR was found to trigger at least three rounds of cell division. This Mn(II)-induced cell division (Mn-CD) did not occur when the culture was in the exponential or death phase. The Mn-CD effect produced daughter cells proportionally reduced in size, pigmentation, and radioresistance but proportionally increased in activity and amount of the oxygen toxicity defense enzymes superoxide dismutase and catalase. In addition, the concentration of an Mn-CD-induced protein was found to remain high throughout the entire Mn-CD phase. It was also found that an untreated culture exhibited a growth curve characterized by a very rapid exponential-stationary transition and that cells which had just reached the early stationary phase were synchronous. Our results suggest the presence of an Mn(II)-sensitive mechanism for controlling cell division. The Mn-CD effect appears to be specific to the cation Mn(II) and the radioresistant bacteria, deinococci.

  10. Spectroscopic investigations on the effect of N-Acetyl-L-cysteine-Capped CdTe Quantum Dots on catalase

    NASA Astrophysics Data System (ADS)

    Sun, Haoyu; Yang, Bingjun; Cui, Erqian; Liu, Rutao

    2014-11-01

    Quantum dots (QDs) are recognized as some of the most promising semiconductor nanocrystals in biomedical applications. However, the potential toxicity of QDs has aroused wide public concern. Catalase (CAT) is a common enzyme in animal and plant tissues. For the potential application of QDs in vivo, it is important to investigate the interaction of QDs with CAT. In this work, the effect of N-Acetyl-L-cysteine-Capped CdTe Quantum Dots with fluorescence emission peak at 612 nm (QDs-612) on CAT was investigated by fluorescence, synchronous fluorescence, fluorescence lifetime, ultraviolet-visible (UV-vis) absorption and circular dichroism (CD) techniques. Binding of QDs-612 to CAT caused static quenching of the fluorescence, the change of the secondary structure of CAT and the alteration of the microenvironment of tryptophan residues. The association constants K were determined to be K288K = 7.98 × 105 L mol-1 and K298K = 7.21 × 105 L mol-1. The interaction between QDs-612 and CAT was spontaneous with 1:1 stoichiometry approximately. The CAT activity was also inhibited for the bound QDs-612. This work provides direct evidence about enzyme toxicity of QDs-612 to CAT in vitro and establishes a new strategy to investigate the interaction between enzyme and QDs at a molecular level, which is helpful for clarifying the bioactivities of QDs in vivo.

  11. Changes in ascorbate peroxidase, catalase, guaiacol peroxidase and superoxide dismutase activities in common bean (Phaseolus vulgaris) nodules under salt stress.

    PubMed

    Jebara, Salwa; Jebara, Moez; Limam, Férid; Aouani, Mohamed Elarbi

    2005-08-01

    To analyse nodular antioxidant enzyme expression in response to salt stress, Phaseolus vulgaris genotype BAT477 was inoculated with reference strain CIAT899, and treated with 50 mM NaCl. Plant growth, nodulation and nitrogen fixing activity were analysed. Results showed that: (1) all parameters, particularly in nodules, were affected by salt treatments, and (2) confirmed preferential growth allocation to roots. The ARA was significantly decreased by salt treatments. Protein dosage confirmed that nodules were more affected by salt treatment than were roots. We analysed superoxide dismutase, catalase, ascorbate peroxidase and peroxidase in nodules, roots and a free rhizobial strain. Our results indicated that SOD and CAT nodular isozymes had bacterial and root origins. The SOD expressed the same CuZn, Fe and Mn SOD isoforms in nodules and roots, whereas in free rhizobia we found only one Fe and Mn SOD. APX and POX nodule and root profiles had only root origins, as no rhizobial band was detected. Under salt stress, plant growth, nitrogen fixation and activities of antioxidant defense enzymes in nodules were affected. Thus, these enzymes appear to preserve symbiosis from stress turned out that NaCl salinity lead to a differential regulation of distinct SOD and POX isoenzyme. So their levels in nodules appeared to be consistent with a symbiotic nitrogen fixing efficiency hypothesis, and they seem to function as the molecular mechanisms underlying the nodule response to salinity. PMID:16146319

  12. Upregulated CDK16 Expression in Serous Epithelial Ovarian Cancer Cells

    PubMed Central

    Zhou, Qi; Yu, Yanni

    2015-01-01

    Background As CDK-16 has been shown to be upregulated in several transformed cancer lines, we hypothesized that the cyclin-dependent kinase 16 (CDK-16) may be upregulated in serous epithelial ovarian cancer (EOC) cells. Therefore, we comparatively examined the mRNA and protein expression of CDK-16 in samples resected from serous EOC patients and normal controls. Material/Methods Tissue samples were collected from 70 serous EOC patients and 40 normal controls. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) was conducted to assess mRNA expression. CDK-16 protein expression was assessed by semi-quantitative immunohistochemical staining. Differences in mRNA and protein expression between serous EOC cells and normal tissue cells were tested with the Kruskal-Wallis test and analysis of variance (ANOVA). Results Both CDK-16 mRNA and protein expression were significantly higher in serous EOC tumor cells as compared to normal control ovarian cells (p<0.01). Although there was no significant correlation between CDK-16 mRNA expression and serous EOC stage (p=0.0794), there was a significant correlation between CDK-16 mRNA expression and serous EOC grade (p<0.0001). Moreover, there were significant correlations between CDK-16 protein expression and serous EOC stage (p<0.0001) and grade (p<0.0001). Conclusions CDK-16 upregulation in serous EOC cells may represent a negative feedback loop to promote ovarian cell differentiation in malignantly-transformed serous EOC cells. Further in-depth investigation on CDK-16s role in serous EOC is needed. PMID:26546806

  13. Upregulated Copper Transporters in Hypoxia-Induced Pulmonary Hypertension

    PubMed Central

    Zimnicka, Adriana M.; Tang, Haiyang; Guo, Qiang; Kuhr, Frank K.; Oh, Myung-Jin; Wan, Jun; Chen, Jiwang; Smith, Kimberly A.; Fraidenburg, Dustin R.; Choudhury, Moumita S. R.; Levitan, Irena; Machado, Roberto F.; Kaplan, Jack H.; Yuan, Jason X.-J.

    2014-01-01

    Pulmonary vascular remodeling and increased arterial wall stiffness are two major causes for the elevated pulmonary vascular resistance and pulmonary arterial pressure in patients and animals with pulmonary hypertension. Cellular copper (Cu) plays an important role in angiogenesis and extracellular matrix remodeling; increased Cu in vascular smooth muscle cells has been demonstrated to be associated with atherosclerosis and hypertension in animal experiments. In this study, we show that the Cu-uptake transporter 1, CTR1, and the Cu-efflux pump, ATP7A, were both upregulated in the lung tissues and pulmonary arteries of mice with hypoxia-induced pulmonary hypertension. Hypoxia also significantly increased expression and activity of lysyl oxidase (LOX), a Cu-dependent enzyme that causes crosslinks of collagen and elastin in the extracellular matrix. In vitro experiments show that exposure to hypoxia or treatment with cobalt (CoCl2) also increased protein expression of CTR1, ATP7A, and LOX in pulmonary arterial smooth muscle cells (PASMC). In PASMC exposed to hypoxia or treated with CoCl2, we also confirmed that the Cu transport is increased using 64Cu uptake assays. Furthermore, hypoxia increased both cell migration and proliferation in a Cu-dependent manner. Downregulation of hypoxia-inducible factor 1α (HIF-1α) with siRNA significantly attenuated hypoxia-mediated upregulation of CTR1 mRNA. In summary, the data from this study indicate that increased Cu transportation due to upregulated CTR1 and ATP7A in pulmonary arteries and PASMC contributes to the development of hypoxia-induced pulmonary hypertension. The increased Cu uptake and elevated ATP7A also facilitate the increase in LOX activity and thus the increase in crosslink of extracellular matrix, and eventually leading to the increase in pulmonary arterial stiffness. PMID:24614111

  14. The upregulation by peplomycin of signal transduction in human cells.

    PubMed

    Yamamoto, T; Yoneda, K; Ueta, E; Osaki, T

    2001-09-01

    To explore the mechanism of pulmonary fibrosis by bleomycin and its derivative, peplomycin (PLM), we examined the influence of PLM on signal transduction in human peripheral blood lymphocytes (HL), monocytes (HM) and fibroblasts (HF). Tyrosine phosphorylation of multiple proteins in HL and HM were induced by 0.001 to 0.05 microg/ml and by 0.01 to 0.5 microg/ml of PLM, respectively. In HF, 116-kDa protein was phosphorylated 0.2 to 5 microg/ml of PLM. When HL were treated with 0.01 microg/ml of PLM, phosphorylation of p56lck and activation of extracellular-signal related kinase-2 (ERK2) were induced. ERK2 was also activated in HM. Coordinately, the ratio of p21ras-binding GTP/GDP was increased by PLM. As well as interleukin-2, PLM induced tyrosine phosphorylation of JAK-3. In addition, PLM upregulated the nuclear translocation of nuclear factor-kappa B and the expression of c-myc-mRNA in HL, HM and HF. Furthermore, 0.01 to 0.001 microg/ml PLM enhanced the cytokine generation by HL and HM, and 1 to 5 microg/ml PLM increased cytokine generation and collagen synthesis by HF. These upregulatory effects of PLM were abrogated by pretreatment of the cells with a tyrosine kinase inhibitor. These results indicate that PLM upregulates signal transduction in a variety of cell types and the upregulation may induce pulmonary fibrosis. PMID:11676197

  15. Upregulation of Monocyte Urokinase Plasminogen Activator Receptor during Human Endotoxemia

    PubMed Central

    Dekkers, Pascale E. P.; ten Hove, Tessa; te Velde, Anje A.; van Deventer, Sander J. H.; van der Poll, Tom

    2000-01-01

    The receptor for urokinase-type plasminogen activator (uPAR) (CD87) plays an important role in leukocyte adhesion and migration. To assess the effect of endotoxin on cellular uPAR, uPAR expression was determined on leukocytes by fluorescence-activated cell sorter analysis in seven healthy subjects following intravenous injection of endotoxin (lot G; 4 ng/kg). Endotoxin induced a transient increase in uPAR expression on monocytes, reaching a 92% ± 46% increase over baseline expression after 6 h (P < 0.05). Endotoxin did not influence uPAR expression on granulocytes, while uPAR remained undetectable on lymphocytes. Endotoxin also increased soluble uPAR levels in plasma (P < 0.05). Stimulation of human whole blood with endotoxin or gram-positive stimuli in vitro also resulted in an upregulation of monocyte uPAR expression. Although tumor necrosis factor alpha (TNF) upregulated monocyte uPAR expression, anti-TNF did not influence the endotoxin-induced increase in monocyte uPAR expression. These data suggest that infectious stimuli may influence monocyte function in vivo by enhancing the expression of uPAR. PMID:10722614

  16. Upregulation of Phosphodiesterase type 5 in the Hyperplastic Prostate.

    PubMed

    Zhang, Wenhao; Zang, Ning; Jiang, Yaoming; Chen, Ping; Wang, Xinghuan; Zhang, Xinhua

    2015-01-01

    Both erectile dysfunction (ED) and lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) are common in the aging male. Numerous clinical trials have demonstrated the efficacy and safety of phosphodiesterase type 5 inhibitors (PDE5-Is) for treating LUTS/BPH with/without ED. However, the influence of BPH on prostatic PDE5 expression has never been studied. A testosterone-induced rat model of BPH was developed and human hyperplastic prostate specimens were harvested during cystoprostatectomy. PDE5, nNOS, eNOS and ?1-adrenoreceptor subtypes (?1aARs, ?1bARs and ?1dARs) were determined with real-time RT-PCR for rat tissues whilst PDE5 and ?1-adrenoreceptor subtypes were determined in human samples. PDE5 was further analyzed with Western-blot and histological examination. Serum testosterone was measured with ELISA. The rat BPH model was validated as having a significantly enlarged prostate. PDE5 localized mainly in fibromuscular stroma in prostate. Our data showed a significant and previously undocumented upregulation of PDE5 in both rat and human BPH, along with increased expression of nNOS and ?1dARs for rat tissues and ?1aARs for human BPH. The upregulation of PDE5 in the hyperplastic prostate could explain the mechanism and contribute to the high effectiveness of PDE5-Is for treating LUTS/BPH. Fibromuscular stroma could be the main target for PDE5-Is within prostate. PMID:26657792

  17. Upregulation of decorin by FXR in vascular smooth muscle cells

    SciTech Connect

    He Fengtian; Zhang Qiuhong; Kuruba, Ramalinga; Gao Xiang; Li Jiang; Li Yong; Gong Wei; Jiang, Yu; Xie Wen; Li Song

    2008-08-08

    Decorin is a member of the family of small leucine-rich proteoglycans that are present in blood vessels and synthesized by vascular smooth muscle cells (VSMCs). Decorin plays complex roles in both normal vascular physiology and the pathogenesis of various types of vascular disorders. However, the mechanisms of regulation of decorin expression in vasculature are not clearly understood. Particularly little information is available about a role of nuclear receptors in the regulation of decorin expression. In the present study, we report that activation of vascular FXR by a specific ligand resulted in upregulation of decorin at the levels of both mRNA and protein. FXR appears to induce decorin expression at a transcriptional level because (1) upregulation of decorin mRNA expression was abolished by the treatment of a transcription inhibitor, actinomycin D; and (2) decorin promoter activity was significantly increased by activation of FXR. Functional analysis of human decorin promoter identified an imperfect inverted repeat DNA motif, IR8 (-2313TGGTCAtagtgtcaTGACCT-2294), as a likely FXR-responsive element that is involved in decorin regulation.

  18. Upregulation of colonic ion channels in APC ( Min/+ ) mice.

    PubMed

    Ousingsawat, Jiraporn; Spitzner, Melanie; Schreiber, Rainer; Kunzelmann, Karl

    2008-08-01

    The adenomatous polyposis coli (APC) tumor suppressor gene is mutated in almost all human colonic cancers. Disturbances in Na(+) absorption have been observed in colonic cancer, and ion channels such as ether a go-go (Eag) or Ca(2+)-sensitive BK channels have been recognized for their oncogenic potential. APC ( Min/+ ) mice have reduced APC expression and develop multiple intestinal neoplasias (Min). Ion channels in the colonic epithelium were examined using electrophysiology and molecular techniques. APC ( Min/+ ) mice developed intestinal neoplasia and experienced a significant weight loss. Due to intestinal bleedings, the hematocrit was largely reduced and plasma aldosterone levels were enhanced. Rectal potential measurements in vivo indicated an increase in amiloride-sensitive Na(+) absorption in APC ( Min/+ ) mice. Quantitative Ussing chamber studies demonstrated enhanced Na(+) absorption via epithelial Na(+) channels (ENaC) and suggested enhanced activity of oncogenic BK and Eag-1 channels. Patch clamp and fluorescence measurements on isolated crypts suggested enhanced K(+) channel activity in the surface epithelium. ENaC-mRNA and membrane protein expression was enhanced in colonic surface epithelial cells. The data suggest that reduced expression of the APC gene with upregulation of the downstream proteins Akt and mTOR and subsequent hyperaldosteronism is paralleled by upregulation of oncogenic potassium channels and enhanced colonic Na(+) absorption. PMID:18247045

  19. Aberrant Upregulation of Astroglial Ceramide Potentiates Oligodendrocyte Injury

    PubMed Central

    Kim, SunJa; Steelman, Andrew J.; Zhang, Yumin; Kinney, Hannah C.; Li, Jianrong

    2015-01-01

    Oligodendroglial injury is a pathological hallmark of many human white matter diseases, including multiple sclerosis and periventricular leukomalacia. Critical regulatory mechanisms of oligodendroglia destruction, however, remain incompletely understood. Ceramide, a bioactive sphingolipid pivotal to sphingolipid metabolism pathways, regulates cell death in response to diverse stimuli and has been implicated in neurodegenerative disorders. We report here that ceramide accumulates in reactive astrocytes in active lesions of multiple sclerosis and periventricular leukomalacia, as well as in animal models of demyelination. Serine palmitoyltransferase, the rate-limiting enzyme for ceramide de novo biosynthesis, was consistently upregulated in reactive astrocytes in the cuprizone mouse model of demyelination. Mass spectrometry confirmed the upregulation of specific ceramides during demyelination and revealed a concomitant increase of sphingosine as well as a suppression of sphingosine-1-phosphate, a potent signaling molecule with key roles in cell survival and mitogenesis. Importantly, this altered sphingolipid metabolism during demyelination was restored upon active remyelination. In culture, ceramide acted synergistically with tumor necrosis factor leading to apoptotic death of oligodendroglia in an astrocyte-dependent manner. Taken together, our findings implicate that disturbed sphingolipid pathways in reactive astrocytes may indirectly contribute to oligodendroglial injury in cerebral white matter disorders. PMID:21615590

  20. HIV Infection Upregulates Caveolin 1 Expression To Restrict Virus Production?

    PubMed Central

    Lin, Shanshan; Wang, Xiao Mei; Nadeau, Peter E.; Mergia, Ayalew

    2010-01-01

    Caveolin 1 (Cav-1) is a major protein of a specific membrane lipid raft known as caveolae. Cav-1 interacts with the gp41 of the human immunodeficiency virus (HIV) envelope, but the role of Cav-1 in HIV replication and pathogenesis is not known. In this report, we demonstrate that HIV infection in primary human monocyte-derived macrophages (MDMs), THP-1 macrophages, and U87-CD4 cells results in a dramatic upregulation of Cav-1 expression mediated by HIV Tat. The activity of p53 is essential for Tat-induced Cav-1 expression, as our findings show enhanced phosphorylation of serine residues at amino acid positions 15 and 46 in the presence of Tat with a resulting Cav-1 upregulation. Furthermore, inhibition of p38 mitogen-activated protein kinase (MAPK) blocked phosphorylation of p53 in the presence of Tat. Infection studies of Cav-1-overexpressing cells reveal a significant reduction of HIV production. Taken together, these results suggest that HIV infection enhances the expression of Cav-1, which subsequently causes virus reduction, suggesting that Cav-1 may contribute to persistent infection in macrophages. PMID:20610713

  1. Up-regulation of metallothionein gene expression in parkinsonian astrocytes.

    PubMed

    Michael, Gregory J; Esmailzadeh, Sharmin; Moran, Linda B; Christian, Lynne; Pearce, Ronald K B; Graeber, Manuel B

    2011-11-01

    The role of glial cells in Parkinson's disease (PD) is unclear. We have previously reported a striking up-regulation of DnaJB6 heat shock protein in PD substantia nigra astrocytes. Whole genome transcriptome analysis also indicated increased expression of metallothionein genes in substantia nigra and cortex of sporadic PD cases. Metallothioneins are metal-binding proteins in the CNS that are released by astrocytes and associated with neuroprotection. Metallothionein expression was investigated in 18 PD cases and 15 non-PD controls using quantitative real-time polymerase chain reaction (qRT-PCR), in situ hybridisation (ISH) and immunocytochemistry (ICC). We observed a strong increase in the expression of metallothioneins MT1E, MT1F, MT1G, MT1H, MT1M, MT1X and MT2A in both PD nigra and frontal cortex. Expression of LRP2 (megalin), the neuronal metallothionein receptor was also significantly increased. qRT-PCR confirmed metallothionein up-regulation. Astrocytes were found to be the main source of metallothioneins 1 and 2 based on ISH results, and this finding was confirmed by ICC. Our findings demonstrate metallothionein expression by reactive astrocytes in PD nigra and support a neuroprotective role for these cells. The traditional view that nigral astrocytes are non-reactive in PD is clearly incorrect. However, it is possible that astrocytes are themselves affected by the disease process which may explain their comparatively modest and previously overlooked response. PMID:21800131

  2. FRZB up-regulated in hepatocellular carcinoma bone metastasis

    PubMed Central

    Huang, Jia; Hu, Wenhao; Lin, Xiangjin; Wang, Xuanwei; Jin, Ketao

    2015-01-01

    The clinical relevance of frizzled-related protein (FRZB) in hepatocellular carcinoma (HCC) bone metastasis remains uncertain. The aim of this study was to assess the clinical relationship of FRZB in patients with HCC bone metastasis after surgical resection. FRZB expression was evaluated by immunohistochemistry in formalin-fixed paraffin embedded (FFPE) HCC and paired bone metastasis tissues from 13 patients that underwent surgical resection. The clinical characteristics of 13 HCC patients with synchronous or metachronous bone metastasis received surgery were retrospectively reviewed. We found that FRZB was positive in 9 HCC tissues (69.2%) and in 11 paired bone metastatic tissues (84.6%) among these 13 paired samples. The expression of FRZB in the bone metastases was noticeably higher than that in the paired HCC tissues. The expression of FRZB was up-regulated in 10 (76.9%) paired bone metastases tissues. FRZB expression was up-regulated in HCC bone metastasis tissue, which suggested that FRZB might play a key role in the HCC bone metastasis. PMID:26722540

  3. Structure of the C-terminal domain of the catalase-peroxidase KatG from Escherichia coli.

    PubMed

    Carpena, Xavier; Melik-Adamyan, William; Loewen, Peter C; Fita, Ignacio

    2004-10-01

    Catalase-peroxidases or KatGs, the apparent in vivo activators of the anti-tubercular pro-drug isoniazid, are active as homodimers, each subunit having two distinct but sequence- and structure-related domains. The N-terminal domain contains the haem group and is catalytically active, while the C-terminal domain lacks the cofactor. The C-terminal domain of KatG from Escherichia coli is expressed as a soluble protein which has been crystallized in triclinic, orthorhombic and tetragonal crystal forms. Packing in the orthorhombic crystals, with eight molecules in the asymmetric unit, follows the pattern of commensurate modulated structures, which explains the diversity of pseudo-origin peaks observed in the native Patterson map. The different crystal forms arise from variations in the length and sequence of the N-terminal extensions in the different constructs. Despite the variability in the N-terminal region, the overall domain conformations beginning with Pro437 are very similar both to each other and to the C-terminal domains within the native structures of the KatGs from Haloarcula marismortui and Burkholderia pseudomallei. Some structural reorganization in the C-terminal domain relative to the N-terminal domain has evolved to compensate for the absence of the haem group. A high percentage of the residues in the C-terminal domains of KatG proteins from different sources are highly conserved and these residues are spread uniformly throughout the domain. The easily folded nature and retention of structure in the C-terminal domain suggests that it may serve as a platform for the folding of the N-terminal domain and for stabilization of the molecular dimer. PMID:15388929

  4. Human disease associated with "Campylobacter upsaliensis" (catalase-negative or weakly positive Campylobacter species) in the United States.

    PubMed Central

    Patton, C M; Shaffer, N; Edmonds, P; Barrett, T J; Lambert, M A; Baker, C; Perlman, D M; Brenner, D J

    1989-01-01

    Catalase-negative or weakly positive (CNW) thermotolerant campylobacteria, first isolated from dogs in 1983, were recently recognized as a new species, "Campylobacter upsaliensis," but their association with human illness has not been established. Twelve human isolates received at the Centers for Disease Control between 1980 and 1986 were identified as CNW campylobacteria by biochemical tests, cellular fatty acid composition, and antimicrobial susceptibility patterns. Eleven CNW Campylobacter strains tested by DNA-DNA hybridization (hydroxyapatite method) were all highly related and were related to two "C. upsaliensis" strains at the species level (86% under optimal conditions and 76% under stringent conditions). Clinical information was obtained for 11 human isolates from three stool and eight blood specimens. They were isolated from four female and seven male patients 6.5 months to 83 years of age residing in 10 different states. The patients had a wide spectrum of illnesses. The stool isolates were obtained from two previously healthy persons during episodes of acute gastroenteritis and from one immunocompromised patient with persistent diarrhea and fever. The blood isolates were obtained from two infants with fever and respiratory symptoms; a young woman with a ruptured ectopic pregnancy; three elderly men with underlying chronic diseases; and two immunocompromised adults. In a bactericidal assay to assess sensitivity to serum, seven of eight blood isolates showed some resistance to killing by pooled normal human serum. These observations suggest that "C. upsaliensis" is a potential human pathogen associated with both gastroenteritis and bacteremia in normal hosts and with opportunistic infection in immunocompromised individuals. PMID:2913038

  5. Effects of source and level of magnesium on catalase activity and its gene expression in livers of broiler chickens.

    PubMed

    Liu, Yongxiang; Guo, Yuming; Wang, Zhong; Nie, We

    2007-08-01

    The effects of dietary supplemental magnesium oxide (MgO), magnesium-L-aspartate (MgAsp) and monomagnesium-di-L-aspartate (MgdiAsp) on hepatic catalase (CAT) activity and its mRNA expression were investigated. A total of 360 one-day-old male Abor Acre broiler chickens were allocated to ten treatments, i.e. control plus 9 treatments from 3 x 3 factorial arrangement (Mg source, Mg level), each treatment with six replicates of 6 chickens. The birds were fed with the basal diet alone or supplemented with magnesium (Mg) at 0.9, 1.8, 2.7 g/kg of the diet from MgO, MgAsp or MgdiAsp. Results showed that hepatic Mg concentration increased quadratically as MgO or MgAsp supplementation increased (p < 0.01). Hepatic CAT activity increased linearly in birds fed with MgAsp or MgdiAsp (p < 0.01) and quadratically in birds fed with MgO (p < 0.05) as dietary Mg supplementation level increased. Hepatic CAT mRNA was linearly correlated with the dietary Mg supplementation level (p < 0.01). There were positive correlations among hepatic CAT activity, its mRNA expression level and hepatic Mg concentration (p < 0.01). No effect of Mg2+ on the purified CAT activity was detected in vitro enzymatic reaction system (p > 0.05). Supplemental MgAsp or MgdiAsp was more efficient to increase hepatic Mg concentrations, enhance hepatic CAT activity and its mRNA expression than MgO (p < 0.01). It can be concluded that dietary Mg supplementation could increase hepatic Mg concentration, enhance CAT mRNA expression and consequently enhance CAT activity, and the organic Mg (MgAsp or MgdiAsp) is much more efficient than the inorganic form (MgO). PMID:17760306

  6. Effects of total dissolved gas supersaturated water on lethality and catalase activity of Chinese sucker (Myxocyprinus asiaticus Bleeker)*

    PubMed Central

    Chen, Shi-chao; Liu, Xiao-qing; Jiang, Wen; Li, Ke-feng; Du, Jun; Shen, Dan-zhou; Gong, Quan

    2012-01-01

    Total dissolved gas (TDG) supersaturation caused by dam sluicing can result in gas bubble trauma (GBT) in fish and threaten their survival. In the present study, Chinese suckers (Myxocyprinus asiaticus Bleeker) were exposed to TDG supersaturated water at levels ranging from 120% to 145% for 48 h. The median lethal concentration (LC50) and the median lethal time (LT50) were determined to evaluate acute lethal effects on Chinese suckers. The results showed that the LC50 values of 4, 6, 8, and 10 h were 142%, 137%, 135%, and 130%, respectively. The LT50 values were 3.2, 4.7, 7.8, 9.2, and 43.4 h, respectively, when TDG supersaturated levels were 145%, 140%, 135%, 130%, and 125%. Furthermore, the biological responses in Chinese suckers were studied by assaying the catalase (CAT) activities in gills and muscles at the supersaturation level of 140% within LT50. The CAT activities in the gills and muscle tissues exhibited a regularity of a decrease after an increase. CAT activities in the muscles were increased significantly at 3/5LT50 (P<0.05) and then came back to the normal level. However, there were no significant differences between the treatment group (TDG level of 140%) and the control group (TDG level of 100%) on CAT activities in the gills before 3/5LT50 (P>0.05), but the activities were significantly lower than the normal level at 4/5LT50 and LT50 (P<0.05). PMID:23024046

  7. Effects of total dissolved gas supersaturated water on lethality and catalase activity of Chinese sucker (Myxocyprinus asiaticus Bleeker).

    PubMed

    Chen, Shi-chao; Liu, Xiao-qing; Jiang, Wen; Li, Ke-feng; Du, Jun; Shen, Dan-zhou; Gong, Quan

    2012-10-01

    Total dissolved gas (TDG) supersaturation caused by dam sluicing can result in gas bubble trauma (GBT) in fish and threaten their survival. In the present study, Chinese suckers (Myxocyprinus asiaticus Bleeker) were exposed to TDG supersaturated water at levels ranging from 120% to 145% for 48 h. The median lethal concentration (LC(50)) and the median lethal time (LT(50)) were determined to evaluate acute lethal effects on Chinese suckers. The results showed that the LC(50) values of 4, 6, 8, and 10 h were 142%, 137%, 135%, and 130%, respectively. The LT(50) values were 3.2, 4.7, 7.8, 9.2, and 43.4 h, respectively, when TDG supersaturated levels were 145%, 140%, 135%, 130%, and 125%. Furthermore, the biological responses in Chinese suckers were studied by assaying the catalase (CAT) activities in gills and muscles at the supersaturation level of 140% within LT(50). The CAT activities in the gills and muscle tissues exhibited a regularity of a decrease after an increase. CAT activities in the muscles were increased significantly at 3/5LT(50) (P<0.05) and then came back to the normal level. However, there were no significant differences between the treatment group (TDG level of 140%) and the control group (TDG level of 100%) on CAT activities in the gills before 3/5LT(50) (P>0.05), but the activities were significantly lower than the normal level at 4/5LT(50) and LT(50) (P<0.05). PMID:23024046

  8. High-performance liquid chromatography ultraviolet assay for human erythrocytic catalase activity by measuring glutathione as o-phthalaldehyde derivative.

    PubMed

    Bhmer, Anke; Jordan, Jens; Tsikas, Dimitrios

    2011-03-15

    The most frequently used catalase (CAT) activity assay is based on the spectrophotometric measurement of hydrogen peroxide (H(2)O(2)) absorbance decrease at 240 nm. Here we report an alternative high-performance liquid chromatography (HPLC) assay for human erythrocytic CAT (heCAT) activity measurement based on glutathione (GSH) analysis as a highly stable, H(2)O(2)-insensitive o-phthalaldehyde (OPA) derivative. The method was developed and validated using an isolated heCAT in phosphate-buffered saline at pH 7.4 and was applied to measure CAT activity in lysed human erythrocytes. heCAT activity was measured at initial concentrations of 5 nM for heCAT, 5mM for H(2)O(2), and 10mM for GSH, and the incubation time was 10 min. Nitrite (NO(2)(-)) was found to be an uncompetitive inhibitor of heCAT activity (IC(50)=9 ?M) and of CAT activity in hemolysate (IC(50)?750 ?M). Nitrate (NO(3)(-)) at concentrations up to 100 ?M did not inhibit heCAT activity. Azide (N(3)(-)) was found to be a very strong inhibitor of the heCAT (IC(50)=0.2 nM) but a relatively weak CAT inhibitor (IC(50)?10 ?M) in human hemolysates. The novel CAT activity assay works under redox conditions that more closely resemble those prevailing in cells and allows high-throughput analysis despite the required HPLC step. PMID:21094119

  9. Detection of Human Intestinal Catalase-Negative, Gram-Positive Cocci by rRNA-Targeted Reverse Transcription-PCR?

    PubMed Central

    Kubota, Hiroyuki; Tsuji, Hirokazu; Matsuda, Kazunori; Kurakawa, Takashi; Asahara, Takashi; Nomoto, Koji

    2010-01-01

    An analytical system based on rRNA-targeted reverse transcription-quantitative PCR (RT-qPCR) for enumeration of catalase-negative, Gram-positive cocci was established. Subgroup- or species-specific primer sets targeting 16S or 23S rRNA from Enterococcus, Streptococcus, and Lactococcus were newly developed. The RT-qPCR method using these primers together with the previously reported primer sets specific for the Enterococcus genus, the Streptococcus genus, and several Streptococcus species was found to be able to quantify the target populations with detection limits of 103 to 104 cells per gram feces, which was more than 100 times as sensitive as the qPCR method (106 to 108 cells per gram feces). The RT-qPCR analysis of fecal samples from 24 healthy adult volunteers using the genus-specific primer sets revealed that Enterococcus and Streptococcus were present as intestinal commensals at population levels of log10 6.2 1.4 and 7.5 0.9 per gram feces (mean standard deviation [SD]), respectively. Detailed investigation using species- or subgroup-specific primer sets revealed that the volunteers harbored unique Enterococcus species, including the E. avium subgroup, the E. faecium subgroup, E. faecalis, the E. casseliflavus subgroup, and E. caccae, while the dominant human intestinal Streptococcus species was found to be S. salivarius. Various Lactococcus species, such as L. lactis subsp. lactis or L. lactis subsp. cremoris, L. garvieae, L. piscium, and L. plantarum, were also detected but at a lower population level (log10 4.6 1.2 per gram feces) and prevalence (33%). These results suggest that the RT-qPCR method enables the accurate and sensitive enumeration of human intestinal subdominant but still important populations, such as Gram-positive cocci. PMID:20581195

  10. Roles of Mn-catalase and a possible heme peroxidase homologue in protection from oxidative stress in Thermus thermophilus.

    PubMed

    Ebihara, Akio; Manzoku, Miho; Fukui, Kenji; Shimada, Atsuhiro; Morita, Rihito; Masui, Ryoji; Kuramitsu, Seiki

    2015-07-01

    Hydrogen peroxide (H2O2) produces hydroxyl radicals that directly attack a variety of biomolecules and cause severe cellular dysfunction. An extremely thermophilic bacterium, Thermus thermophilus HB8, possesses at least three enzymes that can scavenge H2O2: manganese-containing catalase (TTHA0122, MnCAT), a possible peroxiredoxin homologue (TTHA1300), and a possible heme peroxidase (HPX) homologue (TTHA1714). To investigate the roles of these proteins, we attempted to disrupt each of these genes in T. thermophilus HB8. Although we were able to completely disrupt ttha1300, we were unable to completely delete ttha0122 and ttha1714 because of polyploidy. Quantitative real-time PCR showed that, compared to the wild type, 31 % of ttha0122 and 11 % of ttha1714 remained in the ?ttha0122 and ?ttha1714 disruption mutants, respectively. Mutants with reduced levels of ttha0122 or ttha1714 exhibited a significant increase in spontaneous mutation frequency. ?ttha1714 grew slower than the wild type under normal conditions. ?ttha0122 grew very poorly after exposure to H2O2. Moreover, ?ttha0122 did not show H2O2-scavenging activity, whereas ?ttha1300 and ?ttha1714 scavenged H2O2, a property similar to that exhibited by the wild type. MnCAT purified from T. thermophilus HB8 cells scavenged H2O2 in vitro. The recombinant form of the possible HPX homologue, reconstituted with hemin, showed peroxidase activity with H2O2 as an oxidant substrate. Based on these results, we propose that not only MnCAT but also the possible HPX homologue is involved in protecting the cell from oxidative stress in T. thermophilus. PMID:25997395

  11. [Application of visible/near-infrared spectroscopy to the determination of catalase and peroxidase content in barley leaves].

    PubMed

    Zhao, Yun; Zhang, Chu; Liu, Fei; Kong, Wen-Wen; He, Yong

    2014-09-01

    Visible/near-infrared spectroscopy was applied to determine the content of catalase (CAT) and peroxidase (POD) in barley leaves under the herbicide stress of propyl 4-(2-(4, 6-dimethoxypyrimidin-2-yloxy) benzylamino) benzoate (ZJ0273). The spectral data of the barley leaves in the range of 500-900 nm were preprocessed by moving average with 11 points. Seven outlier samples for CAT and 8 outlier samples for POD were detected and removed by Monte Carlo-partial least squares (MCPLS). PLS, least-squares support vector machine (LS-SVM) and extreme learning machine (ELM) models were built for both CAT and POD. ELM model obtained best results for CAT, with correlation coefficient of calibration (Rc) of 0.916 and correlation co-efficient of prediction (Rp) of 0.786. PLS model obtained best prediction results for POD, with Rc of 0.984 and Rp of 0.876. Successive projections algorithm (SPA) was applied to select 8 and 19 effective wavelengths for CAT and POD, respectively. PLS, LS-SVM and ELM models were built using the selected effective wavelengths of CAT and POD. ELM model performed best for CAT and POD prediction, with Rc of 0.928 and Rp of 0.790 for CAT and Rp of 0.965 and Rp of 0.941 for POD. The prediction results using the full spectral data and the effective wavelengths were quite close, and the prediction performance for POD was much better than the prediction performance for CAT, and the studies should be further explored to build more precise and more robust models for CAT and POD determination. The overall results indicated that it was feasible to use visible/near-infrared spectroscopy for CAT and POD content determination in barley leaves under the stress of ZJ0273. PMID:25532330

  12. Gluconic acid production in bioreactor with immobilized glucose oxidase plus catalase on polymer membrane adjacent to anion-exchange membrane.

    PubMed

    Godjevargova, Tzonka; Dayal, Rajeshwar; Turmanova, Sevdalina

    2004-10-20

    Gluconic acid was obtained in the permeate side of the bioreactor with glucose oxidase (GOD) immobilized onto anion-exchange membrane (AEM) of low-density polyethylene grafted with 4-vinylpiridine. The electric resistance of the anion-exchange membranes was increased after the enzyme immobilization on the membrane. The gluconic acid productions were relatively low with the GOD immobilized by any method on the AEM. To increase the enzyme reaction efficiency, GOD was immobilized on membrane of AN copolymer (PAN) adjacent to an anion-exchange membrane in bioreactor. Uses of anion-exchange membrane led to selective removal of the gluconic acid from the glucose solution and reduce the gluconic acid inhibition. The amount of gluconic acid obtained in the permeate side of the bioreactor with the GOD immobilized on the PAN membrane adjacent to the AEM under electrodialysis was about 30 times higher than that obtained with enzyme directly bound to the AEM. The optimal substrate concentration in the feed side was found to be about 1 g/l. Further experiments were carried out with the co-immobilized GOD plus Catalase (CAT) on the PAN membrane adjacent to the AEM to improve the efficiency of the immobilize system. The yield of this process was at least 95%. The storage stability of the co-immobilized GOD and CAT was studied (lost 20% of initial activity for 90 d). The results obtained clearly showed the higher potential of the dual membrane bioreactor with GOD plus CAT bound to ultrafiltration polymer membrane adjacent to the AEM. Storage stability of GOD activity in GOD plus CAT immobilized on PAN//AEM membranes and on AEM. PMID:15497133

  13. 3{prime} UTR sequence-specific mRNA-protein complexes and the post-transcriptional regulation of catalase

    SciTech Connect

    Reimer, D.L.; Ott, R.N.; Singh, S.M.

    1994-09-01

    Recently, sequences in the 3{prime} untranslated region (3{prime} UTR) of some genes have been recognized which may play an important role in the post-transcriptional regulation of gene expression. Mutations in this region of the gene are known to cause at least two diseases including myotonic dystrophy and a lysosomal accumulation disease. The mechanism is thought to involve mRNA-protein interactions that affect translation and/or mRNA stability. Reports of this nature are not common and the significance of the often large 3{prime} UTR on the regulation of gene expression remains speculative. Studies on the 3{prime} UTR mRNA-protein interactions in model eukaryotic genes therefore are critical to better understand the molecular mechanisms involved in post-transcriptional gene regulation. Mouse catalase, encoded by Cas-1, was used as a model to characterize the molecular mechanisms of post-transcriptional gene regulation. The 3{prime} UTR (752 bp) of Cas-1 contains three unusual, near repeats [(CA){sub 31}, (U){sub 15} and (TGTGC){sub 7}]. Gel mobility shift assays using {sup 32}P-labelled transcripts which contain these sequences and tissue homogenates from various sources identified mRNA-protein complexes specific to (CA){sub 31} and (U){sub 15} only. In all strains analyzed, a single protein of 69 kDa which was involved in the (CA){sub 31} complex, was observed in most tissues except lung and was localized to the polysomal fraction. Similarly, two proteins involved in the (U){sub 15} complex, 38 and 47 kDa, were observed in all tissues and strains studied. Only the 38 kDa protein was observed in the polysomal fraction. The results argue for a possible role for these 3{prime} UTR mRNA-binding protein complexes in the post-transcriptional regulation of this antioxidant enzyme.

  14. Geniposide protects against acute alcohol-induced liver injury in mice via up-regulating the expression of the main antioxidant enzymes.

    PubMed

    Wang, Junming; Zhang, Yueyue; Liu, Ruixin; Li, Xiaobing; Cui, Ying; Qu, Lingbo

    2015-04-01

    Geniposide (GP) is one of main compounds in Gardenia jasminoides Ellis, with both medicinal and nutritional value. This study was designed to determine, for the first time, how GP from G. jasminoides protects against acute alcohol-induced liver injury, and the underlying mechanisms. Mice were orally administered alcohol (6.0 g/kg body mass) 2 h after intragastric administration of GP and bifendate, every day for 7 continuous days. Six hours after the alcohol was administered, levels of serum alanine/aspartate transaminase (ALT/AST), hepatic lipid peroxidation (LPO), glutathione (GSH), glutathione-S-transferase (GST), glutathione peroxidase (GPx), copper- and zinc-containing superoxide dismutase (CuZn-SOD), and catalase (CAT), and mRNA expression of CuZn-SOD and CAT were assayed. The results demonstrated that GP (20.0, 40.0, or 80 mg/kg) significantly reversed the excessive, alcohol-induced elevation in both serum ALT/AST and hepatic LPO levels. Moreover, hepatic GSH, GST, GPx, CuZn-SOD, and CAT levels were all decreased in the alcohol-treated mice, whereas treatment with GP reversed these decreases. Further analysis indicated that hepatic mRNA expression of CuZn-SOD and CAT in the alcohol-treated mice was significantly down-regulated, whereas GP up-regulated such decreases. Taken together, this study shows that GP protects against acute alcohol-induced liver injury via up-regulating the expression of the main antioxidant enzymes, and thus ameliorates alcohol-induced oxidative stress injury in the liver. PMID:25730420

  15. Triadimefon pretreatment protects newly assembled membrane system and causes up-regulation of stress proteins in salinity stressed Amaranthus lividus L. during early germination.

    PubMed

    Bhattacharjee, Soumen

    2008-09-01

    Imposition of salinity stress during early germination imposes a secondary oxidative stress in 120-hr-old Amaranthus lividus seedlings (measured in terms of accumulation of reactive oxygen species, antioxidative defense system and oxidative membrane lipid and protein damages). Seeds of Amaranthus when treated with triadimefon along with NaCI salinity significantly enhanced the activities of catalase, peroxidase and superoxide dismutase, compared to untreated salinity stressed 5-day-old seedlings. Triadimefon treatment also reduced the accumulation of both the ROS (H2O2 and O2*-) in 5-day-old Amaranthus seedlings. When oxidative membrane damages were estimated for triadimefon treated and salinity stressed juvenile seedlings and compared with untreated salinity stressed seedlings, it shows a clear reversal in oxidative membrane damages induced by triadimefon under salinity stress. Triadimefon treatment significantly reduces the membrane lipid peroxidation and the loss of membrane protein thiol level in salinity stressed Amaranthus seedlings. That triadimefon treatment under salinity stress restores the membrane integrity and improves the post-germinative seedling growth could be supported by the data of membrane injury index (MII), relative leakage ratio (RLR), membrane permeability status (MPS), relative growth index (RGI) and mean tolerance index (MTI). SDS-PAGE of total extractible proteins revealed that some new proteins were synthesized in triadimefon treated and salinity stressed seedlings as compared to untreated and salinity stressed one. However the most remarkable feature is the up-regulation of some of the stress proteins in triadimefon treated and salinity stressed seedlings. So, it appears that significant extent of salinity tolerance exhibited by triadimefon pretreated Amaranthus seedlings could be related to the mitigation of oxidative damage to the newly assembled membrane system of juvenile tissues as well as synthesis and up-regulation of stress proteins that enhanced salinity tolerance. PMID:19295087

  16. Role of Biological Characteristics of Staphylococcus epidermidis in Intraerythrocytic Invasion and in Modulation of Erythrocyte Catalase and Superoxide Dismutase Activities in Experimental Generalized Infection.

    PubMed

    Shchuplova, E A; Stadnikov, A A; Fadeev, S B

    2015-05-01

    Studies on mouse model of generalized Staphylococcus epidermidis infection have demonstrated that erythrocytes more often contained microorganisms with pronounced antihemoglobin activity and less frequently with hemolytic activity. Infection with S. epidermidis strains characterized by pronounced hemolytic or antihemoglobin activities was associated with inhibition of erythrocyte catalase and superoxide dismutase activities in all cases, except infection with strains with high antihemoglobin activity, when superoxide dismutase activity increased. PMID:26033594

  17. The role played by acid and basic centers in the activity of biomimetic catalysts of the catalase, peroxidase, and monooxidase reactions

    NASA Astrophysics Data System (ADS)

    Magerramov, A. M.; Nagieva, I. T.

    2010-11-01

    The acid-basic centers of heterogeneous carriers of catalase, peroxidase, and monooxigenase biomimetics, in particular, iron protoporphyrin deposited on active or neutral aluminum magnesium silicate, were studied. The catalytic activity of biomimetics was stabilized, which allowed us not only to synthesize fairly effective biomimetics but also to clarify certain details of the mechanism of their action and perform a comparative analysis of the functioning of biomimetics and the corresponding enzymes.

  18. Isolation and characterization of a catalase gene "HuCAT3" from pitaya (Hylocereus undatus) and its expression under abiotic stress.

    PubMed

    Nie, Qiong; Gao, Guo-Li; Fan, Qing-jie; Qiao, Guang; Wen, Xiao-Peng; Liu, Tao; Peng, Zhi-Jun; Cai, Yong-Qiang

    2015-05-25

    Abiotic stresses usually cause H2O2 accumulation, with harmful effects, in plants. Catalase may play a key protective role in plant cells by detoxifying this excess H2O2. Pitaya (Hylocereus undatus) shows broad ecological adaptation due to its high tolerance to abiotic stresses, e.g. drought, heat and poor soil. However, involvement of the pitaya catalase gene (HuCAT) in tolerance to abiotic stresses is unknown. In the present study, a full-length HuCAT3 cDNA (1870 bp) was isolated from pitaya based on our previous microarray data and RACE method. The cDNA sequence and deduced amino acid sequence shared 73-77% and 75-80% identity with other plant catalases, respectively. HuCAT3 contains conserved catalase family domain and catalytic sites. Pairwise comparison and phylogenetic analysis indicated that HuCAT3 is most similar to Eriobotrya japonica CAT, followed by Dimocarpus longan CAT and Nicotiana tabacum CAT1. Expression profile analysis demonstrated that HuCAT3 is mainly expressed in green cotyledons and mature stems, and was regulated by H2O2, drought, cold and salt stress, whereas, its expression patterns and maximum expression levels varied with stress types. HuCAT activity increased as exposure to the tested stresses, and the fluctuation of HuCAT activity was consistent with HuCAT3 mRNA abundance (except for 0.5 days upon drought stress). HuCAT3 mRNA elevations and HuCAT activities changes under cold stress were also in conformity with the cold tolerances among the four genotypes. The obtained results confirmed a major role of HuCAT3 in abiotic stress response of pitaya. This may prove useful in understanding pitaya's high tolerance to abiotic stresses at molecular level. PMID:25752288

  19. Environmental Lead Exposure, Catalase Gene, and Markers of Antioxidant and Oxidative Stress Relation to Hypertension: An Analysis Based on the EGAT Study

    PubMed Central

    Kaojarern, Sukhumpun; Chanprasertyothin, Suwannee; Panpunuan, Pachara; Petchpoung, Krittaya; Tatsaneeyapant, Aninthita; Yoovathaworn, Krongtong; Sura, Thunyachai; Kaojarern, Sming; Sritara, Piyamit

    2015-01-01

    Lead has been linked to the development of hypertension via oxidative stress. Catalase plays an important role in the disposal of hydrogen peroxide in erythrocyte and its activity was determined by CAT gene. The aims of this study were to investigate (1) the association between blood levels of antioxidant markers such as catalase, superoxide dismutase, glutathione, glutathione peroxidase, oxidative stress-marker (malondialdehyde), and blood lead level and (2) the influence of genetic polymorphism of CAT gene (rs769217) on change in blood pressure in general population of EGAT study project. This is a cross-sectional study of 332 normotensive, 432 prehypertensive, and 222 hypertensive male subjects. Hypertensive subjects had significantly higher blood lead level (5.28 μg/dL) compared to normotensive (4.41 μg/dL) and prehypertensive (4.55 μg/dL) subjects (P < 0.05). These significant findings are also found in MDA levels. Moreover, individuals with TT genotype in hypertensive group had significantly higher blood lead and MDA levels (6.06 μg/dL and 9.67 μmol/L) than those with CC genotype (5.32 μg/dL and 8.31 μmol/L, P < 0.05). Our findings suggested that decreased blood catalase activity in this polymorphism together with low level lead exposure induced lipid peroxidation may be responsible for hypertension. PMID:25793211

  20. Catellicoccus marimammalium gen. nov., sp. nov., a novel Gram-positive, catalase-negative, coccus-shaped bacterium from porpoise and grey seal.

    PubMed

    Lawson, Paul A; Collins, Matthew D; Falsen, Enevold; Foster, Geoffrey

    2006-02-01

    Two strains of an unknown Gram-positive, catalase-negative, facultatively anaerobic, coccus-shaped bacterium, originating from a porpoise and a grey seal, were characterized using phenotypic, biochemical and molecular phylogenetic methods. Chemical studies revealed the presence of a cell-wall murein based on L-lysine (type L-lys-gly-D-Asp) and a DNA G+C content of 38 mol%. Comparative 16S rRNA gene sequencing showed that this unidentified coccus-shaped organism formed a hitherto unknown subline closely related to, albeit distinct from, a number of other catalase-negative genera which included Enterococcus, Melissococcus, Tetragenococcus and Vagococcus. Other known Gram-positive, catalase-negative taxa were more distantly related. Tree-branching considerations and sequence divergence values of >6% with recognized taxa were indicative of this novel bacterium representing a separate genus. Based on phenotypic and phylogenetic evidence, it is proposed that this unknown bacterium, recovered from a porpoise and a grey seal, be classified as a novel genus and species, Catellicoccus marimammalium gen. nov., sp. nov. The type strain is M35/04/3T (=CCUG 49459T=CIP 108575T). PMID:16449452

  1. Environmental lead exposure, catalase gene, and markers of antioxidant and oxidative stress relation to hypertension: an analysis based on the EGAT study.

    PubMed

    Sirivarasai, Jintana; Kaojarern, Sukhumpun; Chanprasertyothin, Suwannee; Panpunuan, Pachara; Petchpoung, Krittaya; Tatsaneeyapant, Aninthita; Yoovathaworn, Krongtong; Sura, Thunyachai; Kaojarern, Sming; Sritara, Piyamit

    2015-01-01

    Lead has been linked to the development of hypertension via oxidative stress. Catalase plays an important role in the disposal of hydrogen peroxide in erythrocyte and its activity was determined by CAT gene. The aims of this study were to investigate (1) the association between blood levels of antioxidant markers such as catalase, superoxide dismutase, glutathione, glutathione peroxidase, oxidative stress-marker (malondialdehyde), and blood lead level and (2) the influence of genetic polymorphism of CAT gene (rs769217) on change in blood pressure in general population of EGAT study project. This is a cross-sectional study of 332 normotensive, 432 prehypertensive, and 222 hypertensive male subjects. Hypertensive subjects had significantly higher blood lead level (5.28 μg/dL) compared to normotensive (4.41 μg/dL) and prehypertensive (4.55 μg/dL) subjects (P < 0.05). These significant findings are also found in MDA levels. Moreover, individuals with TT genotype in hypertensive group had significantly higher blood lead and MDA levels (6.06 μg/dL and 9.67 μmol/L) than those with CC genotype (5.32 μg/dL and 8.31 μmol/L, P < 0.05). Our findings suggested that decreased blood catalase activity in this polymorphism together with low level lead exposure induced lipid peroxidation may be responsible for hypertension. PMID:25793211

  2. Fenton reaction-mediated fluorescence quenching of N-acetyl-L-cysteine-protected gold nanoclusters: analytical applications of hydrogen peroxide, glucose, and catalase detection.

    PubMed

    Deng, Hao-Hua; Wu, Gang-Wei; He, Dong; Peng, Hua-Ping; Liu, Ai-Lin; Xia, Xing-Hua; Chen, Wei

    2015-11-21

    Given the importance of hydrogen peroxide (H2O2) in many biological processes and its wide application in various industries, the demand for sensitive, accurate, and economical H2O2 sensors is high. In this study, we used Fenton reaction-stimulated fluorescence quenching of N-acetyl-L-cysteine-protected gold nanoclusters (NAC-AuNCs) as a reporter system for the determination of H2O2. After the experimental conditions were optimized, the sensing platform enabled the analysis of H2O2 with a limit of detection (LOD) as low as 0.027 ?M. As the glucose oxidase cascade leads to the generation of H2O2 and catalase catalyzes the decomposition of H2O2, these two biocatalytic procedures can be probed by the Fenton reaction-mediated quenching of NAC-AuNCs. The LOD for glucose was found to be 0.18 ?M, and the linear range was 0.39-27.22 ?M. The LOD for catalase was 0.002 U mL(-1), and the linear range was 0.01-0.3 U mL(-1). Moreover, the proposed sensing methods were successfully applied for human serum glucose detection and the non-invasive determination of catalase activity in human saliva, demonstrating their great potential for practical applications. PMID:26436146

  3. The peroxidase/catalase-like activities of MFe?O? (M=Mg, Ni, Cu) MNPs and their application in colorimetric biosensing of glucose.

    PubMed

    Su, Li; Qin, Wenjie; Zhang, Huige; Rahman, Zia Ur; Ren, Cuiling; Ma, Sudai; Chen, Xingguo

    2015-01-15

    MFe2O4 (M=Mg, Ni, Cu) magnetic nanoparticles (MNPs) were found to have catalytic activities similar to those of biological enzymes such as catalase and peroxidase. These nanomaterials, as bifunctional catalase/peroxidases (KatGs), not only could catalyze H2O2 to produce hydroxyl radicals, which oxidized peroxidase substrate to produce color, but also could catalyze the decomposition reaction of H2O2 into water and oxygen directly in the same condition through the catalase-like activity. And it was also found that the amount of generated hydroxyl radicals and oxygen was related to the concentration of MFe2O4 (M=Mg, Ni, Cu) MNPs. The peroxidase-like catalytic behavior of MFe2O4 MNPs was analyzed in detail. Under the optimized conditions, NiFe2O4 MNPs were used as a colorimetric biosensor for the detection of 9.410(-7)-2.510(-5) mol L(-1) glucose with a limit of detection (LOD) of 4.510(-7) mol L(-1). The sensor was successfully applied to glucose detection in urine sample. PMID:25127473

  4. Application of high-performance chromatographic and electrophoretic methods to the purification and characterization of glucose oxidase and catalase from Penicillium chrysogenum.

    PubMed

    Eriksson, K O; Kourteva, I; Yao, K Q; Liao, J L; Kilr, F; Hjertn, S; Chaga, G

    1987-06-26

    The high resolving power of the preparative and analytical high-performance chromatographic and electrophoretic methods recently developed in this laboratory for the separation of biopolymers has been demonstrated by the purification and characterization of glucose oxidase and catalase from Penicillium chrysogenum. Crude glucose oxidase was purified to homogeneity in one step by high-performance hydrophobic-interaction chromatography (HIC) on a pentylagarose column. Crude catalase was purified by a combination of HIC and high-performance anion-exchange chromatography on 3-diethylamino-2-hydroxypropylagarose. The homogeneity of the enzymes was monitored by high-performance electrophoresis and free zone electrophoresis. The pI values of these two enzymes determined by isoelectric focusing in the high-performance electrophoresis apparatus were 4.2 and 6.5, respectively. Their molecular weights were determined by high-performance molecular sieve chromatography on an agarose column. Glucose oxidase has a molecular weight of 175,000 and probably consists of two identical subunits, as sodium dodecyl sulphate polyacrylamide gel electrophoresis gave a molecular weight of around 72,000. The molecular weight of catalase, which is probably composed of non-identical subunits, as indicated by sodium dodecyl sulphate electrophoresis, is around 320,000. Some other characteristics of these two enzymes were also investigated, e.g., electrophoretic mobility, pH stability and optimum pH. PMID:3116021

  5. Protopanaxatriol Ginsenoside Rh1 Upregulates Phase II Antioxidant Enzyme Gene Expression in Rat Primary Astrocytes: Involvement of MAP Kinases and Nrf2/ARE Signaling.

    PubMed

    Jung, Ji-Sun; Lee, Sang-Yoon; Kim, Dong-Hyun; Kim, Hee-Sun

    2016-01-01

    Oxidative stress activates several intracellular signaling cascades that may have deleterious effects on neuronal cell survival. Thus, controlling oxidative stress has been suggested as an important strategy for prevention and/or treatment of neurodegenerative diseases. In this study, we found that ginsenoside Rh1 inhibited hydrogen peroxide-induced reactive oxygen species generation and subsequent cell death in rat primary astrocytes. Rh1 increased the expression of phase II antioxidant enzymes, such as heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1, superoxide dismutase-2, and catalase, that are under the control of Nrf2/ARE signaling pathways. Further mechanistic studies showed that Rh1 increased the nuclear translocation and DNA binding of Nrf2 and c-Jun to the antioxidant response element (ARE), and increased the ARE-mediated transcription activities in rat primary astrocytes. Analysis of signaling pathways revealed that MAP kinases are important in HO-1 expression, and act by modulating ARE-mediated transcriptional activity. Therefore, the upregulation of antioxidant enzymes by Rh1 may provide preventive therapeutic potential for various neurodegenerative diseases that are associated with oxidative stress. PMID:26759699

  6. Protopanaxatriol Ginsenoside Rh1 Upregulates Phase II Antioxidant Enzyme Gene Expression in Rat Primary Astrocytes: Involvement of MAP Kinases and Nrf2/ARE Signaling

    PubMed Central

    Jung, Ji-Sun; Lee, Sang-Yoon; Kim, Dong-Hyun; Kim, Hee-Sun

    2016-01-01

    Oxidative stress activates several intracellular signaling cascades that may have deleterious effects on neuronal cell survival. Thus, controlling oxidative stress has been suggested as an important strategy for prevention and/or treatment of neurodegenerative diseases. In this study, we found that ginsenoside Rh1 inhibited hydrogen peroxide-induced reactive oxygen species generation and subsequent cell death in rat primary astrocytes. Rh1 increased the expression of phase II antioxidant enzymes, such as heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1, superoxide dismutase-2, and catalase, that are under the control of Nrf2/ARE signaling pathways. Further mechanistic studies showed that Rh1 increased the nuclear translocation and DNA binding of Nrf2 and c-Jun to the antioxidant response element (ARE), and increased the ARE-mediated transcription activities in rat primary astrocytes. Analysis of signaling pathways revealed that MAP kinases are important in HO-1 expression, and act by modulating ARE-mediated transcriptional activity. Therefore, the upregulation of antioxidant enzymes by Rh1 may provide preventive therapeutic potential for various neurodegenerative diseases that are associated with oxidative stress. PMID:26759699

  7. Prognostic implication of neuropilin-1 upregulation in human nasopharyngeal carcinoma

    PubMed Central

    2013-01-01

    Objective As a receptor for both vascular endothelial growth factors and semaphorin, neuropilin-1 (NRP-1) is reported to be up-regulated in cells of several cancers. However, its roles in human nasopharyngeal carcinoma (NPC) are still unclear. Therefore, the goal of this study was to investigate the expression pattern of NRP-1 in NPC tissues, to clarify the clinical significance of NRP-1 expression in NPC as well as the potential prognostic implication of NRP-1 expression. Methods Immunohistochemistry was performed to detect the expression of NRP-1 in tumor tissue samples from 266 NPC patients. The association of NRP-1 protein expression with the clinicopathological characteristics and the prognosis of NPC were subsequently assessed. Results Immunohistochemical analysis showed that 176 of 266 (66.17%) paraffin-embedded archival NPC biopsies showed high expression of NRP-1, but no non-cancerous nasopharyngeal specimens showed positive expression of NRP-1. In addition, high NRP-1 expression was significantly associated with advanced clinical stage (P?=?0.02), positive recurrence (P?=?0.001) and metastasis status (P?=?0.001) of NPC. Moreover, the NPC patients with higher NRP-1 expression had shorter overall survival, whereas patients with lower NRP-1 expression had better survival (P?upregulation may be a novel biomarker for the prediction of advanced tumor progression and unfavorable prognosis in NPC patients who may benefit from alternative treatment strategy and targeted treatment. Virtual slides The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1507827881105018. PMID:24053763

  8. Upregulation of Phosphodiesterase type 5 in the Hyperplastic Prostate

    PubMed Central

    Zhang, Wenhao; Zang, Ning; Jiang, Yaoming; Chen, Ping; Wang, Xinghuan; Zhang, Xinhua

    2015-01-01

    Both erectile dysfunction (ED) and lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) are common in the aging male. Numerous clinical trials have demonstrated the efficacy and safety of phosphodiesterase type 5 inhibitors (PDE5-Is) for treating LUTS/BPH with/without ED. However, the influence of BPH on prostatic PDE5 expression has never been studied. A testosterone-induced rat model of BPH was developed and human hyperplastic prostate specimens were harvested during cystoprostatectomy. PDE5, nNOS, eNOS and α1-adrenoreceptor subtypes (α1aARs, α1bARs and α1dARs) were determined with real-time RT-PCR for rat tissues whilst PDE5 and α1-adrenoreceptor subtypes were determined in human samples. PDE5 was further analyzed with Western-blot and histological examination. Serum testosterone was measured with ELISA. The rat BPH model was validated as having a significantly enlarged prostate. PDE5 localized mainly in fibromuscular stroma in prostate. Our data showed a significant and previously undocumented upregulation of PDE5 in both rat and human BPH, along with increased expression of nNOS and α1dARs for rat tissues and α1aARs for human BPH. The upregulation of PDE5 in the hyperplastic prostate could explain the mechanism and contribute to the high effectiveness of PDE5-Is for treating LUTS/BPH. Fibromuscular stroma could be the main target for PDE5-Is within prostate. PMID:26657792

  9. Lactobacillus acidophilus upregulates intestinal NHE3 expression and function

    PubMed Central

    Singh, Varsha; Raheja, Geetu; Borthakur, Alip; Kumar, Anoop; Gill, Ravinder K.; Alakkam, Anas; Malakooti, Jaleh

    2012-01-01

    A major mechanism of electroneutral NaCl absorption in the human ileum and colon involves coupling of Na+/H+ and Cl−/HCO3− exchangers. Disturbances in these mechanisms have been implicated in diarrheal conditions. Probiotics such as Lactobacillus have been indicated to be beneficial in the management of gastrointestinal disorders, including diarrhea. However, the molecular mechanisms underlying antidiarrheal effects of probiotics have not been fully understood. We have previously demonstrated Lactobacillus acidophilus (LA) to stimulate Cl−/HCO3− exchange activity via an increase in the surface levels and expression of the Cl−/HCO3− exchanger DRA in vitro and in vivo. However, the effects of LA on NHE3, the Na+/H+ exchanger involved in the coupled electroneutral NaCl absorption, are not known. Current studies were, therefore, undertaken to investigate the effects of LA on the function and expression of NHE3 and to determine the mechanisms involved. Treatment of Caco2 cells with LA or its conditioned culture supernatant (CS) for 8–24 h resulted in a significant increase in Na+/H+ exchange activity, mRNA, and protein levels of NHE3. LA-CS upregulation of NHE3 function and expression was also observed in SK-CO15 cells, a human colonic adenocarcinoma cell line. Additionally, LA treatment increased NHE3 promoter activity, suggesting involvement of transcriptional mechanisms. In vivo, mice gavaged with live LA showed significant increase in NHE3 mRNA and protein expression in the ileum and colonic regions. In conclusion, LA-induced increase in NHE3 expression may contribute to the upregulation of intestinal electrolyte absorption and might underlie the potential antidiarrheal effects of probiotics. PMID:23086913

  10. Effects of aluminum sulphate and citric acid ingestion on lipid peroxidation and on activities of superoxide dismutase and catalase in cerebral hemisphere and liver of developing young chicks.

    PubMed

    Swain, C; Chainy, G B

    1998-10-01

    Effect of oral administration of aluminum sulphate (200 and 400 mg/kg body wt/day) without or with citric acid (62 mg/kg body wt/day) to day-old White Leghorn male chicks (n = 5 per group) for 30 days was studied on the activities of superoxide dismutase (SOD) and catalase, and level of lipid peroxidation in cerebral hemisphere and liver. A 400 mg dose of Al in the presence of citric acid inhibited cytosolic total and CN -sensitive superoxide dismutase activities of the cerebral hemisphere in 7- and 30-day treated chicks, whereas in 15-day treated chicks the enzyme activities were decreased in response to both doses in the presence of citric acid. In case of liver, activities of these enzymes significantly decreased after 7, 15 and 30 days of treatment with 200 and 400 mg Al together with citric acid, whereas 400 mg Al alone inhibited the enzyme activities after 15 and 30 days of treatment. Cerebral catalase activity decreased in response to 400 mg Al when the chicks were also fed with citric acid for 7 and 30 days, but in 15-day treated chicks the enzyme activity was depleted following treatment with 200 and 400 mg Al combined with citric acid. 400 mg Al treatment for 7 days in combination with citric acid inhibited hepatic catalase activity and extension of the treatment period to 15 and 30 days also produced reduction in its activity even in response to the lower Al dose mixed with citric acid. CN -insensitive SOD activity of cerebral hemisphere and liver was unaffected by Al. Al also failed to induce lipid peroxidation in both the tissues throughout the course of exposure. Activities of SOD and catalase of cerebral hemisphere and liver of 30-day old chicks were observed to be inhibited by in vitro incubation with different concentrations of Al. Our in vivo study demonstrates that only CN -sensitive SOD is susceptible to Al. Further, responses of SOD and catalase to Al is tissue specific. The observed inhibition of antioxidant enzyme activities by Al is suggestive of a prooxidant state. Induction of such an oxidative condition of the tissues may be attributed to a direct effect of the metal on enzyme molecules or in their synthesis. PMID:9788754

  11. Simulated Microgravity Induces SOST/Sclerostin Upregulation in Osteocytes

    NASA Technical Reports Server (NTRS)

    Spatz, Jordan; Sibonga, Jean; Wu, Honglu; Barry, Kevin; Bouxsein, Mary; Pajevic, Paola Divieti

    2010-01-01

    Osteocytes are theorized to be the mechanosensors and transducers of mechanical forces in bone, yet the biological mechanism of this action remains elusive. Recent evidence suggests that SOST/Sclerostin is an important regulator of mechano-transduction. To investigate the molecular mechanisms of SOST/Sclerostin regulation under in-vitro and ex-vivo unloading we used the NASA Rotating Wall Vessel(RWV) Bioreactor. For in-vitro experiments, MLOY-4 osteocytic cells were seeded at a concentration of 250,000 cells onto 3D collagen scaffold (BD). Scaffolds (4 per condition) were either rotated in a vertical 50ml NASA/bioreactor vessel at 18 rpm (unloaded), cultured in a horizontal 50 ml NASA bioreactor vessel at 18 rpm (control for the sheared environment of vertical rotating vessel), or cultured in a static T-75 cm dish (static condition ) for 7days. For ex-vivo experiments, calvaria bones were harvested from 12-week old C57/Bl6 mice and sequentially digested with type I/II collagenase to remove periosteal osteoblasts. Calvaria halves (10 per condition) were then exposed to the same set of culture conditions described above. Simulated unloading, as achieved in the NASA RWV, resulted in enlarged, round osteocytes, as assessed by H&E staining, that was reminiscent of prior reports of unloading causing loss of osteocyte morphology and dendritic network connectivity. Semiquantitative realtime qPCR and immunohistochemistry from both in-vitro and ex-vivo RWV experiments demonstrated a four-fold up-regulation of SOST/Sclerostin. Furthermore, mRNA of the transcriptional SOST enhancer Mef2C was upregulated 1.4 fold in ex-vivo calvaria subjected to unloading conditions of the NASA RWV, suggesting that Mef2C might be an important regulator of mechano-sensation. These findings are consistent with results from seven day hindlimb unloading experiments, C57/B6 females, conducted in our laboratory and validate the use of the NASA RWV as a tool to study osteocyte mechanotransduction

  12. Inhibition of mitogen-activated protein kinase pathway can induce upregulation of human leukocyte antigen class I without PD-L1-upregulation in contrast to interferon-? treatment

    PubMed Central

    Mimura, Kousaku; Kua, Ley-Fang; Shiraishi, Kensuke; Kee Siang, Lim; Shabbir, Asim; Komachi, Mayumi; Suzuki, Yoshiyuki; Nakano, Takashi; Yong, Wei-Peng; So, Jimmy; Kono, Koji

    2014-01-01

    Recently, we reported that human leukocyte antigen (HLA) class I expression is predominantly regulated by the mitogen-activated protein kinase (MAPK) pathway as one of the oncogenic regulations of HLA class I expression. In the present study, we examined mechanisms of how HLA class I and PD-L1 are regulated by MAPK inhibitors and interferon-? (IFN-?). Furthermore, we evaluated the expression of major signal transduction molecules by Western blot and anti-tumor CTL activity by a cytotoxic assay when HLA class I and PD-L1 were modulated by MAPK inhibitors and/or IFN-?. As a result, we confirmed, as a more general phenomenon, that the inhibition of MAPK could upregulate HLA class I expression in a panel of human solid tumors (n=26). Of note, we showed that MAPK inhibitors act on the upregulation of HLA class I expression through a different pathway from IFN-?; there was an additive effect in the upregulation of HLA class I when treated with the combination of MAPK inhibitors and IFN-?, and there was no overlapping activation of JAK2/STAT1 and Erk1/2 molecules when treated with either IFN-? or MAPK inhibitors. Furthermore, we showed that IFN-?treatment impaired the tumor-specific CTL activity due to the upregulation of PD-L1 in spite of the upregulation of HLA class I, while MAPK inhibitors can augment the tumor-specific CTL activity due to the upregulated HLA class I without PD-L1 alterations. In conclusion, in addition to the original anti-proliferative activity, MAPK inhibitors may work toward the enhancement of T-cell-mediated anti-tumor immunity through the upregulation of HLA class I without the upregulation of PD-L1. PMID:25154680

  13. Upregulation of SIRT1 deacetylase in phenylephrine-treated cardiomyoblasts.

    PubMed

    Passariello, Catherine L; Zini, Maddalena; Nassi, Paolo A; Pignatti, Carla; Stefanelli, Claudio

    2011-04-15

    The sirtuin SIRT1 is an ubiquitous NAD(+) dependent deacetylase that plays a role in biological processes such as longevity and stress response. In cardiac models, SIRT1 is associated to protection against many stresses. However, the link between SIRT1 and heart hypertrophy is complex and not fully understood. This study focuses specifically on the response of SIRT1 to the α-adrenergic agonist phenylephrine in H9c2 cardiac myoblasts, a cell model of cardiac hypertrophy. After 24 and 48h of phenylephrine treatment, SIRT1 expression and deacetylase activity were significantly increased. SIRT1 upregulation by phenylephrine was not associated to changes in NAD(+) levels, but was blocked by inhibitors of AMP-activated Protein Kinase (AMPK) or by AMPK knockdown by siRNA. When SIRT1 was inhibited with sirtinol or downregulated by siRNA, H9c2 cell viability was significantly decreased following phenylephrine treatment, showing that SIRT1 improves cell survival under hypertrophic stress. We so then propose that the increase in SIRT1 activity and expression in H9c2 cells treated with phenylephrine is an adaptive response to the hypertrophic stress, suggesting that adrenergic stimulation of heart cells activates hypertrophic programming and at the same time also promotes a self-protecting and self-regulating mechanism. PMID:21414296

  14. Up-regulation of FGF23 release by aldosterone.

    PubMed

    Zhang, Bingbing; Umbach, Anja T; Chen, Hong; Yan, Jing; Fakhri, Hajar; Fajol, Abul; Salker, Madhuri S; Spichtig, Daniela; Daryadel, Arezoo; Wagner, Carsten A; Fller, Michael; Lang, Florian

    2016-02-01

    The fibroblast growth factor (FGF23) plasma level is high in cardiac and renal failure and is associated with poor clinical prognosis of these disorders. Both diseases are paralleled by hyperaldosteronism. Excessive FGF23 levels and hyperaldosteronism are further observed in Klotho-deficient mice. The present study explored a putative aldosterone sensitivity of Fgf23 transcription and secretion the putative involvement of the aldosterone sensitive serum & glucocorticoid inducible kinase SGK1, SGK1 sensitive transcription factor NF?B and store operated Ca(2+) entry (SOCE). Serum FGF23 levels were determined by ELISA in mice following sham treatment or exposure to deoxycorticosterone acetate (DOCA) or salt depletion. In osteoblastic UMR106cells transcript levels were quantified by qRT-PCR, cytosolic Ca(2+) concentration utilizing Fura-2-fluorescence, and SOCE from Ca(2+) entry following store depletion by thapsigargin. As a result, DOCA treatment and salt depletion of mice elevated the serum C-terminal FGF23 concentration. In UMR106cells aldosterone enhanced and spironolactone decreased SOCE. Aldosterone further increased Fgf23 transcript levels in UMR106cells, an effect reversed by mineralocorticoid receptor blockers spironolactone and eplerenone, SGK1 inhibitor EMD638683, NF?B-inhibitor withaferin A, and Ca(2+) channel blocker YM58483. In conclusion, Fgf23 expression is up-regulated by aldosterone, an effect sensitive to SGK1, NF?B and store-operated Ca(2+) entry. PMID:26773502

  15. Morphine upregulates kappa-opioid receptors of human lymphocytes.

    PubMed

    Suzuki, S; Chuang, T K; Chuang, L F; Doi, R H; Chuang, R Y

    2001-01-01

    Opioids such as morphine are potent analgesic and addictive compounds. Chronic morphine use also induces immunomodulatory and immunosuppressive effects, as especially evident in HIV-infected patients. Morphine acts on the immune cells primarily through its binding to mu-opioid receptors on the plasma membrane. However, morphine modulation of immune functions still exists in mu-opioid receptor knockout mice, suggesting that in addition to the mu opioid receptors, morphine may also act by mechanisms mediated by either delta or kappa opioid receptors. To determine whether morphine activates kappa opioid receptors (KOR), a quantitative competitive RT-PCR procedure was utilized to quantify the KOR gene expression of morphine-treated cells. A segment of KOR transcript spanning the second extracellular loop, which has the reported dynorphin specificity, and the seventh transmembrane domain of the receptor was amplified from the total RNA of morphine-treated CEM x174 lymphocytes, along with a competitor molecule. The competitor was constructed by deleting a 33-nucleotide fragment from KOR. The results of the competitive RT/PCR indicated that CEM x174 cells expressed KOR mRNA constitutively, in the order of femto-grams. Treatment of 10 microM of morphine resulted in the up-regulation of KOR gene expression 24 hr post-treatment. The observed morphine effect could be reversed by treating the cells with either naloxone (a KOR-partially selective antagonist) or nor-Binaltorphimine (a KOR-selective antagonist). PMID:11727785

  16. Upregulation of cortico-cerebellar functional connectivity after motor learning.

    PubMed

    Mehrkanoon, Saeid; Boonstra, Tjeerd W; Breakspear, Michael; Hinder, Mark; Summers, Jeffery J

    2016-03-01

    Interactions between the cerebellum and primary motor cortex are crucial for the acquisition of new motor skills. Recent neuroimaging studies indicate that learning motor skills is associated with subsequent modulation of resting-state functional connectivity in the cerebellar and cerebral cortices. The neuronal processes underlying the motor-learning-induced plasticity are not well understood. Here, we investigate changes in functional connectivity in source-reconstructed electroencephalography (EEG) following the performance of a single session of a dynamic force task in twenty young adults. Source activity was reconstructed in 112 regions of interest (ROIs) and the functional connectivity between all ROIs was estimated using the imaginary part of coherence. Significant changes in resting-state connectivity were assessed using partial least squares (PLS). We found that subjects adapted their motor performance during the training session and showed improved accuracy but with slower movement times. A number of connections were significantly upregulated after motor training, principally involving connections within the cerebellum and between the cerebellum and motor cortex. Increased connectivity was confined to specific frequency ranges in the mu- and beta-bands. Post hoc analysis of the phase spectra of these cerebellar and cortico-cerebellar connections revealed an increased phase lag between motor cortical and cerebellar activity following motor practice. These findings show a reorganization of intrinsic cortico-cerebellar connectivity related to motor adaptation and demonstrate the potential of EEG connectivity analysis in source space to reveal the neuronal processes that underpin neural plasticity. PMID:26767943

  17. Concordant utrophin upregulation in phenotypically discordant DMD/BMD brothers.

    PubMed

    Vainzof, Mariz; Feitosa, Leticia; Canovas, Marta; Ayub-Guerrieri, Danielle; Pavanello, Rita de Cássia M; Zatz, Mayana

    2016-03-01

    Utrophin expression was investigated in two phenotypically discordant Duchenne muscular dystrophy half-brothers. The youngest was wheelchair-bound at age 9, while his mildly affected older brother was able to walk without difficulties at age 15. DNA analysis revealed an out-of-frame exon 2 duplication in the DMD gene, associated with muscle dystrophin protein deficiency. Utrophin localization and quantity was analyzed and compared in both sibs to verify whether this could explain the milder phenotype of the older brother. Immunofluorescence analysis showed a clear sarcolemmal labeling for utrophin in both of them, which was present in regenerating as well as in mature fibers. On western blot analysis, utrophin amount was increased 3.4 and 3.3 fold respectively, as compared to normal controls, while it was increased 1.7 to 4.0 fold in a group of DMD patients within the typical range of clinical progression. These data are in accordance with our previous observations suggesting no correlation between phenotype severity and utrophin up-regulation or sarcolemmal localization in dystrophinopathies. Finding the protective mechanisms in patients with milder course is of utmost interest to direct therapeutic targets. PMID:26851826

  18. Ptpn22 Modifies Regulatory T Cell Homeostasis via GITR Upregulation.

    PubMed

    Nowakowska, Dominika J; Kissler, Stephan

    2016-03-01

    PTPN22 gene variation associates with multiple autoimmune diseases, including type 1 diabetes and rheumatoid arthritis. Loss of function studies have demonstrated that PTPN22 impinges on the homeostatic behavior of regulatory T (Treg) cells, a lineage critical for immune tolerance. The frequency and absolute number of Treg cells is increased in Ptpn22-deficient mice, but the mechanism driving this increase is unknown. In this study, we show that Ptpn22 knockdown (KD) promoted the expansion of the Treg cell compartment by upregulating the glucocorticoid-induced TNFR family-related protein (GITR) and increasing GITR signaling. Ptpn22 KD did not accelerate cell division but instead prolonged Treg cell survival, as measured by a decrease in the frequency of apoptotic Treg cells. Loss of Ptpn22 caused a concomitant increase in the proportion of CD44(hi)CD62L(lo) effector Treg cells, at the expense of CD44(lo)CD62L(hi) central Treg cells. The increase in Treg cell numbers, but not their differentiation toward an effector phenotype, was dependent on GITR signaling, because blockade of GITR ligand prevented Treg cell expansion caused by Ptpn22 KD. These findings indicate that GITR plays a key role in regulating the overall size of the Treg cell pool. Our results suggest that the size and composition of the Treg cell compartment are independently controlled and have implications for the design of immunotherapies that seek to improve Treg cell function. PMID:26810223

  19. PDGF upregulates CLEC-2 to induce T regulatory cells

    PubMed Central

    Agrawal, Sudhanshu; Ganguly, Sreerupa; Hajian, Pega; Cao, Jia-Ning; Agrawal, Anshu

    2015-01-01

    The effect of platelet derived growth factor (PDGF) on immune cells is not elucidated. Here, we demonstrate PDGF inhibited the maturation of human DCs and induced IL-10 secretion. Culture of PDGF-DCs with T cells induced the polarization of T cells towards FoxP3 expressing T regulatory cells that secreted IL-10. Gene expression studies revealed that PDGF induced the expression of C-type lectin like receptor member 2, (CLEC-2) receptor on DCs. Furthermore, DCs transfected with CLEC-2 induced T regulatory cells in DC-T cell co-culture. CLEC-2 is naturally expressed on platelets. Therefore, to confirm whether CLEC-2 is responsible for inducing the T regulatory cells, T cells were cultured with either CLEC-2 expressing platelets or soluble CLEC-2. Both conditions resulted in the induction of regulatory T cells. The generation of T regulatory cells was probably due to the binding of CLEC-2 with its ligand podoplanin on T cells, since crosslinking of podoplanin on the T cells also resulted in the induction of T regulatory cells. These data demonstrate that PDGF upregulates the expression of CLEC-2 on cells to induce T regulatory cells. PMID:26416420

  20. Ets-1 upregulation mediates angiotensin II-related cardiac fibrosis

    PubMed Central

    Hao, Guanghua; Han, Zhenhua; Meng, Zhe; Wei, Jin; Gao, Dengfeng; Zhang, Hong; Wang, Nanping

    2015-01-01

    Ets-1, the prototypical member of the family of Ets transcription factors, has been shown to participate in tissue fibrotic remodeling. However, its role in cardiac fibrosis has not been established. The aim of this study was to investigate the role of Ets-1 in profibrotic actions of angiotensin II (Ang II) in cardiac fibroblasts (CFs) and in the in vivo heart. In growth-arrested CFs, Ang II induced Ets-1 expression in a time- and concentration-dependent manner. Pretreatment with Ang II type 1 receptor blocker losartan, protein kinase C inhibitor bisindolylmaleimide I, extracellular signal-regulated kinase (ERK) inhibitor PD98059, or c-Jun NH(2)-terminal kinase (JNK) inhibitor SP600125 partly inhibited this induction accompanied with impaired cell proliferation and production of plasminogen activator inhibitor-1 (PAI-1) and connective tissue growth factor (CTGF) protein, the two downstream targets of Ets-1. Knockdown of Ets-1 by siRNA significantly inhibited the inductive effects of Ang II on cell proliferation and expression of CTGF and PAI-1. Moreover, the levels of Ets-1, PAI-1 and CTGF protein were simultaneously upregulated in left ventricle of Ang II-infused rats in parallel with an increase in the activation of ERK and JNK. Our data suggest that Ets-1 may mediate Ang II-induced cardiac fibrotic effects. PMID:26617730

  1. Polyethylene glycol-based low generation dendrimers functionalized with β-cyclodextrin as cryo- and dehydro-protectant of catalase formulations.

    PubMed

    Santagapita, Patricio R; Mazzobre, M Florencia; Cruz, Ariel García; Corti, Horacio R; Villalonga, Reynaldo; Buera, M Pilar

    2013-01-01

    Polyethylene glycol (PEG)-based low generation dendrimers are analyzed as single excipient or combined with trehalose in relation to their structure and efficiency as enzyme stabilizers during freeze-thawing, freeze-drying, and thermal treatment. A novel functional dendrimer (DGo -CD) based on the known PEG's ability as cryo-protector and β-CD as supramolecular stabilizing agent is presented. During freeze-thawing, PEG and β-CD failed to prevent catalase denaturation, while dendrimers, and especially DGo -CD, offered the better protection to the enzyme. During freeze-drying, trehalose was the best protective additive but DGo -CD provided also an adequate catalase stability showing a synergistic behavior in comparison to the activities recovered employing PEG or β-CD as unique additives. Although all the studied dendrimers improved the enzyme remaining activity during thermal treatment of freeze-dried formulations, the presence of amorphous trehalose was critical to enhance enzyme stability. The crystallinity of the protective matrix, either of PEG derivatives or of trehalose, negatively affected catalase stability in the freeze-dried systems. When humidified at 52% of relative humidity, the dendrimers delayed trehalose crystallization in the combined matrices, allowing extending the protection at those conditions in which normally trehalose fails. The results show how a relatively simple covalent combination of a polymer such as PEG with β-CD could significantly affect the properties of the individual components. Also, the results provide further insights about the role played by polymer-enzyme supramolecular interactions (host-guest crosslink, hydrogen bonding, and hydrophobic interactions) on enzyme stability in dehydrated models, being the effect on the stabilization also influenced by the physical state of the matrix. PMID:23596101

  2. Combustion products of 1,3-butadiene inhibit catalase activity and induce expression of oxidative DNA damage repair enzymes in human bronchial epithelial cells.

    PubMed

    Kennedy, Christopher H; Catallo, W James; Wilson, Vincent L; Mitchell, James B

    2009-10-01

    1,3-Butadiene, an important petrochemical, is commonly burned off when excess amounts need to be destroyed. This combustion process produces butadiene soot (BDS), which is composed of a complex mixture of polycyclic aromatic hydrocarbons in particulates ranging in size from <1 microm to 1 mm. An organic extract of BDS is both cytotoxic and genotoxic to normal human bronchial epithelial (NHBE) cells. Based on the oxidizing potential of BDS, we hypothesized that an organic extract of this particulate matter would (1) cause enzyme inactivation due to protein amino acid oxidation and (2) induce oxidative DNA damage in NHBE cells. Thus, our aims were to determine the effect of butadiene soot ethanol extract (BSEE) on both enzyme activity and the expression of proteins involved in the repair of oxidative DNA damage. Catalase was found to be sensitive to BDS as catalase activity was potently diminished in the presence of BSEE. Using Western analysis, both the alpha isoform of human 8-oxoguanine DNA glycosylase (alpha-hOGG1) and human apurinic/apyrimidinic endonuclease (APE-1) were shown to be significantly overexpressed as compared to untreated controls after exposure of NHBE cells to BSEE. Our results indicate that BSEE is capable of effectively inactivating the antioxidant enzyme catalase, presumably via oxidation of protein amino acids. The presence of oxidized biomolecules may partially explain the extranuclear fluorescence that is detected when NHBE cells are treated with an organic extract of BDS. Overexpression of both alpha-hOGG1 and APE-1 proteins following treatment of NHBE cells with BSEE suggests that this mixture causes oxidative DNA damage. PMID:18685817

  3. Relations between occupational exposure to coal mine dusts, erythrocyte catalase and Cu++/Zn++ superoxide dismutase activities, and the severity of coal workers' pneumoconiosis

    PubMed Central

    Nadif, R.; Bourgkard, E.; Dusch, M.; Bernadac, P.; Bertrand, J. P.; Mur, J. M.; Pham, Q. T.

    1998-01-01

    OBJECTIVES: To better understand the relations between occupational exposure, blood antioxidant enzyme activities, total plasma antioxidant concentration, and the severity of coal workers' pneumoconiosis (CWP). METHODS: Blood samples were obtained from miners without CWP exposed to low dust concentrations for > or = 4 years at the time of the study (n = 105), or exposed to high dust concentrations for > or = 14 years at the time of the study (n = 58), and from retired miners with CWP (n = 19). Miners without CWP were classified into three subgroups according to their estimated cumulative exposure to dust. Chest x ray films were obtained for each miner. Miners were classified in five subgroups according to their International Labour Organisation (ILO) profusion grades. Univariate tests were completed by multiple linear regression analyses. RESULTS: The estimated cumulative exposure to dust was strongly positively related to erythrocyte catalase activity and strongly negatively related to Cu++/Zn++ SOD activity only in miners exposed to high dust concentrations for > or = 14 years at the time of the study (F tests p = 0.006 and p = 0.004 respectively). Moreover, catalase activity was strongly related to the severity of CWP expressed as five subgroups of ILO profusion grades (F test p = 0.003); the greatest difference in the mean values was found between the group of 1/1 to 1/2 ILO profusion grades and the group of 2/1 to 3/3 ILO profusion grades. CONCLUSION: These results are in good agreement with the hypothesis that production of reactive oxygen species may be an important event in the exposure to coal mine dusts and the severity of CWP. Erythrocyte catalase and Cu++/Zn++ SOD activities are more closely related to recent exposure to high dust concentrations than to cumulative exposure, and could be considered as biological markers of exposure rather than as markers of early adverse biological effect. PMID:9849540

  4. Immobilization of catalase on electrospun PVA/PA6-Cu(II) nanofibrous membrane for the development of efficient and reusable enzyme membrane reactor.

    PubMed

    Feng, Quan; Zhao, Yong; Wei, Anfang; Li, Changlong; Wei, Qufu; Fong, Hao

    2014-09-01

    In this study, a mat/membrane consisting of overlaid PVA/PA6-Cu(II) composite nanofibers was prepared via the electrospinning technique followed by coordination/chelation with Cu(II) ions; an enzyme of catalase (CAT) was then immobilized onto the PVA/PA6-Cu(II) nanofibrous membrane. The amount of immobilized catalase reached a high value of 64 ± 4.6 mg/g, while the kinetic parameters (Vmax and Km) of enzyme were 3774 μmol/mg·min and 41.13 mM, respectively. Furthermore, the thermal stability and storage stability of immobilized catalase were improved significantly. Thereafter, a plug-flow type of immobilized enzyme membrane reactor (IEMR) was assembled from the PVA/PA6-Cu(II)-CAT membrane. With the increase of operational pressure from 0.02 to 0.2 MPa, the flux value of IEMR increased from 0.20 ± 0.02 to 0.76 ± 0.04 L/m(2)·min, whereas the conversion ratio of H2O2 decreased slightly from 92 ± 2.5% to 87 ± 2.1%. After 5 repeating cycles, the production capacity of IEMR was merely decreased from 0.144 ± 0.006 to 0.102 ± 0.004 mol/m(2)·min. These results indicated that the assembled IEMR possessed high productivity and excellent reusability, suggesting that the IEMR based on electrospun PVA/PA6-Cu(II) nanofibrous membrane might have great potential for various applications, particularly those related to environmental protection. PMID:25093534

  5. Evidence for an Ionic Intermediate in the Transformation of Fatty Acid Hydroperoxide by a Catalase-related Allene Oxide Synthase from the Cyanobacterium Acaryochloris marina*

    PubMed Central

    Gao, Benlian; Boeglin, William E.; Zheng, Yuxiang; Schneider, Claus; Brash, Alan R.

    2009-01-01

    Allene oxides are reactive epoxides biosynthesized from fatty acid hydroperoxides by specialized cytochrome P450s or by catalase-related hemoproteins. Here we cloned, expressed, and characterized a gene encoding a lipoxygenase-catalase/peroxidase fusion protein from Acaryochloris marina. We identified novel allene oxide synthase (AOS) activity and a by-product that provides evidence of the reaction mechanism. The fatty acids 18.4ω3 and 18.3ω3 are oxygenated to the 12R-hydroperoxide by the lipoxygenase domain and converted to the corresponding 12R,13-epoxy allene oxide by the catalase-related domain. Linoleic acid is oxygenated to its 9R-hydroperoxide and then, surprisingly, converted ∼70% to an epoxyalcohol identified spectroscopically and by chemical synthesis as 9R,10S-epoxy-13S-hydroxyoctadeca-11E-enoic acid and only ∼30% to the 9R,10-epoxy allene oxide. Experiments using oxygen-18-labeled 9R-hydroperoxide substrate and enzyme incubations conducted in H218O indicated that ∼72% of the oxygen in the epoxyalcohol 13S-hydroxyl arises from water, a finding that points to an ionic intermediate (epoxy allylic carbocation) during catalysis. AOS and epoxyalcohol synt