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PubMedDate not supplied

A new type 1 diabetes susceptibility locus containing the catalase gene (chromosome 11p13) in a Russian population.

BACKGROUND: Oxidative stress is involved in the origin of type 1 diabetes. Low efficiency of the scavenging antioxidant system has been shown to be related to the pathogenesis of the disease. This, therefore suggests that genes encoding catalase and other antioxidant enzymes may implicate in the development of type 1 diabetes. METHODS: Nine microsatellite markers that cover about 10 megabases around the catalase (CAT) gene on chromosome 11p13 were analyzed using polymerase chain reaction (PCR) and fluorescence-based genotyping on an automatic DNA sequencer. We also evaluated three single-nucleotide polymorphisms (SNP) within genes encoding catalase (T1667T and C(-262)T dimorphism) and ETS homologous factor (EHF) (C255T SNP) using a PCR-restriction fragment-length polymorphism approach. Multipont linkage analysis in 37 affected sibling pairs was performed using GENEHUNTER 2.1. We examined the markers for association with the disease by transmission disequilibrium tests in 57 discordant sibling pairs and by a case-control study in 258 unrelated healthy donors and 247 affected patients. RESULTS: We obtained close-to-suggestive evidence of linkage to type I diabetes, with the maximum linkage peak between markers D11S907 and D11S2008. Analysis of three SNPs at the CAT and EHF gene located within the region of maximum linkage showed that T1667T and C(-262)T markers of the CAT gene are strongly associated with the disease. CONCLUSION: Our findings support evidence of a new putative type 1 diabetes susceptibility locus on chromosome 11p13 and suggest that the CAT gene may play a role in conferring susceptibility to the disorder in Russian patients.

Adult↗
PubMed1987

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

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+.

Animals↗
PubMed2007

Inflammatory response to titanium surfaces with fibrinogen and catalase coatings: an in vitro study.

The aim of the present study was to evaluate the possibility to modulate the early inflammatory response in vitro by coating titanium surfaces with candidate proinflammatory (fibrinogen coated turned titanium "Fib") and antiinflammatory proteins (catalase on top of fibrinogen coated turned titanium "Cat"). Additionally, turned titanium surfaces (Ti) were used as controls. The discs were incubated with human mononuclear cells. Adhered cells were investigated with respect to number, viability, differentiation (acute marker 27E10 vs. chronic marker RM3/1), and cytokine production (TNF-alpha and IL-10), after 24 and 72 h. The results indicated that it is possible to modulate the inflammatory response with protein coatings. However, the strongest inflammatory response, indicated by increased number of adhered cells and release of pro and antiinflammatory mediators, was induced by Cat. Furthermore, the cytokine production on this surface was not sensitive to LPS stimulation. Differentiation measured as the expression of the chronic cell surface marker, dominated after 72 h for all surface modifications and Cat displayed an increased number compared to the others. A decrease in the total number of adhered cells and amounts of TNF-alpha were observed on all surfaces over time. The cell viability was, in general, high for all tested surfaces. In conclusion, the study proved it possible to influence the early inflammatory response in vitro by immobilizing protein coatings to titanium surfaces. However, the catalase surface demonstrated the strongest inflammatory response, and the possibility to selectively use the potent antiinflammatory capacity of catalase needs to be further evaluated.

Catalase↗
PubMed1992

Immunohistochemical identification of superoxide dismutases, catalase, and glutathione-S-transferases in rat femora.

We used light microscopic immunohistochemistry to locate manganese superoxide dismutase, copper zinc superoxide dismutase, catalase, and glutathione-S-transferases in demineralized femora from rats of 4-14 weeks of age. Immunoblots confirmed the specificity of the polyclonal antibodies for the rat proteins of interest. Each of the enzymes exhibited a unique staining pattern. Copper-zinc superoxide dismutase was detected within some articular and epiphyseal chondrocytes of younger animals. Manganese superoxide dismutase was detected within some articular and epiphyseal chondrocytes, within some osteoprogenitor cells and osteoblasts, within many osteoclasts, and within some vascular smooth muscle cells. Catalase was identified within articular chondrocytes, epiphyseal chondrocytes, and osteocytes, whereas staining at the periphery of hypertrophic chondrocytes suggested extracellular and/or cell membrane-associted catalase. Glutathione-S-transferases were detected within and at the periphery of epiphyseal and articular chondrocytes and less prominently within cortical osteocytes. There were no major age-related changes in antioxidant enzyme distribution.

Animals↗
PubMed2003

Catalase, but not MnSOD, inhibits glucose deprivation-activated ASK1-MEK-MAPK signal transduction pathway and prevents relocalization of Daxx: hydrogen peroxide as a major second messenger of metabolic oxidative stress.

Overexpression of catalase, but not manganese superoxide dismutase (MnSOD), inhibited glucose deprivation-induced cytotoxicity and c-Jun N-terminal kinase 1 (JNK1) activation in human prostate adenocarcinoma DU-145 cells. Suppression of JNK1 activation by catalase overexpression resulted from inhibition of apoptosis signal-regulating kinase 1 (ASK1) activation by preventing dissociation of thioredoxin (TRX) from ASK1. Overexpression of catalase also inhibited relocalization of Daxx from the nucleus to the cytoplasm as well as association of Daxx with ASK1 during glucose deprivation. Taken together, hydrogen peroxide (H(2)O(2)) rather than superoxide anion (O(2) (*-)) acts as a second messenger of metabolic oxidative stress to activate the ASK1-MAPK/extracellular signal-regulated kinase (ERK) kinase (MEK)-mitogen-activated protein kinase (MAPK) signal transduction pathway.

Adaptor Proteins, Signal Transducing↗
PubMedDate not supplied

Bcl-2 overexpression decreases BCNU sensitivity of a human glioblastoma line through enhancement of catalase activity.

The aim of this study was to evaluate the role of bcl-2 in 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) sensitivity of the ADFS human glioblastoma cell line in vitro and in vivo. To this end, the ADFS line expressing a low level of the bcl-2 protein was transfected with a bcl-2 expression vector. We found that bcl-2 overexpressing clones were less sensitive to in vitro BCNU treatment than the control clone. Cell cycle analysis demonstrated that while BCNU induced a consistent block in S/G2-M phases of the cell cycle in the control clone, it did not affect the cell cycle phase distribution of the two bcl-2 transfectants. The different sensitivity to BCNU was unrelated to the ability of bcl-2 to inhibit apoptosis, while bcl-2 appeared to protect bcl-2 transfectants from BCNU toxicity through an increase of catalase activity. The ability of the catalase inhibitor, sodium azide, to increase the BCNU sensitivity of the bcl-2 transfectants to levels of the BCNU-treated control clone substantiated the role of the catalase activity. The effect of bcl-2 in reducing sensitivity to BCNU was also confirmed by in vivo experiments. Xenografts of bcl-2 overexpressing tumors were less sensitive to BCNU treatment than xenografts originating from control cells.

Animals↗
PubMed2006

Cytoprotective effect of phloroglucinol on oxidative stress induced cell damage via catalase activation.

We investigated the cytoprotective effect of phloroglucinol, which was isolated from Ecklonia cava (brown alga), against oxidative stress induced cell damage in Chinese hamster lung fibroblast (V79-4) cells. Phloroglucinol was found to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydrogen peroxide (H(2)O(2)), hydroxy radical, intracellular reactive oxygen species (ROS), and thus prevented lipid peroxidation. As a result, phloroglucinol reduced H(2)O(2) induced apoptotic cells formation in V79-4 cells. In addition, phloroglucinol inhibited cell damage induced by serum starvation and radiation through scavenging ROS. Phloroglucinol increased the catalase activity and its protein expression. In addition, catalase inhibitor abolished the protective effect of phloroglucinol from H(2)O(2) induced cell damage. Furthermore, phloroglucinol increased phosphorylation of extracellular signal regulated kinase (ERK). Taken together, the results suggest that phloroglucinol protects V79-4 cells against oxidative damage by enhancing the cellular catalase activity and modulating ERK signal pathway.

Animals↗
PubMed1993

Cellular resistance to oxidative stress is accompanied by resistance to cisplatin: the significance of increased catalase activity and total glutathione in hydrogen peroxide-resistant fibroblasts.

Studies designed to better understand the involvement of cellular resistance to oxidative stress in mechanisms of cellular resistance to cisplatin were undertaken using H2O2-resistant variants of the HA1 Chinese hamster fibroblast cell line. H2O2-resistant cell lines were resistant to clonogenic inactivation mediated by cisplatin with dose modifying factors at 10% survival of 1.5-3.0, relative to HA1 cells. The most cisplatin resistant of these cell lines (OC5) also demonstrated fewer DNA-DNA crosslinks induced by cisplatin, relative to HA1. Since H2O2-resistant cells contained increased catalase activity as well as total glutathione (GSH) content, the involvement of these cellular antioxidants in the resistance to cisplatin toxicity was evaluated. Treatment of HA1 and H2O2-resistant cell lines (OC5, OC14) with 9 mM aminotriazole reduced catalase activity by 60-65% but had no effect on the cytotoxicity of cisplatin. In contrast, treatment with 5 mM buthionine sulfoximine reduced total GSH by 90% and sensitized the cells to cisplatin cytotoxicity. Furthermore, extracellular reaction of GSH with cisplatin prior to treating HA1 cells reduced the toxicity of the compound, indicating that this reaction is capable of participating in the detoxification of cisplatin. These results indicate that cellular adaptation to oxidative stress renders cells resistant to DNA damage as well as to cytotoxicity associated with cisplatin treatment. Furthermore, increases in total GSH content (but not catalase activity) appear to partially account for cisplatin resistance demonstrated by H2O2-resistant cells.

Animals↗
PubMed1980

Hepatic catalase in rats bearing Walker tumor in the brain.

Rats were injected with 10(5) cells of Walker carcinosarcoma 256 in ascites form into discrete areas of the brain (RAS, midbrain-hypothalamus, and anterior and posterior cortex), and at necropsy on the sixth day postoperation the animals were sacrificed, the brains were examined for tumors, and liver homogenates were analyzed for catalase content. The latter was significantly depressed in the tumor-bearing animals as compared to the corresponding saline-injected controls. The findings are of interest considering that the tumors were relatively small; however, they occupied significant areas of the entire brain. Although small or moderate body weight losses were encountered, the inhibitory effect was not due to inanition, a known depressant. Liver catalase was little altered in rats with solid tumors in the various brain areas originating from fragments measuring 1 mm3 and harvested from donors with intramuscular Walker tumor, as was also the case with tumor-free rats submitted to hypothalamic lesioning. Brain catalase levels were not affected by any of the treatments.

Animals↗
PubMed2005

High-field EPR investigations of Mn(III)Mn(IV) and Mn(II)Mn(III) states of dimanganese catalase and related model systems.

Multi-frequency EPR experiments at 9, 34 and 94 GHz are reported on the antiferromagnetically coupled mixed valence Mn(II)Mn(III) complex of manganese catalase and on several dinuclear manganese model systems. They are compared with similar experiments obtained earlier for the Mn(III)Mn(IV) states. It is demonstrated how accurate information on the G- and 55Mn hyperfine tensors can be derived from this approach. Furthermore, the effect of oxidation state, planarity of the manganese-oxygen core and the type of ligands bridging the manganese ions on the magnetic resonance parameters and the related electronic structure is investigated. 'Broken-symmetry' density functional calculations on two Mn(III)Mn(IV) complexes, including the superoxidized state of the catalase, are presented. The agreement between calculated and experimental EPR parameters and complex geometries is remarkably good. Implications of these results for the structure and function of the dimanganese catalase are discussed.

Anisotropy↗
PubMedDate not supplied

Determination of catalase-like activity in plants based on the amperometric monitoring of hydrogen peroxide consumption using a carbon paste electrode modified with ruthenium(IV) Oxide.

A carbon paste electrode containing ruthenium(IV) oxide as a modifier was tested as an effective hydrogen peroxide amperometric sensor in bulk measurements (hydrodynamic amperometry). Factors that influence its overall analytical perform ance, such as pH and the applied potential, were examined. The RuO2-modified electrode displayed high sensitivity towards hydrogen peroxide, with detection limits as low as 0.02 mm at pH 7.4 and 0.007 mM at pH 9.0. The method was applied for monitoring the decomposition of hydrogen peroxide (by catalase) in phosphate buffer of pH 7.4. The relative response of the electrode towards ascorbic acid was assessed and it was found that the selectivity of the RuO2-modified electrode towards hydrogen peroxide over ascorbic acid could be significantly improved by electro-polymerizing m-phenylenediamine on its surface prior to measurements. The RuO2-modified electrode was used for the kinetic (fixed time) determination of catalase activity in the range of 4-40 U/mL (detection limit 1.2 U/mL). The method was applied to the determination of catalase-like activity in various plant materials (recov-ery ranged from 93 to 101%, detection limit 480 U/100 g).

Biosensing Techniques↗
PubMed2001

Substrate flow in catalases deduced from the crystal structures of active site variants of HPII from Escherichia coli.

The active site of heme catalases is buried deep inside a structurally highly conserved homotetramer. Channels leading to the active site have been identified as potential routes for substrate flow and product release, although evidence in support of this model is limited. To investigate further the role of protein structure and molecular channels in catalysis, the crystal structures of four active site variants of catalase HPII from Escherichia coli (His128Ala, His128Asn, Asn201Ala, and Asn201His) have been determined at approximately 2.0-A resolution. The solvent organization shows major rearrangements with respect to native HPII, not only in the vicinity of the replaced residues but also in the main molecular channel leading to the heme distal pocket. In the two inactive His128 variants, continuous chains of hydrogen bonded water molecules extend from the molecular surface to the heme distal pocket filling the main channel. The differences in continuity of solvent molecules between the native and variant structures illustrate how sensitive the solvent matrix is to subtle changes in structure. It is hypothesized that the slightly larger H(2)O(2) passing through the channel of the native enzyme will promote the formation of a continuous chain of solvent and peroxide. The structure of the His128Asn variant complexed with hydrogen peroxide has also been determined at 2.3-A resolution, revealing the existence of hydrogen peroxide binding sites both in the heme distal pocket and in the main channel. Unexpectedly, the largest changes in protein structure resulting from peroxide binding are clustered on the heme proximal side and mainly involve residues in only two subunits, leading to a departure from the 222-point group symmetry of the native enzyme. An active role for channels in the selective flow of substrates through the catalase molecule is proposed as an integral feature of the catalytic mechanism. The Asn201His variant of HPII was found to contain unoxidized heme b in combination with the proximal side His-Tyr bond suggesting that the mechanistic pathways of the two reactions can be uncoupled.

Alleles↗
PubMed2006

Structural and dynamical properties of manganese catalase and the synthetic protein DF1 and their implication for reactivity from classical molecular dynamics calculations.

There is a pressing need for accurate force fields to assist in metalloprotein analysis and design. Recent work on the design of mimics of dimetal proteins highlights the requirements for activity. DF1 is a de novo designed protein, which mimics the overall fold and active site geometry of a series of diiron and dimanganese proteins. Specifically, the dimanganese form of DF1 is a mimic of the natural enzyme manganese catalase, which catalyzes the dismutation reaction of hydrogen peroxide into water and oxygen. During catalytic turnover, the active site has to accommodate both the reduced and the oxidized state of the dimanganese core. The biomimetic protein DF1 is only stable in the reduced form and thus not active. Furthermore, the synthetic protein features an additional bridging glutamate sidechain, which occupies the substrate binding site. The goal of this study is to develop classical force fields appropriate for design of such important dimanganese proteins. To this aim, we use a nonbonded model to represent the metal-ligand interactions, which implicitly takes into account charge transfer and local polarization effects between the metal and its ligands. To calibrate this approach, we compare and contrast geometric and dynamical properties of manganese catalase and DF1. Having demonstrated a good correspondence with experimental structural data, we examine the effect of mutating the bridging glutamate to aspartate (M1) and serine (M2). Classical MD based on the refined forcefield shows that these point mutations affect not only the immediate coordination sphere of the manganese ions, but also the relative position of the helices, improving the similarity to Mn-catalase, especially in case of M2. On the basis of these findings, classical molecular dynamics calculations with the active site parameterization scheme introduced herein seem to be a promising addition to the protein design toolbox.

Binding Sites↗
PubMed2004

Elemental sulfur: toxicity in vivo and in vitro to bacterial luciferase, in vitro yeast alcohol dehydrogenase, and bovine liver catalase.

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.

Alcohol Dehydrogenase↗
PubMed1993

tBOOH acts as a suicide substrate for catalase.

The effects of t-butyl hydroperoxide (tBOOH) on bovine liver catalase were investigated. tBOOH is accepted as a substrate of catalase and in the absence of hydrogen donors leads to a destruction of the enzyme via compound II formation. During the decomposition of this enzyme-substrate complex catalase serves as internal hydrogen donor which results in destruction of the enzyme. Evidence for this destruction is given by: a decrease of the Soret band in the uv/vis spectrum, iron release from the enzyme, decrease of the catalatic activity of the enzyme measured by oxygen release from hydrogen peroxide. Hydrogen donors like NADH and o-dianisidine have been found to protect the enzyme from destruction by tBOOH but lead to a structural alteration of the enzyme, shown by alteration of the electrophoretic mobility. In the presence of the hydrogen donor tBOOH is completely reduced to t-butanol, which is thought to proceed in a peroxidase-like reaction.

Catalase↗
PubMed1997

In vitro photoinactivation of catalase isoforms from cotyledons of sunflower (Helianthus annuus L.).

Catalase (EC 1.11.1.6) isoforms CAT 2 through CAT 8 were purified from peroxisomes of sunflower (Helianthus annuus L.) cotyledons and photoinactivated in vitro. Action and absorbance spectra between 380 and 727 nm wavelength showed most prominent maxima at 405 nm suggesting an inactivation mediated by light absorption of heme groups. First order kinetics of inactivation were observed for CAT 6 through CAT 8 (isoform group B), which are composed of four 55-kDa subunits. Inactivation constants ki depended on photon fluence rates in the studied range between 8.3 and 660 microE m(-2) s(-1). The maximal value of ki was about 4.0 h(-1), corresponding to a half-life of about 10 min. Heme groups and 55-kDa apoprotein moieties of group B isoforms were degraded during irradiation, but both degradation processes occurred at rates lower than those of inactivation. Quantitative evaluations contradicted the view that photoinactivation was caused by destruction or dissociation of heme but suggested apoprotein damage leading to the loss of activity. Group A isoforms CAT 2 through CAT 5, containing both 55- and 59-kDa subunits, were less photosensitive than the isoforms of group B. In addition, irradiated group A isoforms reached a low plateau of residual activity, whereas group B isoforms were inactivated completely. The 59-kDa subunits in group A isoforms were much more resistant to photodegradation than the 55-kDa subunits of group B isoforms and also much more resistant than their own 55-kDa cosubunits. Results presented here are compared with catalase photoinactivation and turnover in vivo and discussed with respect to a physiological significance of catalase isoforms in plant peroxisomes.

Animals↗
PubMed1993

Nitrite production by stimulated human polymorphonuclear leukocytes supplemented with azide and catalase.

The formation of nitric oxide by human phagocytes as measured by nitrite production is controversial. We report here that nitrite production by phorbol myristate acetate (PMA)-stimulated human polymorphonuclear leukocytes (PMN) is considerably increased by the addition of azide and a further increase occurs when catalase also is added. Nitrite production by the PMN-PMA-azide-catalase system is unaffected by superoxide dismutase or monomethylarginine but is markedly reduced by the substitution of chronic granulomatous disease for normal neutrophils. The stimulated neutrophils could be replaced by the H2O2-generating enzyme system glucose-glucose oxidase. These findings suggest that nitrite production does not, in this instance, reflect nitric oxide synthase activity by human neutrophils but rather the catalase-catalyzed conversion of azide to nitrite in the presence of H2O2 generated by the stimulated PMN.

Azides↗
PubMed1997

Transforming growth factor beta is a modulator of platelet-derived growth factor action in vascular smooth muscle cells: a possible role for catalase activity and glutathione peroxidase activity.

Transforming growth factor-beta (TGF-beta) has been implicated in mediating the growth of vascular smooth muscle cells (VSMCs) after vascular injury. In this study, we examined the mechanism underlying the growth-modulating effects of TGF-beta in confluent VSMCs. Stimulation of rat VSMC by TGF-beta decreased both their catalase activity and glutathione peroxidase activity in a dose-dependent manner. In mitogenesis assays using the confluent cells, TGF-beta was not a direct mitogen for VSMC, but potentiated the stimulatory effect of platelet-derived growth factor (PDGF)-BB. This enhancement of mitogenesis was blunted by the addition of the scavenging enzyme catalase or the chemical antioxidant N-acetyl-L-cysteine. In summary, TGF-beta enhances the mitogenic effect response of PDGF-BB, largely depending on the dysregulation of catalase activity and glutathione peroxidase activity by TGF-beta.

Animals↗