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Sample records for mn-superoxide dismutase single

  1. Radiation resistance and the CuZn superoxide dismutase, Mn superoxide dismutase, catalase, and glutathione peroxidase activities of seven human cell lines.

    PubMed

    Marklund, S L; Westman, N G; Roos, G; Carlsson, J

    1984-10-01

    CuZn superoxide dismutase, Mn superoxide dismutase, catalase, and glutathione peroxidase form the primary enzymic defense against toxic oxygen reduction metabolites in cells. To test the importance of these protective enzymes in the cellular radiation response, the enzymic activities of seven different human cell lines were determined in parallel with their clonogenic survival characteristics. A positive correlation between the content of glutathione peroxidase in cell lines and their extrapolation numbers (n) and quasithreshold doses (Dq) was detected. Between the cellular contents of the other enzymes and D0, n, and Dq no positive correlations could be established. An interesting finding was a very high Mn superoxide dismutase content in a malignant mesothelioma cell line P7, which had an extremely high D0, 5.0 Gy.

  2. The Mn-superoxide dismutase single nucleotide polymorphism rs4880 and the glutathione peroxidase 1 single nucleotide polymorphism rs1050450 are associated with aging and longevity in the oldest old.

    PubMed

    Soerensen, Mette; Christensen, Kaare; Stevnsner, Tinna; Christiansen, Lene

    2009-05-01

    The free radical theory of aging states that reactive oxygen species (ROS) play a key role in age-related accumulation of cellular damage, and consequently influence aging and longevity. Therefore, variation in genes encoding proteins protecting against ROS could be expected to influence variation in aging and life span. The rs4880 and rs1050450 SNPs in the manganese superoxide dismutase (MnSOD) and glutathione peroxidase 1 (GPX1) genes, respectively, are associated with age-related diseases and appear to affect the activities of the encoded variant proteins. In this study we genotyped these SNPs in 1650 individuals from the Danish 1905 cohort (follow-up time: 1998-2008, age at intake: 92-93 years, number of deaths: 1589 (96.3%)) and investigated the association with aging and longevity. We found decreased mortality of individuals holding either the MnSOD rs4880 C or the GPX1 rs1050450 T alleles (HR (MnSOD(CC/CT))=0.91, P=0, p=0.002 and HR (GPX1(TT/TC))=0.93, p=0.008). Furthermore, a synergetic effect of the alleles was observed (HR=0.76, p=0.001). Finally, moderate positive associations with good self rated health, decreased disability and increased cognitive capacity were observed. Our results thus indicate that genetic variation in MnSOD and GPX1 may be associated with aging and longevity.

  3. Structure and gene expression of the E. coli Mn-superoxide dismutase gene.

    PubMed Central

    Takeda, Y; Avila, H

    1986-01-01

    Superoxide dismutase is an enzyme which converts superoxide O2- to hydrogen peroxide. Using a single synthetic oligonucleotide 33mer, we screened the E. coli DNA library and isolated a clone containing the E. coli manganese-superoxide dismutase gene. We determined the DNA sequence. The analysis of the DNA sequence and in vivo as well as in vitro transcription has shown the following. The DNA sequence suggests two possible promoters. However, only one of them seems active during normal aerobic growth. Purified RNA polymerase initiates in vitro transcription from the same promoter. It is not clear whether the second promoter is functional. It is possible that this promoter could be activated under different growth conditions. There is an inverted repeat sequence which could form a stem-loop structure downstream of the translation stop codon TAA of the Mn-SOD gene. The results of the analysis of in vivo and in vitro RNA have shown that this is the transcription termination signal. Thus, the Mn-SOD gene constitutes a single gene operon. There is an almost perfect 19 base palindrome at the -35 region. The position and the size of the palindrome suggest that this could be a regulatory site. Images PMID:3520487

  4. Corroborative models of the cobalt(II) inhibited Fe/Mn superoxide dismutases.

    PubMed

    Scarpellini, Marciela; Wu, Amy J; Kampf, Jeff W; Pecoraro, Vincent L

    2005-07-11

    Attempting to model superoxide dismutase (SOD) enzymes, we designed two new N3O-donor ligands to provide the same set of donor atoms observed in the active site of these enzymes: K(i)Pr2TCMA (potassium 1,4-diisopropyl-1,4,7-triazacyclononane-N-acetate) and KBPZG (potassium N,N-bis(3,5-dimethylpyrazolylmethyl) glycinate). Five new Co(II) complexes (1-5) were obtained and characterized by X-ray crystallography, mass spectrometry, electrochemistry, magnetochemistry, UV-vis, and electron paramagnetic resonance (EPR) spectroscopies. The crystal structures of 1 and 3-5 revealed five-coordinate complexes, whereas complex 2 is six-coordinate. The EPR data of complexes 3 and 4 agree with those of the Co(II)-substituted SOD, which strongly support the proposition that the active site of the enzyme structurally resembles these models. The redox behavior of complexes 1-5 clearly demonstrates the stabilization of the Co(II) state in the ligand field provided by these ligands. The irreversibility displayed by all of the complexes is probably related to an electron-transfer process followed by a rearrangement of the geometry around the metal center for complexes 1 and 3-5 that probably changes from a trigonal bipyramidal (high spin, d7) to octahedral (low spin, d6) as Co(II) is oxidized to Co(III), which is also expected to be accompanied by a spin-state conversion. As the redox potentials to convert the Co(II) to Co(III) are high, it can be inferred that the redox potential of the Co(II)-substituted SOD may be outside the range required to convert the superoxide radical (O2*-) to hydrogen peroxide, and this is sufficient to explain the inactivity of the enzyme. Finally, the complexes reported here are the first corroborative structural models of the Co(II)-substituted SOD.

  5. Effects of oxidative stress on expression of extracellular superoxide dismutase, CuZn-superoxide dismutase and Mn-superoxide dismutase in human dermal fibroblasts.

    PubMed

    Strålin, P; Marklund, S L

    1994-03-01

    To determine the effect of oxidative stress on expression of extracellular superoxide dismutase (EC-SOD), CuZn-SOD and Mn-SOD, two fibroblast lines were exposed for periods of up to 4 days to a wide concentration range of oxidizing agents: xanthine oxidase plus hypoxanthine, paraquat, pyrogallol, alpha-naphthoflavone, hydroquinone, catechol, Fe2+ ions, Cu2+ ions, buthionine sulphoximine, diethylmaleate, t-butyl hydroperoxide, cumene hydroperoxide, selenite, citiolone and high oxygen partial pressure. The cell lines were cultured both under serum starvation and at a serum concentration that permitted growth. Under no condition was there any evidence of EC-SOD induction. Instead, the agents uniformly, dose-dependently and continuously reduced EC-SOD expression. We interpret the effect to be due to toxicity. Enhancement of the protection against oxidative stress by addition of CuZn-SOD, catalase and low concentrations of selenite did not influence the expression of any of the SOD isoenzymes. Removal of EC-SOD from cell surfaces by heparin also did not influence SOD expression. Mn-SOD was moderately induced by high doses of the first 11 oxidants. Apart from reduction at high toxic doses, there were no significant effects on the CuZn-SOD activity by any of the treatments. Thus EC-SOD, previously shown to be profoundly influenced by inflammatory cytokines, was not induced by its substrate or other oxidants. In a similar fashion, Mn-SOD, previously shown to be greatly induced and depressed by cytokines, was only moderately influenced by oxidants. We suggest that the regulation of these SOD isoenzymes in mammalian tissues primarily occurs in a manner co-ordinated by cytokines, rather than as a response of individual cells to oxidants.

  6. Implication of (Mn)superoxide dismutase of Enterococcus faecalis in oxidative stress responses and survival inside macrophages.

    PubMed

    Verneuil, Nicolas; Mazé, Alain; Sanguinetti, Maurizio; Laplace, Jean-Marie; Benachour, Abdellah; Auffray, Yanick; Giard, Jean-Christophe; Hartke, Axel

    2006-09-01

    The gene encoding the manganese-containing superoxide dismutase (MnSOD) of Enterococcus faecalis was characterized. It is transcribed monocistronically from an upstream promoter identified by rapid amplification of cDNA ends (RACE)-PCR. A sodA mutant was constructed and characterized. Growth of the mutant strain was not significantly different from that of its wild-type counterpart in standing and aerated cultures. However, the mutant was more sensitive towards menadione and hydroperoxide stresses. The response to H(2)O(2) stress was analysed in more detail, and the mode of killing of this oxidant was different under anaerobic and aerobic conditions. Cultures grown and challenged under anaerobic conditions were highly sensitive to treatment with 35 mM H(2)O(2). They were largely protected by the iron chelator deferoxamine, which suggested that killing was mainly due to an enhanced Fenton reaction. In contrast, neither strain was protected by the iron chelators deferoxamine and diethylenetriaminepentaacteic acid when grown and challenged under aerobic conditions, which suggested that inactivation of the cells by H(2)O(2) was due to another killing mode. The sodA mutant was more sensitive under these conditions, showing that MnSOD is also important for protecting the cells from damage under aerobic conditions. Finally, the MnSOD of Ent. faecalis may be considered to be a virulence factor, since survival of the corresponding mutant strain was highly affected inside mouse peritoneal macrophages.

  7. Stimulation of Mn-superoxide dismutase expression by tumor necrosis factor-. alpha. : Quantitative determination of Mn-SOD protein levels in TNF-resistant and sensitive cells by ELISA

    SciTech Connect

    Taniguchi, N.; Kawaguchi, T.; Suzuki, K.; Matsuda, Y.; Hoshi, S. ); Ishikawa, M. )

    1991-03-11

    Human Mn-Superoxide Dismutase (Mn-SOD) was purified and crystallized. A monoclonal antibody to the Mn-SOD was developed. The antigen-binding epitope was found to be located on C-terminal peptides. This made it possible to quantitate the immunoreactive Mn-SOD by ELISA. Marked increase in protein levels of Mn-SOD was found in TNF-resistant cell lines after treatment with Tumor Necrosis Factor (TNF). No such increase was observed in Cu, Zn-SOD protein in either TNF-resistant or sensitive cells. These results support the data that the Mn-SOD is one of the rescue proteins required for resistance to TNF cytotoxicity in these cell lines. Mn-SOD was also responsive to TNF stimulation in KURAMOCHI, a human ovarian adenocarcinoma cell line. This may explain the authors' previous result that Mn-SOD protein is highly expressed in epithelial ovarian cancer.

  8. A Germin-Like Protein Gene (CchGLP) of Capsicum chinense Jacq. Is Induced during Incompatible Interactions and Displays Mn-Superoxide Dismutase Activity

    PubMed Central

    León-Galván, Fabiola; de Jesús Joaquín-Ramos, Ahuizolt; Torres-Pacheco, Irineo; Barba de la Rosa, Ana P.; Guevara-Olvera, Lorenzo; González-Chavira, Mario M.; Ocampo-Velazquez, Rosalía V.; Rico-García, Enrique; Guevara-González, Ramón Gerardo

    2011-01-01

    A germin-like gene (CchGLP) cloned from geminivirus-resistant pepper (Capsicum chinense Jacq. Line BG-3821) was characterized and the enzymatic activity of the expressed protein analyzed. The predicted protein consists of 203 amino acids, similar to other germin-like proteins. A highly conserved cupin domain and typical germin boxes, one of them containing three histidines and one glutamate, are also present in CchGLP. A signal peptide was predicted in the first 18 N-terminal amino acids, as well as one putative N-glycosylation site from residues 44–47. CchGLP was expressed in E. coli and the recombinant protein displayed manganese superoxide dismutase (Mn-SOD) activity. Molecular analysis showed that CchGLP is present in one copy in the C. chinense Jacq. genome and was induced in plants by ethylene (Et) and salicylic acid (SA) but not jasmonic acid (JA) applications in the absence of pathogens. Meanwhile, incompatible interactions with either Pepper golden mosaic virus (PepGMV) or Pepper huasteco yellow vein virus (PHYVV) caused local and systemic CchGLP induction in these geminivirus-resistant plants, but not in a susceptible accession. Compatible interactions with PHYVV, PepGMV and oomycete Phytophthora capsici did not induce CchGLP expression. Thus, these results indicate that CchGLP encodes a Mn-SOD, which is induced in the C. chinense geminivirus-resistant line BG-3821, likely using SA and Et signaling pathways during incompatible interactions with geminiviruses PepGMV and PHYVV. PMID:22174599

  9. The paradigm that all oxygen-respiring eukaryotes have cytosolic CuZn-superoxide dismutase and that Mn-superoxide dismutase is localized to the mitochondria does not apply to a large group of marine arthropods.

    PubMed

    Brouwer, M; Brouwer, T H; Grater, W; Enghild, J J; Thogersen, I B

    1997-10-28

    The enzyme superoxide dismutase (SOD), which catalyzes the dismutation of the superoxide radical, is present in the cytosol and mitochondria of all oxygen-respiring eukaryotes. The cytosolic form contains copper and zinc (CuZnSOD), whereas the mitochondrial form contains manganese (MnSOD). The latter protein is synthesized in the cytosol as a MnSOD precursor, containing an N-terminal mitochondrial-targeting sequence. CuZnSOD is sensitive toward cyanide (CN) and hydrogen peroxide (H2O2), but MnSOD is not. Assays for SOD activity in cytosol from the hepatopancreas of the blue crab, Callinectes sapidus, showed the presence of a CN/H2O2-insensitive form of SOD. No CN/H2O2-sensitive CuZnSOD was found. This unexpected phenomenon was shown to occur in all decapod crustacea (crabs, lobsters, shrimp) examined. The cytosolic and mitochondrial SODs of C. sapidus were purified by means of ion-exchange, size-exclusion, and reverse-phase HPLC. The cytosolic SOD is a homodimeric protein, which exists in a monomer-dimer equilibrium (24 kDa left and right arrow 48 kDa). The protein contains approximately 1 Mn per subunit. No copper or zinc is present. Amino acid sequence analysis identified the novel cytosolic SOD as a MnSOD precursor with an abnormal mitochondrial-targeting sequence. The mitochondrial SOD of C. sapidus is similar to the MnSOD found in other eukaryotes. N-Terminal amino sequences of mitochondrial and cytosolic blue crab MnSOD differ in several positions. The MnSODs are thus encoded for by two different genes. The paradigm that all eukaryotes contain intracellular CuZnSOD and that MnSOD occurs exclusively in the mitochondria appears not to apply to a large group of marine arthropods.

  10. Detection and characterisation of mutations responsible for allele-specific protein thermostabilities at the Mn-superoxide dismutase gene in the deep-sea hydrothermal vent polychaete Alvinella pompejana.

    PubMed

    Bruneaux, Matthieu; Mary, Jean; Verheye, Marie; Lecompte, Odile; Poch, Olivier; Jollivet, Didier; Tanguy, Arnaud

    2013-05-01

    Alvinella pompejana (Polychaeta, Alvinellidae) is one of the most thermotolerant marine eukaryotes known to date. It inhabits chimney walls of deep-sea hydrothermal vents along the East Pacific Rise (EPR) and is exposed to various challenging conditions (e.g. high temperature, hypoxia and the presence of sulphides, heavy metals and radiations), which increase the production of dangerous reactive oxygen species (ROS). Two different allelic forms of a manganese-superoxide dismutase involved in ROS detoxification, ApMnSOD1 and ApMnSOD2, and differing only by two substitutions (M110L and A138G) were identified in an A. pompejana cDNA library. RFLP screening of 60 individuals from different localities along the EPR showed that ApMnSOD2 was rare (2 %) and only found in the heterozygous state. Dynamic light scattering measurements and residual enzymatic activity experiments showed that the most frequent form (ApMnSOD1) was the most resistant to temperature. Their half-lives were similarly long at 65 °C (>110 min) but exhibited a twofold difference at 80 °C (20.8 vs 9.8 min). Those properties are likely to be explained by the occurrence of an additional sulphur-containing hydrogen bond involving the M110 residue and the effect of the A138 residue on the backbone entropy. Our results confirm the thermophily of A. pompejana and suggest that this locus is a good model to study how the extreme thermal heterogeneity of the vent conditions may help to maintain old rare variants in those populations.

  11. Construction of a Fusion Enzyme Exhibiting Superoxide Dismutase and Peroxidase Activity.

    PubMed

    Sharapov, M G; Novoselov, V I; Ravin, V K

    2016-04-01

    A chimeric gene construct encoding human peroxiredoxin 6 and Mn-superoxide dismutase from Escherichia coli was developed. Conditions for expression of the fusion protein in E. coli cell were optimized. Fusing of the enzymes into a single polypeptide chain with peroxiredoxin 6 at the N-terminus (PSH) did not affect their activities. On the contrary, the chimeric protein with reverse order of enzymes (SPH) was not obtained in a water-soluble active form. The active chimeric protein (PSH) exhibiting both peroxidase and superoxide dismutase activities was prepared and its physicochemical properties were characterized.

  12. Characterization of the Single Superoxide Dismutase of Staphylococcus xylosus

    PubMed Central

    Barrière, Charlotte; Brückner, Reinhold; Talon, Régine

    2001-01-01

    Staphylococcus xylosus is a facultative anaerobic bacterium used as a starter culture for fermented meat products. In an attempt to analyze the antioxidant capacities of this organism, the superoxide dismutase (SOD) was characterized. S. xylosus contains a single cytoplasmic SOD, which was not inhibited by H2O2. The SOD activity in crude extracts was completely lost upon metal depletion, but it could be recovered by manganese and very weakly by iron. It is therefore suggested that the S. xylosus SOD is a manganese-preferring enzyme. The corresponding gene, sod, was isolated from a genomic library of S. xylosus DNA and complemented the growth defect of an Escherichia coli SOD-deficient mutant. As deduced from the nucleotide sequence, sod encodes a protein of 199 amino acids with a molecular mass of 22.5 kDa. Two transcriptional start sites 25 and 120 bp upstream of the sod start codon were identified. A terminator-like structure downstream of the gene suggested a monocistronic sod mRNA. Regulation of sod expression was studied using fusions of the sod promoters to a genomic promoterless β-galactosidase gene. The sod expression was not affected by manganese and increased slightly with paraquat. It was induced during stationary phase in a complex medium but not in a chemically defined medium. To investigate the physiological role of SOD, a mutant devoid of SOD activity was constructed. Growth experiments showed that sod is not essential for aerobic growth in complex medium. However, in chemically defined medium without leucine, isoleucine, and valine, the sod mutant hardly grew, in contrast to the wild-type strain. In addition, the mutant was sensitive to hyperbaric oxygen and to paraquat. Therefore, sod plays an important role in the protection of S. xylosus from oxidative stress. PMID:11526011

  13. The Single Superoxide Dismutase of Rhodobacter capsulatus Is a Cambialistic, Manganese-Containing Enzyme

    PubMed Central

    Tabares, Leandro C.; Bittel, Cristian; Carrillo, Néstor; Bortolotti, Ana; Cortez, Néstor

    2003-01-01

    The phototrophic bacterium Rhodobacter capsulatus contains a single, oxygen-responsive superoxide dismutase (SODRc) homologous to iron-containing superoxide dismutase enzymes. Recombinant SODRc, however, displayed higher activity after refolding with Mn2+, especially when the pH of the assay mixture was raised. SODRc isolated from Rhodobacter cells also preferentially contains manganese, but metal discrimination depends on the culture conditions, with iron fractions increasing from 7% in aerobic cultures up to 40% in photosynthetic cultures. Therefore, SODRc behaves as a Mn-containing dismutase with cambialistic properties. PMID:12730184

  14. [Molecular markers associated with prostate cancer: 3-nitrotyrosine and genetic and proteic expression of Mn-superoxide dismutasa (Mn-SOD)].

    PubMed

    Floriano-Sánchez, Esaú; Castro-Marín, Melchor; Cárdenas-Rodríguez, Noemí

    2009-11-01

    Recent reports place prostate cancer (PCa) as third cause of death in the World among males, in Mexico it is the leading cause of male death. In this study, we studied molecular markers and one genetic marker related in tissues with PCa and benign prostatic hyperplasia (BPH): The Mn-superoxide dismutase (Mn-SOD) gen and protein, prostate specific antigen (PSA) and 3-nitrotyrosine (3-NT). It was evaluated if various markers of oxidative stress show altered expression in prostate cancer and BPH. 80 biopsies were obtained. The conditions to amplify and evaluate the immunoreactivity of the genes of interest (Mn-SOD and 3-NT) and the correlation between PSA and Mn-SOD immunoreactivity in prostate cancer and benign prostatic hyperplasia were standardized. Gene overexpression and Mn-SOD and 3-NT immunoreactivity were greater in prostate cancer with respect to the BPH group. Correlation between levels of PSA and the Mn-SOD immunoreactivity was not observed. The above results suggest that the parameters evaluated can be used as tumor markers making the determinations in biopsies of patients suspected of prostate cancer.

  15. Single mutations at the subunit interface modulate copper reactivity in Photobacterium leiognathi Cu,Zn superoxide dismutase.

    PubMed

    Stroppolo, M E; Pesce, A; D'Orazio, M; O'Neill, P; Bordo, D; Rosano, C; Milani, M; Battistoni, A; Bolognesi, M; Desideri, A

    2001-05-04

    The functional properties and X-ray structures of five mutant forms of Photobacterium leiognathi Cu,Zn superoxide dismutase carrying single mutations at residues located at the dimer association interface have been investigated. When compared to the wild-type enzyme, the three-dimensional structures of the mutants show structural perturbations limited to the proximity of the mutation sites and substantial identity of active site geometry. Nonetheless, the catalytic rates of all mutants, measured at neutral pH and low ionic strength by pulse radiolysis, are higher than that of the wild-type protein. Such enzymatic activity increase is paralleled by enhanced active site accessibility to external chelating agents, which, in the mutated enzyme, remove more readily the active site copper ion. It is concluded that mutations at the prokaryotic Cu,Zn superoxide dismutase subunit interface can transduce dynamical perturbation to the active site region, promoting substrate active site accessibility. Such long-range intramolecular communication effects have not been extensively described before within the Cu,Zn superoxide dismutase homology family.

  16. Structures of two superoxide dismutases from Bacillus anthracis reveal a novel active centre

    SciTech Connect

    Boucher, Ian W.; Kalliomaa, Anne K.; Levdikov, Vladimir M.; Blagova, Elena V.; Fogg, Mark J.; Brannigan, James A. Wilson, Keith S.; Wilkinson, Anthony J.

    2005-07-01

    The crystal structures of two manganese superoxide dismutases from B. anthracis were solved by X-ray crystallography using molecular replacement. The BA4499 and BA5696 genes of Bacillus anthracis encode proteins homologous to manganese superoxide dismutase, suggesting that this organism has an expanded repertoire of antioxidant proteins. Differences in metal specificity and quaternary structure between the dismutases of prokaryotes and higher eukaryotes may be exploited in the development of therapeutic antibacterial compounds. Here, the crystal structure of two Mn superoxide dismutases from B. anthracis solved to high resolution are reported. Comparison of their structures reveals that a highly conserved residue near the active centre is substituted in one of the proteins and that this is a characteristic feature of superoxide dismutases from the B. cereus/B. anthracis/B. thuringiensis group of organisms.

  17. Lipid peroxidation and expression of copper-zinc and manganese superoxide dismutase in lungs of premature infants with hyaline membrane disease and bronchopulmonary dysplasia.

    PubMed

    Strange, R C; Cotton, W; Fryer, A A; Jones, P; Bell, J; Hume, R

    1990-11-01

    The putative involvement of reactive oxygen species in the etiology of lung damage in infants receiving mechanical ventilation has been examined by comparing the levels of peroxidation and expression of the antioxidant enzymes, CuZn and Mn superoxide dismutase, in lungs from control and affected infants as well as from fetuses and infants who died postnatally after term delivery. Mean levels (+/- SD) of lung peroxidation, determined with a thiobarbituric acid method, were similar in affected and control premature neonates and in fetal subjects (1.87 +/- 1.26, 1.92 +/- 2.07, and 1.19 +/- 1.36 nmol/mg protein, respectively). Expression of CuZn and Mn superoxide dismutases was also similar in these subjects and in the patients who died postnatally. Thus activity measurements and immunoblotting studies showed continuous expression of these enzymes throughout development with no apparent change in protein levels or size. Immunohistochemical examination of lung tissue showed expression of CuZn and Mn superoxide dismutases in epithelial, smooth muscle, endothelial, and some mesenchyme components. In patients with bronchopulmonary dysplasia, alveolar walls were thickened by an excess of fibrous tissue and terminal air spaces were lined mainly by type II pneumatocytes. All structures, including abnormal fibrous components, were positive for both CuZn and Mn superoxide dismutase. Our data show that, unlike some experimental animals, expression of at least these antioxidant enzymes in human infants born prematurely is similar to that in adults, and indicate that such infants are better adapted for life in an oxygen-containing environment than previously suspected.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. The Antitumor Effect of Single-domain Antibodies Directed Towards Membrane-associated Catalase and Superoxide Dismutase.

    PubMed

    Bauer, Georg; Motz, Manfred

    2016-11-01

    Neutralizing single-domain antibodies directed towards catalase or superoxide dismutase (SOD) caused efficient reactivation of intercellular reactive oxygen species/reactive nitrogen species (ROS/RNS)-dependent apoptosis-inducing signaling specifically in human tumor cells. Single-domain antibodies targeted tumor cell-specific membrane-associated SOD and catalase, but not the corresponding intracellular enzymes. They were shown to be about 200-fold more effective than corresponding classical recombinant antigen-binding fragments and more than four log steps more efficient than monoclonal antibodies. Combined addition of single-domain antibodies against catalase and SOD caused a remarkable synergistic effect. Proof-of-concept experiments in immunocompromised mice using human tumor xenografts and single-domain antibodies directed towards SOD showed an inhibition of tumor growth. Neutralizing single-domain antibodies directed to catalase and SOD also caused a very strong synergistic effect with the established chemotherapeutic agent taxol, indicating an overlap of signaling pathways. This effect might also be useful in order to avoid unwanted side-effects and to drastically lower the costs for taxol-based therapy. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  19. Perkinsus marinus superoxide dismutase 2 (PmSOD2) localizes to single-membrane subcellular compartments

    SciTech Connect

    Fernandez-Robledo, Jose A.; Schott, Eric J.; Vasta, Gerardo R.

    2008-10-17

    Perkinsus marinus (Phylum Perkinsozoa), a protozoan parasite of oysters, is considered one of the earliest diverging groups of the lineage leading to dinoflagellates. Perkinsus trophozoites are phagocytosed by oyster hemocytes, where they are likely exposed to reactive oxygen species. As part of its reactive oxygen detoxifying pathway, P. marinus possesses two iron-cofactored SOD (PmSOD1 and PmSOD2). Immunoflourescence analysis of P. marinus trophozoites and gene complementation in yeast revealed that PmSOD1 is targeted to the mitochondria. Surprisingly, although PmSOD2 is characterized by a bipartite N-terminus extension typical of plastid targeting, in preliminary immunofluorescence studies it was visualized as punctuate regions in the cytoplasm that could not be assigned to any organelle. Here, we used immunogold electron microscopy to examine the subcellular localization PmSOD2 in P. marinus trophozoites. Gold grains were mostly associated with single-membrane vesicle-like structures, and eventually, localized to electron-dense, apparently amorphous material present in the lumen of a larger, unique compartment. The images suggested that PmSOD2 is targeted to small vesicles that fuse and/or discharge their content into a larger compartment, possibly the large vacuole typical of the mature trophozoites. In light of the in silico targeting prediction, the association of PmSOD2 with single-membrane compartments raises interesting questions regarding its organellar targeting, and the nature of a putative relic plastid in Perkinsus species.

  20. AMELIORATION OF ETHANOL-INDUCED DYSMORPHOGENESIS IN RODENT EMBRYOS IN VITRO USING ADENOVIRAL-MEDIATED EXPRESSION OF CU,ZN-SUPEROXIDE DISMUTASE (SOD1) OR MN-SUPEROXIDE DISMUTASE (SOD2)

    EPA Science Inventory

    Ethanol produces dysmorphogenesis in offspring when pregnant animals are exposed in vivo (Chaudhuri 2000; Hannigan and Armant, 2000) and by direct exposure of neurulation staged embryos to ethanol in vitro (Kotch et al., 1995; Hunter et al., 1994 ; Thompson and Folb, 1982). The a...

  1. AMELIORATION OF ETHANOL-INDUCED DYSMORPHOGENESIS IN RODENT EMBRYOS IN VITRO USING ADENOVIRAL-MEDIATED EXPRESSION OF CU,ZN-SUPEROXIDE DISMUTASE (SOD1) OR MN-SUPEROXIDE DISMUTASE (SOD2)

    EPA Science Inventory

    Ethanol produces dysmorphogenesis in offspring when pregnant animals are exposed in vivo (Chaudhuri 2000; Hannigan and Armant, 2000) and by direct exposure of neurulation staged embryos to ethanol in vitro (Kotch et al., 1995; Hunter et al., 1994 ; Thompson and Folb, 1982). The a...

  2. Behavioral and Neurotransmitter Abnormalities in Mice Deficient for Parkin, DJ-1 and Superoxide Dismutase

    PubMed Central

    Hennis, Meghan R.; Seamans, Katherine W.; Marvin, Marian A.; Casey, Bradford H.; Goldberg, Matthew S.

    2013-01-01

    Parkinson’s disease (PD) is a progressive neurodegenerative disease characterized by loss of neurons in the substantia nigra that project to the striatum and release dopamine. The cause of PD remains uncertain, however, evidence implicates mitochondrial dysfunction and oxidative stress. Although most cases of PD are sporadic, 5-10% of cases are caused by inherited mutations. Loss-of-function mutations in Parkin and DJ-1 were the first to be linked to recessively inherited Parkinsonism. Surprisingly, mice bearing similar loss-of-function mutations in Parkin and DJ-1 do not show age-dependent loss of nigral dopaminergic neurons or depletion of dopamine in the striatum. Although the normal cellular functions of Parkin and DJ-1 are not fully understood, we hypothesized that loss-of-function mutations in Parkin and DJ-1 render cells more sensitive to mitochondrial dysfunction and oxidative stress. To test this hypothesis, we crossed mice deficient for Parkin and DJ-1 with mice deficient for the mitochondrial antioxidant protein Mn-superoxide dismutase (SOD2) or the cytosolic antioxidant protein Cu-Zn-superoxide dismutase (SOD1). Aged Parkin-/-DJ-1-/- and Mn-superoxide dismutase triple deficient mice have enhanced performance on the rotorod behavior test. Cu/Zn-superoxide dismutase triple deficient mice have elevated levels of dopamine in the striatum in the absence of nigral cell loss. Our studies demonstrate that on a Parkin/DJ-1 null background, mice that are also deficient for major antioxidant proteins do not have progressive loss of dopaminergic neurons but have behavioral and striatal dopamine abnormalities. PMID:24386432

  3. A pilot study of the association of manganese superoxide dismutase and glutathione peroxidase 1 single gene polymorphisms with prostate cancer and serum prostate specific antigen levels

    PubMed Central

    Atilgan, Dogan; Gencten, Yusuf; Benli, Ismail; Ozyurt, Huseyin; Uluocak, Nihat; Erdemir, Fikret

    2015-01-01

    Introduction The aim of the study was to evaluate the potential association of single gene polymorphisms of the antioxidant enzymes manganese superoxide dismutase (MnSOD) and glutathione peroxidase (GPX1) with prostate cancer (PCa). Material and methods Manganese superoxide dismutase and glutathione peroxidase 1 genotypes and allele frequencies in 49 prostate cancer cases (PCa group) and 98 control subjects were determined. Analysis of genotypes in control group individuals were performed in two subgroups according to serum prostate-specific antigen levels: the control group (n = 49), with prostate specific antigen (PSA) level < 4 ng/ml; and the nonPCa-high PSA control group (n = 49), with serum PSA > 4 ng/ml. Determination of MnSOD Ala-9Val and GPX1 Pro198Leu polymorphisms was performed using real-time polymerase chain reaction amplification. Results No association was found between GPX1 polymorphisms and PCa in all groups (p > 0.05). In the PCa group, the frequency of homozygote Val allele carriers was significantly higher in comparison to nonPCa-high PSA control cases. Therefore, Val/Val genotype was found significantly suspicious for PCa risk (OR = 2.48; 95% CI: 1.37–4.48; p = 0.002). Furthermore, an overall protective effect of the Ala allele of the MnSOD polymorphism on PCa risk was detected. These findings in this small Turkish population suggested that individual risk of PCa may be modulated by MnSOD polymorphism especially in patients with high PSA, but GPX1 polymorphism seemed to have no effect on PCa risk. Conclusions The presence of genetic variants of antioxidant enzymes could have a potential influence on genesis of prostatic malignancy. PMID:26528342

  4. Cu/Zn superoxide dismutase and catalase activities in Pinus mugo needles growing at elevated stands in the mountains, and their photochemical efficiency of PSII.

    PubMed

    Miszalski, Zbigniew; Libik, Marta; Surówka, Ewa; Niewiadomska, Ewa

    2005-08-01

    Pinus mugo needles were sampled at different altitudes (1420, 1590 and 1920 m a.s.l.) to analyse levels of oxidative stress and changes in maximum photochemical efficiency of PSII. Polyacrylamide gel electrophoresis demonstrated that almost all superoxide dismutase activity represented Cu/Zn superoxide dismutase, and only 4-6% represents Mn superoxide dismutase. In extracts from plants sampled at 1590 and 1920 m a.s.l., lower activity of Cu/Zn superoxide dismutase was found. Comparing these data with immunoblots, it can be concluded that the differences in superoxide dismutase activity was related to protein amount. In needles from higher altitudes, a decrease in catalase activity was detected, as opposed to the protein amount, which was higher in needles from the higher stands. Considering the decrease in catalase and Cu/Zn superoxide dismutase activities in needles collected at 1590 and 1920 m a.s.l., we suggest that higher levels of oxidative stress may induce changes in photochemical efficiency of PSII.

  5. Three novel superoxide dismutase genes identified in the marine polychaete Perinereis nuntia and their differential responses to single and combined metal exposures.

    PubMed

    Won, Eun-Ji; Ra, Kongtae; Kim, Kyung-Tae; Lee, Jae-Seong; Lee, Young-Mi

    2014-09-01

    To identify superoxide dismutase (SOD) genes and evaluate their usefulness as potential markers for monitoring metal toxicity in aquatic environment, we cloned, sequenced, and characterized 3 SOD genes (Cu/Zn-SOD1, Cu/Zn-SOD2, and Mn-SOD) from the marine polychaete Perinereis nuntia. The accumulated metal contents and expressions of 3 SOD genes were compared after exposure to single and combinations of heavy metals, As, Ni, and Pb. The deduced amino acid sequences of the 3 SODs had evolutionary conserved domains, such as metal binding sites, and signature sequences. The phylogenetic analysis revealed that Cu/Zn-SOD1, Cu/Zn-SOD2, and Mn-SOD were clustered with extracellular Cu/Zn-SOD, intracellular Cu/Zn-SOD and mitochondrial Mn-SOD, respectively, of other species. The accumulated contents of Ni and Pb increased significantly in a time - dependent manner after exposure to both single and combination of the metals. However, the concentration of As did not change significantly in the exposure test. The quantitative real-time polymerase chain reaction (PCR) array showed that the 3 SOD genes had differential expression patterns depending on the exposure condition. The expression of all SODs mRNAs was significantly elevated in response to Pb alone and in combination with As. The mRNA level of Cu/Zn-SOD1 was the highest after exposure to Pb alone, while that of Mn-SOD was remarkably enhanced after exposure to a combination of As and Pb. Exposure to Ni alone rapidly elevated the expression of Cu/Zn-SOD1 and Mn-SOD mRNA, which then gradually decreased. Exposure to As had no significant effect on the modulation of any of the SOD genes of P. nuntia. These results suggest that all SOD genes might play important roles in cellular protection as antioxidant enzymes against heavy metal toxicity via different modes of action in P. nuntia and might have the potential to act as indicators in an environment containing a mixture of metals.

  6. Models of Superoxide Dismutases

    SciTech Connect

    Cabelli, Diane E.; Riley, Dennis; Rodriguez, Jorge A.; Valentine, Joan Selverstone; Zhu, Haining

    1998-05-20

    In this review we have focused much of our discussion on the mechanistic details of how the native enzymes function and how mechanistic developments/insights with synthetic small molecule complexes possessing SOD activity have influenced our understanding of the electron transfer processes involved with the natural enzymes. A few overriding themes have emerged. Clearly, the SOD enzymes operate at near diffusion controlled rates and to achieve such catalytic turnover activity, several important physical principles must be operative. Such fast electron transfer processes requires a role for protons; i.e., proton-coupled electron transfer (''H-atom transfer'') solves the dilemma of charge separation developing in the transition state for the electron transfer step. Additionally, outer-sphere electron transfer is likely a most important pathway for manganese and iron dismutases. This situation arises because the ligand exchange rates on these two ions in water never exceed {approx}10{sup +7} s{sup -1}; consequently, 10{sup +9} catalytic rates require more subtle mechanistic insights. In contrast, copper complexes can achieve diffusion controlled (>10{sup +9}) exchange rates in water; thus inner-sphere electron transfer processes are more likely to be operative in the Cu/Zn enzymes. Recent studies have continued to expand our understanding of the mechanism of action of this most important class of redox active enzymes, the superoxide dismutases, which have been critical in the successful adaptation of life on this planet to an oxygen-based metabolism. The design of SOD mimic drugs, synthetic models compounds that incorporate this superoxide dismutase catalytic activity and are capable of functioning in vivo, offers clear potential benefits in the control of diseases, ranging from the control of neurodegenerative conditions, such as Parkinson's or Alzheimer's disease, to cancer.

  7. Superoxide dismutase: an evolutionary puzzle

    SciTech Connect

    Lee, Y.M.; Friedman, D.J.; Ayala, F.J.

    1985-02-01

    The authors have obtained the complete amino acid sequence of copper/zinc-containing superoxide dismutase (SOD, superoxide:superoxide oxidoreductase, EC 1.15.1.1) from Drosophila melanogaster. The sequence of this enzyme is also known for man, horse, cow, and the yeast Saccharomyces cerevisiae. The rate of evolution of this enzyme is far from constant. The number of amino acid substitutions per 100 residues per 100 million years is 30.9 when the three mammals are compared to each other, 10.6 when Drosophila is compared to the three mammals, and 5.8 when the yeast is compared to the four animals. The first value represents one of the fastest evolutionary rates for any protein, the second is similar to the globin rate, and the third is similar to some cytochromes and other slowly evolving proteins. Hence, SOD is not acceptable evolutionary clock. Another peculiarity of this enzyme is that a two-amino-acid deletion must have occurred independently in the lineages going to the cow and to Drosophila. The authors conclude that using the primary structure of a single gene or protein to time evolutionary events or to reconstruct phylogenetic relationships is potentially fraught with error.

  8. The Cu, Zn Superoxide Dismutase: Not Only a Dismutase Enzyme

    PubMed Central

    Mondola, Paolo; Damiano, Simona; Sasso, Anna; Santillo, Mariarosaria

    2016-01-01

    The Cu,Zn superoxide dismutase (SOD1) is an ubiquitary cytosolic dimeric carbohydrate free molecule, belonging to a family of isoenzymes involved in the scavenger of superoxide anions. This effect certainly represents the main and well known function ascribed to this enzyme. Here we highlight new aspects of SOD1 physiology that point out some inedited effects of this enzyme in addition to the canonic role of oxygen radical enzymatic dismutation. In the last two decades our research group produced many data obtained in in vitro studies performed in many cellular lines, mainly neuroblastoma SK-N-BE cells, indicating that this enzyme is secreted either constitutively or after depolarization induced by high extracellular K+ concentration. In addition, we gave many experimental evidences showing that SOD1 is able to stimulate, through muscarinic M1 receptor, pathways involving ERK1/2, and AKT activation. These effects are accompanied with an intracellular calcium increase. In the last part of this review we describe researches that link deficient extracellular secretion of mutant SOD1G93A to its intracellular accumulation and toxicity in NSC-34 cells. Alternatively, SOD1G93A toxicity has been attributed to a decrease of Km for H2O2 with consequent OH radical formation. Interestingly, this last inedited effect of SOD1G93A could represent a gain of function that could be involved in the pathogenesis of familial Amyotrophic Lateral Sclerosis (fALS). PMID:27965593

  9. The Cu, Zn Superoxide Dismutase: Not Only a Dismutase Enzyme.

    PubMed

    Mondola, Paolo; Damiano, Simona; Sasso, Anna; Santillo, Mariarosaria

    2016-01-01

    The Cu,Zn superoxide dismutase (SOD1) is an ubiquitary cytosolic dimeric carbohydrate free molecule, belonging to a family of isoenzymes involved in the scavenger of superoxide anions. This effect certainly represents the main and well known function ascribed to this enzyme. Here we highlight new aspects of SOD1 physiology that point out some inedited effects of this enzyme in addition to the canonic role of oxygen radical enzymatic dismutation. In the last two decades our research group produced many data obtained in in vitro studies performed in many cellular lines, mainly neuroblastoma SK-N-BE cells, indicating that this enzyme is secreted either constitutively or after depolarization induced by high extracellular K(+) concentration. In addition, we gave many experimental evidences showing that SOD1 is able to stimulate, through muscarinic M1 receptor, pathways involving ERK1/2, and AKT activation. These effects are accompanied with an intracellular calcium increase. In the last part of this review we describe researches that link deficient extracellular secretion of mutant SOD1(G93A) to its intracellular accumulation and toxicity in NSC-34 cells. Alternatively, SOD1(G93A) toxicity has been attributed to a decrease of Km for H2O2 with consequent OH radical formation. Interestingly, this last inedited effect of SOD1(G93A) could represent a gain of function that could be involved in the pathogenesis of familial Amyotrophic Lateral Sclerosis (fALS).

  10. Superoxide dismutases in chronic gastritis.

    PubMed

    Švagelj, Dražen; Terzić, Velimir; Dovhanj, Jasna; Švagelj, Marija; Cvrković, Mirta; Švagelj, Ivan

    2016-04-01

    Human gastric diseases have shown significant changes in the activity and expression of superoxide dismutase (SOD) isoforms. The aim of this study was to detect Mn-SOD activity and expression in the tissue of gastric mucosa, primarily in chronic gastritis (immunohistochemical Helicobacter pylori-negative gastritis, without other pathohistological changes) and to evaluate their possible connection with pathohistological diagnosis. We examined 51 consecutive outpatients undergoing endoscopy for upper gastrointestinal symptoms. Patients were classified based on their histopathological examinations and divided into three groups: 51 patients (archive samples between 2004-2009) with chronic immunohistochemical Helicobacter pylori-negative gastritis (mononuclear cells infiltration were graded as absent, moderate, severe) divided into three groups. Severity of gastritis was graded according to the updated Sydney system. Gastric tissue samples were used to determine the expression of Mn-SOD with anti-Mn-SOD Ab immunohistochemically. The Mn-SOD expression was more frequently present in specimens with severe and moderate inflammation of gastric mucosa than in those with normal mucosa. In patients with normal histological finding, positive immunoreactivity of Mn-SOD was not found. Our results determine the changes in Mn-SOD expression occurring in the normal gastric mucosa that had undergone changes in the intensity of chronic inflammatory infiltrates in the lamina propria.

  11. Preliminary crystallographic analysis of the Megavirus superoxide dismutase

    PubMed Central

    Lartigue, Audrey; Philippe, Nadège; Jeudy, Sandra; Abergel, Chantal

    2012-01-01

    Megavirus chilensis, a close relative of the Mimivirus giant virus, is able to replicate in Acanthamoeba castellanii. The first step of viral infection involves the internalization of the virions in host vacuoles. It has been experimentally demonstrated that Mimivirus particles contain many proteins capable of resisting oxidative stress, as encountered in the phagocytic process. These proteins are conserved in Megavirus, which has an additional gene (Mg277) encoding a putative superoxide dismutase. The Mg277 ORF product was overexpressed in Escherichia coli, purified and crystallized. A SAD data set was collected to 2.24 Å resolution at the selenium peak wavelength on the BM30 beamline at the ESRF from a single crystal of selenomethionine-substituted recombinant superoxide dismutase protein. PMID:23192047

  12. Induction of Superoxide Dismutase by Molecular Oxygen

    PubMed Central

    Gregory, Eugene M.; Fridovich, Irwin

    1973-01-01

    Oxygen induces superoxide dismutase in Streptococcus faecalis and in Escherichia coli B. S. faecalis grown under 20 atm of O2 had 16 times more of this enzyme than did anaerobically grown cells. In the case of E. coli, changing the conditions of growth from anaerobic to 5 atm of O2 caused a 25-fold increase in the level of superoxide dismutase. Induction of this enzyme was a response to O2 rather than to pressure, since 20 atm of N2 was without effect. Induction of superoxide dismutase was a rapid process, and half of the maximal level was reached within 90 min after N2-grown cells of S. faecalis were exposed to 20 atm of O2 at 37 C. S. faecalis did not contain perceptible levels of catalase under any of the growth conditions investigated by Stanier, Doudoroff, and Adelberg (23), and the concentration of catalase in E. coli was not affected by the presence of O2 during growth. S. faecalis, which had been grown under 100% O2 and which therefore contained an elevated level of superoxide dismutase, was more resistant of 46 atm of O2 than were cells which had been grown under N2. E. coli grown under N2 contained as much superoxide dismutase as did S. faecalis grown under 1 atm of O2. The E. coli which had been grown under N2 was as resistant to the deleterious effects of 50 atm of O2 as was S. faecalis which had been grown under 1 atm of O2. These results are consistent with the proposal that the peroxide radical is an important agent of the toxicity of oxygen and that superoxide dismutase may be a component of the systems which have been evolved to deal with this potential toxicity. Images PMID:4196244

  13. Metal Uptake by Manganese Superoxide Dismutase

    PubMed Central

    Whittaker, James W.

    2009-01-01

    Manganese superoxide dismutase is an important antioxidant defense metalloenzyme that protects cells from damage by the toxic oxygen metabolite, superoxide free radical, formed as an unavoidable by-product of aerobic metabolism. Many years of research have gone into understanding how the metal cofactor interacts with small molecules in its catalytic role. In contrast, very little is presently known about how the protein acquires its metal cofactor, an important step in the maturation of the protein and one that is absolutely required for its biological function. Recent work is beginning to provide insight into the mechanisms of metal delivery to manganese superoxide dismutase in vivo and in vitro. PMID:19699328

  14. Phenotypes of mice lacking extracellular superoxide dismutase and copper- and zinc-containing superoxide dismutase.

    PubMed

    Sentman, Marie-Louise; Granström, Micael; Jakobson, Håkan; Reaume, Andrew; Basu, Samar; Marklund, Stefan L

    2006-03-17

    Mice lacking the secreted extracellular superoxide dismutase (EC-SOD) or the cytosolic copper- and zinc-containing SOD (CuZn-SOD) show relatively mild phenotypes. To explore the possibility that the isoenzymes have partly overlapping functions, single and double knockout mice were examined. The absence of EC-SOD was found to be without effect on the lifespan of mice, and the reduced lifespan of CuZn-SOD knockouts was not further shortened by EC-SOD deficiency. The urinary excretion of isoprostanes was increased in CuZn-SOD knockout mice, and plasma thiobarbituric acid-reactive substances levels were elevated in EC-SOD knockout mice. These oxidant stress markers showed potentiated increases in the absence of both isoenzymes. Other alterations were mainly found in CuZn-SOD knockout mice, such as halved glutathione peroxidase activity in the tissues examined and increased glutathione and iron in the liver. There were no changes in tissue content of the alternative superoxide scavenger ascorbate, but there was a 25% reduction in ascorbate in blood plasma in mice lacking CuZn-SOD. No increase was found in the urinary excretion of the terminal metabolites of NO, nitrite, and nitrate in any of the genotypes. In conclusion, apart from the increases in the global urinary and plasma oxidant stress markers, our phenotype studies revealed no other evidence that the copper- and zinc-containing SOD isoenzymes have overlapping roles.

  15. Differential effects of superoxide dismutase and superoxide dismutase/catalase mimetics on human breast cancer cells.

    PubMed

    Shah, Manisha H; Liu, Guei-Sheung; Thompson, Erik W; Dusting, Gregory J; Peshavariya, Hitesh M

    2015-04-01

    Reactive oxygen species (ROS) such as superoxide and hydrogen peroxide (H2O2) have been implicated in development and progression of breast cancer. In the present study, we have evaluated the effects of the superoxide dismutase (SOD) mimetic MnTmPyP and the SOD/catalase mimetic EUK 134 on superoxide and H2O2 formation as well as proliferation, adhesion, and migration of MCF-7 and MDA-MB-231 cells. Superoxide and H2O2 production was examined using dihydroethidium and Amplex red assays, respectively. Cell viability and adhesion were measured using a tetrazolium-based MTT assay. Cell proliferation was determined using trypan blue assay. Cell cycle progression was analyzed using flow cytometry. Clonal expansion of a single cell was performed using a colony formation assay. Cell migration was measured using transwell migration assay. Dual luciferase assay was used to determine NF-κB reporter activity. EUK 134 effectively reduced both superoxide and H2O2, whereas MnTmPyP removed superoxide but enhanced H2O2 formation. EUK 134 effectively attenuated viability, proliferation, clonal expansion, adhesion, and migration of MCF-7 and MDA-MB-231 cells. In contrast, MnTmPyP only reduced clonal expansion of MCF-7 and MDA-MB-231 cells but had no effect on adhesion and cell cycle progression. Tumor necrosis factor-alpha-induced NF-κB activity was reduced by EUK 134, whereas MnTmPyP enhanced this activity. These data indicate that the SOD mimetic MnTmPyP and the SOD/catalase mimetic EUK 134 exert differential effects on breast cancer cell growth. Inhibition of H2O2 signaling using EUK 134-like compound might be a promising approach to breast cancer therapy.

  16. Conformationally gated metal uptake by apo-manganese superoxide dismutase

    PubMed Central

    Whittaker, Mei M.; Whittaker, James W.

    2009-01-01

    Metal uptake by apo-manganese superoxide dismutase in vitro is a complex process exhibiting multiphase “gated” reaction kinetics and a striking sigmoidal temperature profile that has led to a model of conformationally gated metal binding, requiring conversion between “closed” and “open” forms. The present work systematically explores the structural determinants of metal binding in both WT apoprotein and mutational variants as a test of mechanistic models. The pH dependence of metallation under physiological conditions (37°C) shows it is linked to ionization of a single proton with a pKa of 7.7. Size exclusion chromatography demonstrates that the apoprotein is dimeric even when it is fully converted to the open form. The role of molecular motions in metal binding has been probed by using disulfide engineering to introduce covalent constraints into the protein. While restricting motion at domain interfaces has no effect, constraining the subunit interface significantly perturbs metal uptake, but does not prevent the process. Mutagenesis of residues in the active site environment results in a dramatic shift in the transition temperature by as much as 20°C or loss of pH-sensitivity. Based on these results, a mechanism for metal uptake by manganese superoxide dismutase is proposed involving reorientation of active site residues to form a metal entry channel. PMID:18841998

  17. A superoxide dismutase of metacestodes of Taenia taeniaeformis.

    PubMed

    Leid, R W; Suquet, C M

    1986-03-01

    Superoxide dismutase was purified from Taenia taeniaeformis metacestodes by sequential ion exchange chromatography on quaternary-amino-ethyl-cellulose, gel filtration chromatography on ACA 44 and ion exchange chromatography on DEAE-cellulose, followed by chromatofocusing on polybuffer exchanger 94. This isolation procedure resulted in the detection of a single protein-staining band on alkaline gels, coincident with enzyme activity. We have, however, detected what appear to be two peaks of enzyme activity within this single protein-staining band. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis using gradient slab gels and analysis under reducing conditions, resulted in the detection of only one protein at an apparent Mr of 16,600, while analysis under non-reducing conditions, gave a single protein of an apparent Mr of 64,000. The isoelectric point of the purified protein is 6.6. Boiling for 3 min completely destroyed the enzyme, whereas incubation for 2 h at 37 degrees C resulted in the loss of 56% of the enzymic activity. Incubation with 10 mM KCN resulted in 83% inhibition of the enzyme. We have detected up to 168 U ml-1 of enzyme activity in the cyst fluid surrounding the parasite in situ. This is the first instance in which any parasite superoxide dismutase has been purified to apparent homogeneity. Parasite-mediated enzymic destruction of superoxide anion can not only protect against oxygen toxicity as a result of normal parasite respiratory processes but also may serve as yet another mechanism used by tissue-dwelling parasites to evade host immunologic attack.

  18. Superoxide Dismutase in the Symbiont Anabaena azollae Strasb. 1

    PubMed Central

    Canini, A.; Galiazzo, F.; Rotilio, G.; Caiola, M. Grilli

    1991-01-01

    Superoxide dismutase was investigated in the symbiont Anabaena azollae Strasb. living in Azolla filiculoides Lam. In vegetative cells, three isoenzymatic forms of superoxide dismutase, containing manganese, iron, and the hybrid iron-manganese, respectively, were present. Hybrid superoxide dismutase, detected for the first time in cyanobacteria, was 7% of the total superoxide dismutase present in vegetative cells. All three superoxide dismutase forms increased in the Anabaena vegetative cells obtained from irradiated plants grown in winter. In heterocysts, only an iron superoxide dismutase was present, which amounted to 25% of total vegetative cell superoxide dismutase activity. Hybrid superoxide dismutase appeared in heterocysts after irradiation. In vegetative cells of Anabaena from plants grown in summer, the basal level of total superoxide dismutase increased by 60% as compared with winter, and was unaffected by irradiation. The levels of superoxide dismutase in heterocysts from control and exposed plants grown in summer were comparable to those observed in heterocysts obtained from the plants grown during winter. No direct correlation was found between nitrogenase activity and superoxide dismutase in heterocysts. The presence of cyanophycin granules, either within the heterocyst pore channel or close to the transversal septum of vegetative cells, suggested a mechanism to stop communications between vegetative cells and heterocysts. ImagesFigure 1Figure 3Figure 4Figure 5 PMID:16668392

  19. Extracellular superoxide dismutase of boar seminal plasma.

    PubMed

    Kowalowka, M; Wysocki, P; Fraser, L; Strzezek, J

    2008-08-01

    Superoxide dismutase (SOD) is an enzymatic component of the antioxidant defense system that protects spermatozoa by catalysing the dismutation of superoxide anions to hydrogen peroxide and oxygen. Age and season effects on SOD activity in the seminal plasma were measured in boars at the onset of 8 months through a 35-month period. It was found that age-related changes in SOD activity in the seminal plasma were markedly higher in boars less than 2 years of age. However, it appeared that SOD activity was established at the early sexual maturity age (8-12 months). There were variations in SOD activity throughout the season, being significantly higher in spring and autumn than in summer. A secretory extracellular form of SOD (EC-SOD) was purified to homogeneity (350-fold) from boar seminal plasma, using a three-step purification protocol (affinity chromatography followed by ion exchange and ceramic hydroxyapatite chromatography). The molecular properties and specificity of SOD (molecular mass, isoelectric point, optimum pH, thermostability and susceptibility to inhibitors) confirmed that the purified enzyme is an extracellular form of Cu/Zn-superoxide dismutase occurring in boar seminal plasma. The results of this study indicate that EC-SOD is an important antioxidant enzyme of boar seminal plasma, which plays an important physiological role in counteracting oxidative stress in spermatozoa.

  20. Superoxide Dismutases and Reactive Oxygen Species

    SciTech Connect

    Cabelli, D.E.

    2011-01-01

    The 'free radical theory' of aging was introduced over a half-century ago. In this theory, much of the deleterious effects of aging were attributed to the cumulative buildup of damage from reactive oxygen species. When discussing reactive oxygen species (ROS) in aerobic systems, both superoxide radicals (O{sub 2}{sup -}) and superoxide dismutases (SODs) are considered to play prominent roles. O{sub 2}{sup -} is formed by attachment of the electron to oxygen (O{sub 2}) that is present in tens to hundreds of micromolar concentration in vivo. SODs are enzymes that serve to eliminate O{sub 2}{sup -} by rapidly converting it to O{sub 2} and hydrogen peroxide (H{sub 2}O{sub 2}). Both the radical and the enzyme will be discussed with the focus on the systems that are present in humans.

  1. Induction of superoxide dismutases in Photobacterium leiognathi.

    PubMed

    Kobayashi, H; Tonokawa, H; Fukasawa, S; Yamakura, F

    1991-01-01

    We investigated the induction of Cu,Zn-SOD (bacteriocuprein) and Fe-SOD in Photobacterium leiognathi DK-A1 which was isolated from the light organ of the squid, Droteuthis kensaki. The induction of superoxide dismutases depended on the addition of paraquat to the medium. Induction of SOD by paraquat was attributed mostly to the bacteriocuprein by measuring of the activities of both SODs by using densitometry of isoelectrofocusing gel. When paraquat was added to the culture at various times in the early log phase of growth, the most efficient induction of the SODs, which was measured at the time of harvesting the cells (17 hours after inoculation), was observed when paraquat was added at 60 min after the inoculation. Catalase was not significantly induced by the addition of paraquat or increasing of oxygen concentration. We developed an assay of SOD by modification of a cytochrome c-xanthine oxidase method using a computer equipped absorption spectrophotometer.

  2. 2-methoxyestradiol does not inhibit superoxide dismutase.

    PubMed

    Kachadourian, R; Liochev, S I; Cabelli, D E; Patel, M N; Fridovich, I; Day, B J

    2001-08-15

    It has been reported in the literature that the endogenous estrogen metabolite 2-methoxyestradiol (2-ME) inhibits both manganese and copper,zinc superoxide dismutases (Mn and Cu,Zn SODs) and that this mechanism is responsible for 2-ME's ability to kill cancer cells. In fact, as demonstrated using several SOD assays including pulse radiolysis, 2-ME does not inhibit SOD but rather interferes with the SOD assay originally used. Nevertheless, as confirmed by aconitase inactivation measurements and lactate dehydrogenase release in human leukemia HL-60 cells, 2-ME does increase superoxide production in these cells and is more toxic than its non-O-methylated precursor 2-hydroxyestradiol. Other mechanisms previously suggested in the literature may explain 2-ME's ability to increase intracellular superoxide levels in tumor cells. Copyright 2001 Academic Press.

  3. Superoxide dismutase activity in thermally stressed Staphylococcus aureus.

    PubMed Central

    Bucker, E R; Martin, S E

    1981-01-01

    The effects of heat and NaCl on the activity of superoxide dismutase from Staphylococcus aureus were examined. A linear decrease in superoxide dismutase activity occurred when S. aureus MF-31 cells were thermally stressed for 90 min at 52% C in 100 mM potassium phosphate buffer (pH 7.2). After 20 min of heating, only 5% of the superoxide dismutase activity was lost. Heating for 60, 90 and 120 min resulted in decreases of approximately 10, 22, and 68%, respectively. The rates of thermal inactivation of superoxide dismutase from S. aureus strains 196E and 210 were similar and slightly greater than those of strains MF-31, S-6, and 181. The addition of NaCl before or after heating resulted in increased losses of superoxide dismutase activity. PMID:7235693

  4. Manganese Superoxide Dismutase in Cancer Prevention

    PubMed Central

    Robbins, Delira

    2014-01-01

    Abstract Significance: Cancer is the second leading cause of death in the United States. Considering the quality of life and treatment cost, the best way to fight against cancer is to prevent or suppress cancer development. Cancer is preventable as indicated by human papilloma virus (HPV) vaccination and tamoxifen/raloxifen treatment in breast cancer prevention. The activities of superoxide dismutases (SODs) are often lowered during early cancer development, making it a rational candidate for cancer prevention. Recent Advances: SOD liposome and mimetics have been shown to be effective in cancer prevention animal models. They've also passed safety tests during early phase clinical trials. Dietary supplement-based SOD cancer prevention provides another opportunity for antioxidant-based cancer prevention. New mechanistic studies have revealed that SOD inhibits not only oncogenic activity, but also subsequent metabolic shifts during early tumorigenesis. Critical Issues: Lack of sufficient animal model studies targeting specific cancers; and lack of clinical trials and support from pharmaceutical industries also hamper efforts in further advancing SOD-based cancer prevention. Future Directions: To educate and obtain support from our society that cancer is preventable. To combine SOD-based therapeutics with other cancer preventive agents to obtain synergistic effects. To formulate a dietary supplementation-based antioxidant approach for cancer prevention. Lastly, targeting specific populations who are prone to carcinogens, which can trigger oxidative stress as the mechanism of carcinogenesis. Antioxid. Redox Signal. 20, 1628–1645. PMID:23706068

  5. The structural biochemistry of the superoxide dismutases

    PubMed Central

    Perry, J.J.P.; Shin, D.S.; Getzoff, E.D.; Tainer, J.A.

    2011-01-01

    The discovery of superoxide dismutases (SODs), which convert superoxide radicals to molecular oxygen and hydrogen peroxide, has been termed the most important discovery of modern biology never to win a Nobel Prize. Here, we review the reasons this discovery has been underappreciated, as well as discuss the robust results supporting its premier biological importance and utility for current research. We highlight our understanding of SOD function gained through structural biology analyses, which reveal important hydrogen-bonding schemes and metal-binding motifs. These structural features create remarkable enzymes that promote catalysis at faster than diffusion-limited rates by using electrostatic guidance. These architectures additionally alter the redox potential of the active site metal center to a range suitable for the superoxide disproportionation reaction and protect against inhibition of catalysis by molecules such as phosphate. SOD structures may also control their enzymatic activity through product inhibition; manipulation of these product inhibition levels has the potential to generate therapeutic forms of SOD. Markedly, structural destabilization of the SOD architecture can lead to disease, as mutations in Cu,ZnSOD may result in familial amyotrophic lateral sclerosis, a relatively common, rapidly progressing and fatal neurodegenerative disorder. We describe our current understanding of how these Cu,ZnSOD mutations may lead to aggregation/fibril formation, as a detailed understanding of these mechanisms provides new avenues for the development of therapeutics against this so far untreatable neurodegenerative pathology. PMID:19914407

  6. Periplasmic Superoxide Dismutase in Meningococcal Pathogenicity

    PubMed Central

    Wilks, Kathryn E.; Dunn, Kate L. R.; Farrant, Jayne L.; Reddin, Karen M.; Gorringe, Andrew R.; Langford, Paul R.; Kroll, J. Simon

    1998-01-01

    Meningococcal sodC encodes periplasmic copper- and zinc-cofactored superoxide dismutase (Cu,Zn SOD) which catalyzes the conversion of the superoxide radical anion to hydrogen peroxide, preventing a sequence of reactions leading to production of toxic hydroxyl free radicals. From its periplasmic location, Cu,Zn SOD was inferred to acquire its substrate from outside the bacterial cell and was speculated to play a role in preserving meningococci from the action of microbicidal oxygen free radicals produced in the context of host defense. A sodC mutant was constructed by allelic exchange and was used to investigate the role of Cu,Zn SOD in pathogenicity. Wild-type and mutant meningococci grew at comparable rates and survived equally long in aerobic liquid culture. The mutant showed no increased sensitivity to paraquat, which generates superoxide within the cytosol, but was approximately 1,000-fold more sensitive to the toxicity of superoxide generated in solution by the xanthine/xanthine oxidase system. These data support a role for meningococcal Cu,Zn SOD in protection against exogenous superoxide. In experiments to translate this into a role in pathogenicity, wild-type and mutant organisms were used in an intraperitoneal mouse infection model. The sodC mutant was significantly less virulent. We conclude that periplasmic Cu,Zn SOD contributes to the virulence of Neisseria meningitidis, most likely by reducing the effectiveness of toxic oxygen host defenses. PMID:9423860

  7. Superoxide Dismutase as an Anaerobic Polypeptide 1

    PubMed Central

    Monk, Lorna S.; Fagerstedt, Kurt V.; Crawford, Robert M. M.

    1987-01-01

    The perennating organ, the rhizome, was chosen for examination of response to anoxia in the species Iris pseudacorus L., Iris germanica L. var Quechei, and Glyceria maxima (Hartm.) Holmberg. These monocots are known to differ in their tolerance of anoxia. Intact rhizomes were subjected to periods of prolonged anoxia of up to 28 days and superoxide dismutase (SOD) activity was determined in a 48 hour postanoxic recovery phase. Tests were performed to ensure the accuracy of the measured enzyme activities. In the most anoxia tolerant species, I. pseudacorus, SOD activity rose continuously during the period of imposed anoxia, and levels were maintained in the postanoxic recovery phases: 28 days brought about a 13-fold increase to 1576 U SOD per milligram protein. Small increases were found in the less anoxia tolerant I. germanica during anoxic/postanoxic phases, while a drop in activity was recorded in the least anoxia tolerant G. maxima. However, initial levels in G. maxima were more than twice as high as in the other two species. Experiments applying cycloheximide to anoxic rhizome slices of I. pseudacorus inhibited the increase in SOD activity. This indicates that SOD is, paradoxically, induced under anoxia and we suggest that in this species SOD is one of the enzymes identified as anaerobic polypeptides. The significance of the induction of an `oxygen-protecting' enzyme during complete oxygen deprivation is discussed with regard to a possible critical role during recovery from anoxic stress. PMID:16665795

  8. Manganese Superoxide Dismutase: Guardian of the Powerhouse

    PubMed Central

    Holley, Aaron K.; Bakthavatchalu, Vasudevan; Velez-Roman, Joyce M.; St. Clair, Daret K.

    2011-01-01

    The mitochondrion is vital for many metabolic pathways in the cell, contributing all or important constituent enzymes for diverse functions such as β-oxidation of fatty acids, the urea cycle, the citric acid cycle, and ATP synthesis. The mitochondrion is also a major site of reactive oxygen species (ROS) production in the cell. Aberrant production of mitochondrial ROS can have dramatic effects on cellular function, in part, due to oxidative modification of key metabolic proteins localized in the mitochondrion. The cell is equipped with myriad antioxidant enzyme systems to combat deleterious ROS production in mitochondria, with the mitochondrial antioxidant enzyme manganese superoxide dismutase (MnSOD) acting as the chief ROS scavenging enzyme in the cell. Factors that affect the expression and/or the activity of MnSOD, resulting in diminished antioxidant capacity of the cell, can have extraordinary consequences on the overall health of the cell by altering mitochondrial metabolic function, leading to the development and progression of numerous diseases. A better understanding of the mechanisms by which MnSOD protects cells from the harmful effects of overproduction of ROS, in particular, the effects of ROS on mitochondrial metabolic enzymes, may contribute to the development of novel treatments for various diseases in which ROS are an important component. PMID:22072939

  9. Manganese superoxide dismutase in cancer prevention.

    PubMed

    Robbins, Delira; Zhao, Yunfeng

    2014-04-01

    Cancer is the second leading cause of death in the United States. Considering the quality of life and treatment cost, the best way to fight against cancer is to prevent or suppress cancer development. Cancer is preventable as indicated by human papilloma virus (HPV) vaccination and tamoxifen/raloxifen treatment in breast cancer prevention. The activities of superoxide dismutases (SODs) are often lowered during early cancer development, making it a rational candidate for cancer prevention. SOD liposome and mimetics have been shown to be effective in cancer prevention animal models. They've also passed safety tests during early phase clinical trials. Dietary supplement-based SOD cancer prevention provides another opportunity for antioxidant-based cancer prevention. New mechanistic studies have revealed that SOD inhibits not only oncogenic activity, but also subsequent metabolic shifts during early tumorigenesis. Lack of sufficient animal model studies targeting specific cancers; and lack of clinical trials and support from pharmaceutical industries also hamper efforts in further advancing SOD-based cancer prevention. To educate and obtain support from our society that cancer is preventable. To combine SOD-based therapeutics with other cancer preventive agents to obtain synergistic effects. To formulate a dietary supplementation-based antioxidant approach for cancer prevention. Lastly, targeting specific populations who are prone to carcinogens, which can trigger oxidative stress as the mechanism of carcinogenesis.

  10. The peroxidase activity of mitochondrial superoxide dismutase.

    PubMed

    Ansenberger-Fricano, Kristine; Ganini, Douglas; Mao, Mao; Chatterjee, Saurabh; Dallas, Shannon; Mason, Ronald P; Stadler, Krisztian; Santos, Janine H; Bonini, Marcelo G

    2013-01-01

    Manganese superoxide dismutase (MnSOD) is an integral mitochondrial protein known as a first-line antioxidant defense against superoxide radical anions produced as by-products of the electron transport chain. Recent studies have shaped the idea that by regulating the mitochondrial redox status and H(2)O(2) outflow, MnSOD acts as a fundamental regulator of cellular proliferation, metabolism, and apoptosis, thereby assuming roles that extend far beyond its proposed antioxidant functions. Accordingly, allelic variations of MnSOD that have been shown to augment levels of MnSOD in mitochondria result in a 10-fold increase in prostate cancer risk. In addition, epidemiologic studies indicate that reduced glutathione peroxidase activity along with increases in H(2)O(2) further increase cancer risk in the face of MnSOD overexpression. These facts led us to hypothesize that, like its Cu,ZnSOD counterpart, MnSOD may work as a peroxidase, utilizing H(2)O(2) to promote mitochondrial damage, a known cancer risk factor. Here we report that MnSOD indeed possesses peroxidase activity that manifests in mitochondria when the enzyme is overexpressed. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Role of extracellular superoxide dismutase in hypertension.

    PubMed

    Gongora, Maria Carolina; Qin, Zhenyu; Laude, Karine; Kim, Ha Won; McCann, Louise; Folz, J Rodney; Dikalov, Sergey; Fukai, Tohru; Harrison, David G

    2006-09-01

    We previously found that angiotensin II-induced hypertension increases vascular extracellular superoxide dismutase (ecSOD), and proposed that this is a compensatory mechanism that blunts the hypertensive response and preserves endothelium-dependent vasodilatation. To test this hypothesis, we studied ecSOD-deficient mice. ecSOD(-/-) and C57Blk/6 mice had similar blood pressure at baseline; however, the hypertension caused by angiotensin II was greater in ecSOD(-/-) compared with wild-type mice (168 versus 147 mm Hg, respectively; P<0.01). In keeping with this, angiotensin II increased superoxide and reduced endothelium-dependent vasodilatation in small mesenteric arterioles to a greater extent in ecSOD(-/-) than in wild-type mice. In contrast to these findings in resistance vessels, angiotensin II paradoxically improved endothelium-dependent vasodilatation, reduced intracellular and extracellular superoxide, and increased NO production in aortas of ecSOD(-/-) mice. Whereas aortic expression of endothelial NO synthase, Cu/ZnSOD, and MnSOD were not altered in ecSOD(-/-) mice, the activity of Cu/ZnSOD was increased by 80% after angiotensin II infusion. This was associated with a concomitant increase in expression of the copper chaperone for Cu/ZnSOD in the aorta but not in the mesenteric arteries. Moreover, the angiotensin II-induced increase in aortic reduced nicotinamide-adenine dinucleotide phosphate oxidase activity was diminished in ecSOD(-/-) mice as compared with controls. Thus, during angiotensin II infusion, ecSOD reduces hypertension, minimizes vascular superoxide production, and preserves endothelial function in resistance arterioles. We also identified novel compensatory mechanisms involving upregulation of copper chaperone for Cu/ZnSOD, increased Cu/ZnSOD activity, and decreased reduced nicotinamide-adenine dinucleotide phosphate oxidase activity in larger vessels. These compensatory mechanisms preserve large vessel function when ecSOD is absent in

  12. Manganese superoxide dismutase: beyond life and death

    PubMed Central

    Holley, Aaron K.; Dhar, Sanjit Kumar; Xu, Yong

    2010-01-01

    Manganese superoxide dismutase (MnSOD) is a nuclear-encoded antioxidant enzyme that localizes to the mitochondria. Expression of MnSOD is essential for the survival of aerobic life. Transgenic mice expressing a luciferase reporter gene under the control of the human MnSOD promoter demonstrate that the level of MnSOD is reduced prior to the formation of cancer. Overexpression of MnSOD in transgenic mice reduces the incidences and multiplicity of papillomas in a DMBA/TPA skin carcinogenesis model. However, MnSOD deficiency does not lead to enhanced tumorigenicity of skin tissue similarly treated because MnSOD can modulate both the p53-mediated apoptosis and AP-1-mediated cell proliferation pathways. Apoptosis is associated with an increase in mitochondrial levels of p53 suggesting a link between MnSOD deficiency and mitochondrial-mediated apoptosis. Activation of p53 is preventable by application of a SOD mimetic (MnTE-2-PyP5+). Thus, p53 translocation to mitochondria and subsequent inactivation of MnSOD explain the observed mitochondrial dysfunction that leads to transcription-dependent mechanisms of p53-induced apoptosis. Administration of MnTE-2-PyP5+ following apoptosis but prior to proliferation leads to suppression of protein carbonyls and reduces the activity of AP-1 and the level of the proliferating cellular nuclear antigen, without reducing the activity of p53 or DNA fragmentation following TPA treatment. Remarkably, the incidence and multiplicity of skin tumors are drastically reduced in mice that receive MnTE-2-PyP5+ prior to cell proliferation. The results demonstrate the role of MnSOD beyond its essential role for survival and suggest a novel strategy for an antioxidant approach to cancer intervention. PMID:20454814

  13. Lung Extracellular Superoxide Dismutase Overexpression Lessens Bleomycin-Induced Pulmonary Hypertension and Vascular Remodeling

    PubMed Central

    Van Rheen, Zachary; Fattman, Cheryl; Domarski, Shannon; Majka, Susan; Klemm, Dwight; Stenmark, Kurt R.; Nozik-Grayck, Eva

    2011-01-01

    Interstitial lung disease is a devastating disease in humans that can be further complicated by the development of secondary pulmonary hypertension. Accumulating evidence indicates that the oxidant superoxide can contribute to the pathogenesis of both interstitial lung disease and pulmonary hypertension. We used a model of pulmonary hypertension secondary to bleomycin-induced pulmonary fibrosis to test the hypothesis that an imbalance in extracellular superoxide and its antioxidant defense, extracellular superoxide dismutase, will promote pulmonary vascular remodeling and pulmonary hypertension. We exposed transgenic mice overexpressing lung extracellular superoxide dismutase and wild-type littermates to a single dose of intratracheal bleomycin, and evaluated the mice weekly for up to 35 days. We assessed pulmonary vascular remodeling and the expression of several genes critical to lung fibrosis, as well as pulmonary hypertension and mortality. The overexpression of extracellular superoxide dismutase protected against late remodeling within the medial, adventitial, and intimal layers of the vessel wall after the administration of bleomycin, and attenuated pulmonary hypertension at the same late time point. The overexpression of extracellular superoxide dismutase also blocked the early up-regulation of two key genes in the lung known to be critical in pulmonary fibrosis and vascular remodeling, the transcription factor early growth response–1 and transforming growth factor–β. The overexpression of extracellular superoxide dismutase attenuated late pulmonary hypertension and significantly improved survival after exposure to bleomycin. These data indicate an important role for an extracellular oxidant/antioxidant imbalance in the pathogenesis of pulmonary vascular remodeling associated with secondary pulmonary hypertension attributable to bleomycin-induced lung fibrosis. PMID:20539010

  14. Peroxynitrite-mediated tyrosine nitration catalyzed by superoxide dismutase.

    PubMed

    Ischiropoulos, H; Zhu, L; Chen, J; Tsai, M; Martin, J C; Smith, C D; Beckman, J S

    1992-11-01

    Peroxynitrite (ONOO-), the reaction product of superoxide (O2-) and nitric oxide (NO), may be a major cytotoxic agent produced during inflammation, sepsis, and ischemia/reperfusion. Bovine Cu,Zn superoxide dismutase reacted with peroxynitrite to form a stable yellow protein-bound adduct identified as nitrotyrosine. The uv-visible spectrum of the peroxynitrite-modified superoxide dismutase was highly pH dependent, exhibiting a peak at 438 nm at alkaline pH that shifts to 356 nm at acidic pH. An equivalent uv-visible spectrum was obtained by Cu,Zn superoxide dismutase treated with tetranitromethane. The Raman spectrum of authentic nitrotyrosine was contained in the spectrum of peroxynitrite-modified Cu,Zn superoxide dismutase. The reaction was specific for peroxynitrite because no significant amounts of nitrotyrosine were formed with nitric oxide (NO), nitrogen dioxide (NO2), nitrite (NO2-), or nitrate (NO3-). Removal of the copper from the Cu,Zn superoxide dismutase prevented formation of nitrotyrosine by peroxynitrite. The mechanism appears to involve peroxynitrite initially reacting with the active site copper to form an intermediate with the reactivity of nitronium ion (NO2+), which then nitrates tyrosine on a second molecule of superoxide dismutase. In the absence of exogenous phenolics, the rate of nitration of tyrosine followed second-order kinetics with respect to Cu,Zn superoxide dismutase concentration, proceeding at a rate of 1.0 +/- 0.1 M-1.s-1. Peroxynitrite-mediated nitration of tyrosine was also observed with the Mn and Fe superoxide dismutases as well as other copper-containing proteins.

  15. The crystal structure of superoxide dismutase from Plasmodium falciparum

    PubMed Central

    Boucher, Ian W; Brzozowski, Andrzej M; Brannigan, James A; Schnick, Claudia; Smith, Derek J; Kyes, Sue A; Wilkinson, Anthony J

    2006-01-01

    Background Superoxide dismutases (SODs) are important enzymes in defence against oxidative stress. In Plasmodium falciparum, they may be expected to have special significance since part of the parasite life cycle is spent in red blood cells where the formation of reactive oxygen species is likely to be promoted by the products of haemoglobin breakdown. Thus, inhibitors of P. falciparum SODs have potential as anti-malarial compounds. As a step towards their development we have determined the crystal structure of the parasite's cytosolic iron superoxide dismutase. Results The cytosolic iron superoxide dismutase from P. falciparum (PfFeSOD) has been overexpressed in E. coli in a catalytically active form. Its crystal structure has been solved by molecular replacement and refined against data extending to 2.5 Å resolution. The structure reveals a two-domain organisation and an iron centre in which the metal is coordinated by three histidines, an aspartate and a solvent molecule. Consistent with ultracentrifugation analysis the enzyme is a dimer in which a hydrogen bonding lattice links the two active centres. Conclusion The tertiary structure of PfFeSOD is very similar to those of a number of other iron-and manganese-dependent superoxide dismutases, moreover the active site residues are conserved suggesting a common mechanism of action. Comparison of the dimer interfaces of PfFeSOD with the human manganese-dependent superoxide dismutase reveals a number of differences, which may underpin the design of parasite-selective superoxide dismutase inhibitors. PMID:17020617

  16. Superoxide Dismutase and Oxygen Toxicity in a Eukaryote

    PubMed Central

    Gregory, Eugene M.; Goscin, Stephen A.; Fridovich, Irwin

    1974-01-01

    Saccharomyces cerevisiae var. ellipsoideus contained 6.5 times more superoxide dismutase and 2.3 times more catalase when grown under 100% O2 than when grown anaerobically. Growth under oxygen caused equal increases in both the cyanide-sensitive and the cyanide-insensitive superoxide dismutases of this organism. Experience with other eukaryotes has shown that cyanide sensitivity is a property of the cupro-zinc superoxide dismutase of the cytosol, whereas cyanide insensitivity is a property of the corresponding mangani-enzyme found in mitochondria. Cu2+, which has been shown to increase the radioresistance of yeast, also caused an increase of both of the superoxide dismutases of S. cerevisiae. Yeast which had been grown under 1 atm of O2 were more resistant toward the lethal effects of 20 atm of O2 than were yeast which had been grown in the absence of O2. Escherichia coli K-12 his− responded to growth under 1 atm of O2 by increasing its content of catalase and of peroxidase, but not of superoxide dismutase. This contrasts with E. coli B, which was previously shown to respond to O2 by a striking increase in superoxide dismutase. E. coli K-12 his− did not gain resistance toward 20 atm of O2 because of having been grown under 1 atm of O2. Once again, this contrasts with the behavior of E. coli B. These data indicate that, in both prokaryotes and in eukaryotes, superoxide dismutase is an important component of the defenses against oxygen toxicity. PMID:4590469

  17. Purification and characterization of iron-cofactored superoxide dismutase from Enteromorpha linza

    NASA Astrophysics Data System (ADS)

    Lü, Mingsheng; Cai, Ruanhong; Wang, Shujun; Liu, Zhaopu; Jiao, Yuliang; Fang, Yaowei; Zhang, Xiaoxin

    2013-11-01

    A superoxide dismutase was purified from Enteromorpha linza using a simple and safe procedure, which comprised phosphate buffer extraction, ammonium sulphate precipitation, ion exchange chromatography on Q-sepharose column, and gel filtration chromatography on Superdex 200 10/300GL. The E. linza superoxide dismutase ( ElSOD) was purified 103.6-fold, and a yield of 19.1% and a specific activity of 1 750 U/mg protein were obtained. The SDS-PAGE exhibited ElSOD a single band near 23 kDa and the gel filtration study showed ElSOD's molecular weight is near 46 kDa in nondenatured condition, indicating it's a homodimeric protein. El SOD is an iron-cofactored superoxide dismutase (Fe-SOD) because it was inhibited by hydrogen peroxide, insensitive to potassium cyanide. The optimal temperature for its maximal enzyme activity was 35°C, and it still had 29.8% relative activity at 0°C, then ElSOD can be classified as a cold-adapted enzyme. ElSOD was stable when temperature was below 40°C or the pH was within the range of 5-10. The first 11 N-terminal amino acids of ElSOD were ALELKAPPYEL, comparison of its N-terminal sequence with other Fe-SOD N-terminal sequences at the same position suggests it is possibly a chloroplastic Fe-SOD.

  18. Intermolecular transmission of superoxide dismutase 1 misfolding in living cells

    PubMed Central

    Grad, Leslie I.; Guest, Will C.; Yanai, Anat; Pokrishevsky, Edward; O'Neill, Megan A.; Gibbs, Ebrima; Semenchenko, Valentyna; Yousefi, Masoud; Wishart, David S.; Plotkin, Steven S.; Cashman, Neil R.

    2011-01-01

    Human wild-type superoxide dismutase-1 (wtSOD1) is known to coaggregate with mutant SOD1 in familial amyotrophic lateral sclerosis (FALS), in double transgenic models of FALS, and in cell culture systems, but the structural determinants of this process are unclear. Here we molecularly dissect the effects of intracellular and cell-free obligately misfolded SOD1 mutant proteins on natively structured wild-type SOD1. Expression of the enzymatically inactive, natural familial ALS SOD1 mutations G127X and G85R in human mesenchymal and neural cell lines induces misfolding of wild-type natively structured SOD1, as indicated by: acquisition of immunoreactivity with SOD1 misfolding-specific monoclonal antibodies; markedly enhanced protease sensitivity suggestive of structural loosening; and nonnative disulfide-linked oligomer and multimer formation. Expression of G127X and G85R in mouse cell lines did not induce misfolding of murine wtSOD1, and a species restriction element for human wtSOD1 conversion was mapped to a region of sequence divergence in loop II and β-strand 3 of the SOD1 β-barrel (residues 24–36), then further refined surprisingly to a single tryptophan residue at codon 32 (W32) in human SOD1. Time course experiments enabled by W32 restriction revealed that G127X and misfolded wtSOD1 can induce misfolding of cell-endogenous wtSOD1. Finally, aggregated recombinant G127X is capable of inducing misfolding and protease sensitivity of recombinant human wtSOD1 in a cell-free system containing reducing and chelating agents; cell-free wtSOD1 conversion was also restricted by W32. These observations demonstrate that misfolded SOD1 can induce misfolding of natively structured wtSOD1 in a physiological intracellular milieu, consistent with a direct protein–protein interaction. PMID:21930926

  19. Structural features promoting dioxygen production by Dechloromonas aromatica chlorite dismutase

    PubMed Central

    Goblirsch, Brandon R.; Streit, Bennett R.; DuBois, Jennifer L.

    2010-01-01

    Chlorite dismutase (Cld) is a heme enzyme capable of rapidly and selectively decomposing chlorite (ClO2−) to Cl− and O2. The ability of Cld to promote O2 formation from ClO2− is unusual. Heme enzymes generally utilize ClO2− as an oxidant for reactions such as oxygen atom transfer to, or halogenation of, a second substrate. The X-ray crystal structure of Dechloromonas aromatica Cld co-crystallized with the substrate analogue nitrite (NO2−) was determined to investigate features responsible for this novel reactivity. The enzyme active site contains a single b-type heme coordinated by a proximal histidine residue. Structural analysis identified a glutamate residue hydrogen-bonded to the heme proximal histidine that may stabilize reactive heme species. A solvent-exposed arginine residue likely gates substrate entry to a tightly confined distal pocket. On the basis of the proposed mechanism of Cld, initial reaction of ClO2− within the distal pocket generates hypochlorite (ClO−) and a compound I intermediate. The sterically restrictive distal pocket probably facilitates the rapid rebound of ClO− with compound I forming the Cl− and O2 products. Common to other heme enzymes, Cld is inactivated after a finite number of turnovers, potentially via the observed formation of an off-pathway tryptophanyl radical species through electron migration to compound I. Three tryptophan residues of Cld have been identified as candidates for this off-pathway radical. Finally, a juxtaposition of hydrophobic residues between the distal pocket and the enzyme surface suggests O2 may have a preferential direction for exiting the active site. PMID:20386942

  20. Structural features promoting dioxygen production by Dechloromonas aromatica chlorite dismutase

    SciTech Connect

    Goblirsch, Brandon R.; Streit, Bennett R.; DuBois, Jennifer L.; Wilmot, Carrie M.

    2010-08-12

    Chlorite dismutase (Cld) is a heme enzyme capable of rapidly and selectively decomposing chlorite (ClO{sub 2}{sup -}) to Cl{sup -} and O{sub 2}. The ability of Cld to promote O{sub 2} formation from ClO{sub 2}{sup -} is unusual. Heme enzymes generally utilize ClO{sub 2}{sup -} as an oxidant for reactions such as oxygen atom transfer to, or halogenation of, a second substrate. The X-ray crystal structure of Dechloromonas aromatica Cld co-crystallized with the substrate analogue nitrite (NO{sub 2}{sup -}) was determined to investigate features responsible for this novel reactivity. The enzyme active site contains a single b-type heme coordinated by a proximal histidine residue. Structural analysis identified a glutamate residue hydrogen-bonded to the heme proximal histidine that may stabilize reactive heme species. A solvent-exposed arginine residue likely gates substrate entry to a tightly confined distal pocket. On the basis of the proposed mechanism of Cld, initial reaction of ClO{sub 2}{sup -} within the distal pocket generates hypochlorite (ClO{sup -}) and a compound I intermediate. The sterically restrictive distal pocket probably facilitates the rapid rebound of ClO{sup -} with compound I forming the Cl{sup -} and O{sub 2} products. Common to other heme enzymes, Cld is inactivated after a finite number of turnovers, potentially via the observed formation of an off-pathway tryptophanyl radical species through electron migration to compound I. Three tryptophan residues of Cld have been identified as candidates for this off-pathway radical. Finally, a juxtaposition of hydrophobic residues between the distal pocket and the enzyme surface suggests O{sub 2} may have a preferential direction for exiting the active site.

  1. Superoxide dismutase and O2 lethality in Bacteroides fragilis.

    PubMed Central

    Privalle, C T; Gregory, E M

    1979-01-01

    Exposure of midlog Bacteroides fragils (VPI 2393) to 2% O2-98% N2 caused a three- to fivefold increase in superoxide dismutase specific activity within the cells. The increase in specific activity was completed within 90 min after exposure to oxygen and was dependent upon protein synthesis. Cells containing the higher superoxide dismutase level were more resistant to the effects of 5 atm of oxygen tension than were cells containing the lower level of superoxide dismutase but were equally resistant to 5 atm of nitrogen tension. Similar results were observed upon comparing viability experiments with B. fragilis and B. vulgatus. Superoxide dismutase activity in sonic extracts of B. fragilis was rapidly inactivated by exposure to 5 mM H2O2 and was inhibited by 1 mM NaN3 but not 5 mM NaCN. The inhibition pattern is identical to the pattern demonstrated for the purified iron-containing enzyme from Escherichia coli B and suggests that the superoxide dismutase in B. fragilis is an iron enzyme. PMID:438129

  2. Absence of superoxide dismutase activity causes nuclear DNA fragmentation during the aging process

    SciTech Connect

    Muid, Khandaker Ashfaqul; Karakaya, Hüseyin Çaglar; Koc, Ahmet

    2014-02-07

    Highlights: • Aging process increases ROS accumulation. • Aging process increases DNA damage levels. • Absence of SOD activity does not cause DNA damage in young cells. • Absence of SOD activity accelerate aging and increase oxidative DNA damages during the aging process. - Abstract: Superoxide dismutases (SOD) serve as an important antioxidant defense mechanism in aerobic organisms, and deletion of these genes shortens the replicative life span in the budding yeast Saccharomyces cerevisiae. Even though involvement of superoxide dismutase enzymes in ROS scavenging and the aging process has been studied extensively in different organisms, analyses of DNA damages has not been performed for replicatively old superoxide dismutase deficient cells. In this study, we investigated the roles of SOD1, SOD2 and CCS1 genes in preserving genomic integrity in replicatively old yeast cells using the single cell comet assay. We observed that extend of DNA damage was not significantly different among the young cells of wild type, sod1Δ and sod2Δ strains. However, ccs1Δ mutants showed a 60% higher amount of DNA damage in the young stage compared to that of the wild type cells. The aging process increased the DNA damage rates 3-fold in the wild type and more than 5-fold in sod1Δ, sod2Δ, and ccs1Δ mutant cells. Furthermore, ROS levels of these strains showed a similar pattern to their DNA damage contents. Thus, our results confirm that cells accumulate DNA damages during the aging process and reveal that superoxide dismutase enzymes play a substantial role in preserving the genomic integrity in this process.

  3. Cu/Zn superoxide dismutases in developing cotton fibers

    USDA-ARS?s Scientific Manuscript database

    Hydrogen peroxide (H2O2) and other reactive oxygen species (ROS) are important signaling molecules in diverse physiological processes. Previously, we discovered superoxide dismutase (SOD) activity in extracellular protein preparations from fiber-bearing cotton (Gossypium hirsutum L.) seeds. We sho...

  4. Bacteriocuprein superoxide dismutase of Photobacterium leiognathi. Isolation and sequence of the gene and evidence for a precursor form.

    PubMed

    Steinman, H M

    1987-02-05

    The gene encoding the bacteriocuprein superoxide dismutase from Photobacterium leiognathi, American Type Culture Collection strain 25521, was cloned in a pUC12 vector and sequenced. The nucleotide sequence predicted a 22-residue leader peptide amino-terminal to the known bacteriocuprein sequence. The expected precursor bacteriocuprein was directly identified in the in vitro translation products of the cloned gene by polyacrylamide gel electrophoresis and automated Edman degradation. Enzymatically active bacteriocuprein that lacked the leader peptide was identified in sonic extracts of Escherichia coli hosts containing the cloned gene. A single transcript of 580 nucleotides was observed in blots of total P. leiognathi RNA, and a unique site of transcriptional initiation was identified by primer extension analysis. P. leiognathi bacteriocuprein is the first bacteriocuprein whose gene has been isolated and sequenced and the first copper-zinc superoxide dismutase in which a leader peptide has been found. The presence of a leader peptide suggests that the bacteriocuprein is localized in the membrane or periplasm, in contrast to the eukaryotic copper-zinc superoxide dismutases, which are cytoplasmic enzymes. Such a difference in intracellular location could be important for understanding the presence and function of the uncommon, bacteriocuprein superoxide dismutase in P. leiognathi.

  5. Production and some properties of catalase and superoxide dismutase from the anaerobe Bacteroides distasonis.

    PubMed Central

    Gregory, E M; Kowalski, J B; Holdeman, L V

    1977-01-01

    The catalase level of Bacteroides distasonis (ATCC 8503, type strain) varied with the amount of hemin supplied to the medium when the cells were grown in either a prereduced medium containing 0.5% peptone, 0.5% yeast extract, and 1% glucose or in a prereduced, defined heme-deficient medium. The effect of hemin on catalase production could not be duplicated by ferrous sulfate or ferrous ammonium citrate. Catalase activity reached peak values in late log phase, whereas superoxide dismutase specific activity remained constant throughout the culture growth cycle. The catalase was a nondialyzable, cyanide and azide-sensitive, heat-labile protein that coeluted with bovine erythrocyte catalase from Sepharose 6 B. Analysis of polyacrylamide gels stained for catalase activity and for heme showed a correspondence between the single catalytic activity band and one of three heme-protein bands. These data suggest a heme-protein of approximately 250,000 molecular weight. The superoxide dismutase was a cyanide-insensitive protein of approximately 40,000 molecular weight that migrated electrophoretically on acrylamide gels as a single band of activity. PMID:845116

  6. Regulation of superoxide dismutase synthesis in Candida albicans.

    PubMed

    Gunasekaran, U; Yang, R; Gunasekaran, M

    1998-01-01

    The synthesis of superoxide dismutase [SOD: EC 1.15.1.1] in response to various cultural conditions was examined in Candida albicans, an opportunistic yeast which causes candidiasis in immunosuppressed patients. SOD plays an important role in protecting cells from teh oxidative damage of superoxide radicals. Maximum SOD activity was found after 72 hrs of yeast growth. The optimum pH and temperature for the SOD activity were 7 and 40 degrees C, respectively. The major SOD activity was found in the cytosol fraction and the level of extracellular SOD was very low. The enzyme was stimulated to varying degrees by cholic acid, procaine and tocopherol. On the basis of inhibitor studies and other enzyme properties, the isolated enzyme from C. albicans is identified as a copper and zinc superoxide dismutase.

  7. Superoxide dismutase protects Escherichia coli against killing by human serum.

    PubMed

    McManus, D C; Josephy, P D

    1995-02-20

    To assess the role of superoxide dismutase in protecting Escherichia coli from killing by human serum and neutrophils, we constructed isogenic, smooth-lipopolysaccharide K-12 strains, either sod wild-type, delta sodA, or delta sodA delta sodB. The delta sodA delta sodB strain was killed by serum much more readily than either the wild-type or delta sodA strain. After allowing for this serum sensitivity difference, the delta sodA delta sodB strain also showed increased susceptibility to phagocytic killing by human neutrophils. These results indicate that superoxide dismutase protects E. coli from killing by serum (complement system) and by human neutrophils, possibly by a role in maintaining bacterial membrane structure.

  8. Impaired tolerance to repetitive hypoxia in hippocampal slices of Cu,Zn superoxide dismutase transgenic mice.

    PubMed

    Büchner, M; Li, H; Huber, R; Timmler, M; Sehrsam, I; Kasischke, K; Völkel, H; Ludolph, A C; Riepe, M W

    1999-12-03

    Energy metabolism is impaired in the Cu,Zn superoxide dismutase transgenic mouse model of amyotrophic lateral sclerosis. The goal was to investigate tolerance against single and repetitive hypoxia in C57B6SJL-TgN(SOD1-G93A)1GUR mice (G93A mice). Posthypoxic recovery (15 min hypoxia, 45 min recovery) of population spike amplitude in hippocampal region CA1 was 38 +/- 29% (mean +/- SD) in controls and 67 +/- 41% (ns) in G93A mice at day 40. Upon in vivo pretreatment with 20 mg/kg 3-nitropropionate posthypoxic recovery increased to 82 +/- 32% (P < 0.01) in controls and decreased to 35 +/- 33% in G93A mice (P < 0.05 to pretreated controls). Results at day 80 and 110 were similar. We conclude that G93A mice show a long-lasting impairment to sustain repetitive hypoxic episodes whereas tolerance to a single hypoxic episode is comparable to controls.

  9. Superoxide dismutase, catalase and acetylcholinesterase: biomarkers for the joint effects of cadmium, zinc and methyl parathion contamination in water.

    PubMed

    Ling, XuePing; Zhang, YiHeng; Lu, YingHua; Huang, HeQing

    2011-10-01

    Heavy metals are known to reduce the activities of antioxidant enzymes (e.g. superoxide dismutase, catalase), while organophosphorous insecticides are known to inhibit the activity of the enzyme acetylcholinesterase. In this study, the activities of these three enzymes in zebrafish (Danio rerio) tissues were assessed to evaluate the consequences heavy metal and organophosphate contamination in aquatic systems. When the fish were contacted with water containing a single pollutant, superoxide dismutase activity was affected by the presence of Cd but not by methyl parathion or Zn. However, catalase and acetylcholinesterase activities were sensitive to all three pollutants. The combined treatment showed that the three enzymes could be chosen as biomarkers of joint pollution by both metals and organophosphate. Toxicity tests showed an antagonism interaction between methyl parathion and Cd or Zn, and the change of enzyme activities at 96 hours was in accordance with that.

  10. Production of superoxide dismutases from Proteus mirabilis and Proteus vulgaris.

    PubMed

    Dayton, T M; Diefenbach, K A; Fuller, M L; Valtos, J; Niederhoffer, E C

    1996-04-01

    Proteus mirabilis and Proteus vulgaris expressed a combination of superoxide dismutase (Sod) activities, which was assigned to FeSod1, FeSod2 and MnSod for P. mirabilis, and FeSod, MnSod and CuZnSod for P. vulgaris. Production of the Sod proteins was dependent on the availability of iron, whether cells were grown under anaerobiosis or aerobiosis and growth phase. Nalidixic acid and chloramphenicol inhibited cell growth and the iron- and dioxygen-dependent production of Sod. These results support the involvement of metal ions and redox status in the production of Proteus Sods.

  11. Superoxide Dismutase Mimics: Chemistry, Pharmacology, and Therapeutic Potential

    PubMed Central

    Rebouças, Júlio S.; Spasojević, Ivan

    2010-01-01

    Abstract Oxidative stress has become widely viewed as an underlying condition in a number of diseases, such as ischemia–reperfusion disorders, central nervous system disorders, cardiovascular conditions, cancer, and diabetes. Thus, natural and synthetic antioxidants have been actively sought. Superoxide dismutase is a first line of defense against oxidative stress under physiological and pathological conditions. Therefore, the development of therapeutics aimed at mimicking superoxide dismutase was a natural maneuver. Metalloporphyrins, as well as Mn cyclic polyamines, Mn salen derivatives and nitroxides were all originally developed as SOD mimics. The same thermodynamic and electrostatic properties that make them potent SOD mimics may allow them to reduce other reactive species such as peroxynitrite, peroxynitrite-derived CO3·−, peroxyl radical, and less efficiently H2O2. By doing so SOD mimics can decrease both primary and secondary oxidative events, the latter arising from the inhibition of cellular transcriptional activity. To better judge the therapeutic potential and the advantage of one over the other type of compound, comparative studies of different classes of drugs in the same cellular and/or animal models are needed. We here provide a comprehensive overview of the chemical properties and some in vivo effects observed with various classes of compounds with a special emphasis on porphyrin-based compounds. Antioxid. Redox Signal. 13, 877–918. PMID:20095865

  12. Copper complexes of bioactive ligands with superoxide dismutase activity.

    PubMed

    Khalid, Huma; Hanif, Muhammad; Hashmi, Muhammad Ali; Mahmood, Tariq; Ayub, Khurshid; Monim-Ul-Mehboob, Muhammad

    2013-11-01

    Free radicals or reactive oxygen species (ROS) are highly toxic and their damaging effects result in a variety of detrimental health issues such as neurodegenerative, cardiovascular and age-related diseases. Human body has evolved an effective defense system including superoxide dismutase (SOD) and catalase against the toxicity of these free radicals. SOD is a metalloenzyme and it acts as an excellent antioxidant to protect the body from superoxide radicals that are generated in the biological system. However, the clinical use of SOD is limited due to its short in vivo life span, and its large size that hampered its penetration across the cell membranes. Pharmaceuticals that provide ROS scavenging systems are the most effective when the production of ROS exceeds the scavenging capacity of endogenous SOD as a result of aging or pathological processes. Inspired by the Nature, scientists have designed metal-based mimics of the superoxide dismutase. This review focuses on different copper complexes that are developed from bioactive ligands and mimic the protecting action of the SOD.

  13. Molecular characterization of two superoxide dismutases from Hydra vulgaris

    PubMed Central

    Dash, Bhagirathi; Metz, Richard; Huebner, Henry J.; Porter, Weston; Phillips, Timothy D.

    2007-01-01

    Apparent full-length cDNA sequences coding for manganese superoxide dismutase (HvMnSOD) and extracellular superoxide dismutase (HvEC-SOD) were isolated from Hydra vulgaris in order to understand their expression and 3D structures; and explore their possibility of being used as for biomarkers for environmental stress and toxicity. The deduced HvMnSOD protein consists of 219 amino acids of which first 21 amino acids constitute a presumed mitochondria-targeting signal peptide whereas HvEC-SOD protein consists of 189 amino acids of which first 19 amino acids constitute a presumed signal peptide. Molecular model generated for HvMnSOD displayed the N-terminal long alpha antiparallel hairpin and the C-terminal mixed alpha/beta fold characteristic of MnSODs and that for HvEC-SOD displayed the characteristic CuZnSOD beta-barrel fold. Hydrae subjected to thermal, starvation, metal and oxidative stress responded by regulating MnSOD and EC-SOD mRNA transcription. These results indicated that these genes are involved in the cellular stress response and (anti)oxidative processes triggered by stressor and contaminant exposure. Hence the expression of these SODs in hydra may have potential as molecular biomarkers for assessing stress, toxicity and pro-oxidant quality of chemicals and aquatic environmental quality. PMID:17150313

  14. Electroconvulsive shock in rats: changes in superoxide dismutase and glutathione peroxidase activity.

    PubMed

    Eraković, V; Zupan, G; Varljen, J; Radosević, S; Simonić, A

    2000-03-29

    Seizures trigger a variety of biochemical processes including an influx of extracellular Ca(2+), activation of membrane phospholipases, liberation of free fatty acids, diacylglycerols, eicosanoids, lipid peroxides and free radicals. These lipid metabolites along with abnormal ion homeostasis may be involved in cell injury and cell death. The aim of this study was to determine brain antioxidant enzyme activities in rats with electroconvulsive shock (ECS)-induced seizures. ECS, single or repeated, induced a decrease in superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities in various brain regions. The most prominent changes of enzymatic activities were observed in rats that received five ECSs with 24-h recovery period between them. Decreased SOD activity was observed in the frontal cortex of all treated animals except those sacrificed 24 h after single ECS, in the cerebellum of the animals that received repeated ECSs, in the hippocampus of animals that were decapitated 2 h after a single ECS and in the pons-medulla region of rats that received five daily ECSs. Decreased GPX activity was found in all examined brain regions of the rats that received five ECSs, the cortex and hippocampus of rats that were decapitated 2 h after single ECS and the cortex of those that received 10 ECSs with 48 h between them. The results show that neither 24-h nor 48-h recovery period was sufficient for the normalisation of antioxidative enzyme activities after repeated ECS treatment.

  15. Cupric yersiniabactin is a virulence-associated superoxide dismutase mimic.

    PubMed

    Chaturvedi, Kaveri S; Hung, Chia S; Giblin, Daryl E; Urushidani, Saki; Austin, Anthony M; Dinauer, Mary C; Henderson, Jeffrey P

    2014-02-21

    Many Gram-negative bacteria interact with extracellular metal ions by expressing one or more siderophore types. Among these, the virulence-associated siderophore yersiniabactin (Ybt) is an avid copper chelator, forming stable cupric (Cu(II)-Ybt) complexes that are detectable in infected patients. Here we show that Ybt-expressing E. coli are protected from intracellular killing within copper-replete phagocytic cells. This survival advantage is highly dependent upon the phagocyte respiratory burst, during which superoxide is generated by the NADPH oxidase complex. Chemical fractionation links this phenotype to a previously unappreciated superoxide dismutase (SOD)-like activity of Cu(II)-Ybt. Unlike previously described synthetic copper-salicylate (Cu(II)-SA) SOD mimics, the salicylate-based natural product Cu(II)-Ybt retains catalytic activity at physiologically plausible protein concentrations. These results reveal a new virulence-associated adaptation based upon spontaneous assembly of a non-protein catalyst.

  16. Extracellular Superoxide Dismutase: Growth Promoter or Tumor Suppressor?

    PubMed Central

    Laukkanen, Mikko O.

    2016-01-01

    Extracellular superoxide dismutase (SOD3) gene transfer to tissue damage results in increased healing, increased cell proliferation, decreased apoptosis, and decreased inflammatory cell infiltration. At molecular level, in vivo SOD3 overexpression reduces superoxide anion (O2−) concentration and increases mitogen kinase activation suggesting that SOD3 could have life-supporting characteristics. The hypothesis is further strengthened by the observations showing significantly increased mortality in conditional knockout mice. However, in cancer SOD3 has been shown to either increase or decrease cell proliferation and survival depending on the model system used, indicating that SOD3-derived growth mechanisms are not completely understood. In this paper, the author reviews the main discoveries in SOD3-dependent growth regulation and signal transduction. PMID:27293512

  17. Cupric Yersiniabactin Is a Virulence-Associated Superoxide Dismutase Mimic

    PubMed Central

    2013-01-01

    Many Gram-negative bacteria interact with extracellular metal ions by expressing one or more siderophore types. Among these, the virulence-associated siderophore yersiniabactin (Ybt) is an avid copper chelator, forming stable cupric (Cu(II)-Ybt) complexes that are detectable in infected patients. Here we show that Ybt-expressing E. coli are protected from intracellular killing within copper-replete phagocytic cells. This survival advantage is highly dependent upon the phagocyte respiratory burst, during which superoxide is generated by the NADPH oxidase complex. Chemical fractionation links this phenotype to a previously unappreciated superoxide dismutase (SOD)-like activity of Cu(II)-Ybt. Unlike previously described synthetic copper-salicylate (Cu(II)-SA) SOD mimics, the salicylate-based natural product Cu(II)-Ybt retains catalytic activity at physiologically plausible protein concentrations. These results reveal a new virulence-associated adaptation based upon spontaneous assembly of a non-protein catalyst. PMID:24283977

  18. Superoxide dismutase activity in radioresistant tissues of irradiated rabbits.

    PubMed

    Stoklasová, A; Kovárová, H; Ledvina, M

    1992-01-01

    The activities of Cu, Zn-containing superoxide dismutase were studied in radioresistant tissues (liver, brain, erythrocytes) of whole-body irradiated rabbits with 6.0 Gy and 24.0 Gy with local shielding. No significant changes were observed after irradiation with 6.0 Gy. Both the changes in Cu, Zn-SOD activity and the protein concentrations were more pronounced after exposure to 24.0 Gy with local shielding of the head and abdominal region. The dose on the shielded regions was about 6.0 Gy. Local shielding of rabbits irradiated with a lethal dose 24.0 Gy influenced positively the survival of animals. However, the decrease in SOD activity on 60th day after irradiation seems to be unfavourable for further survival of rabbits, if we accept that SOD content in tissue is maintained at a rather constant level.

  19. Reduced superoxide dismutase activity in xeroderma pigmentosum fibroblasts

    SciTech Connect

    Nishigori, C.; Miyachi, Y.; Imamura, S.; Takebe, H. )

    1989-10-01

    This study was performed in order to assess the possible protective effect of superoxide dismutase (SOD) on ultraviolet (UV) damage in xeroderma pigmentosum (XP) fibroblasts. SOD activity in fibroblasts originating from seven xeroderma pigmentosum (XP) patients was significantly lower than that in normal cells (p less than 0.005). Average SOD activity in XP cells belonging to complementation group A was 3.68 +/- 0.54 (n = 7) and that in normal human cells was 5.79 +/- 1.59 (n = 6). Addition of SOD before and during UV irradiation (UVB and UVC) to the cells caused no change in the amount of unscheduled DNA synthesis and UV survival. A possible involvement of reduced SOD in XP and a possible protective effect by SOD on UV damage is discussed.

  20. Preclinical trials of human erythrocyte superoxide dismutase injection.

    PubMed

    Zhou, C; Fang, Y; Jiang, D; Yang, S; Lu, X; Sui, J; Li, P; Ren, J

    2000-07-01

    To assess the quality of human erythrocyte superoxide dismutase (SOD) injection reaching the official standard for its clinical uses. Human erythrocyte SOD injection prepared by McCord-Fridovich's method without column chromatography but with some modifications was used in preclinical trials, to observe the general pharmacology and pharmacodynamics of the product. The quality of human erythrocyte SOD injection conformed to the official standard of a biological product, which was found to be non-toxic and did not have any effects on the central and autonomic nervous systems as well as cardiovascular and respiratory systems. The efficacy of anti-inflammation and promotion of immuno-regulation especially on carrageenan and adjuvant-induced polyarthritis were shown in animals. Human erythrocyte SOD injection is appropriate for prophylactic and therapeutic uses in clinical trials.

  1. Superoxide dismutase amplifies organismal sensitivity to ionizing radiation

    SciTech Connect

    Scott, M.D.; Meshnick, S.R.; Eaton, J.W.

    1989-02-15

    Although increased superoxide dismutase (SOD) activity is often associated with enhanced resistance of cells and organisms to oxidant challenges, few direct tests of the antioxidant importance of this enzyme have been carried out. To assess the importance of SOD in defending against gamma-radiation, we employed Escherichia coli with deficient, normal, and super-normal enzyme activities. Surprisingly, the radiation sensitivity of E. coli actually increases as bacterial SOD activity increases. Elevated intracellular SOD activity sensitizes E. coli to radiation-induced mortality, whereas SOD-deficient bacteria show normal or decreased radiosensitivity. Toxic effects of activated oxygen species are involved in this phenomenon; bacterial SOD activity has no effect on radiation sensitivity under anaerobic conditions or on the lethality of other, non-oxygen-dependent, toxins such as ultraviolet radiation.

  2. Stability of ALS-related Superoxide Dismutase Protein variants

    NASA Astrophysics Data System (ADS)

    Lusebrink, Daniel; Plotkin, Steven

    Superoxide dismutase (SOD1) is a metal binding, homodimeric protein, whose misfolding is implicated in the neurodegenerative disease amyotrophic lateral sclerosis (ALS). Monomerization is believed to be a key step in the propagation of the disease. The dimer stability is often difficult to measure experimentally however, because it is entangled with protein unfolding and metal loss. We thus computationally investigate the dimer stability of mutants of SOD1 known to be associated with ALS. We report on systematic trends in dimer stability, as well as intriguing allosteric communication between mutations and the dimer interface. We study the dimer stabilities in molecular dynamics simulations and obtain the binding free energies of the dimers from pulling essays. Mutations are applied in silicoand we compare the differences of binding free energies compared to the wild type.

  3. Metalloantibiotic Mn(II)-bacitracin complex mimicking manganese superoxide dismutase

    SciTech Connect

    Piacham, Theeraphon; Isarankura-Na-Ayudhya, Chartchalerm; Nantasenamat, Chanin; Yainoy, Sakda; Ye Lei; Buelow, Leif; Prachayasittikul, Virapong . E-mail: mtvpr@mucc.mahidol.ac.th

    2006-03-24

    Superoxide dismutase (SOD) activities of various metallobacitracin complexes were evaluated using the riboflavin-methionine-nitro blue tetrazolium assay. The radical scavenging activity of various metallobacitracin complexes was shown to be higher than those of the negative controls, e.g., free transition metal ions and metal-free bacitracin. The SOD activity of the complex was found to be in the order of Mn(II) > Cu(II) > Co(II) > Ni(II). Furthermore, the effect of bacitracin and their complexation to metals on various microorganisms was assessed by antibiotic susceptibility testing. Moreover, molecular modeling and quantum chemical calculation of the metallobacitracin complex was performed to evaluate the correlation of electrostatic charge of transition metal ions on the SOD activity.

  4. Strain variation in bacteriocuprein superoxide dismutase from symbiotic Photobacterium leiognathi.

    PubMed

    Dunlap, P V; Steinman, H M

    1986-02-01

    Photobacterium leiognathi ATCC 25521 (the type strain and light-organ symbiont of ponyfish) is one of the few bacteria that produces a copper-zinc superoxide dismutase, termed bacteriocuprein. We enzymologically and immunologically characterized the bacteriocuprein superoxide dismutases in sonicates from the type strain and nine additional strains of P. leiognathi, each isolated from the light organ of a separate ponyfish specimen, representing seven ponyfish species. The results indicate considerable strain variation. (i) The level of bacteriocuprein enzymatic activity varied greatly among strains from different species of ponyfish. In four of the nine strains, activity was low or undetectable, while in five strains it was comparable to that in the type strain. (ii) The bacteriocuprein in one strain had a specific activity much lower than that of the type strain, and in another strain, no bacteriocuprein activity and no cross-reactive polypeptide were detectable. (iii) A new electrophoretic variant, which migrated slower than that of strains from fish captured in Thailand and Japan, was identified in strains from fish captured in the Philippine Islands. (iv) Enzymological and immunological differences were observed in bacteriocupreins of strains from male and female specimens of the same ponyfish species, for the two species in which specimens of both sexes were examined. These observations raise the possibility that specific variations in the bacteriocupreins of P. leiognathi might be characteristic of the species, geographical source, or sex of the ponyfish host. Thus, the data indicate that the possibility of strain variation should be considered when other species are screened for bacteriocupreins.

  5. Purification and characterization of superoxide dismutase from chicken liver.

    PubMed

    Oztürk-Urek, R; Tarhan, L

    2001-02-01

    Superoxide dismutase (SOD; EC 1.15.1.1) is an enzyme that protects against oxidative stress from superoxide radicals in living cells. This enzyme has been isolated, purified and partially characterized from chicken liver. The following steps were carried out in order to purify chicken liver SOD. Initially, the liver was homogenized and hemoglobin was removed. Subsequently protein precipitation was effected with (NH(4))(2)SO(4), methanol, (NH(4))(2)SO(4)-methanol and polyethylene glycol methods. The product from polyethylene glycol-3350 precipitation was found to have the highest SOD activity. Polyethylene glycol was removed by chromatography using a PD-10 column. After passing through an ultrafilter, the superoxide dismutase was fractionated by DEAE-ion chromatography and then Sephadex G-75 gel filtration chromatography. During this purification procedure, a specific activity of 4818.2 IU/mg was reached, corresponding to 285.8-fold purification. The purified enzyme, which was characterized as cyanide-sensitive SOD, contained two subunits having Cu and Zn elements with a molecular weight of 16000+/-500 for each. The optimum pH of purified CuZnSOD was determined to be 8.9. The enzyme was found to have good pH stability in the pH range 6.0-7.5 at 25 degrees C over a 2-h incubation period and displayed good thermal stability up to 45 degrees C at pH 7.4 over a 1-h incubation period. The SOD enzyme was not inhibited by DTT and beta-mercaptoethanol, but inhibited by CN(-) and H(2)O(2). In the presence of 2 mM iodoacetamide, the enzyme showed an approximately 40% activity loss. Finally, the inhibitory effect of ionic strength on SOD was also investigated.

  6. Molecular characterization of a manganese superoxide dismutase and copper/zinc superoxide dismutase from the mussel Mytilus galloprovincialis.

    PubMed

    Wang, Qing; Yuan, Zeyi; Wu, Huifeng; Liu, Feng; Zhao, Jianmin

    2013-05-01

    The full-length cDNA sequences coding respectively for a manganese superoxide dismutase (Mg-MnSOD) and copper/zinc superoxide dismutase (Mg-CuZnSOD) were cloned from Mytilus galloprovincialis. Mg-MnSOD and Mg-CuZnSOD cDNAs encoded a polypeptide of 228 and 211 amino acids, respectively. Sequence analysis indicated Mg-MnSOD was a mitochondrial MnSOD and Mg-CuZnSOD was an intracellular CuZnSOD. Multiple alignment analysis showed that both Mg-MnSOD and Mg-CuZnSOD sequences had the common features conserved in MnSODs and CuZnSODs, respectively. Phylogenetic analysis revealed that Mg-MnSOD clustered together with MnSODs from other mollusks, whereas Mg-CuZnSOD clustered with other mollusk intracellular CuZnSODs with a wider phylogenetic distance. By quantitative real-time RT-PCR (qPCR) analysis, both Mg-MnSOD and Mg-CuZnSOD transcripts were detected in all tissues examined with the highest expression level in hepatopancreas. Following bacterial challenge, the expression level of Mg-MnSOD and Mg-CuZnSOD increased first and subsequently decreased to the original level in hemocytes. In hepatopancreas, Mg-CuZnSOD mRNA was up-regulated significantly at 72 h and 96 h post challenge, while the level of Mg-MnSOD transcript had no significant change. Therefore, Mg-MnSOD and Mg-CuZnSOD expressions were inducible and they were probably involved in the immune response against bacterial challenge. These results suggest that these SODs may play important roles in the immune defense system of M. galloprovincialis and perhaps contribute to the protective effects against oxidative stress in this mussel.

  7. Isolation and characterization of Cu,Zn superoxide dismutase of the shark Prionace glauca.

    PubMed

    Galtieri, A; Natoli, G; Lania, A; Calabrese, L

    1986-01-01

    A Cu,Zn superoxide dismutase was purified for the first time from an elasmobranch species (Prionace glauca) and showed the following differences with respect to other animal superoxide dismutases. The enzyme displays a low isoelectric point. The enzyme activity is unusually independent of ionic strength. The isolated enzyme has 30% of its copper in the reduced state.

  8. Cu,Zn Superoxide Dismutase is a Peroxisomal Enzyme in Human Fibroblast and Hepatoma Cells

    NASA Astrophysics Data System (ADS)

    Keller, Gilbert-Andre; Warner, Thomas G.; Steimer, Kathelyn S.; Hallewell, Robert A.

    1991-08-01

    The intracellular localization of Cu,Zn superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1) has been examined by immunofluorescence using four monoclonal anti-Cu,Zn superoxide dismutase antibodies raised against a recombinant human Cu,Zn superoxide dismutase derivative produced and purified from Escherichia coli. Colocalization with catalase, a peroxisomal matrix enzyme, was used to demonstrate the peroxisomal localization of Cu,Zn superoxide dismutase in human fibroblasts and hepatoma cells. In the fibroblasts of Zellweger syndrome patients, the enzyme is not transported to the peroxisomal ghosts but, like catalase, remains in the cytoplasm. In addition, immunocryoelectron microscopy of yeast cells expressing human Cu,Zn superoxide dismutase showed that the enzyme is translocated to the peroxisomes.

  9. Superoxide dismutase SOD-1 modulates C. elegans pathogen avoidance behavior

    PubMed Central

    Horspool, Alexander M.; Chang, Howard C.

    2017-01-01

    The C. elegans nervous system mediates protective physiological and behavioral responses amid infection. However, it remains largely unknown how the nervous system responds to reactive oxygen species (ROS) activated by pathogenic microbes during infection. Here, we show superoxide dismutase-1 (SOD-1), an enzyme that converts superoxide into less toxic hydrogen peroxide and oxygen, functions in the gustatory neuron ASER to mediate C. elegans pathogen avoidance response. When C. elegans first encounters pathogenic bacteria P. aeruginosa, SOD-1 is induced in the ASER neuron. After prolonged P. aeruginosa exposure, ASER-specific SOD-1 expression is diminished. In turn, C. elegans starts to vacate the pathogenic bacteria lawn. Genetic knockdown experiments reveal that pathogen-induced ROS activate sod-1 dependent behavioral response non cell-autonomously. We postulate that the delayed aversive response to detrimental microbes may provide survival benefits by allowing C. elegans to temporarily utilize food that is tainted with pathogens as an additional energy source. Our data offer a mechanistic insight into how the nervous system mediates food-seeking behavior amid oxidative stress and suggest that the internal state of redox homeostasis could underlie the behavioral response to harmful microbial species. PMID:28322326

  10. 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.

  11. Production of Dioxygen in the Dark: Dismutases of Oxyanions

    PubMed Central

    Ojha, Sunil

    2016-01-01

    O2 generating reactions are exceedingly rare in biology and difficult to mimic synthetically. Perchlorate-respiring bacteria enzymatically detoxify chlorite (ClO2−), the end product of the perchlorate (ClO4−) respiratory pathway, by rapidly converting it to dioxygen (O2) and chloride (Cl−). This reaction is catalyzed by a heme-containing protein, called chlorite dismutase (Cld), which bears no structural or sequence relationships with known peroxidases or other heme proteins and is part of a large family of proteins with more than one biochemical function. The original assumptions from the 1990s that perchlorate is not a natural product and that perchlorate respiration might be confined to a taxonomically narrow group of species have been called into question, as have the roles of perchlorate respiration and Cld-mediated reactions in the global biogeochemical cycle of chlorine. In this chapter, the chemistry and biochemistry of Cld-mediated O2 generation, as well as the biological and geochemical context of this extraordinary reaction, are described. PMID:25707466

  12. Copper, ceruloplasmin, superoxide dismutase and iron parameters in Parkinson's disease.

    PubMed

    Tórsdóttir, G; Kristinsson, J; Sveinbjörnsdóttir, S; Snaedal, J; Jóhannesson, T

    1999-11-01

    In a previous study we found copper dyshomeostasis in patients with Alzheimer's disease. In this study, levels of copper in plasma, of ceruloplasmin in serum and ceruloplasmin oxidative activity as well as superoxide dismutase (SOD) activity in erythrocytes were determined in 40 patients with Parkinson's disease and their healthy age- and gender-matched controls. Copper concentrations did not differ significantly in the two groups, whereas both ceruloplasmin concentrations and ceruloplasmin oxidative activity were significantly lower in the patients, also relative to ceruloplasmin mass. SOD activity was not significantly different in the two groups but decreased significantly with the duration of disease. The same was found for ceruloplasmin oxidative activity. Ceruloplasmin oxidative activity and SOD activity did not decrease with age. Levels of serum iron, serum ferritin and total iron binding capacity were determined in about 30 of the patients and an equal number of controls and were not found to differ. Transferrin levels were significantly lower in the patients than in their controls but, conversely, the transferrin saturation was significantly higher in the patients. The results indicate that patients with Alzheimer's disease and Parkinson's disease have defective ceruloplasmin and SOD activities in common and that these defects are not necessarily associated with major disturbances in iron homeostasis.

  13. Superoxide dismutase from the extremely halophilic archaebacterium Halobacterium cutirubrum.

    PubMed Central

    May, B P; Dennis, P P

    1987-01-01

    Halobacterium cutirubrum, a member of the archaebacteria, contains one superoxide dismutase (EC 1.15.1.1). This enzyme functions in the high-ionic-strength intracellular environment and protects the organism against the toxic effects of the superoxide anion. The enzyme has been purified to about 90% homogeneity by a four-step procedure which never removes it from conditions of high ionic strength. The subunits of the purified enzyme have a molecular weight of 25,000 and are possibly in tetrameric association. The enzyme shows anomalously high resistance to azide inhibition and sensitivity to inactivation by hydrogen peroxide. Metal analysis indicates 0.2 atom of Mn, less than 0.03 atom of Cu, and less than 0.001 atom of Fe per subunit. The low content of Mn may explain the low specific activity found for this enzyme compared with that of eubacterial enzymes. Optimum activity occurs in 2 M KCl; KCl gives about twice as much activity as NaCl over the range of 2 to 4 M. The enzyme appears to be related to those isolated from other archaebacteria but also exhibits several novel features. Images PMID:3104309

  14. Status of Superoxide Dismutase in Transfusion Dependent Thalassaemia

    PubMed Central

    Rujito, Lantip; Mulatsih, Sri; Sofro, Abdul Salam M.

    2015-01-01

    Background: Thalassemia is a collection of genetic impairments in beta and alpha genes causing various states of anemia. Severe types of the disease need lifelong transfusions, leading to oxidant-antioxidant disturbance due to massive iron deposits. Aims: The aim of this study was to assess the antioxidant enzyme Superoxide Dismutase (SOD) and ferritin levels of thalassemia major patients in a peripheral health facility. Materials and Methods: Two hundred and nine probands were recruited and performed laboratory experiments for SOD and Ferritin levels. Chelation administration and clinical score were taken from interviewing the family and from medical report data. Results: The study showed that SOD intensity was lower (162.41 u/ml) compared to the normal cutoff point (P = 0.001), while the mean of Ferritin levels was ten times over the normal value (4226,67 ng/dl). Observations also reported that chelation medicine was not administrated properly. Conclusions: The data indicates that thalassemic patients have oxidant-antioxidant uproar due to oxidative stress. Monitored chelating administration, selective antioxidant, and a well-balanced diet may prevent oxidative injury. PMID:26110130

  15. Superoxide Dismutase 1 Nanozyme for Treatment of Eye Inflammation

    PubMed Central

    Kost, Olga A.; Beznos, Olga V.; Davydova, Nina G.; Manickam, Devika S.; Nikolskaya, Irina I.; Guller, Anna E.; Binevski, Petr V.; Chesnokova, Natalia B.; Shekhter, Anatoly B.; Klyachko, Natalia L.; Kabanov, Alexander V.

    2016-01-01

    Use of antioxidants to mitigate oxidative stress during ocular inflammatory diseases has shown therapeutic potential. This work examines a nanoscale therapeutic modality for the eye on the base of antioxidant enzyme, superoxide dismutase 1 (SOD1), termed “nanozyme.” The nanozyme is produced by electrostatic coupling of the SOD1 with a cationic block copolymer, poly(L-lysine)-poly(ethyleneglycol), followed by covalent cross-linking of the complexes with 3,3′-dithiobis(sulfosuccinimidylpropionate) sodium salt. The ability of SOD1 nanozyme as well as the native SOD1 to reduce inflammatory processes in the eye was examined in vivo in rabbits with immunogenic uveitis. Results suggested that topical instillations of both enzyme forms demonstrated anti-inflammatory activity; however, the nanozyme was much more effective compared to the free enzyme in decreasing uveitis manifestations. In particular, we noted statistically significant differences in such inflammatory signs in the eye as the intensities of corneal and iris edema, hyperemia of conjunctiva, lens opacity, fibrin clots, and the protein content in aqueous humor. Clinical findings were confirmed by histological data. Thus, SOD1-containing nanozyme is potentially useful therapeutic agent for the treatment of ocular inflammatory disorders. PMID:26697135

  16. Superoxide dismutase activity in normal and preeclamptic placentas.

    PubMed

    Wiktor, H; Kankofer, M

    1998-12-01

    A deficiency in superoxide dismutase (SOD) activity in preeclamptic placentas can lead to an excess of superoxide radicals and may be responsible for the development and the severity of preeclampsia (PE). Our studies were undertaken in order to determine placental SOD activity and to investigate their association with the development and the severity of PE. The activity of SOD was determined using a spectrophotometric method in 22 placentas from normal term pregnancies (group K), 24 placentas from pregnancies complicated by severe PE (group PE), and 21 placentas from pregnancies complicated by severe PE and intrauterine growth retardation (IUGR) (group PEI). Mean activity of SOD (MSOD) in 45 preeclamptic placentas 3.89 +/- 1.32 (M +/- SD) was significantly lower (P = 0.008) as compared to MSOD in the group K (6.75 +/- 1.96). MSOD in the PEI group (3.5 +/- 1.29) was significantly lower (P = 0.03) as compared to MSOD in the group K. MSOD in the PE group (4.23 +/- 1.25) was lower than MSOD in the group K, but this difference was not statistically significant (P = 0.11). MSOD in the group PEI was lower as compared to MSOD in the PE group, however this difference was not statistically significant (P = 0.23). The studies revealed decreased SOD activity in preeclamptic placentas in comparison to normal placentas.

  17. Kinetics of chlorite dismutase in a perchlorate degrading reactor sludge.

    PubMed

    Nadaraja, Anupama Vijaya; Veetil, Prajeesh Gangadharan Puthiya; Vidyadharan, Athira; Bhaskaran, Krishnakumar

    2013-01-01

    Kinetics of chlorite dismutase (CD), the terminal enzyme involved in the perchlorate (ClO4(-)) reduction pathway, in a ClO4(-)-degrading bioreactor are reported in this study. Enzyme activity was determined from dissolved oxygen released during disproportionation of chlorite (ClO2(-)). CD activity was in the range 29.8-36.4 U/mg dry weight sludge, and kinetic constants Vmax and K(m) of the enzyme were 37.83 U/mg dry weight and 0.28 mM, respectively. Among reactor operational conditions, enzyme activity was observed at pH 4.0-9.0, with an optimum at pH 6.0. Redox potential in the range -50 to +120mV and NaCl up to 3.5 g/L had no significant effect on CD activity. However, co-occurring pollutants such as ammonium at 10 ppm, nitrite at 50 ppm and EDTA at 100 microM reduced CD activity substantially. The present study highlights ideal bioreactor conditions to avoid ClO2(-) toxicity, while indicating the buffering potential of a mixed microbial system against inhibiting factors to maintain stable CD activity in bioreactors.

  18. Measurement of chlorite dismutase activities in perchlorate respiring bacteria.

    PubMed

    Xu, Jianlin; Logan, Bruce E

    2003-08-01

    Chlorite dismutase (CD) catalyzes the disproportionation of chlorite to chloride (ClO(2)(-)-->Cl(-)+O(2)) and is present in bacteria capable of cell respiration using perchlorate or chlorate. The activity of this enzyme has previously been measured by monitoring oxygen evolution using a Clark-type dissolved oxygen (DO) probe. We demonstrate here, using two other methods to measure CD activity (a chloride-specific electrode and ion chromatography (IC)) via chloride production, that the DO probe method underestimates dismutation rates. Of the three methods, the chloride probe was the easiest to use and did not require extensive sample handling or post-experimental analysis. Using the chloride electrode method, we determined whole cell rate constants (V(max)=64 U/mg DW, K(m)=0.17 mM) for the chlorate-grown suspensions of Dechlorosoma sp. strain KJ. We compared the CD activities of strain KJ at a fixed chlorite concentration (0.6 mM) to four other perchlorate respiring bacteria (PRB), and to one non-PRB (Pseudomonas aeruginosa). Chlorate-grown cultures of the five PRB strains had CD activities ranging from 25 to 50 U/mg of cell dry weight (DW), while aerobically grown cultures of the PRB had much lower CD activities (0.5-4 U/mg DW). To our knowledge, this is the first systematic comparison of the different methods to measure CD activities, and the first comparison of CD activities of different PRBs.

  19. Determination of superoxide dismutase mimetic activity in common culinary herbs.

    PubMed

    Chohan, Magali; Naughton, Declan P; Opara, Elizabeth I

    2014-01-01

    Under conditions of oxidative stress, the removal of superoxide, a free radical associated with chronic inflammation, is catalysed by superoxide dismutase (SOD). Thus in addition to acting as an antioxidant, SOD may also be utilized as an anti-inflammatory agent. Some plant derived foods have been shown to have SOD mimetic (SODm) activity however it is not known if this activity is possessed by culinary herbs which have previously been shown to possess both antioxidant and anti-inflammatory properties. The aim of the study was to ascertain if the culinary herbs rosemary, sage and thyme possess SODm activity, and to investigate the influence of cooking and digestion on this activity. Transition metal ion content was also determined to establish if it could likely contribute to any SODm activity detected. All extracts of uncooked (U), cooked (C) and cooked and digested (C&D) herbs were shown to possess SODm activity, which was significantly correlated with previously determined antioxidant and anti-inflammatory activities of these herbs. SODm activity was significantly increased following (C) and (C&D) for rosemary and sage only. The impact of (C) and (C&D) on the SODm for thyme may have been influenced by its transition metal ion content. SODm activity may contribute to the herbs' antioxidant and anti-inflammatory activities however the source and significance of this activity need to be established.

  20. Superoxide dismutase activity of Cu-bound prion protein

    NASA Astrophysics Data System (ADS)

    Hodak, Miroslav; Lu, Wenchang; Bernholc, Jerry

    2009-03-01

    Misfolding of the prion protein, PrP, has been linked to a group of neurodegenerative diseases, including the mad cow disease in cattle and the Creutzfeldt-Jakob disease in humans. The normal function of PrP is still unknown, but it was found that the PrP can efficiently bind Cu(II) ions. Early experiments suggested that Cu-PrP complex possesses significant superoxide dismutase (SOD) activity, but later experiments failed to confirm it and at present this issue remains unresolved. Using a recently developed hybrid DFT/DFT method, which combines Kohn-Sham DFT for the solute and its first solvation shells with orbital-free DFT for the remainder of the solvent, we have investigated SOD activity of PrP. The PrP is capable of incorporating Cu(II) ions in several binding modes and our calculations find that each mode has a different SOD activity. The highest activity found is comparable to those of well-known SOD proteins, suggesting that the conflicting experimental results may be due to different bindings of Cu(II) in those experiments.

  1. Superoxide dismutase 3 attenuates experimental Th2-driven allergic conjunctivitis.

    PubMed

    Lee, Hyun Jung; Kim, Bo-Mi; Shin, Soojung; Kim, Tae-Yoon; Chung, So-Hyang

    2017-03-01

    Allergic conjunctivitis is an inflammatory eye disease mediated by Th2 type immune response. The role of extracellular superoxide dismutase 3 (SOD3) in immune response and allergic conjunctival inflammation was examined in a murine model for experimental allergic conjunctivitis (EAC). Allergic conjunctivitis was induced in mice by allergen challenge with ovalbumin in alum via the conjunctival sac. SOD3 was topically applied and allergy indicators were compared. Clinical signs associated with conjunctivitis, such as OVA-specific IgE production, IgG1/G2a ratio and eosinophil infiltration, were drastically reduced in mice treated with SOD3. They also had less dendritic cells and CD4(+) T cells in conjunctiva than controls. Attenuated allergic inflammation was accredited to reduced Th2 type cytokine responses and increased Treg cytokine in draining lymph node. The characteristics of EAC were attributed to the absence of SOD3. Our findings suggest that SOD3 might be considered as a potential target for Th2-driven allergic conjunctival inflammation. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Metabolic alterations in yeast lacking copper-zinc superoxide dismutase.

    PubMed

    Sehati, Sadaf; Clement, Matthew H S; Martins, Jake; Xu, Lei; Longo, Valter D; Valentine, Joan S; Gralla, Edith B

    2011-06-01

    Yeast lacking copper-zinc superoxide dismutase (sod1∆) have a number of oxygen-dependent defects, including auxotrophies for lysine and methionine and sensitivity to oxygen. Here we report additional defects in metabolic regulation. Under standard growth conditions with glucose as the carbon source, yeast undergo glucose repression in which mitochondrial respiration is deemphasized, energy is mainly derived from glycolysis, and ethanol is produced. When glucose is depleted, the diauxic shift is activated, in which mitochondrial respiration is reemphasized and stress resistance increases. We find that both of these programs are adversely affected by the lack of Sod1p. Key events in the diauxic shift do not occur and sod1∆ cells do not utilize ethanol and stop growing. The ability to shift to growth on ethanol is gradually lost as time in culture increases. In early stages of culture, sod1∆ cells consume more oxygen and have more mitochondrial mass than wild-type cells, indicating that glucose repression is not fully activated. These changes are at least partially dependent on the activity of the Hap2,3,4,5 complex, as indicated by CYC1-lacZ reporter assays. These changes may indicate a role for superoxide in metabolic signaling and regulation and/or a role for glucose derepression in defense against oxidative stress. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Biodegradable polycaprolactone (PCL) nanosphere encapsulating superoxide dismutase and catalase enzymes.

    PubMed

    Singh, Sushant; Singh, Abhay Narayan; Verma, Anil; Dubey, Vikash Kumar

    2013-12-01

    Biodegradable polycaprolactone (PCL) nanosphere encapsulating superoxide dismutase (SOD) and catalase (CAT) were successfully synthesized using double emulsion (w/o/w) solvent evaporation technique. Characterization of the nanosphere using dynamic light scattering, field emission scanning electron microscope, and Fourier transform infrared spectroscopy revealed a spherical-shaped nanosphere in a size range of 812 ± 64 nm with moderate protein encapsulation efficiency of 55.42 ± 3.7 % and high in vitro protein release. Human skin HaCat cells were used for analyzing antioxidative properties of SOD- and CAT-encapsulated PCL nanospheres. Oxidative stress condition in HaCat cells was optimized with exposure to hydrogen peroxide (H2O2; 1 mM) as external stress factor and verified through reactive oxygen species (ROS) analysis using H2DCFDA dye. PCL nanosphere encapsulating SOD and CAT together indicated better antioxidative defense against H2O2-induced oxidative stress in human skin HaCat cells in comparison to PCL encapsulating either SOD or CAT alone as well as against direct supplement of SOD and CAT protein solution. Increase in HaCat cells SOD and CAT activities after treatment hints toward uptake of PCL nanosphere into the human skin HaCat cells. The result signifies the role of PCL-encapsulating SOD and CAT nanosphere in alleviating oxidative stress.

  4. Biologically active metal-independent superoxide dismutase mimics

    SciTech Connect

    Mitchell, J.B.; Samuni, A.; Krishna, M.C.; DeGraff, W.G.; Ahn, M.S.; Samuni, U.; Russo, A. )

    1990-03-20

    Superoxide dismutase (SOD) is an enzyme that detoxifies superoxide (O2.-), a potentially toxic oxygen-derived species. Attempts to increase intracellular concentrations of SOD by direct application are complicated because SOD, being a relatively large molecule, does not readily cross cell membranes. We have identified a set of stable nitroxides that possess SOD-like activity, have the advantage of being low molecular weight, membrane permeable, and metal independent, and at pH 7.0 have reaction rate constants with O2.- ranging from 1.1 x 10(3) to 1.3 x 10(6) M-1 s-1. These SOD mimics protect mammalian cells from damage induced by hypoxanthine/xanthine oxidase and H{sub 2}O{sub 2}, although they exhibit no catalase-like activity. In addition, the nitroxide SOD mimics rapidly oxidize DNA-FeII and thus may interrupt the Fenton reaction and prevent formation of deleterious OH radicals and/or higher oxidation states of metal ions. Whether by SOD-like activity and/or interception of an electron from redox-active metal ions they protect cells from oxidative stress and may have use in basic and applied biological studies.

  5. Subcutaneous administration of bovine superoxide dismutase protects lungs from radiation-induced lung injury.

    PubMed

    Antonic, Vlado; Rabbani, Zahid N; Jackson, Isabel L; Vujaskovic, Zeljko

    2015-10-01

    The objective of the present study was to determine whether single administration of the antioxidant enzyme bovine superoxide dismutase (bSOD) after radiation therapy (RT) mitigates development of pulmonary toxicity in rats. Female F344 rats (n = 60) were divided among six experimental groups: (1) RT, single dose of 21 Gy to the right hemithorax; (2) RT + 5 mg/kg bSOD; (3) RT + 15 mg/kg bSOD; (4) No RT; (5) sham RT + 5 mg/kg bSOD; and (6) sham RT + 15 mg/kg bSOD. A single subcutaneous injection of bSOD (5 or 15 mg/kg) was administered 24 h post-radiation. The effects of bSOD on radiation-induced lung injury were assessed by measurement of body weight, breathing frequency, and histopathological changes. Immunohistochemistry was used to evaluate oxidative stress (8-OHdG(+), NOX4(+), nitrotyrosine(+), and 4HNE(+) cells), macrophage activation (ED1(+)), and expression of profibrotic transforming growth factor-β or TGF-β in irradiated tissue. Radiation led to an increase in all the evaluated parameters. Treatment with 15 mg/kg bSOD significantly decreased levels of all the evaluated parameters including tissue damage and breathing frequency starting 6 weeks post-radiation. Animals treated with 5 mg/kg bSOD trended toward a suppression of radiation-induced lung damage but did not reach statistical significance. The single application of bSOD (15 mg/kg) ameliorates radiation-induced lung injury through suppression of reactive oxygen species/reactive nitrogen species or ROS/RNS-dependent tissue damage.

  6. Erythrocyte copper chaperone for superoxide dismutase and superoxide dismutase as biomarkers for hepatic copper concentrations in Labrador retrievers.

    PubMed

    Dirksen, K; Roelen, Y S; van Wolferen, M E; Kruitwagen, H S; Penning, L C; Burgener, I A; Spee, B; Fieten, H

    2016-12-01

    Hereditary hepatic copper accumulation in Labrador retrievers leads to hepatitis with fibrosis and eventually cirrhosis. The development of a non-invasive blood-based biomarker for copper status in dogs could be helpful in identifying dogs at risk and to monitor copper concentrations during treatment. In this study, two cellular copper metabolism proteins, Cu/Zn superoxide dismutase (SOD1) and its chaperone (copper chaperone for SOD1, CCS) were measured in erythrocytes and tested for association with hepatic copper concentrations in 15 Labrador retrievers with normal or increased hepatic copper concentrations. Antibodies against CCS and SOD1 were applicable for use in canine specimens. This was demonstrated by the loss of immune-reactive bands for CCS and SOD1 in siRNA treated canine bile duct epithelial cells. Erythrocyte CCS and CCS/SOD1 ratios were decreased 2.37 (P <0.001) and 3.29 (P <0.001) fold in the high copper group compared to the normal copper group. Erythrocyte CCS and CCS/SOD1 ratio are potential new biomarkers for hepatic copper concentrations in Labrador retrievers and could facilitate early diagnosis and treatment monitoring for copper-associated hepatitis in dogs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Chaperonin 20 might be an iron chaperone for superoxide dismutase in activating iron superoxide dismutase (FeSOD)

    PubMed Central

    Kuo, Wen-Yu; Huang, Chien-Hsun; Jinn, Tsung-Luo

    2013-01-01

    Activation of Cu/Zn superoxide dismutases (CuZnSODs) is aided by Cu incorporation and disulfide isomerization by Cu chaperone of SOD (CCS). As well, an Fe-S cluster scaffold protein, ISU, might alter the incorporation of Fe or Mn into yeast MnSOD (ySOD2), thus leading to active or inactive ySOD2. However, metallochaperones involved in the activation of FeSODs are unknown. Recently, we found that a chloroplastic chaperonin cofactor, CPN20, could mediate FeSOD activity. To investigate whether Fe incorporation in FeSOD is affected by CPN20, we used inductively coupled plasma mass spectrometry to analyze the ability of CPN20 to bind Fe. CPN20 could bind Fe, and the Fe binding to FeSOD was increased with CPN20 incubation. Thus, CPN20 might be an Fe chaperone for FeSOD activation, a role independent of its well-known co-chaperonin activity. PMID:23299425

  8. Antioxidant Capacity and Superoxide Dismutase Activity in Adrenoleukodystrophy.

    PubMed

    Turk, Bela R; Theisen, Benjamin E; Nemeth, Christina L; Marx, Joel S; Shi, Xiaohai; Rosen, Melissa; Jones, Richard O; Moser, Ann B; Watkins, Paul A; Raymond, Gerald V; Tiffany, Carol; Fatemi, Ali

    2017-05-01

    X-linked adrenoleukodystrophy (ALD) may switch phenotype to the fatal cerebral form (ie, cerebral ALD [cALD]), the cause of which is unknown. Determining differences in antioxidant capacity and superoxide dismutase (SOD) levels between phenotypes may allow for the generation of a clinical biomarker for predicting the onset of cALD, as well as initiating a more timely lifesaving therapy. To identify variations in the levels of antioxidant capacity and SOD activity between ALD phenotypes in patients with cALD or adrenomyeloneuropathy (AMN), heterozygote female carriers, and healthy controls and, in addition, correlate antioxidant levels with clinical outcome scores to determine a possible predictive value. Samples of monocytes and blood plasma were prospectively collected from healthy controls, heterozygote female carriers, and patients with AMN or cALD. We are counting each patient as 1 sample in our study. Because adrenoleukodystrophy is an X-linked disease, the affected group populations of cALD and AMN are all male. The heterozygote carriers are all female. The samples were assayed for total antioxidant capacity and SOD activity. The data were collected in an academic hospital setting. Eligibility criteria included patients who received a diagnosis of ALD and heterozygote female carriers, both of which groups were compared with age-matched controls. The prospective samples (n = 30) were collected between January 2015 to January 2016, and existing samples were collected from tissue storage banks at the Kennedy Krieger Institute (n = 30). The analyses were performed during the first 3 months of 2016. Commercially available total antioxidant capacity and SOD assays were performed on samples of monocytes and blood plasma and correlated with magnetic resonance imaging severity score. A reduction in antioxidant capacity was shown between the healthy controls (0.225 mmol trolox equivalent) and heterozygote carriers (0.181 mmol trolox equivalent), and significant

  9. A Manganese Superoxide Dismutase (SOD2)-Mediated Adaptive Response

    PubMed Central

    Grdina, David J.; Murley, Jeffrey S.; Miller, Richard C.; Mauceri, Helena J.; Sutton, Harold G.; Thirman, Michael J.; Li, Jian Jian; Woloschak, Gayle E.; Weichselbaum, Ralph R.

    2013-01-01

    Very low doses of ionizing radiation, 5 to 100 mGy, can induce adaptive responses characterized by elevation in cell survival and reduction in micronuclei formation. Utilizing these end points, RKO human colon carcinoma and transformed mouse embryo fibroblasts (MEF), wild-type or knockout cells missing TNF receptors 1 and 2 (TNFR1−R2−), and C57BL/6 and TNFR1−R2− knockout mice, we demonstrate that intact TNF signaling is required for induction of elevated manganese superoxide dismutase (SOD2) activity (P < 0.001) and the subsequent expression of these SOD2-mediated adaptive responses when cells are challenged at a later time with 2 Gy. In contrast, amifostine’s free thiol form WR1065 can directly activate NF-κB giving rise to elevated SOD2 activity 24 h later and induce an adaptive response in both MEF wild-type and TNF signaling defective TNFR1−R2− cells. Transfection of cells with SOD2 siRNA completely abolishes both the elevation in SOD2 activity and expression of the adaptive responses. These results were confirmed in vivo using a micronucleus assay in splenocytes derived from C57BL/6 and TNFR1−R2− knockout mice that were exposed to 100 mGy or 400 mg/kg amifostine 24 h prior to exposure to a 2 Gy whole-body dose. A dose of 100 mGy also conferred enhanced protection to C57BL/6 mice exposed 24 h later to 100 mg/kg of N-Ethyl-N-nitrosourea (ENU). While very low radiation doses require an intact TNF signaling process to induce a SOD2-mediated adaptive response, amifostine can induce a similar adaptive response in both TNF receptor competent and knockout cells, respectively. PMID:23237540

  10. Mineral status and superoxide dismutase enzyme activity in Alzheimer's disease.

    PubMed

    Rodrigues, Gilmara Péres; Cozzolino, Silvia Maria Franciscato; Marreiro, Dilina do Nascimento; Caldas, Daniele Rodrigues Carvalho; da Silva, Kelcylene Gomes; de Sousa Almondes, Kaluce Gonçalves; Neto, José Machado Moita; Pimentel, José Alexandre Coelho; de Carvalho, Cecília Maria Resende Gonçalves; Nogueira, Nadir do Nascimento

    2017-12-01

    The study evaluated the dietary intake of zinc and copper, as measured by plasma and erythrocyte concentrations, the Cu/Zn ratio and measure the erythrocyte superoxide dismutase enzyme (eSOD) activity and the relationship between these markers and the degree of dementia in elderly individuals with and without Alzheimer's Disease (AD). A total of 93 elderly people aged 60-94 years were divided into two groups: with AD (n=44) and without AD (n=49). The NINCDS-ADRDA criteria were used for diagnosing AD, and dementia staging was determined using the Clinical Dementia Rating (CDR) scale. The dietary intake of Zn and Cu was obtained from a standard 3-day food record. Plasma and erythrocyte concentrations of the minerals were determined by flame atomic absorption spectrophotometry and by measuring eSOD activity in an automatic biochemical analyzer. The results showed dietary intake of Zn and Cu above the reference values with no differences observed between the two groups (p>0.05). Plasma and erythrocyte normocupremia as well as alteration in the Zn pool, with its reduced plasma concentrations and high in the erythrocytes, were observed in both groups (p>0.05). The plasma Cu/Zn ratio were not significantly different in patients with and without AD (p>0.05). The eSOD activity was high in both patient groups (p>0.05). However, among elderly patients with AD there was a positive correlation between this marker and dementia severity. According to our study results, we conclude that plasma and erythrocyte concentrations of Cu and Zn, as well as Cu/Zn ratio among elderly individuals is not related to Alzheimer's Disease. However, antioxidant activity of eSOD is associated with dementia severity. Copyright © 2017 Elsevier GmbH. All rights reserved.

  11. Therapeutic effect of lecithinized superoxide dismutase on pulmonary emphysema.

    PubMed

    Tanaka, Ken-Ichiro; Tanaka, Yuta; Miyazaki, Yuri; Namba, Takushi; Sato, Keizo; Aoshiba, Kazutetsu; Azuma, Arata; Mizushima, Tohru

    2011-09-01

    No medication exists that clearly improves the mortality of chronic obstructive pulmonary disease (COPD). Oxidative molecules, in particular superoxide anions, play important roles in the COPD-associated abnormal inflammatory response and pulmonary emphysema, which arises because of an imbalance in proteases and antiproteases and increased apoptosis. Superoxide dismutase (SOD) catalyzes the dismutation of superoxide anions. Lecithinized human Cu/Zn- SOD (PC-SOD) has overcome a number of the clinical limitations of SOD, including low tissue affinity and low stability in plasma. In this study, we examine the effect of PC-SOD on elastase-induced pulmonary emphysema, an animal model of COPD. The severity of the pulmonary inflammatory response and emphysema in mice was assessed by various criteria, such as the number of leukocytes in the bronchoalveolar lavage fluid and the enlargement of airspace. Not only intravenous administration but also inhalation of PC-SOD suppressed elastase-induced pulmonary inflammation, emphysema, and dysfunction. Inhalation of PC-SOD suppressed the elastase-induced increase in the pulmonary level of superoxide anions and apoptosis. Inhalation of PC-SOD also suppressed elastase-induced activation of proteases and decreased in the level of antiproteases and expression of proinflammatory cytokines and chemokines. We also found that inhalation of PC-SOD suppressed cigarette smoke-induced pulmonary inflammation. The results suggest that PC-SOD protects against pulmonary emphysema by decreasing the pulmonary level of superoxide anions, resulting in the inhibition of inflammation and apoptosis and amelioration of the protease/antiprotease imbalance. We propose that inhalation of PC-SOD would be therapeutically beneficial for COPD.

  12. Superoxide dismutase and oxygen toxicity defenses in the genus Neisseria.

    PubMed Central

    Archibald, F S; Duong, M N

    1986-01-01

    Among aerotolerant cells, Neisseria gonorrhoeae is very unusual because despite its obligately aerobic lifestyle and frequent isolation from purulent exudates containing polymorphonuclear leukocytes vigorously evolving O2- and H2O2, it contains no superoxide dismutase (SOD). Strains (14) of N. gonorrhoeae were compared with each other and with strains of Neisseria meningitidis, Neisseria mucosa, and Neisseria subflava under identical growth conditions for their contents of the oxy-protective enzymes catalase, peroxidase, and SOD, as well as respiratory chain proteins and activity. The absence of SOD from N. gonorrhoeae strains was demonstrated under a variety of oxygen-stress conditions. The neisserial species showed very different SOD, catalase, and peroxidase profiles. These profiles correlated well with the tolerance of the species to various intra- and extracellular oxygen insults. The high tolerance of N. gonorrhoeae for extracellular O2- and H2O2 appeared to be due to very high constitutive levels of peroxidase and catalase activity combined with a cell envelope impervious to O2-. Nevertheless, N. gonorrhoeae 19424 was much more sensitive to an intracellular flux of O2- than were the other (SOD-containing) neisserial species. The responses of N. gonorrhoeae and N. meningitidis respiratory and oxy-protective enzymes to growth under high and low oxygen tensions were followed, and a novel response, the apparent repression of the respiratory chain intermediates, respiration, and SOD, peroxidase, and catalase activity, was observed. The gonococcal catalase was partially purified and characterized. The results suggest that the very active terminal oxidase, low pO2 natural habitat, O2-stable catalase, and possibly the high glutathione content of the organism explain its aerobic survival in the absence of SOD. PMID:3943903

  13. Pharmacological induction of vascular extracellular superoxide dismutase expression in vivo.

    PubMed

    Oppermann, Marc; Balz, Vera; Adams, Volker; Dao, Vu Thao-Vi; Bas, Murat; Suvorava, Tatsiana; Kojda, Georg

    2009-07-01

    Pentaerythritol tetranitrate (PETN) treatment reduces progression of atherosclerosis and endothelial dysfunction and decreases oxidation of low-density lipoprotein (LDL) in rabbits. These effects are associated with decreased vascular superoxide production, but the underlying molecular mechanisms remain unknown. Previous studies demonstrated that endogenous nitric oxide could regulate the expression of extracellular superoxide dismutase (ecSOD) in conductance vessels in vivo. We investigated the effect of PETN and overexpression of endothelial nitric oxide synthase (eNOS(++)) on the expression and activity of ecSOD. C57BL/6 mice were randomized to receive placebo or increasing doses of PETN for 4 weeks and eNOS(++) mice with a several fold higher endothelial-specific eNOS expression were generated. The expression of ecSOD was determined in the lung and aortic tissue by real-time PCR and Western blot. The ecSOD activity was measured using inhibition of cytochrome C reduction. There was no effect of PETN treatment or eNOS overexpression on ecSOD mRNA in the lung tissue, whereas ecSOD protein expression increased from 2.5-fold to 3.6-fold (P < 0.05) by 6 mg PETN/kg body weight (BW)/day and 60 mg PETN/kg BW/day, respectively. A similar increase was found in aortic homogenates. eNOS(++) lung cytosols showed an increase of ecSOD protein level of 142 +/- 10.5% as compared with transgene-negative littermates (P < 0.05), which was abolished by N(omega)-nitro-L-arginine treatment. In each animal group, the increase of ecSOD expression was paralleled by an increase of ecSOD activity. Increased expression and activity of microvascular ecSOD are likely induced by increased bioavailability of vascular nitric oxide. Up-regulation of vascular ecSOD may contribute to the reported antioxidative and anti-atherosclerotic effects of PETN.

  14. The Interaction of Mitochondrial Iron with Manganese Superoxide Dismutase*

    PubMed Central

    Naranuntarat, Amornrat; Jensen, Laran T.; Pazicni, Samuel; Penner-Hahn, James E.; Culotta, Valeria C.

    2009-01-01

    Superoxide dismutase 2 (SOD2) is one of the rare mitochondrial enzymes evolved to use manganese as a cofactor over the more abundant element iron. Although mitochondrial iron does not normally bind SOD2, iron will misincorporate into Saccharomyces cerevisiae Sod2p when cells are starved for manganese or when mitochondrial iron homeostasis is disrupted by mutations in yeast grx5, ssq1, and mtm1. We report here that such changes in mitochondrial manganese and iron similarly affect cofactor selection in a heterologously expressed Escherichia coli Mn-SOD, but not a highly homologous Fe-SOD. By x-ray absorption near edge structure and extended x-ray absorption fine structure analyses of isolated mitochondria, we find that misincorporation of iron into yeast Sod2p does not correlate with significant changes in the average oxidation state or coordination chemistry of bulk mitochondrial iron. Instead, small changes in mitochondrial iron are likely to promote iron-SOD2 interactions. Iron binds Sod2p in yeast mutants blocking late stages of iron-sulfur cluster biogenesis (grx5, ssq1, and atm1), but not in mutants defective in the upstream Isu proteins that serve as scaffolds for iron-sulfur biosynthesis. In fact, we observed a requirement for the Isu proteins in iron inactivation of yeast Sod2p. Sod2p activity was restored in mtm1 and grx5 mutants by depleting cells of Isu proteins or using a dominant negative Isu1p predicted to stabilize iron binding to Isu1p. In all cases where disruptions in iron homeostasis inactivated Sod2p, we observed an increase in mitochondrial Isu proteins. These studies indicate that the Isu proteins and the iron-sulfur pathway can donate iron to Sod2p. PMID:19561359

  15. Autoxidation of ubiquinol-6 is independent of superoxide dismutase.

    PubMed

    Schultz, J R; Ellerby, L M; Gralla, E B; Valentine, J S; Clarke, C F

    1996-05-28

    Ubiquinone (Q) is an essential, lipid soluble, redox component of the mitochondrial respiratory chain. Much evidence suggests that ubiquinol (QH2) functions as an effective antioxidant in a number of membrane and biological systems by preventing peroxidative damage to lipids. It has been proposed that superoxide dismutase (SOD) may protect QH2 form autoxidation by acting either directly as a superoxide-semiquinone oxidoreductase or indirectly by scavenging superoxide. In this study, such an interaction between QH2 and SOD was tested by monitoring the fluorescence of cis-parinaric acid (cPN) incorporated phosphatidylcholine (PC) liposomes. Q6H2 was found to prevent both fluorescence decay and generation of lipid peroxides (LOOH) when peroxidation was initiated by the lipid-soluble azo initiator DAMP, dimethyl 2,2'-azobis (2-methylpropionate), while Q6 or SOD alone had no inhibitory effect. Addition of either SOD or catalase to Q6H2-containing liposomes had little effect on the rate of peroxidation even when incubated in 100% O2. Hence, the autoxidation of QH2 is a competing reaction that reduces the effectiveness of QH2 as an antioxidant and was not slowed by either SOD or catalase. The in vivo interaction of SOD and QH2 was also tested by employing yeast mutant strains harboring deletions in either CuZnSOD and/or MnSOD. The sod mutant yeast strains contained the same percent Q6H2 per cell as wild-type cells. These results indicate that the autoxidation of QH2 is independent of SOD.

  16. Superoxide dismutase-inhibitible reduction of cytochrome c by the alloxan radical. Implications for alloxan cytotoxicity.

    PubMed Central

    Winterbourn, C C

    1982-01-01

    Cytochrome c was reduced when superoxide was generated from xanthine oxidase in the presence of alloxan, and by the reaction of alloxan and with reduced glutathione. In each case, most of the reduction was inhibited by superoxide dismutase, but considerably more enzyme was required than with superoxide alone. This indicates that the superoxide dismutase-inhibitible cytochrome c reduction was mainly due to a direct reaction with the alloxan radical, and implies that other reactions that are inhibited by superoxide dismutase could be due to either alloxan radicals or superoxide. PMID:6299273

  17. Superoxide dismutase 2 as a marker to differentiate tuberculous pleural effusions from malignant pleural effusions.

    PubMed

    Wang, Maoshui; Zhang, Zhiqiang; Wang, Xinfeng

    2014-01-01

    Our previous study demonstrated that superoxide dismutase levels were higher in tuberculous pleural effusions than in malignant pleural effusions, but that this difference could not be used to discriminate between the two. The objective of the present study was to investigate the levels of superoxide dismutase 2 in pleural effusions and to evaluate the diagnostic significance of pleural effusion superoxide dismutase 2. Superoxide dismutase 2 concentrations were determined in pleural effusions from 54 patients with tuberculous pleural effusion and 33 with malignant pleural effusion using an enzyme-linked immunosorbent assay (ELISA) kit. Pleural effusion interferon gamma and tumor necrosis factor alpha levels were also analyzed by ELISA. The Mann-Whitney U test was used to evaluate the significance of differences. Associations between superoxide dismutase 2 concentrations and sex, age and smoking habits were assessed using Spearman's or Pearson's correlation coefficient analysis. Receiver operator characteristic analysis was performed to evaluate the value of superoxide dismutase 2 levels in the discrimination of tuberculous pleural effusion from malignant pleural effusion. Superoxide dismutase 2 levels were significantly higher in patients with tuberculous pleural effusion compared with those with malignant pleural effusion (p<0.05). When superoxide dismutase 2 was used to differentiate between tuberculous pleural effusions and malignant pleural effusions, the area under the receiver operator characteristic curve was 0.909 (95% confidence interval, 0.827-0.960; p<0.01). With a cut-off value of 54.2 ng/mL, the sensitivity, specificity, positive likelihood ratio and negative likelihood ratio were 75.8% (95%CI: 57.7-88.9%), 98.1% (95%CI: 90.1-99.7%), 40.91 and 0.25, respectively. Furthermore, significant correlations between pleural effusion superoxide dismutase 2 and interferon gamma (r=0.579, p<0.01) and between pleural effusion superoxide dismutase 2 and tumor

  18. Superoxide dismutase activity of Mycobacterium avium, M. intracellulare, and M. scrofulaceum.

    PubMed Central

    Mayer, B K; Falkinham, J O

    1986-01-01

    Superoxide dismutase (EC 1.15.1.1) (SOD) activity has been detected in crude cell extracts of representative strains of the Mycobacterium avium, M. intracellulare, and M. scrofulaceum (MAIS) group. Polyacrylamide gel electrophoresis demonstrated a single SOD activity band for each of the MAIS strains, though there were differences in mobility. All M. avium and M. intracellulare and two of five M. scrofulaceum strains demonstrated a single activity band of identical mobility (Rf = 0.83), while the SOD activity band for the three remaining M. scrofulaceum strains migrated farther (Rf = 0.85). The differences in mobility correlated with differences in sensitivity to NaN3 and H2O2. The SOD activities of the majority of the MAIS strains which displayed the slower-migrating activity band were inhibited 22 to 81% after 15 min of exposure to 5 mM H2O2, suggesting that both iron and manganese may be present in a single enzyme. The SOD activities of the three M. scrofulaceum strains which had the faster-migrating activity band were inhibited 100% after only 5 min of exposure to 5 mM H2O2 and exhibited greater sensitivity to 5 and 10 mM NaN3, characteristics of an iron-containing SOD. A concentration of 1 mM KCN did not cause inhibition of enzyme activity in any of the MAIS strains tested. Extracellular SOD activity was detected in four of six MAIS strains and was shown to be identical in mobility to the SOD activity of the crude extracts. Images PMID:3744555

  19. Altered Thiol Chemistry in Human Amyotrophic Lateral Sclerosis-linked Mutants of Superoxide Dismutase 1*

    PubMed Central

    Solsona, Carles; Kahn, Thomas B.; Badilla, Carmen L.; Álvarez-Zaldiernas, Cristina; Blasi, Juan; Fernandez, Julio M.; Alegre-Cebollada, Jorge

    2014-01-01

    Neurodegenerative diseases share a common characteristic, the presence of intracellular or extracellular deposits of protein aggregates in nervous tissues. Amyotrophic Lateral Sclerosis (ALS) is a severe and fatal neurodegenerative disorder, which affects preferentially motoneurons. Changes in the redox state of superoxide dismutase 1 (SOD1) are associated with the onset and development of familial forms of ALS. In human SOD1 (hSOD1), a conserved disulfide bond and two free cysteine residues can engage in anomalous thiol/disulfide exchange resulting in non-native disulfides, a hallmark of ALS that is related to protein misfolding and aggregation. Because of the many competing reaction pathways, traditional bulk techniques fall short at quantifying individual thiol/disulfide exchange reactions. Here, we adapt recently developed single-bond chemistry techniques to study individual disulfide isomerization reactions in hSOD1. Mechanical unfolding of hSOD1 leads to the formation of a polypeptide loop held by the disulfide. This loop behaves as a molecular jump rope that brings reactive Cys-111 close to the disulfide. Using force-clamp spectroscopy, we monitor nucleophilic attack of Cys-111 at either sulfur of the disulfide and determine the selectivity of the reaction. Disease-causing mutations G93A and A4V show greatly altered reactivity patterns, which may contribute to the progression of familial ALS. PMID:25096579

  20. Glutathionylation of the iron superoxide dismutase from the psychrophilic eubacterium Pseudoalteromonas haloplanktis.

    PubMed

    Castellano, Immacolata; Ruocco, Maria Rosaria; Cecere, Francesca; Di Maro, Antimo; Chambery, Angela; Michniewicz, Andzelika; Parlato, Giuseppe; Masullo, Mariorosario; De Vendittis, Emmanuele

    2008-05-01

    Our previous work showed that the adduct between beta-mercaptoethanol and the single cysteine residue (Cys57) in superoxide dismutase from the psychrophilic eubacterium Pseudoalteromonas haloplanktis (PhSOD) reduces the enzyme inactivation by peroxynitrite. In this work, immunoblotting experiments prove that peroxynitrite inactivation of PhSOD involves formation of nitrotyrosine residue(s). In order to study the role of Cys57 as a redox-sensor residue modifiable by cellular thiols, a recombinant PhSOD and two Cys57 mutants were produced and characterized. Recombinant and mutant enzymes share similar activity and peroxynitrite inactivation, but different reactivity towards three glutathione forms. Indeed, oxidized glutathione and S-nitrosoglutathione, but reduced glutathione, lead to S-glutathionylation of recombinant PhSOD. This new covalent modification for a Fe-SOD does not occur in both Cys57 mutants, thus indicating that its target is Cys57. Moreover, mass spectrometry analysis confirmed that S-glutathionylation of Cys57 takes place also with endogenous PhSOD. Formation of this mixed disulfide in PhSOD protects the enzyme from tyrosine nitration and peroxynitrite inactivation. PhSOD undergoes S-glutathionylation during its overproduction in E. coli cells and in a growing culture of P. haloplanktis. In both cases the extent of glutathionylated PhSOD is enhanced upon cell exposure to oxidative agents. We suggest that S-glutathionylation of PhSOD could represent a further cold-adaptation strategy to improve the antioxidant cellular defence mechanism.

  1. Dynamics-function correlation in Cu, Zn superoxide dismutase: a spectroscopic and molecular dynamics simulation study.

    PubMed Central

    Falconi, M; Stroppolo, M E; Cioni, P; Strambini, G; Sergi, A; Ferrario, M; Desideri, A

    2001-01-01

    A single mutation (Val29-->Gly) at the subunit interface of a Cu, Zn superoxide dismutase dimer leads to a twofold increase in the second order catalytic rate, when compared to the native enzyme, without causing any modification of the structure or the electric field distribution. To check the role of dynamic processes in this catalytic enhancement, the flexibility of the dimeric protein at the subunit interface region has been probed by the phosphorescence and fluorescence properties of the unique tryptophan residue. Multiple spectroscopic data indicate that Trp83 experiences a very similar, and relatively hydrophobic, environment in both wild-type and mutant protein, whereas its mobility is distinctly more restrained in the latter. Molecular dynamics simulation confirms this result, and provides, at the molecular level, details of the dynamic change felt by tryptophan. Moreover, the simulation shows that the loops surrounding the active site are more flexible in the mutant than in the native enzyme, making the copper more accessible to the incoming substrate, and being thus responsible for the catalytic rate enhancement. Evidence for increased, dynamic copper accessibility also comes from faster copper removal in the mutant by a metal chelator. These results indicate that differences in dynamic, rather than structural, features of the two enzymes are responsible for the observed functional change. PMID:11371434

  2. Biochemical properties of Cu/Zn-superoxide dismutase from fungal strain Aspergillus niger 26

    NASA Astrophysics Data System (ADS)

    Dolashki, Aleksandar; Abrashev, Radoslav; Stevanovic, Stefan; Stefanova, Lilyana; Ali, Syed Abid; Velkova, Ludmila; Hristova, Rumyana; Angelova, Maria; Voelter, Wolfgang; Devreese, Bart; Van Beeumen, Jozef; Dolashka-Angelova, Pavlina

    2008-12-01

    The fungal strain Aspergillus niger produces two superoxide dismutases, Cu/Zn-SOD and Mn-SOD. The primary structure of the Cu/Zn-SOD has been determined by Edman degradation of peptide fragments derived from proteolytic digests. A single chain of the protein, consisting of 153 amino acid residues, reveals a very high degree of structural homology with the amino acid sequences of other Aspergillus Cu/Zn-SODs. The molecular mass of ANSOD, measured by MALDI-MS and ESI-MS, and calculated by its amino acid sequence, was determined to be 15 821 Da. Only one Trp residue, at position 32, and one disulfide bridge were identified. However, neither a Tyr residue nor a carbohydrate chain occupying an N-linkage site (-Asn-Ile-Thr-) were found. Studies on the temperature and pH dependence of fluorescence, and on the temperature dependence of CD spectroscopic properties, confirmed that the enzyme is very stable, which can be explained by the stabilising effect of the disulfide bridge. The enzyme retains about 53% of its activity after incubation for a period of 30 min at 60 °C, and 15% at 85 °C.

  3. Crystal structure of nitrated human manganese superoxide dismutase: mechanism of inactivation.

    PubMed

    Quint, Patrick; Reutzel, Robbie; Mikulski, Rose; McKenna, Robert; Silverman, David N

    2006-02-01

    A cellular consequence of the reaction of superoxide and nitric oxide is enhanced peroxynitrite levels. Reaction of peroxynitrite with manganese superoxide dismutase (MnSOD) causes nitration of the active-site residue Tyr34 and nearly complete inhibition of catalysis. We report the crystal structures at 2.4 A resolution of human MnSOD nitrated by peroxynitrite and the unmodified MnSOD. A comparison of these structures showed no significant conformational changes of active-site residues or solvent displacement. The side chain of 3-nitrotyrosine 34 had a single conformation that extended toward the manganese with O1 of the nitro group within hydrogen-bonding distance (3.1 A) of Nepsilon2 of the second-shell ligand Gln143. Also, nitration of Tyr34 caused a weakening, as evidenced by the lengthening, of a hydrogen bond between its phenolic OH and Gln143, part of an extensive hydrogen-bond network in the active site. Inhibition of catalysis can be attributed to a steric effect of 3-nitrotyrosine 34 that impedes substrate access and binding, and alteration of the hydrogen-bond network that supports proton transfer in catalysis. It is also possible that an electrostatic effect of the nitro group has altered the finely tuned redox potential necessary for efficient catalysis, although the redox potential of nitrated MnSOD has not been measured.

  4. Exogenous Superoxide Dismutase: Action on Liver Oxidative Stress in Animals with Streptozotocin-Induced Diabetes

    PubMed Central

    Di Naso, Fábio Cangeri; Simões Dias, Alexandre; Porawski, Marilene; Marroni, Norma Anair Possa

    2011-01-01

    Aim. To investigate the effects of exogenous antioxidant copper zinc superoxide dismutase (Cu/Zn SOD) on oxidative stress in the experimental model of diabetes mellitus (DM). Methods. Twenty eight male Wistar rats divided in four groups were used: control (CO), controls treated with SOD (CO + SOD), diabetics (DM), and diabetics treated with SOD (DM + SOD). SOD (orgotein, 13 mg/Kg body weight was administered. DM was induced by a single streptozotocin injection (i.p., 70 mg/kg), and 60 days later, we evaluated liver oxidative stress. Results. Liver lipoperoxidation was increased in the DM group and significantly decreased in the DM + SOD group. Nitrite and nitrate measures were reduced in the DM and increased in the DM + SOD group, while iNOS expression in the DM group was 32% greater than in the CO and 53% greater in the DM + SOD group than in the DM group (P < .01). P65 expression was 37% higher in the DM (P < .05), and there was no significant difference between the DM and DM + SOD groups. Conclusion. SOD treatment reduced liver oxidative stress in diabetic animals, even though it did not change NFκB. SOD also increased NO, probably by the increased dismutation of the superoxide radical. The iNOS expression increase, which became even more evident after SOD administration. PMID:21437212

  5. Peroxynitrite-induced nitration of tyrosine-34 does not inhibit Escherichia coli iron superoxide dismutase.

    PubMed Central

    Soulère, L; Claparols, C; Périé, J; Hoffmann, P

    2001-01-01

    The peroxynitrite anion is a potent oxidizing agent, formed by the diffusion-limited combination of nitric oxide and superoxide, and its production under physiological conditions is associated with the pathologies of a number of inflammatory and neurodegenerative diseases. Nitration of Escherichia coli iron superoxide dismutase (Fe-SOD) by peroxynitrite was investigated, and demonstrated by spectral changes and electrospray mass spectroscopic analysis. HPLC and mass studies of the tryptic digests of the mono-nitrated Fe-SOD indicated that tyrosine-34 was the residue most susceptible to nitration by peroxynitrite. Exclusive nitration of this residue occurred when Fe-SOD was exposed to a cumulative dose of 0.4 mM peroxynitrite. Unlike with human Mn-SOD, this single modification did not inactivate E. coli Fe-SOD at pH 7.4. When Fe-SOD was exposed to higher concentrations of peroxynitrite (7 mM), eight tyrosine residues per subunit of the protein, of the nine available, were nitrated without loss of catalytic activity of the enzyme. The pK(a) of nitrated tyrosine-34 was determined to be 7.95+/-0.15, indicating that the peroxynitrite-modified enzyme appreciably maintains its protonation state under physiological conditions. PMID:11736645

  6. Structural Evidence for a Copper-Bound Carbonate Intermediate in the Peroxidase and Dismutase Activities of Superoxide Dismutase

    PubMed Central

    Strange, Richard W.; Hough, Michael A.; Antonyuk, Svetlana V.; Hasnain, S. Samar

    2012-01-01

    Copper-zinc superoxide dismutase (SOD) is of fundamental importance to our understanding of oxidative damage. Its primary function is catalysing the dismutation of superoxide to O2 and H2O2. SOD also reacts with H2O2, leading to the formation of a strong copper-bound oxidant species that can either inactivate the enzyme or oxidise other substrates. In the presence of bicarbonate (or CO2) and H2O2, this peroxidase activity is enhanced and produces the carbonate radical. This freely diffusible reactive oxygen species is proposed as the agent for oxidation of large substrates that are too bulky to enter the active site. Here, we provide direct structural evidence, from a 2.15 Å resolution crystal structure, of (bi)carbonate captured at the active site of reduced SOD, consistent with the view that a bound carbonate intermediate could be formed, producing a diffusible carbonate radical upon reoxidation of copper. The bound carbonate blocks direct access of substrates to Cu(I), suggesting that an adjunct to the accepted mechanism of SOD catalysed dismutation of superoxide operates, with Cu(I) oxidation by superoxide being driven via a proton-coupled electron transfer mechanism involving the bound carbonate rather than the solvent. Carbonate is captured in a different site when SOD is oxidised, being located in the active site channel adjacent to the catalytically important Arg143. This is the probable route of diffusion from the active site following reoxidation of the copper. In this position, the carbonate is poised for re-entry into the active site and binding to the reduced copper. PMID:22984565

  7. Pharmacological induction of vascular extracellular superoxide dismutase expression in vivo

    PubMed Central

    Oppermann, Marc; Balz, Vera; Adams, Volker; Thao-Vi Dao, Vu; Bas, Murat; Suvorava, Tatsiana; Kojda, Georg

    2009-01-01

    Pentaerythritol tetranitrate (PETN) treatment reduces progression of atherosclerosis and endothelial dysfunction and decreases oxidation of low-density lipoprotein (LDL) in rabbits. These effects are associated with decreased vascular superoxide production, but the underlying molecular mechanisms remain unknown. Previous studies demonstrated that endogenous nitric oxide could regulate the expression of extracellular superoxide dismutase (ecSOD) in conductance vessels in vivo. We investigated the effect of PETN and overexpression of endothelial nitric oxide synthase (eNOS++) on the expression and activity of ecSOD. C57BL/6 mice were randomized to receive placebo or increasing doses of PETN for 4 weeks and eNOS++ mice with a several fold higher endothelial-specific eNOS expression were generated. The expression of ecSOD was determined in the lung and aortic tissue by real-time PCR and Western blot. The ecSOD activity was measured using inhibition of cytochrome C reduction. There was no effect of PETN treatment or eNOS overexpression on ecSOD mRNA in the lung tissue, whereas ecSOD protein expression increased from 2.5-fold to 3.6-fold (P < 0.05) by 6 mg PETN/kg body weight (BW)/day and 60 mg PETN/kg BW/day, respectively. A similar increase was found in aortic homogenates. eNOS++ lung cytosols showed an increase of ecSOD protein level of 142 ± 10.5% as compared with transgene-negative littermates (P < 0.05), which was abolished by Nω-nitro-L-arginine treatment. In each animal group, the increase of ecSOD expression was paralleled by an increase of ecSOD activity. Increased expression and activity of microvascular ecSOD are likely induced by increased bioavailability of vascular nitric oxide. Up-regulation of vascular ecSOD may contribute to the reported antioxidative and anti-atherosclerotic effects of PETN. PMID:19320775

  8. Brain ischemic preconditioning is abolished by antioxidant drugs but does not up-regulate superoxide dismutase and glutathion peroxidase.

    PubMed

    Puisieux, François; Deplanque, Dominique; Bulckaen, Hélène; Maboudou, Patrice; Gelé, Patrick; Lhermitte, Michel; Lebuffe, Gilles; Bordet, Régis

    2004-11-19

    The present work examined the hypothesis that brain ischemic tolerance induced by ischemic preconditioning (IPC) is triggered by an initial oxidative stress and is associated with an increase in antioxidant enzyme activities as one end-effector of the neuroprotection. Wistar rats were preconditioned by a single 3-min occlusion of the middle cerebral artery. After a various duration of reperfusion (30 min, 24, 72 or 168 h), rats were subjected to a 60-min focal ischemia and sacrificed 24 h later. Cerebral infarcts were significantly reduced when performed during the 24- to 72-h time window after IPC. The pretreatment with the protein synthesis inhibitor, cycloheximide (1 mg/kg, i.p., 30 min prior to IPC), completely suppressed the neuroprotection. The free radical scavenger, dimethylthiourea (DMTU; 300 mg/kg, i.p., 30 min prior to IPC) and the antioxidant ebselen (10 mg/kg, oral cramming, 2 h before and 12 h after IPC) also abolished the IPC-induced protection of the brain. Nevertheless, IPC did not induce any delayed changes in antioxidant enzyme (superoxide dismutase, glutathion peroxidase) activities nor in the neuronal expression of Mn and Cu/Zn superoxide dismutase. These results indicate that an initial oxidative stress could be involved as a trigger of IPC, while antioxidant enzymes do not play a key role as end-effectors in such a neuroprotection.

  9. Role of Superoxide Dismutase 2 Gene Ala16Val Polymorphism and Total Antioxidant Capacity in Diabetes and its Complications

    PubMed Central

    Pourvali, Katayoun; Abbasi, Mehrnaz; Mottaghi, Azadeh

    2016-01-01

    Diabetes Mellitus (DM) is a chronic heterogeneous disorder and oxidative stress is a key participant in the development and progression of it and its complications. Anti-oxidant status can affect vulnerability to oxidative damage, onset and progression of diabetes and diabetes complications. Superoxide dismutase 2 (SOD2) is one of the major antioxidant defense systems against free radicals. SOD2 is encoded by the nuclear SOD2 gene located on the human chromosome 6q25 and the Ala16Val polymorphism has been identified in exon 2 of the human SOD2 gene. Ala16Val (rs4880) is the most commonly studied SOD2 single nucleotide polymorphism (SNP) in SOD2 gene. This SNP changes the amino acid at position 16 from valine (Val) to alanine (Ala), which has been shown to cause a conformational change in the target sequence of manganese superoxide dismutase (MnSOD) and also affects MnSOD activity in mitochondria. Ala16Val SNP and changes in the activity of the SOD2 antioxidant enzyme have been associated with altered progression and risk of different diseases. Association of this SNP with diabetes and some of its complications have been studied in numerous studies. This review evaluated how rs4880, oxidative stress and antioxidant status are associated with diabetes and its complications although some aspects of this line still remain unclear. PMID:27141263

  10. Sensitive spectrophotometric method for the determination of superoxide dismutase activity in tissue extracts

    SciTech Connect

    Paoletti, F.; Aldinucci, D.; Mocali, A.; Caparrini, A.

    1986-05-01

    Superoxide dismutase (EC 1.15.1.1) has been assayed by a spectrophotometric method based on the inhibition of a superoxide-driven NADH oxidation. The assay consists of a purely chemical reaction sequence which involves EDTA. Mn(II), mercaptoethanol, and molecular oxygen, requiring neither auxiliary enzymes nor sophisticated equipment. The method is very flexible and rapid and is applicable with high sensitivity to the determination of both pure and crude superoxide dismutase preparations. The decrease of the rate of NADH oxidation is a function of enzyme concentration, and saturation levels are attainable. Fifty percent inhibition, corresponding to one unit of the enzyme, is produced by approximately 15 ng of pure superoxide dismutase. Experiments on rat liver cytosol have shown the specificity of the method for superoxide dismutase. Moreover, common cellular components do not interfere with the measurement, except for hemoglobin when present at relatively high concentrations. The assay is performed at physiological pH and is unaffected by catalase.

  11. Purification of human copper, zinc superoxide dismutase by copper chelate affinity chromatography

    SciTech Connect

    Weslake, R.J.; Chesney, S.L.; Petkau, A.; Friesen, A.D.

    1986-05-15

    Copper, zinc superoxide dismutase was isolated from human red blood cell hemolysate by DEAE-Sepharose and copper chelate affinity chromatography. Enzyme preparations had specific activities ranging from 3400 to 3800 U/mg and recoveries were approximately 60% of the enzyme activity in the lysate. Copper chelate affinity chromatography resulted in a purification factor of about 60-fold. The homogeneity of the superoxide dismutase preparation was analyzed by sodium dodecyl sulfate-gel electrophoresis, analytical gel filtration chromatography, and isoelectric focusing.

  12. Induction of Cu,Zn-superoxide dismutase after cortical contusion injury during hypothermia.

    PubMed

    Fukuhara, T; Nishio, S; Ono, Y; Kawauchi, M; Asari, S; Ohmoto, T

    1994-09-19

    To determine the effect of hypothermia on superoxide injury after cerebral contusion, the induction of Cu,Zn-superoxide dismutase was examined 6 h after contusion in rats using Northern blotting. Cu,Zn-superoxide dismutase gene expression increased at the periphery of the contusion, which may indicate the severity of the superoxide stimulus. This increase was preserved after contusion under hypothermia, which may show that superoxide injury is still severe although brain edema is decreased.

  13. Spectroscopic characterization of recombinant Cu,Zn superoxide dismutase from Photobacterium leiognathi expressed in Escherichia coli: evidence for a novel catalytic copper binding site.

    PubMed

    Foti, D; Lo Curto, B; Cuzzocrea, G; Stroppolo, M E; Polizio, F; Venanzi, M; Desideri, A

    1997-06-10

    Cu,Zn superoxide dismutase from Photobacterium leiognathi has been cloned and expressed in Escherichia coli. The circular dichroism spectrum in the UV region of the recombinant protein indicates an higher content of random coil structure with respect to the eukaryotic enzymes. Investigation of the active site by optical, CD, and EPR spectroscopy indicates a different coordination geometry around the catalytic copper site with respect to the eukaryotic enzymes. In particular a different orientation of the metal bridging histidine is suggested. The pH dependence of the copper EPR spectrum shows the presence of a single equilibrium which is at least one unit lower than the pK value observed for the bovine enzyme. Despite such structural differences the catalytic rate of this enzyme is identical to that observed for the eukaryotic Cu,Zn superoxide dismutase, suggesting that the overall electric field distribution is similar to that observed in the eukaryotic enzymes.

  14. A novel superoxide dismutase from Cicer arietinum L. seedlings: isolation, purification and characterization.

    PubMed

    Singh, Sushant; Singh, Abhay Narayan; Verma, Anil; Dubey, Vikash Kumar

    2013-07-01

    Superoxide dismutase is an important enzyme with various therapeutic applications. Search of a new source of superoxide dismutase with novel properties has significant importance. The current work reports purification of a novel superoxide dismutase enzyme with unique characteristics. A copper zinc superoxide dismutase (Cu-Zn SOD) was purified and characterized from Cicer arietinum L. seedlings germinated under aluminium (Al+3) stress. The specific activity of purified protein was 158 units/mg with 28 fold purification. The superoxide dismutase is a homodimeric protein with approx subunit molecular weight of 33.27 kDa. The enzyme is identified as Cu-Zn category of superoxide dismutase, reflected by H2O2 induced inhibition of in-gel activity and presence of quantifiable copper and zinc ions. The optimum pH range for purified Cu-Zn SOD activity was observed within 6.5-8.5 (highest at pH 8.0) and the pH stability was in the range of 6.0-8.5. The enzyme was more stable at low temperature (below 30°C) and the Km of purified Cu-Zn SOD for riboflavin as substrate was 10.16 ± 2.5 µM. The N-terminal amino acid sequence showed homology at conserved residues with other plant Cu-Zn SODs.

  15. Neonatal developmental pattern of superoxide dismutase and aniline hydroxylase in rat lung

    SciTech Connect

    Kakkar, P.; Jaffery, F.N.; Viswanathan, P.N.

    1986-10-01

    The developmental biology of superoxide dismutase and aniline hydroxylase was followed in rat lungs from prenatal stage to 3 months old. Total superoxide dismutase activity as determined by spectrophotometry as well as electrophoresis was high in the prenatal rat lung, decreased in the first 24 hr postpartum, increased within 7 days, and then decreased gradually to adult levels. On polyacrylamide gel electrophoresis only two isozymic forms of superoxide dismutase were located as achromatic zones in the fetal lung. In the adult rat lung, there were three molecular forms of superoxide dismutase, two in the postmitochondrial supernatant and one in the mitochondrial fraction. Unlike superoxide dismutase, aniline hydroxylase was detectable only after 5 days of age and the activity exhibited a gradual increase afterward up to 1 month of age. The developmental pattern of superoxide dismutase and aniline hydroxylase activities in lung may be significant in understanding the mechanism of body defenses and their regulatory modulations in response to toxic air pollutants and environmental stress.

  16. Manganese Superoxide Dismutase Protects against 6-Hydroxydopamine Injury in Mouse Brains*

    PubMed Central

    Callio, Jason; Oury, Tim D.; Chu, Charleen T.

    2007-01-01

    Dopaminergic neurons of the substantia nigra are susceptible to toxin-based insults. Intrastriatal injection of 6-hydroxydopamine results in selective toxicity to these neurons. A mechanistic role for reactive oxygen species is supported by observations that antioxidants confer protection from 6-hydroxydopamine. Although cell culture studies have suggested extracellular or nonmitochondrial mechanisms in 6-hydroxydopamine toxicity, the compartmentalization of oxidative injury mechanisms is incompletely defined in vivo. Transgenic mice overexpressing mitochondrial manganese superoxide dismutase or extracellular superoxide dismutase received unilateral intrastriatal injections of 6-hydroxydopamine. Mice that overexpress manganese superoxide dismutase showed significantly smaller striatal lesions than littermate controls. There were no differences in nonspecific striatal injury associated with contralateral vehicle injection. Manganese superoxide dismutase overexpression also protected against loss of neuronal cell bodies in the substantia nigra. In contrast, mice overexpressing extracellular superoxide dismutase showed no protection from 6-hydroxydopamine toxicity in either brain region. Protection of the nigrostriatal system by overexpression of manganese super-oxide dismutase supports a role for mitochondrially derived superoxide in 6-hydroxydopamine toxicity. Mitochondrial oxidative stress appears to be a common mechanism among diverse models of Parkinson disease, whether involving toxins, mutated genes, or cybrid cells containing patient mitochondria. Antioxidant therapies that target this subcellular compartment may prove promising. PMID:15755737

  17. Changes in superoxide dismutase mRNA expression by streptozotocin-induced diabetes.

    PubMed Central

    Kamata, K.; Kobayashi, T.

    1996-01-01

    1. Experiments were designed to investigate the involvement of superoxide anions in the attenuated endothelium-dependent relaxation of the rat aorta from streptozotocin (STZ)-induced diabetic rats. 2. The endothelium-dependent relaxation responses to acetylcholine (ACh, 10(-7) M) in helical strips of the aorta precontracted with noradrenaline (NA, 5 x 10(-3) approximately 3 x 10(-7) M) were significantly decreased in STZ-induced diabetic rats. The recovery phase of the relaxation after single administration of ACh in the STZ-induced diabetic rats was more rapid than those in control vessels. 3. Preincubation of aortic strips with superoxide dismutase (SOD, 60 u ml-1) normalized the recovery phase of the relaxation of diabetic aorta after single administration of ACh, whereas catalase (150 u ml-1) or indomethacin (10(-5) M) had no effects on the relaxation. 4. SOD (180 u ml-1) caused relaxation in NA precontracted aortic strips and the degree of the SOD-induced relaxation was significantly greater in diabetic aorta as compared with age-matched control vessels. 5. When the changes in mRNA expressions of Mn-SOD or Cu-Zn-SOD were observed, Mn-SOD mRNA expression was markedly decreased, and Cu-Zn-SOD was slightly decreased in diabetic aorta. 6. These results suggest that the rapid destruction of NO by superoxide anions may occur in the STZ-induced diabetic rats, and this may be due to a decrease in mRNA expression of Mn-SOD or Cu-Zn-SOD. Images Figure 4 PMID:8894182

  18. The primary structure of Cu-Zn superoxide dismutase from Photobacterium leiognathi: evidence for a separate evolution of Cu-Zn superoxide dismutase in bacteria.

    PubMed

    Steffens, G J; Bannister, J V; Bannister, W H; Flohé, L; Günzler, W A; Kim, S M; Otting, F

    1983-06-01

    The complete amino-acid sequence of the copper-zinc superoxide dismutase of the Photobacterium leiognathi was determined. The fragmentation strategy employed included cyanogen bromide cleavage at its methionine residues and the only tryptophan residue. The S-carboxymethylated chain was further cleaved by means of trypsin, in order to obtain overlapping fragments. For sequence determination automated solid or liquid-phase techniques of Edman degradation were used. C-Terminal amino acids of the entire chain were determined after treatment with carboxypeptidase A. Comparison of the primary structure of this bacterial Cu-Zn superoxide dismutase with the established amino-acid sequences of the other eukaryotic Cu-Zn superoxide dismutases revealed clear homologies. Correspondingly, the Cu-Zn-binding amino-acid residues of the active centre were localized: His45, His47, His70, His79, His125 and Asp91. The two cysteine residues in position 52 and 147 were homologous to the cysteine residues, modelling the essential intrachain disulfide bridge of the corresponding bovine enzyme. As only 25-30% of aligned sequence positions were found to be identical, the enzyme of P. leiognathi shows only a remote phylogenetic relationship towards eukaryotic Cu-Zn superoxide dismutases. When compared to the established phylogenetic tree of the cytochrome c family, this indicates a separate evolution of Cu-Zn superoxide dismutase in Photobacterium. Therefore, a natural gene transfer from the eukaryotic host (ponyfish) to the prokaryotic photobacterium, which Martin and Fridovich postulated 1981 (J. Biol. Chem. 256, 6080-6089) on the basis of amino-acid compositions, can be excluded.

  19. Superoxide dismutase activity of the naturally occurring human serum albumin-copper complex without hydroxyl radical formation.

    PubMed

    Kato, Ryunosuke; Akiyama, Matofusa; Kawakami, Hiroyoshi; Komatsu, Teruyuki

    2014-01-01

    The superoxide radical anion (O2(.-)) is biologically toxic and contributes to the pathogenesis of various diseases. Here we describe the superoxide dismutase (SOD) activity of human serum albumin (HSA) complexed with a single Cu(II) ion at the N-terminal end (HSA-Cu complex). The structure of this naturally occurring copper-coordinated blood serum protein has been characterized by several physicochemical measurements. The O2(.-) dismutation ability of the HSA-Cu (1:1) complex is almost the same as that of the well-known SOD mimics, such as Mn(III) -tetrakis(N-methylpyridinium)porphyrin. Interestingly, the HSA-Cu complex does not induce a subsequent Fenton reaction to produce the hydroxyl radical (OH(.)), which is one of the most harmful reactive oxygen species.

  20. Manipulating Conserved Heme Cavity Residues of Chlorite Dismutase: Effect on Structure, Redox Chemistry, and Reactivity

    PubMed Central

    2013-01-01

    Chlorite dismutases (Clds) are heme b containing oxidoreductases that convert chlorite to chloride and molecular oxygen. In order to elucidate the role of conserved heme cavity residues in the catalysis of this reaction comprehensive mutational and biochemical analyses of Cld from “Candidatus Nitrospira defluvii” (NdCld) were performed. Particularly, point mutations of the cavity-forming residues R173, K141, W145, W146, and E210 were performed. The effect of manipulation in 12 single and double mutants was probed by UV–vis spectroscopy, spectroelectrochemistry, pre-steady-state and steady-state kinetics, and X-ray crystallography. Resulting biochemical data are discussed with respect to the known crystal structure of wild-type NdCld and the variants R173A and R173K as well as the structures of R173E, W145V, W145F, and the R173Q/W146Y solved in this work. The findings allow a critical analysis of the role of these heme cavity residues in the reaction mechanism of chlorite degradation that is proposed to involve hypohalous acid as transient intermediate and formation of an O=O bond. The distal R173 is shown to be important (but not fully essential) for the reaction with chlorite, and, upon addition of cyanide, it acts as a proton acceptor in the formation of the resulting low-spin complex. The proximal H-bonding network including K141-E210-H160 keeps the enzyme in its ferric (E°′ = −113 mV) and mainly five-coordinated high-spin state and is very susceptible to perturbation. PMID:24364531

  1. Effects of Altered Levels of Extracellular Superoxide Dismutase and Irradiation on Hippocampal Neurogenesis in Female Mice

    SciTech Connect

    Zou, Yani; Leu, David; Chui, Jennifer; Fike, John R.; Huang, Ting-Ting

    2013-11-15

    Purpose: Altered levels of extracellular superoxide dismutase (EC-SOD) and cranial irradiation have been shown to affect hippocampal neurogenesis. However, previous studies were only conducted in male mice, and it was not clear if there was a difference between males and females. Therefore, female mice were studied and the results compared with those generated in male mice from an earlier study. Methods and Materials: Female wild-type, EC-SOD-null (KO), and EC-SOD bigenic mice with neuronal-specific expression of EC-SOD (OE) were subjected to a single dose of 5-Gy gamma rays to the head at 8 weeks of age. Progenitor cell proliferation, differentiation, and long-term survival of newborn neurons were determined. Results: Similar to results from male mice, EC-SOD deficiency and irradiation both resulted in significant reductions in mature newborn neurons in female mice. EC-SOD deficiency reduced long-term survival of newborn neurons whereas irradiation reduced progenitor cell proliferation. Overexpression of EC-SOD corrected the negative impacts from EC-SOD deficiency and irradiation and normalized the production of newborn neurons in OE mice. Expression of neurotrophic factors brain-derived neurotrophic factor and neurotrophin-3 were significantly reduced by irradiation in wild-type mice, but the levels were not changed in KO and OE mice even though both cohorts started out with a lower baseline level. Conclusion: In terms of hippocampal neurogenesis, EC-SOD deficiency and irradiation have the same overall effects in males and females at the age the studies were conducted.

  2. Cloning and constitutive expression of Deschampsia antarctica Cu/Zn superoxide dismutase in Pichia pastoris

    PubMed Central

    Sánchez-Venegas, Jaime R; Navarrete, Alejandro; Dinamarca, Jorge; Bravo Ramírez, León A; Moraga, Ana Gutiérrez; Gidekel, Manuel

    2009-01-01

    Background Deschampsia antarctica shows tolerance to extreme environmental factors such as low temperature, high light intensity and an increasing UV radiation as result of the Antarctic ozone layer thinning. It is very likely that the survival of this species is due to the expression of genes that enable it to tolerate high levels of oxidative stress. On that account, we planned to clone the D. antarctica Cu/ZnSOD gene into Pichia pastoris and to characterize the heterologous protein. Findings The Copper/Zinc superoxide dismutase (Cu/ZnSOD) gene, SOD gene, was isolated from a D. antarctica by cDNA library screening. This SOD gene was cloned in the expression vector pGAPZαA and successfully integrated into the genome of the yeast P. pastoris SMD1168H. A constitutive expression system for the expression of the recombinant SOD protein was used. The recombinant protein was secreted into the YPD culture medium as a glycosylated protein with a 32 mg/l expression yield. The purified recombinant protein possesses a specific activity of 440 U/mg. Conclusion D. antarctica Cu/ZnSOD recombinant protein was expressed in a constitutive system, and purified in a single step by means of an affinity column. The recombinant SOD was secreted to the culture medium as a glycoprotein, corresponding to approximately 13% of the total secreted protein. The recombinant protein Cu/ZnSOD maintains 60% of its activity after incubation at 40°C for 30 minutes and it is stable (80% of activity) between -20°C and 20°C. The recombinant SOD described in this study can be used in various biotechnological applications. PMID:19821975

  3. Myeloperoxidase and superoxide dismutase polymorphisms are associated with an increased risk of developing pancreatic adenocarcinoma.

    PubMed

    Wheatley-Price, Paul; Asomaning, Kofi; Reid, Amy; Zhai, Rihong; Su, Li; Zhou, Wei; Zhu, Andrew; Ryan, David P; Christiani, David C; Liu, Geoffrey

    2008-03-01

    Pancreatic cancer risk has been linked to chronic pancreatitis and periodontitis, suggesting a role for inflammation in disease etiology. Myeloperoxidase (MPO) and superoxide dismutase (SOD2) are enzymes that regulate reactive oxygen species and contain recognized single nucleotide polymorphisms (SNPs) that confer altered enzyme activity. One hundred twenty-two patients with pancreatic cancer and 331 age- and sex-matched controls were analyzed for polymorphisms of the MPO - guanine 463 adenine (-G463A) and the SOD2 alanine (Ala)-to-valine (Val) polymorphism at codon 16 (Ala16Val) genes. Cases and controls were analyzed for associations between these polymorphisms, adjusting for sex, age, history of alcohol use and smoking history. The variant A allele of MPO -G463A was associated with a lower risk of pancreatic cancer (adjusted odds ratio [OR] for pancreatic cancer, 0.57; 95% confidence interval [95% CI], 0.4-0.9; P = .02). The SOD2 homozygous variant genotype (Val/Val) was associated with a greater risk of pancreatic cancer (adjusted OR, 1.96; 95% CI, 1.0-3.8; P = .04). Compared with individuals who carried both low-risk alleles (A/- and Ala/-), significantly more cases than controls carried both high-risk genotypes (G/G and Val/Val; adjusted OR, 4.31; 95% CI, 1.8-10; P = .001), or 1 high-risk genotype (adjusted OR, 1.96; 95% CI, 1.1-3.4; P = .01). Polymorphisms of the inflammatory pathway genes MPO -G463A and SOD2 Ala16Val are associated with elevated pancreatic cancer risk. Oxidative stress may play an important role in pancreatic cancer carcinogenesis.

  4. Superoxide dismutase 1 is positively selected to minimize protein aggregation in great apes.

    PubMed

    Dasmeh, Pouria; Kepp, Kasper P

    2017-08-01

    Positive (adaptive) selection has recently been implied in human superoxide dismutase 1 (SOD1), a highly abundant antioxidant protein with energy signaling and antiaging functions, one of very few examples of direct selection on a human protein product (exon); the molecular drivers of this selection are unknown. We mapped 30 extant SOD1 sequences to the recently established mammalian species tree and inferred ancestors, key substitutions, and signatures of selection during the protein's evolution. We detected elevated substitution rates leading to great apes (Hominidae) at ~1 per 2 million years, significantly higher than in other primates and rodents, although these paradoxically generally evolve much faster. The high evolutionary rate was partly due to relaxation of some selection pressures and partly to distinct positive selection of SOD1 in great apes. We then show that higher stability and net charge and changes at the dimer interface were selectively introduced upon separation from old world monkeys and lesser apes (gibbons). Consequently, human, chimpanzee and gorilla SOD1s have a net charge of -6 at physiological pH, whereas the closely related gibbons and macaques have -3. These features consistently point towards selection against the malicious aggregation effects of elevated SOD1 levels in long-living great apes. The findings mirror the impact of human SOD1 mutations that reduce net charge and/or stability and cause ALS, a motor neuron disease characterized by oxidative stress and SOD1 aggregates and triggered by aging. Our study thus marks an example of direct selection for a particular chemical phenotype (high net charge and stability) in a single human protein with possible implications for the evolution of aging.

  5. Lack of significant effects of superoxide dismutase and catalase on development of reperfusion arrhythmias.

    PubMed

    Hagar, J M; Hale, S L; Ilvento, J P; Kloner, R A

    1991-01-01

    It has been reported that agents having the ability to scavenge oxygen-derived free radicals reduce the severity of ventricular arrhythmias that occur after brief coronary occlusion and reperfusion. Superoxide dismutase plus catalase (SOD + CAT) or placebo was administered in a blinded randomized fashion prior to coronary occlusion in rats (n = 25 each group) undergoing a 5-min left coronary occlusion followed by 15 min of reperfusion. During reperfusion, ventricular tachycardia (VT) developed in 96% of animals in both groups. Reperfusion ventricular fibrillation (VF) developed in 60% of the placebo group vs 56% in the SOD + CAT group (p = 1.0). Irreversible VF occurred in 40% of the placebo group vs 20% in the SOD + CAT group (p = 0.22). Atrioventricular block occurred in 12% of placebo and 4% of SOD + CAT animals (p = 0.61). There were no significant difference between groups in duration of VT (85 +/- 15 s (mean +/- SEM) placebo vs 81 +/- 14 s SOD + CAT, p = 0.81), total duration of VT plus VF (391 +/- 76 s placebo vs 256 +/- 64 SOD + CAT, p = 0.45) or numbers of single ventricular ectopic beats (65 +/- 15 placebo vs 97 +/- 18 SOD + CAT, p = 0.18). Heart rate at reperfusion was slightly higher in control than SOD + CAT animals (340 +/- 33 vs 319 +/- 32, p = 0.02). Risk zone size, determined by Monastral blue injection, was equal in both groups (34 +/- 2% of ventricular mass). The occurrence of reperfusion VF in this model could not be predicted by heart rate at reperfusion (331 +/- 33 VF animlas vs 328 +/- 36 no VF, p = 0.77), or by risk zone size (34 +/- 2%, VF and no VF groups).(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Isolation and in silico analysis of Fe-superoxide dismutase in the cyanobacterium Nostoc commune.

    PubMed

    Kesheri, Minu; Kanchan, Swarna; Richa; Sinha, Rajeshwar P

    2014-12-15

    Cyanobacteria are known to endure various stress conditions due to the inbuilt potential for oxidative stress alleviation owing to the presence of an array of antioxidants. The present study shows that Antarctic cyanobacterium Nostoc commune possesses two antioxidative enzymes viz., superoxide dismutase (SOD) and catalase that jointly cope with environmental stresses prevailing at its natural habitat. Native-PAGE analysis illustrates the presence of a single prominent isoform recognized as Fe-SOD and three distinct isoforms of catalase. The protein sequence of Fe-SOD in N. commune retrieved from NCBI protein sequence database was used for in silico analysis. 3D structure of N. commune was predicted by comparative modeling using MODELLER 9v11. Further, this model was validated for its quality by Ramachandran plot, ERRAT, Verify 3D and ProSA-web which revealed good structure quality of the model. Multiple sequence alignment showed high conservation in N and C-terminal domain regions along with all metal binding positions in Fe-SOD which were also found to be highly conserved in all 28 cyanobacterial species under study, including N. commune. In silico prediction of isoelectric point and molecular weight of Fe-SOD was found to be 5.48 and 22,342.98Da respectively. The phylogenetic tree revealed that among 28 cyanobacterial species, Fe-SOD in N. commune was the closest evolutionary homolog of Fe-SOD in Nostoc punctiforme as evident by strong bootstrap value. Thus, N. commune may serve as a good biological model for studies related to survival of life under extreme conditions prevailing at the Antarctic region. Moreover cyanobacteria may be exploited for biochemical and biotechnological applications of enzymatic antioxidants. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Effect of Oxidative Damage on the Stability and Dimerization of Superoxide Dismutase 1

    PubMed Central

    Petrov, Drazen; Daura, Xavier; Zagrovic, Bojan

    2016-01-01

    During their life cycle, proteins are subject to different modifications involving reactive oxygen species. Such oxidative damage to proteins may lead to the formation of insoluble aggregates and cytotoxicity and is associated with age-related disorders including neurodegenerative diseases, cancer, and diabetes. Superoxide dismutase 1 (SOD1), a key antioxidant enzyme in human cells, is particularly susceptible to such modifications. Moreover, this homodimeric metalloenzyme has been directly linked to both familial and sporadic amyotrophic lateral sclerosis (ALS), a devastating, late-onset motor neuronal disease, with more than 150 ALS-related mutations in the SOD1 gene. Importantly, oxidatively damaged SOD1 aggregates have been observed in both familial and sporadic forms of the disease. However, the molecular mechanisms as well as potential implications of oxidative stress in SOD1-induced cytotoxicity remain elusive. In this study, we examine the effects of oxidative modification on SOD1 monomer and homodimer stability, the key molecular properties related to SOD1 aggregation. We use molecular dynamics simulations in combination with thermodynamic integration to study microscopic-level site-specific effects of oxidative “mutations” at the dimer interface, including lysine, arginine, proline and threonine carbonylation, and cysteine oxidation. Our results show that oxidative damage of even single residues at the interface may drastically destabilize the SOD1 homodimer, with several modifications exhibiting a comparable effect to that of the most drastic ALS-causing mutations known. Additionally, we show that the SOD1 monomer stability decreases upon oxidative stress, which may lead to partial local unfolding and consequently to increased aggregation propensity. Importantly, these results suggest that oxidative stress may play a key role in development of ALS, with the mutations in the SOD1 gene being an additional factor. PMID:27074676

  8. On the selectivity of superoxide dismutase mimetics and its importance in pharmacological studies

    PubMed Central

    Muscoli, Carolina; Cuzzocrea, Salvatore; Riley, Dennis P; Zweier, Jay L; Thiemermann, Christoph; Wang, Zhi-Qiang; Salvemini, Daniela

    2003-01-01

    The list of pathophysiological conditions associated with the overproduction of superoxide expands every day. Much of the knowledge compiled on the role of this radical in disease has been gathered using the native superoxide dismutase enzyme and, more recently, by the use of superoxide dismutase knockout models or transgenic models that overexpress the various isoforms of the enzyme. Although the native enzyme has shown promising anti-inflammatory properties in both preclinical and clinical studies, there were drawbacks and issues associated with its use as a therapeutic agent and pharmacological tool. Based on the concept that removal of superoxide modulates the course of inflammation, synthetic, low-molecular-weight mimetics of the superoxide dismutase enzymes that could overcome some of the limitations associated with the use of the native enzyme have been designed. In this review, we will discuss the advances made using various superoxide dismutase mimetics that led to the proposal that superoxide (and/or the product of its interaction with nitric oxide, peroxynitrite) is an important mediator of inflammation, and to the conclusion that superoxide dismutase mimetics can be utilized as therapeutic agents in diseases of various etiologies. The importance of the selectivity of such compounds in pharmacological studies will be discussed. PMID:14522841

  9. 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.

  10. Characterization of the Bacillus stearothermophilus manganese superoxide dismutase gene and its ability to complement copper/zinc superoxide dismutase deficiency in Saccharomyces cerevisiae.

    PubMed Central

    Bowler, C; Van Kaer, L; Van Camp, W; Van Montagu, M; Inzé, D; Dhaese, P

    1990-01-01

    Recombinant clones containing the manganese superoxide dismutase (MnSOD) gene of Bacillus stearothermophilus were isolated with an oligonucleotide probe designed to match a part of the previously determined amino acid sequence. Complementation analyses, performed by introducing each plasmid into a superoxide dismutase-deficient mutant of Escherichia coli, allowed us to define the region of DNA which encodes the MnSOD structural gene and to identify a promoter region immediately upstream from the gene. These data were subsequently confirmed by DNA sequencing. Since MnSOD is normally restricted to the mitochondria in eucaryotes, we were interested (i) in determining whether B. stearothermophilus MnSOD could function in eucaryotic cytosol and (ii) in determining whether MnSOD could replace the structurally unrelated copper/zinc superoxide dismutase (Cu/ZnSOD) which is normally found there. To test this, the sequence encoding bacterial MnSOD was cloned into a yeast expression vector and subsequently introduced into a Cu/ZnSOD-deficient mutant of the yeast Saccharomyces cerevisiae. Functional expression of the protein was demonstrated, and complementation tests revealed that the protein was able to provide tolerance at wild-type levels to conditions which are normally restrictive for this mutant. Thus, in spite of the evolutionary unrelatedness of these two enzymes, Cu/ZnSOD can be functionally replaced by MnSOD in yeast cytosol. Images FIG. 2 FIG. 4 FIG. 5 PMID:2407726

  11. Distribution of Iron-Containing Superoxide Dismutase in Vascular Plants 12

    PubMed Central

    Bridges, Susan M.; Salin, Marvin L.

    1981-01-01

    Superoxide dismutases (EC 1.15.1.1) in vascular plants representing different evolutionary levels were characterized using polyacrylamide gel electrophoresis. The three forms of the enzyme were distinguished from each other based on the following criteria: a) the Cu-Zn enzyme is sensitive to cyanide wherease the Fe and Mn enzymes are not; and b) the Cu-Zn and Fe enzymes are inhibited by H2O2 whereas the Mn enzyme is H2O2-resistant. Of the 43 plant families investigated, the Fe-containing superoxide dismutase was found in three families: Gingkoaceae, Nymphaceae, and Cruciferae. PMID:16661901

  12. Superoxide dismutase transgenes in sugarbeets confer resistance to oxidative agents and the fungus C. beticola.

    PubMed

    Tertivanidis, Konstantinos; Goudoula, Catherine; Vasilikiotis, Christos; Hassiotou, Efthymia; Perl-Treves, Rafael; Tsaftaris, Athanasios

    2004-06-01

    Sugarbeets carrying superoxide dismutase transgenes were developed in order to investigate the possibility of enhancing their resistance to oxidative stress. Binary T-DNA vectors carrying the chloroplastic and cytosolic superoxide dismutase genes from tomato, were used for Agrobacterium-mediated transformation of sugarbeet petioles. The transgenic plants were subjected to treatments known to cause oxidative stress, such as the herbicide methyl viologen and a natural photosensitizer toxin produced by the fungus Cercospora beticola, namely cercosporin. The transgenic plants exhibited increased tolerance to methyl viologen, to pure cercosporin, as well as to leaf infection with the fungus C. beticola.

  13. Extraction of erythrocyte enzymes for the preparation of polyhemoglobin-catalase-superoxide dismutase.

    PubMed

    Gu, Jingsong; Chang, Thomas Ming Swi

    2009-01-01

    In sustained severe ischemia, reperfusion with oxygen carriers may result in ischemia-reperfusion injuries because of the release of damaging oxygen radicals. A nanobiotechnology-based polyhemogloin-calatase-superoxide dismutase can prevent this because the oxygen carrier, polyhemoglobin, is linked to antioxidant enzymes, catalase and superoxide dismutase. However, these antioxidant enzymes come from nonhuman sources and recombinant human enzymes are expensive. This paper describes our study on extracting these enzymes from red blood cells and analyzing the amount of enzymes needed for adequate protection from ischemia-reperfusion.

  14. Parasitization by Scleroderma guani influences expression of superoxide dismutase genes in Tenebrio molitor

    USDA-ARS?s Scientific Manuscript database

    Superoxide dismutase (SOD) is an antioxidant enzyme involved in detoxifying reactive oxygen species. In this study, we identified genes encoding the extracellular and intracellular copper-zinc SODs (ecCuZnSOD and icCuZnSOD) and a manganese SOD (MnSOD) in the yellow mealworm beetle, Tenebrio molitor....

  15. Exogenous superoxide dismutase may lose its antidotal ability on rice leaves

    USDA-ARS?s Scientific Manuscript database

    Leaf diffusates of the resistant rice cultivars suppressed spore germination of blast fungus (Magnaporthe grisea). Bovine Cu-Zn superoxide dismutase (SOD) added to the diffusate abolished its toxicity. However, the enzyme added to the inoculum did not affect the toxicity of the diffusate. Even the s...

  16. 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...

  17. Superoxide Dismutase Protects Cells from DNA Damage Induced by Trivalent Methylated Arsenicals

    EPA Science Inventory

    Superoxide dismutase (SOD) catalyzes the conversion of superoxide to hydrogen peroxide. Heterozygous mice of strain B6; 129S7-Sod1(tm1Leb)/J were obtained from Jackson Laboratories and bred to produce offspring that were heterozygous (+/Sod1(tm1Leb)), homozygous wild-type (+/+), ...

  18. 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...

  19. Copper complexes of 1,10-phenanthroline and related compounds as superoxide dismutase mimetics.

    PubMed

    Bijloo, G J; van der Goot, H; Bast, A; Timmerman, H

    1990-11-01

    In a preliminary study we tested CuSO4.5H2O, (Cu(II]2[3,5-diisopropylsalicylate]4.2H2O and a number of copper complexes of substituted 1,10-phenanthrolines for superoxide anion dismutase activity. It appeared that this activity depends on the ligands involved and might be governed by the redox potential of the Cu(I) complex/Cu(II) complex couple. The strong superoxide anion dismutase activity of Cu(II)[DMP]2 complex can be expected considering its high redox potential. Rather surprisingly is the superoxide anion dismutase activity of the Cu(I)[DMP]2 complex since it involves oxidation to Cu(II)[DMP]2 complex. From regression analysis it was established that steric and field effects of the substituents of the investigated phenanthrolines play an important role in SOD activity and therefore it is concluded that complex formation is important for the superoxide dismutase-like activity.

  20. Superoxide dismutase expression and oxidative damage in a case of myopathy in brown pelicans (Pelecanus occidentalis).

    PubMed

    Giri, Dipak K; Miller, Debra L; Thompson, Larry J; Mailler, Lesley; Styer, Eloise; Baldwin, Charles

    2007-05-01

    Four brown pelicans (Pelecanus occidentalis) housed at a rehabilitation facility were found dead after a 3-day history of muscle weakness and after being fed for about 2 weeks from a recent shipment of fish. The birds had pale streaking of the skeletal and heart muscles. Microscopically, the skeletal muscle, and to a lesser extent the cardiac muscle, had severe myocyte degeneration and necrosis characterized by microvacuolation with loss of cross-striations, condensation of cytoplasm, fragmentation, mineralization, and inflammatory cell infiltrates consisting of multinucleated cells, macrophages, and few heterophils. The findings were consistent with myopathy, and a nutritional myopathy caused by eating rancid fish was suspected. Immunohistochemical staining revealed abundant immunoreactive copper zinc superoxide dismutase and manganese superoxide dismutase either as diffuse homogeneous precipitates or granular aggregates in the cytoplasm of affected cells. Immunoreactivity was directly related to degree of cellular damage as estimated by light microscopic examination. We suggest that the lack of protection, despite upregulation of superoxide dismutase, is most likely attributable to supersaturation of oxidants beyond the capacity of superoxide dismutases to scavenge.

  1. Copper-Zinc Superoxide Dismutase: A Unique Biological "Ligand" for Bioinorganic Studies.

    ERIC Educational Resources Information Center

    Valentine, Joan Selverstone; de Freitas, Duarte Mota

    1985-01-01

    Discusses superoxide dismutase (SOD) research and the properties of copper, zinc (Cu, Zn)-SOD. Emphasizes the controversy concerning the role of Cu,Zn-SOD and other SOD enzymes as protective agents in reactions involving dioxygen metabolism, and the properties of Cu, Zn-SOD that make it an interesting biological ligand for physical studies of…

  2. Nitration and Inactivation of Manganese Superoxide Dismutase in Chronic Rejection of Human Renal Allografts

    NASA Astrophysics Data System (ADS)

    MacMillan-Crow, L. A.; Crow, John P.; Kerby, Jeffrey D.; Beckman, Joseph S.; Thompson, John A.

    1996-10-01

    Inflammatory processes in chronic rejection remain a serious clinical problem in organ transplantation. Activated cellular infiltrate produces high levels of both superoxide and nitric oxide. These reactive oxygen species interact to form peroxynitrite, a potent oxidant that can modify proteins to form 3-nitrotyrosine. We identified enhanced immunostaining for nitrotyrosine localized to tubular epithelium of chronically rejected human renal allografts. Western blot analysis of rejected tissue demonstrated that tyrosine nitration was restricted to a few specific polypeptides. Immunoprecipitation and amino acid sequencing techniques identified manganese superoxide dismutase, the major antioxidant enzyme in mitochondria, as one of the targets of tyrosine nitration. Total manganese superoxide dismutase protein was increased in rejected kidney, particularly in the tubular epithelium; however, enzymatic activity was significantly decreased. Exposure of recombinant human manganese superoxide dismutase to peroxynitrite resulted in a dose-dependent (IC50 = 10 μ M) decrease in enzymatic activity and concomitant increase in tyrosine nitration. Collectively, these observations suggest a role for peroxynitrite during development and progression of chronic rejection in human renal allografts. In addition, inactivation of manganese superoxide dismutase by peroxynitrite may represent a general mechanism that progressively increases the production of peroxynitrite, leading to irreversible oxidative injury to mitochondria.

  3. Superoxide Dismutase Protects Cells from DNA Damage Induced by Trivalent Methylated Arsenicals

    EPA Science Inventory

    Superoxide dismutase (SOD) catalyzes the conversion of superoxide to hydrogen peroxide. Heterozygous mice of strain B6; 129S7-Sod1(tm1Leb)/J were obtained from Jackson Laboratories and bred to produce offspring that were heterozygous (+/Sod1(tm1Leb)), homozygous wild-type (+/+), ...

  4. Sympathetic denervation caused by long-term noradrenaline infusions; prevention by desipramine and superoxide dismutase.

    PubMed

    Albino Teixeira, A; Azevedo, I; Branco, D; Rodrigues-Pereira, E; Osswald, W

    1989-05-01

    1. The effects of continuous intravenous infusion of noradrenaline (0.01 and 0.1 microgram kg-1 h-1) were studied in both the infused lateral saphenous vein and the contralateral saphenous vein of normal dogs. Noradrenaline, saline, noradrenaline + desipramine or noradrenaline + superoxide dismutase were infused using Alzet osmotic minipumps. 2. After a 5 day infusion period, the noradrenaline content in plasma and in both saphenous veins was determined, and the venous tissues submitted to light microscope morphometry and ultrastructural study and used for the determination of their O-methylation capacity (with [3H]-isoprenaline as a substrate). 3. Noradrenaline caused dose-dependent damage to the sympathetic nerve endings of the lateral saphenous veins. Concomitant changes in extraneuronal structure and function were observed (hypertrophy of smooth muscle cells, nuclear dysmorphy, thickening of the vessel wall, impairment in O-methylation capacity). 4. Desipramine and superoxide dismutase prevented or reduced the effects of noradrenaline on both the morphological and the biochemical parameters; the protection afforded by superoxide dismutase was more marked than that by desipramine. 5. It is concluded that moderately high doses of noradrenaline exert a 6-hydroxydopamine-like effect and that this chemical sympathectomy is partially or totally prevented by desipramine or superoxide dismutase. The data suggest that a substance derived from noradrenaline, in the formation of which free oxygen radicals are involved and which is subject to neuronal uptake, is the chemical entity responsible for the neurotoxic effect observed.

  5. Nutritional status of zinc and activity superoxide dismutase in chronic renal patients undergoing hemodialysis.

    PubMed

    Noleto Magalhães, R C; Guedes Borges de Araujo, C; Batista de Sousa Lima, V; Machado Moita Neto, J; do Nascimento Nogueira, N; do Nascimento Marreiro, D

    2011-01-01

    Chronic kidney disease promotes changes in the zinc nutritional status and in the antioxidant defense system. This study assessed the relationship between the parameters of the zinc nutritional status and the activity of superoxide dismutase in patients with chronic renal failure who are receiving hemodialysis. 134 individuals, aged between 18 and 85 years, were divided into two groups: case group (hemodialyzed patients, n = 63) and control group (n = 71). Zinc concentrations in plasma and erythrocytes were determined using the flame atomic absorption spectrophotometry technique. The activity of superoxide dismutase enzyme was determined according to Ransod kit. The mean values of plasma zinc were 62.02 ± 13.59 μg/dL and 65.58 ± 8.88 μg/dL, and for erythrocytary zinc the values were 54.52 ± 22.82 μgZn/gHb and 48.01 ± 15.08 μgZn/gHb for the chronic renal patients and the control group, respectively. The activity of superoxide dismutase was significantly lower in patients when compared with the control group (p < 0.05). The activity of superoxide dismutase in patients with chronic renal failure undergoing hemodialysis, which is influenced by zinc concentracions, was significantly lower. There was an inadequate response of this enzyme to oxidative stress in patients undergoing hemodialysis.

  6. Unexpected Diversity of Chlorite Dismutases: a Catalytically Efficient Dimeric Enzyme from Nitrobacter winogradskyi ▿ †

    PubMed Central

    Mlynek, Georg; Sjöblom, Björn; Kostan, Julius; Füreder, Stephanie; Maixner, Frank; Gysel, Kira; Furtmüller, Paul Georg; Obinger, Christian; Wagner, Michael; Daims, Holger; Djinović-Carugo, Kristina

    2011-01-01

    Chlorite dismutase (Cld) is a unique heme enzyme catalyzing the conversion of ClO2− to Cl− and O2. Cld is usually found in perchlorate- or chlorate-reducing bacteria but was also recently identified in a nitrite-oxidizing bacterium of the genus Nitrospira. Here we characterized a novel Cld-like protein from the chemolithoautotrophic nitrite oxidizer Nitrobacter winogradskyi which is significantly smaller than all previously known chlorite dismutases. Its three-dimensional (3D) crystal structure revealed a dimer of two identical subunits, which sharply contrasts with the penta- or hexameric structures of other chlorite dismutases. Despite a truncated N-terminal domain in each subunit, this novel enzyme turned out to be a highly efficient chlorite dismutase (Km = 90 μM; kcat = 190 s−1; kcat/Km = 2.1 × 106 M−1 s−1), demonstrating a greater structural and phylogenetic diversity of these enzymes than was previously known. Based on comparative analyses of Cld sequences and 3D structures, signature amino acid residues that can be employed to assess whether uncharacterized Cld-like proteins may have a high chlorite-dismutating activity were identified. Interestingly, proteins that contain all these signatures and are phylogenetically closely related to the novel-type Cld of N. winogradskyi exist in a large number of other microbes, including other nitrite oxidizers. PMID:21441524

  7. Copper-Zinc Superoxide Dismutase: A Unique Biological "Ligand" for Bioinorganic Studies.

    ERIC Educational Resources Information Center

    Valentine, Joan Selverstone; de Freitas, Duarte Mota

    1985-01-01

    Discusses superoxide dismutase (SOD) research and the properties of copper, zinc (Cu, Zn)-SOD. Emphasizes the controversy concerning the role of Cu,Zn-SOD and other SOD enzymes as protective agents in reactions involving dioxygen metabolism, and the properties of Cu, Zn-SOD that make it an interesting biological ligand for physical studies of…

  8. ROLE OF COPPER,ZINC-SUPEROXIDE DISMUTASE IN CATALYZING NITROTYROSINE FORMATION IN MURINE LIVER

    USDA-ARS?s Scientific Manuscript database

    The solely known function of Cu,Zn-superoxide dismutase (SOD1) is to catalyze the dismutation of superoxide anion into hydrogen peroxide. Our objective was to determine if SOD1 catalyzed murine liver protein nitration induced by acetaminophen (APAP) and lipopolysaccharide (LPS). Liver and plasma ...

  9. Molecular Cloning and Expression of Sequence Variants of Manganese Superoxide Dismutase Genes from Wheat

    USDA-ARS?s Scientific Manuscript database

    Reactive oxygen species (ROS) are very harmful to living organisms due to the potential oxidation of membrane lipids, DNA, proteins, and carbohydrates. Transformed E.coli strain QC 871, superoxide dismutase (SOD) double-mutant, with three sequence variant MnSOD1, MnSOD2, and MnSOD3 manganese supero...

  10. Induction of peroxidases and superoxide dismutases in transformed embryogenic calli of alfalfa (Medicago sativa L.)

    USDA-ARS?s Scientific Manuscript database

    Activities of peroxidase (POD) and superoxide dismutase (SOD) enzymes were analyzed in non-regenerative transformed embryogenic lines of alfalfa (Medicago sativa L.) carrying wound-inducible oryzacystatin I (OC-I), wound-inducible oryzacystatin I antisense (OC-Ias) or hygromycin phosphotransferase (...

  11. Superoxide dismutase activity in mesocarp tissue from divergent Cucumis melo L. genotypes

    USDA-ARS?s Scientific Manuscript database

    Muskmelon (Cucumis melo L.) fruit matrix is unique among plant foods in being able to provide a protective medium in which the antioxidant activity of the enzyme superoxide dismutase (SOD) is preserved during the digestive process, and therefore, being able to elicit in vivo pharmacological effects ...

  12. Identification of two peanut germin-like genes and the potential superoxide dismutase activity

    USDA-ARS?s Scientific Manuscript database

    Germin and germin-like protein (GLP) genes are members of large multigene families. These genes have been reported to play a role directly or indirectly in plant defense response. A number of GLPs have been demonstrated to have superoxidase dismutase (SOD) or oxalate oxidase (OxO) activity, leading ...

  13. [Alterations in two enzymes: superoxide dismutase and glutathion peroxidase in developmental infantile psychosis (infantile autism) (author's transl)].

    PubMed

    Golse, B; Debray-Ritzen, P; Durosay, P; Puget, K; Michelson, A M

    1978-11-01

    After they gave a classification of the different circumstances under which the infantile autism can exist, the authors expose the data of their researches on the intermediate metabolism of oxygen of those children. Superoxyde dismutase I and glutathion peroxydase activities seem to be abnormal in the erythrocytes whereas only superoxyde dismutase I activity appears to be abnormal in the platelets.

  14. Isolation and reconstitution of iron- and manganese-containing superoxide dismutases from Bacteroides thetaiotaomicron.

    PubMed Central

    Pennington, C D; Gregory, E M

    1986-01-01

    Superoxide dismutase (SOD) from extracts of anaerobically maintained Bacteroides thetaiotaomicron was a dimer of equally sized 23,000-molecular-weight monomers joined noncovalently. A preparation with a specific activity of 1,200 U/mg contained 1.1 g-atom of Fe, 0.6 g-atom of Zn, and less than 0.05 g-atom of Mn per mol of dimer. The apoprotein, prepared by dialysis of iron-SOD in 5 M guanidinium chloride-20 mM 8-hydroxyquinoline, had no superoxide-scavenging activity when renatured without exogenous metal. Enzymatic activity was restored to the denatured apoprotein by dialysis against either 1 mM Fe(NH4)2 or 1 mM MnCl2 in 20 mM Tris (pH 7.0). The Fe-reconstituted enzyme and the native enzyme were inhibited approximately 50% by 0.2 mM NaN3, whereas the Mn-reconstituted enzyme was inhibited 60% by 10 mM NaN3. Aeration of the anaerobic cells resulted in a fourfold induction of an azide-resistant SOD. The enzyme (43,000 molecular weight) isolated from aerated cells was a dimer of equally sized subunits. The metal content was 1.0 g-atom of Mn, 0.55 g-atom of Fe, and 0.3 g-atom of Zn per mol of dimer. Enzymatic activity of the denatured apoprotein from this enzyme was also restored on addition of either iron or manganese. The constitutive Fe-SOD and the O2-induced Mn-SOD, tested alone and in combination, migrated identically on acrylamide gels, had similar amino acid compositions, and had alanine as the sole N-terminal amino acid. These data are consistent with the synthesis of a single apoprotein in either anaerobically maintained or oxygenated cells. We have observed a similar phenomenon with SOD from Bacteroides fragilis (E. M. Gregory, Arch. Biochem. Biophys. 238:83-89, 1985). PMID:3700336

  15. Using superoxide dismutase/catalase mimetics to manipulate the redox environment of neural precursor cells.

    PubMed

    Limoli, C L; Giedzinski, E; Baure, J; Doctrow, S R; Rola, R; Fike, J R

    2006-01-01

    Past work has shown that neural precursor cells are predisposed to redox sensitive changes, and that oxidative stress plays a critical role in the acute and persistent changes that occur within the irradiated CNS. Irradiation leads to a marked rise in reactive oxygen species (ROS) that correlates with oxidative endpoints in vivo and reductions in neurogenesis. To better understand the impact of oxidative stress on neural precursor cells, and to determine if radiation-induced oxidative damage and precursor cell loss after irradiation could be reduced, a series of antioxidant compounds (EUK-134, EUK-163, EUK-172, EUK-189) were tested, three of which possess both superoxide dismutase (SOD) and catalase activities and one (EUK-163) whose only significant activity is SOD. Our results show that these SOD/catalase mimetics apparently increase the oxidation of a ROS-sensitive fluorescent indicator dye, particularly after short (12 h) treatments, but that longer treatments (24 h) decrease oxidation attributable to radiation-induced ROS. Similarly, other studies found that cells incubated with CuZnSOD showed some increase in intracellular ROS levels. Subsequent data suggested that the dye-oxidising capabilities of the EUK compounds were linked to differences in their catalase activity and, most likely, their ability to catalyse peroxidative pathways. In unirradiated mice, the EUK-134 analogue induced some decrease of proliferating precursor cells and immature neurons 48 h after radiation, an effect that may be attributable to cytotoxicity and/or inhibition of precursor proliferation. In irradiated mice, a single injection of EUK-134 was not found to be an effective radioprotector at acute times (48 h). The present results support continued development of our in vitro model as a tool for predicting certain in vivo responses, and suggest that in some biological systems the capability to scavenge superoxide but produce excess H(2)O(2), as is known for CuZnSOD, may be

  16. Transcriptional response of lysozyme, metallothionein, and superoxide dismutase to combined exposure to heavy metals and bacteria in Mactra veneriformis.

    PubMed

    Fang, Yan; Yang, Hongsheng; Liu, Baozhong; Zhang, Libing

    2013-01-01

    The response of the defense components lysozyme (LYZ), metallothionein (MT), and superoxide dismutase (SOD) to combined exposure to heavy metals and bacteria was assessed at transcriptional level in the surf clam Mactra veneriformis. First, the full-length LYZ cDNA containing 808 nucleotides and encoding 194 deduced amino acids was identified from the clam. Multiple alignments revealed that MvLYZ had a high identity with invertebrate-type LYZs from other mollusks. Next, clams were exposed to Vibrio parahaemolyticus and a mixture of cadmium and mercury, alone or in combination, for 7 days. Cumulative mortality of clams and mRNA expressions of the three defense components were analyzed. The highest cumulative mortality took place in the combined treatment on day 7. The expression of the three genes was up-regulated in response to treatments compared to the control with different response times and transcriptional levels; the response to combined exposure occurred earlier than to single exposure. Among the experimental groups, MvLYZ expression and MvSOD expression peaked in the combined treatment on day 3, whereas MvMT expression peaked in heavy metals treatment on day 5. Furthermore, interactive effects of heavy metals and Vibrio on transcriptional response changed over the exposure time. Therefore, transcriptional regulation of the three genes under combined exposure was more complex than under single exposure.

  17. Manganese superoxide dismutase, but not CuZn superoxide dismutase, is highly expressed in the granulomas of pulmonary sarcoidosis and extrinsic allergic alveolitis.

    PubMed

    Lakari, E; Pääkkö, P; Kinnula, V L

    1998-08-01

    The role of antioxidant defense mechanisms in the pathogenesis of granulomatous human lung diseases remains open to investigation. In this study we investigated the immunoreactivity of two important superoxide radical scavenging intracellular antioxidant enzymes, manganese superoxide dismutase (MnSOD) and copperzinc superoxide dismutase (CuZnSOD), in pulmonary sarcoidosis and extrinsic allergic alveolitis. In histologically normal lung MnSOD was variable but mostly positive in the cells of bronchial epithelium, alveolar epithelium especially in type II pneumocytes, and alveolar macrophages. Copperzinc SOD showed positive immunoreactivity most markedly in the bronchial epithelium. The biopsies of 22 patients with pulmonary sarcoidosis and 10 with extrinsic allergic alveolitis indicated that MnSOD was highly stained in the granulomas of both diseases, with 60 to 100% of the granulomas showing intensive immunoreactivity. Western blots conducted on the cell samples of bronchoalveolar lavage (BAL) fluid revealed significantly higher amounts of MnSOD in sarcoidosis and extrinsic allergic alveolitis than in the controls. Immunohistochemistry on the cells obtained from BAL fluid showed positive immunoreactivity of MnSOD in the macrophages but not in the lymphocytes. In contrast, copperzinc SOD was not induced in either of these diseases. We conclude that MnSOD is highly expressed in the granulomas of pulmonary sarcoidosis and extrinsic allergic alveolitis, and variable but mostly positive in alveolar macrophages, possibly owing to cytokine mediated induction during the granuloma formation.

  18. Alteration of cellular phenotype and responses to oxidative stress by manganese superoxide dismutase and a superoxide dismutase mimic in RWPE-2 human prostate adenocarcinoma cells.

    PubMed

    Zhong, Weixiong; Yan, Tao; Webber, Mukta M; Oberley, Terry D

    2004-06-01

    To study biologic effects of increased manganese superoxide dismutase (MnSOD) on cell behavior, we overexpressed MnSOD in a human prostate cancer cell line RWPE-2 by cDNA transfection. Stable transfectants of MnSOD showed a two- to threefold increase in MnSOD protein and enzymatic activity and a decrease in growth rate with prolonged cell population doubling times. Western blot analysis showed a 1.5- to twofold increase in the cyclin-dependent kinase inhibitor p21(Waf1) in MnSOD transfectants. Overexpression of MnSOD resulted in a seven- to eightfold increase in reduced glutathione (GSH), 18- to 26-fold increase in oxidized glutathione (GSSG), and a two- to threefold decrease in the ratio of GSH to GSSG. MnSOD-overexpressing cells showed an increase in sensitivity to the cytotoxicity of buthionine sulfoximine, a glutathione-depleting agent, and vitamin C, but a decrease in sensitivity to sodium selenite. Treatment with a superoxide dismutase (SOD) mimic MnTMPyP resulted in similar effects of MnSOD overexpression on cell responses to vitamin C and selenium. These data demonstrate that overexpression of MnSOD or treatment with SOD mimics can result in antioxidant or prooxidant effects in cells, depending on the presence of other antioxidants and prooxidants. MnSOD also has redox regulatory effects on cell growth and gene expression. These findings suggest that MnSOD and SOD mimics have the potential for cancer prevention or treatment.

  19. Cryo-Trapping the Distorted Octahedral Reaction Intermediate of Manganese Superoxide Dismutase

    NASA Technical Reports Server (NTRS)

    Borgstahl, Gloria; Snell, Edward H.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Superoxide dismutase protects organisms from potentially damaging oxygen radicals by catalyzing the disproportion of superoxide to oxygen and hydrogen peroxide. We report the use of cryogenic temperatures to kinetically trap the 6th ligand bound to the active site of manganese superoxide dismutase. Using cryocrystallography and synchrotron radiation, we describe at 1.55A resolution the six-coordinate, distorted octahedral geometry assumed by the active site during catalysis and compare it to the room temperature, five-coordinate trigonal-bipyramidal active site. Gateway residues Tyr34, His30 and a tightly bound water molecule are implicated in closing off the active site and blocking the escape route of superoxide during dismutation.

  20. Cryo-Trapping the Distorted Octahedral Reaction Intermediate of Manganese Superoxide Dismutase

    NASA Technical Reports Server (NTRS)

    Borgstahl, Gloria; Snell, Edward H.

    2000-01-01

    Superoxide dismutase protects organisms from potentially damaging oxygen radicals by catalyzing the disproportion of superoxide to oxygen and hydrogen peroxide. We report the use of cryogenic temperatures to kinetically trap the 6th ligand bound to the active site of manganese superoxide dismutase. Using cryocrystallography and synchrotron radiation, we describe at 1.55A resolution the six-coordinate, distorted octahedral geometry assumed by the active site during catalysis and compare it to the room temperature, five-coordinate trigonal-bipyramidal active site. Gateway residues Tyr34, His30 and a tightly bound water molecule are implicated in closing off the active site and blocking the escape route of superoxide during dismutation.

  1. [Erythrocyte superoxide dismutase (eSOD) determination in positive moments of psychosis].

    PubMed

    Vaiva, G; Thomas, P; Leroux, J M; Cottencin, O; Dutoit, D; Erb, F; Goudemand, M

    1994-01-01

    Dysregulation of free radical metabolism has been supposed to be involved in schizophrenia etiopathogeny. Recently, Wang et al. showed a red blood cell super oxide dismutase increase in positive schizophrenia (Crow's type I), but neither in negative schizophrenia (Crow's type II) nor in controls. The study included 28 in-patients suffering from acute positive psychosis who were compared with 15 controls. We confirmed the results of Wang. We found a significantly red blood cell Super oxide dismutase increase in positive psychosis, in comparison to negative psychosis and controls (p = 0.0001). This SOD increase was in relationship with the degree of clinical psychomotor excitement. After 21 days of neuroleptic treatment, SOD activity decreased and reached standard values. These results support the hypothesis of striking relationships between catecholaminergic hyper-metabolism and SOD increase, in positive psychosis. These could account for psychotic positive symptoms improvement with neuroleptic treatment, which blocks dopamine pathways.

  2. The effects of superoxide dismutase knockout on the oxidative stress parameters and survival of mouse erythrocytes.

    PubMed

    Grzelak, Agnieszka; Kruszewski, Marcin; Macierzyńska, Ewa; Piotrowski, Łukasz; Pułaski, Łukasz; Rychlik, Błazej; Bartosz, Grzegorz

    2009-01-01

    The erythrocytes of 12-month old Sod1 (-/-) mice showed an increased level of reactive oxygen species (ROS), as estimated by the degree of dihydroethidine and dihydrorhodamine oxidation, and the increased level of Heinz bodies. No indices of severe oxidative stress were found in the red blood cells and blood plasma of Sod1 (-/-) mice as judged from the lack of significant changes in the levels of erythrocyte and plasma glutathione, plasma protein thiol and carbonyl groups and thiobarbituric-acid reactive substances in the blood plasma. However, a decreased erythrocyte lifespan, increased reticulocyte count and splenomegaly were noted, indicating the importance of superoxide dismutase for maintaining erythrocyte viability. The levels of erythrocyte ROS and Heinz bodies and the reticulocyte count were indistinguishable in Sod1 (+/+) and Sod1 (+/-) mice, suggesting that a superoxide dismutase activity decrease to half of its normal value may be sufficient to secure the protective effects of the enzyme.

  3. Intracellular localization of the superoxide dismutases of Escherichia coli: a reevaluation.

    PubMed Central

    Britton, L; Fridovich, I

    1977-01-01

    All of the superoxide dismutase isozymes of Escherichia coli have been shown to occur in the cell matrix, and none have been found in the periplasm. This was the case with both E. coli B and E. coli K-12, whether grown on a low phosphate medium or on a Trypticase soy-yeast extract medium. Alkaline phosphatase was used as a marker of the periplasm; adenosine deaminase and glucose 6-phosphate dehydrogenase were used as matrix markers, and consistent results were obtained by osmotic shock, spheroplast formation, and use of a diazonium salt that penetrates the periplasm but cannot cross the plasma membrane. A previous report that the iron-containing superoxide dismutase of E. coli is a periplasmic enzyme is now seen to have been in error. PMID:330499

  4. Iron superoxide dismutases in eukaryotic pathogens: new insights from Apicomplexa and Trypanosoma structures.

    PubMed

    Phan, Isabelle Q H; Davies, Douglas R; Moretti, Nilmar Silvio; Shanmugam, Dhanasekaran; Cestari, Igor; Anupama, Atashi; Fairman, James W; Edwards, Thomas E; Stuart, Kenneth; Schenkman, Sergio; Myler, Peter J

    2015-05-01

    Prior studies have highlighted the potential of superoxide dismutases as drug targets in eukaryotic pathogens. This report presents the structures of three iron-dependent superoxide dismutases (FeSODs) from Trypanosoma cruzi, Leishmania major and Babesia bovis. Comparison with existing structures from Plasmodium and other trypanosome isoforms shows a very conserved overall fold with subtle differences. In particular, structural data suggest that B. bovis FeSOD may display similar resistance to peroxynitrite-mediated inactivation via an intramolecular electron-transfer pathway as previously described in T. cruzi FeSOD isoform B, thus providing valuable information for structure-based drug design. Furthermore, lysine-acetylation results in T. cruzi indicate that acetylation occurs at a position close to that responsible for the regulation of acetylation-mediated activity in the human enzyme.

  5. Methamphetamine toxicity is attenuated in mice that overexpress human manganese superoxide dismutase.

    PubMed

    Maragos, W F; Jakel, R; Chesnut, D; Pocernich, C B; Butterfield, D A; St Clair, D; Cass, W A

    2000-09-29

    We have investigated methamphetamine (MA) toxicity in transgenic mice that overexpress the human form of mitochondrial manganese superoxide dismutase (MnSOD). Our results reveal a significant reduction in the long-term depletion of striatal dopamine and protein oxidation following repeated administration of MA in transgenic vs. non-transgenic littermates. These findings support the notion that ROS contribute to MA-induced brain damage and suggest that mitochondria may play an important role in this form of neurodegeneration.

  6. Investigation of Ion Binding in Chlorite Dismutases by Means of Molecular Dynamics Simulations

    PubMed Central

    2014-01-01

    Chlorite dismutases are prokaryotic heme b oxidoreductases that convert chlorite to chloride and dioxygen. It has been postulated that during turnover hypochlorite is formed transiently, which might be responsible for the observed irreversible inactivation of these iron proteins. The only charged distal residue in the heme cavity is a conserved and mobile arginine, but its role in catalysis and inactivation is not fully understood. In the present study, the pentameric chlorite dismutase (Cld) from the bacterium Candidatus Nitrospira defluvii was probed for binding of the low spin ligand cyanide, the substrate chlorite, and the intermediate hypochlorite. Simulations were performed with the enzyme in the ferrous, ferric, and compound I state. Additionally, the variant R173A was studied. We report the parametrization for the GROMOS force field of the anions ClO–, ClO2–, ClO3–, and ClO4– and describe spontaneous binding, unbinding, and rebinding events of chlorite and hypochlorite, as well as the dynamics of the conformations of Arg173 during simulations. The findings suggest that (i) chlorite binding to ferric NdCld occurs spontaneously and (ii) that Arg173 is important for recognition and to impair hypochlorite leakage from the reaction sphere. The simulation data is discussed in comparison with experimental data on catalysis and inhibition of chlorite dismutase. PMID:24988286

  7. Irradiation Enhances Hippocampus-Dependent Cognition in Mice Deficient in Extracellular Superoxide Dismutase

    PubMed Central

    Raber, Jacob; Villasana, Laura; Rosenberg, Jenna; Zou, Yani; Huang, Ting Ting; Fike, John R.

    2009-01-01

    The effects of ionizing irradiation on the brain are associated with oxidative stress. While oxidative stress following irradiation is generally viewed as detrimental for hippocampal function, it might have beneficial effects as part of an adaptive or preconditioning response to a subsequent challenge. Here we show that in contrast to what is seen in wild-type mice, irradiation enhances hippocampus-dependent cognitive measures in mice lacking extracellular superoxide dismutase. These outcomes were associated with genotype-dependent effects on measures of oxidative stress. When cortices and hippocampi were analyzed for nitrotyrosine formation as an index of oxidative stress, the levels were chronically elevated in mice lacking extracellular superoxide dismutase. However, irradiation caused a greater increase in nitrotyrosine levels in wild-type mice than mice lacking extracellular superoxide dismutase. These paradoxical genotype-dependent effects of irradiation on measures of oxidative stress and cognitive function underscore potential beneficial effects associated with chronic oxidative stress if it exists prior to a secondary insult such as irradiation. PMID:20020436

  8. Yeast and Mammalian Metallothioneins Functionally Substitute for Yeast Copper-Zinc Superoxide Dismutase

    NASA Astrophysics Data System (ADS)

    Tamai, Katherine T.; Gralla, Edith B.; Ellerby, Lisa M.; Valentine, Joan S.; Thiele, Dennis J.

    1993-09-01

    Copper-zinc superoxide dismutase catalyzes the disproportionation of superoxide anion to hydrogen peroxide and dioxygen and is thought to play an important role in protecting cells from oxygen toxicity. Saccharomyces cerevisiae strains lacking copper-zinc superoxide dismutase, which is encoded by the SOD1 gene, are sensitive to oxidative stress and exhibit a variety of growth defects including hypersensitivity to dioxygen and to superoxide-generating drugs such as paraquat. We have found that in addition to these known phenotypes, SOD1-deletion strains fail to grow on agar containing the respiratory carbon source lactate. We demonstrate here that expression of the yeast or monkey metallothionein proteins in the presence of copper suppresses the lactate growth defect and some other phenotypes associated with SOD1-deletion strains, indicating that copper metallothioneins substitute for copper-zinc superoxide dismutase in vivo to protect cells from oxygen toxicity. Consistent with these results, we show that yeast metallothionein mRNA levels are dramatically elevated under conditions of oxidative stress. Furthermore, in vitro assays demonstrate that yeast metallothionein, purified or from whole-cell extracts, exhibits copper-dependent antioxidant activity. Taken together, these data suggest that both yeast and mammalian metallothioneins may play a direct role in the cellular defense against oxidative stress by functioning as antioxidants.

  9. Assessment of antioxidants status and superoxide dismutase activity in HIV-infected children.

    PubMed

    Pugliese, Camila; Patin, Rose Vega; Palchetti, Cecilia Zanin; Claudio, Cristiane Chiantelli; Gouvêa, Aída de Fátima Thomé Barbosa; Succi, Regina Célia de Menezes; Amancio, Olga Maria Silverio; Cozzolino, Silvia Maria Franciscato; Oliveira, Fernanda Luisa Ceragioli

    2014-01-01

    This study aims to assess the nutritional status of selenium, copper and zinc; and also the erythrocyte superoxide dismutase activity of HIV-infected children compared to a control group. A cross-sectional study was carried out with prepubertal HIV-infected children (n=51) and their healthy siblings (n=32). All biochemical measurements including plasma selenium, serum copper levels, serum and erythrocyte zinc levels and erythrocyte superoxide dismutase activity were evaluated according to dietary, clinical and biochemical parameters. Compared to the control group, the HIV-infected children had lower z-score values for height-for-age (p=0.0006), higher prevalence of stunting (11.8%) (p=0.047), lower selenium levels (p=0.0006) and higher copper levels (p=0.019). No difference was found concerning superoxide dismutase activity (p>0.05). The HIV-infected group presented a higher proportion (45.1%) of children with zinc intakes below the estimated average requirement (p=0.014); however, no association with zinc biochemical parameters was found. HIV-infected children have an inadequate selenium and copper nutritional status, which could influence the progression to AIDS. An adequate micronutrient status could improve the clinical conditions in these patients and minimize free radical production and cellular oxidative stress. Copyright © 2014. Published by Elsevier Editora Ltda.

  10. Superoxide Dismutase, Catalase, and α-Tocopherol Content of Stored Potato Tubers 1

    PubMed Central

    Spychalla, James P.; Desborough, Sharon L.

    1990-01-01

    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 α-tocopherol were assayed from four potato cultivars stored at 3°C and 9°C for 40 weeks. Tubers stored at 3°C demonstrated increased superoxide dismutase activities (up to 72%) compared to tubers stored at 9°C. Time dependent increases in the levels of superoxide dismutase, catalase, and α-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. PMID:16667819

  11. Superoxide Dismutase, Catalase, and alpha-Tocopherol Content of Stored Potato Tubers.

    PubMed

    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 degrees C and 9 degrees C for 40 weeks. Tubers stored at 3 degrees C demonstrated increased superoxide dismutase activities (up to 72%) compared to tubers stored at 9 degrees 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.

  12. 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.

  13. Structure of glycosylated Cu/Zn-superoxide dismutase from Kluyveromyces yeast NBIMCC 1984

    NASA Astrophysics Data System (ADS)

    Dolashka-Angelova, Pavlina; Moshtanska, Vesela; Kujumdzieva, Anna; Atanasov, Boris; Petrova, Vencislava; Voelter, Wolfgang; Beeumen, Jozef Van

    2010-09-01

    The primary structure of Cu/Zn-superoxide dismutase from Kluyveromyces marxianus NBIMCC 1984 was elucidated by N-terminal sequence analysis of the intact protein and by determination of the amino acid sequences of tryptic peptides by MALDI-TOF-TOF tandem mass spectrometry. The molecular mass of one subunit of the homodimer SOD, containing 152 amino acid residues, was calculated to be 15858.3 Da while a value of 17096.63 Da was obtained by MALDI-TOF MS. This difference is explained by the presence of N-glycosylation of one linkage site, -Asn-Ile/Leu-Thr-, and a glycan chain with the structure Hex 5 GlcNAc 2. Glycosylation of K.marxianus superoxide dismutase is a post-translational modification. Recent developments in mass spectrometry have enabled detailed structural analyses of covalent modifications of proteins. Therefore, in this paper, we introduce a covalent modification of Cu/Zn-SOD from K. marxianus NBIMCC 1984, by analysis of the enzymatic liberated N-glycan from the enzyme using MALDI-TOF and tandem mass spectrometry on a Q-Trap mass spectrometer. This is the first report of the structure of the oligosaccharide of a naturally-glycosylated superoxide dismutase, determined by mass spectrometry.

  14. 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.

  15. Molecular cloning and biochemical characterization of iron superoxide dismutase from the rodent malaria parasite Plasmodium vinckei.

    PubMed

    Prakash, Kirtika; Goyal, Manish; Soni, Awakash; Siddiqui, Arif Jamal; Bhardwaj, Jyoti; Puri, Sunil K

    2014-12-01

    Plasmodium parasite utilizes superoxide dismutase family proteins to limit the toxicity of reactive oxygen species, such as produced through hemoglobin degradation. These proteins play an important role in parasite survival during intra-erythrocytic phase. We have identified, and biochemically characterized a putative iron dependent superoxide dismutase from rodent malaria parasite Plasmodium vinckei (PvSOD1). The recombinant PvSOD1 protein was purified to homogeneity through a combination of affinity and gel filtration chromatography. Crosslinking, Native-PAGE and FPLC gel filtration analyses documented that PvSOD1 exists as a dimer in solution, a common feature shared by other Fe-SODs. PvSOD1 is cytosolic in localization and its expression is comparatively higher during trophozoite as compared to that of ring and schizont stages. Enzymatic activity of recombinant PvSOD1 was validated using conventional zymogram analyses and xanthine-xanthine oxidase system. Under optimal conditions, PvSOD1 was highly active and catalyzed the dismutation of superoxide radicals. Furthermore, PvSOD1 showed activity over a broad range of pH and temperature. Inhibition studies suggested that PvSOD1 was inactivated by hydrogen peroxide, and peroxynitrite, but not by cyanide and azide. Since, PvSOD1 plays a central role in oxidative defense mechanism, therefore, characterization of PvSOD1 will be exploited in the screening of new superoxide dismutase inhibitors for their antimalarial activity.

  16. A Multinuclear Copper(I) Cluster Forms the Dimerization Interface in Copper-Loaded Human Copper Chaperone for Superoxide Dismutase

    SciTech Connect

    Stasser, J.P.; Siluvai, G.S.; Barry, A.N.; Blackburn, N.J.

    2009-06-04

    Copper binding and X-ray aborption spectroscopy studies are reported on untagged human CCS (hCCS; CCS = copper chaperone for superoxide dismutase) isolated using an intein self-cleaving vector and on single and double Cys to Ala mutants of the hCCS MTCQSC and CSC motifs of domains 1 (D1) and 3 (D3), respectively. The results on the wild-type protein confirmed earlier findings on the CCS-MBP (maltose binding protein) constructs, namely, that Cu(I) coordinates to the CXC motif, forming a cluster at the interface of two D3 polypeptides. In contrast to the single Cys to Ser mutations of the CCS-MBP protein (Stasser, J. P., Eisses, J. F., Barry, A. N., Kaplan, J. H., and Blackburn, N. J. (2005) Biochemistry 44, 3143-3152), single Cys to Ala mutations in D3 were sufficient to eliminate cluster formation and significantly reduce CCS activity. Analysis of the intensity of the Cu-Cu cluster interaction in C244A, C246A, and C244/246A variants suggested that the nuclearity of the cluster was greater than 2 and was most consistent with a Cu4S6 adamantane-type species. The relationship among cluster formation, oligomerization, and metal loading was evaluated. The results support a model in which Cu(I) binding converts the apo dimer with a D2-D2 interface to a new dimer connected by cluster formation at two D3 CSC motifs. The predominance of dimer over tetramer in the cluster-containing species strongly suggests that the D2 dimer interface remains open and available for sequestering an SOD1 monomer. This work implicates the copper cluster in the reactive form and adds detail to the cluster nuclearity and how copper loading affects the oligomerization states and reactivity of CCS for its partner SOD1.

  17. The design of synthetic superoxide dismutase mimetics: seven-coordinate water soluble manganese(ii) and iron(ii) complexes and their superoxide dismutase-like activity studies.

    PubMed

    Singh, Ovender; Tyagi, Nidhi; Olmstead, Marilyn M; Ghosh, Kaushik

    2017-10-06

    Bio-inspired manganese [Mn(N5Py)(H2O)(CH3OH)](ClO4)2 (1) and iron [Fe(N5Py)(H2O)(ClO4)]ClO4 (2) complexes derived from a pentadentate ligand (N5Py = 2,6-bis((E)-1-phenyl-2-(pyridin-2-ylmethylene)hydrazinyl)pyridine) framework containing a N5 binding motif were synthesized and characterized using different spectroscopic methods. The molecular structures of complexes 1 and 2 were determined by X-ray crystallography. These complexes were found to be stable under physiological conditions and exhibited an excellent superoxide dismutase (SOD) activity. The SOD activity was determined by a xanthine-xanthine oxidase-nitro blue tetrazolium assay and the IC50 values were determined to be 1.53 and 2.09 μM, respectively.

  18. A novel porphyrin derivative and its metal complexes: Electrochemical, photoluminescence, thermal, DNA-binding and superoxide dismutase activity studies

    NASA Astrophysics Data System (ADS)

    Purtaş, Savaş; Köse, Muhammet; Tümer, Ferhan; Tümer, Mehmet; Gölcü, Ayşegül; Ceyhan, Gökhan

    2016-02-01

    In this study, a new porphyrin-Schiff base ligand (L) and its metal complexes (Cu(II), Fe(III), Mn(III), Pt(II) and Zn(II)) were synthesized. The starting material 4-ethyl-2,6-bis(hydroxymethyl)phenol (A) was synthesized from 4-ethylphenol and formaldehyde in the alkaline media. The compound (A) was then oxidized to the 4-ethyl-2,6-diformylphenol (B). The starting compounds (A) and (B) were obtained as single crystals. Structures of the compounds (A) and (B) were determined by the X-ray crytallography technique. The porphyrin ligand (L) and its metal complexes were characterized by the analytical and spectroscopic methods. Electronic, electrochemical and thermal properties of the synthesised compounds were investigated. Superoxide dismutase activities (SOD) of the porphyrin Schiff base complexes were investigated and results were discussed. Additionally, the DNA (fish sperm FSdsDNA) binding studies of the complexes were performed using UV-vis spectroscopy. Competitive studies with ethidium bromide (EB) show that the compounds interact efficiently with DNA through an intercalating way.

  19. Isoenzymes of superoxide dismutase in nodules of Phaseolus vulgaris L. , Pisum sativum L. , and Vigna unguiculata (L. ) Walp

    SciTech Connect

    Becana, M.; Paris, F.J.; Sandalio, L.M.; Del Rio, L.A. Unidad de Bioquimica Vegetal, Granada )

    1989-08-01

    The activity and isozymic composition of superoxide dismutase were determined in nodules of Phaseolus vulgaris L., Pisum sativum L., and Vigna unguiculata (L.) Walp. A Mn-SOD was present in Rhizobium and two in Bradyrhizobium and bacteroids. Nodule mitochondria from all three legume species had a single Mn-SOD with similar relative mobility, whereas the cytosol contained several CuZn-SODs: two in Phaseolus and Pisum, and four in Vigna. In the cytoplasm of V. unguiculata nodules, a Fe-containing SOD was also present, with an electrophoretic mobility between those of CuZn- and Mn-SODs, and an estimated molecular weight of 57,000. Total SOD activity of the soluble fraction of host cells, expressed on a nodule fresh weight basis, exceeded markedly that of bacteroids. Likewise, specific SOD activities of free-living bacteria were superior or equal to those of their symbiotic forms. Soluble extracts of bacteria and bacteroids did not show peroxidase activity, but the nodule cell cytoplasm contained diverse peroxidase isozymes which were readily distinguishable from leghemoglobin components by electrophoresis. Data indicated that peroxidases and leghemoglobins did not significantly interfere with SOD localization on gels. Treatment with chloroform-ethanol scarcely affected the isozymic pattern of SODs and peroxidases, and had limited success in the removal of leghemoglobin.

  20. Theoretical prediction of familial amyotrophic lateral sclerosis missense mutation effects on Cu/Zn superoxide dismutase structural stability

    SciTech Connect

    Potier, M.; Tu, Y.

    1994-09-01

    Cu/Zn superoxide dismutase (SOD) deficiency is associated with the progressive paralytic disorder familial amyotrophic lateral sclerosis (FALS). Fifteen missense mutations in the SOD gene were identified in several patients. These mutations may prevent correct promoter folding or hamper homodimer formation necessary for SOD activity. To understand the effect of the missense mutations on SOD structure and function, we used a theoretical analysis of structural effects based on two predictive methods using the modeled tertiary structure of human SOD. The first method uses the TORSO program which optimizes amino acid side-chains repacking in both wild-type and mutant SODs and calculates protein internal packing energy. The second method uses a hydrophobicity scale of the amino acid residues and considers both solvent accessibility and hydrophobic nature of residue substitutions to compute a stabilization energy change ({delta}E). These predictive methods have been tested in 187 single and multiple missense mutants of 8 proteins (T4 lysozyme, human carbonic anhydrase II, chymotrypsin inhibitor 2, f1 gene V protein, barnase, {lambda}-repressor, chicken and human lysozymes) with experimentally determined thermostability. The overall prediction accuracy with these proteins was 88%. Analysis of FALS missense mutations {delta}E predicts that 14 of 15 mutations destabilize the SOD structure. The other missense mutation is located at the homodimer interface and may hinder dimer formation. This approach is applicable to any protein with known tertiary structure to predict missense mutation effects on protein stability.

  1. Superoxide dismutase/catalase mimetic EUK-134 prevents diaphragm muscle weakness in monocrotalin-induced pulmonary hypertension.

    PubMed

    Himori, Koichi; Abe, Masami; Tatebayashi, Daisuke; Lee, Jaesik; Westerblad, Håkan; Lanner, Johanna T; Yamada, Takashi

    2017-01-01

    Patients with pulmonary hypertension (PH) suffer from inspiratory insufficiency, which has been associated with intrinsic contractile dysfunction in diaphragm muscle. Here, we examined the role of redox stress in PH-induced diaphragm weakness by using the novel antioxidant, EUK-134. Male Wistar rats were randomly divided into control (CNT), CNT + EUK-134 (CNT + EUK), monocrotaline-induced PH (PH), and PH + EUK groups. PH was induced by a single intraperitoneal injection of monocrotaline (60 mg/kg body weight). EUK-134 (3 mg/kg body weight/day), a cell permeable mimetic of superoxide dismutase (SOD) and catalase, was daily intraperitoneally administered starting one day after induction of PH. After four weeks, diaphragm muscles were excised for mechanical and biochemical analyses. There was a decrease in specific tetanic force in diaphragm bundles from the PH group, which was accompanied by increases in: protein expression of NADPH oxidase 2/gp91phox, SOD2, and catalase; 3-nitrotyrosine content and aggregation of actin; glutathione oxidation. Treatment with EUK-134 prevented the force decrease and the actin modifications in PH diaphragm bundles. These data show that redox stress plays a pivotal role in PH-induced diaphragm weakness. Thus, antioxidant treatment can be a promising strategy for PH patients with inspiratory failure.

  2. Corpus luteum derived copper, zinc-superoxide dismutase serves as a luteinizing hormone-release inhibiting factor in sheep.

    PubMed

    Al-Gubory, Kaïs H; Huet, Jean-Claude; Pernollet, Jean-Claude; Martal, Jacques; Locatelli, Alain

    2003-01-31

    In the present study, we report the purification and characterization of a polypeptide from the sheep corpus luteum of pregnancy with a potent luteinizing hormone-release inhibiting factor (LH-RIF) bioactivity that stained as a single band in SDS-PAGE with an apparent molecular mass of 16000 Da. The amino acid sequences obtained after sequence analysis of peptides derived from the trypsin digestion of LH-RIF were subjected to a protein data bank search and were found to be identical with regions of sheep copper, zinc-superoxide dismutase (Cu,Zn-SOD). The measured mass of LH-RIF (15604.2+/-1.9 Da) was found to be similar to the theoretical mass of sheep Cu,Zn-SOD (15603.5 Da), with a disulfide bond and N acetylated alanine at the N-terminus. The inhibitory action of Cu,Zn-SOD on pulsatile LH secretion would suggest that this antioxidant may play an important role, either independently or in concert with some neurotransmitters, in the neuroendocrine regulation of sheep female reproductive function.

  3. Superoxide dismutase/catalase mimetic EUK-134 prevents diaphragm muscle weakness in monocrotalin-induced pulmonary hypertension

    PubMed Central

    Tatebayashi, Daisuke; Lee, Jaesik; Westerblad, Håkan; Lanner, Johanna T.

    2017-01-01

    Patients with pulmonary hypertension (PH) suffer from inspiratory insufficiency, which has been associated with intrinsic contractile dysfunction in diaphragm muscle. Here, we examined the role of redox stress in PH-induced diaphragm weakness by using the novel antioxidant, EUK-134. Male Wistar rats were randomly divided into control (CNT), CNT + EUK-134 (CNT + EUK), monocrotaline-induced PH (PH), and PH + EUK groups. PH was induced by a single intraperitoneal injection of monocrotaline (60 mg/kg body weight). EUK-134 (3 mg/kg body weight/day), a cell permeable mimetic of superoxide dismutase (SOD) and catalase, was daily intraperitoneally administered starting one day after induction of PH. After four weeks, diaphragm muscles were excised for mechanical and biochemical analyses. There was a decrease in specific tetanic force in diaphragm bundles from the PH group, which was accompanied by increases in: protein expression of NADPH oxidase 2/gp91phox, SOD2, and catalase; 3-nitrotyrosine content and aggregation of actin; glutathione oxidation. Treatment with EUK-134 prevented the force decrease and the actin modifications in PH diaphragm bundles. These data show that redox stress plays a pivotal role in PH-induced diaphragm weakness. Thus, antioxidant treatment can be a promising strategy for PH patients with inspiratory failure. PMID:28152009

  4. The SOD2 gene, encoding a manganese-type superoxide dismutase, is up-regulated during conidiogenesis in the plant-pathogenic fungus Colletotrichum graminicola.

    PubMed

    Fang, G-C; Hanau, R M; Vaillancourt, L J

    2002-07-01

    The SOD2 gene, encoding a manganese-type superoxide dismutase (MnSOD), was identified from Colletotrichum graminicola among a collection of cDNAs representing genes that are up-regulated during conidiogenesis. The SOD2 gene consists of a 797-bp open reading frame that is interrupted by three introns and is predicted to encode a polypeptide of 208 amino acids. All conserved residues of the MnSOD protein family, including four consensus metal binding domains, are present in the predicted SOD2 protein. However, the predicted protein does not appear to contain a signal peptide that would target it to the mitochondria. Northern hybridizations revealed that expression of the approximately 900-bp SOD2 transcript is closely associated with differentiation of both oval and falcate conidia. Southern analysis indicated that there is only a single copy of the gene. SOD2 disruption strains were morphologically and pathogenically indistinguishable from wild-type strains. The dispensability of the MnSOD enzyme may be due to the activities of two other SOD enzymes, a highly expressed iron-type superoxide dismutase and a much less abundant copper/zinc type, that were also detected in C. graminicola.

  5. The effect of. gamma. irradiation and cystamine on superoxide dismutase activity in the bone marrow and erythocytes of rats. [/sup 60/Co

    SciTech Connect

    Krizala, J.; Stoklasova, A.; Kovarova, H.; Ledvina, M.

    1982-09-01

    The effect of a single dose of cystamine (50 mg/kg body wt; ip) on superoxide dismutase activity (E.C. 1.15.1.1; SOD) was studied in the cytosol fraction of bone marrow cells and erythrocytes of peripheral blood. The experiments were carried out on irradiated (8.0 Gy /sup 60/Co) and nonirradiated male Wistar rats. Whole-body irradiation caused a decrease in the specific activity of superoxide dismutase in the bone marrow which persisted for more than 14 days, whereas an increased activity occurred in erythrocytes at the same intervals. Cystamine administration to rats prior to irradiation led to decreased SOD activity in the bone marrow that was less pronounced than in the nonprotected, irradiated animals. In erythrocytes, treatment with cystamine prior to irradiation considerably increased SOD activity (especially on Day 14); this increase was much more pronounced than that after either cystamine administration or irradiation. The administration of cystamine to nonirradiated animals led to a decrease in SOD activity in the bone marrow on the third day only; however, in erythrocytes the activity increased (mostly on Day 14). Irradiation of the bone marrow was reflected in a substantial decrease of its cellularity that was, to a certain extent, normalized after cystamine treatment. The SOD activity per bone marrow cell (expressed in U/10/sup 6/ cells) was increased in the protected rats on the third day after irradiation, but this increase was not as pronounced as in nonprotected, irradiated rats.

  6. [Superoxide dismutase and catalase activities in carotenoid-synthesizing fungi Blakeslea trispora and Neurospora crassa under the oxidative stress].

    PubMed

    Gessler, N N; Sokolov, A V; Bykhovskiĭ, V Ia; Belozerskaia, T A

    2002-01-01

    The addition of menadione into the medium during cultivation of Neurospora crassa in the dark activated its constitutive superoxide dismutase. Exposure to light not only activated superoxide dismutase and catalase, but also increased the content of neurosporaxanthin. Superoxide dismutase activity in the mixed (+/-) mycelium of Blakeslea trispora synthesizing beta-carotene in the dark was much lower than that in Neurospora crassa. The superoxide dismutase activity further decreased in oxidative stress. The catalase activity decreased with an increase in the content of beta-carotene. Our results indicate that neurosporaxanthin possesses photoprotective properties in Neurospora crassa. In Blakeslea trispora (+/-) fungi, this compound acts as a major antioxidant during inactivation of enzymes that detoxify reactive oxygen species.

  7. Overproduction of Petunia Chloroplastic Copper/Zinc Superoxide Dismutase Does Not Confer Ozone Tolerance in Transgenic Tobacco 1

    PubMed Central

    Pitcher, Lynne H.; Brennan, Eileen; Hurley, Arthur; Dunsmuir, Pamela; Tepperman, James M.; Zilinskas, Barbara A.

    1991-01-01

    Transgenic tobacco (Nicotiana tabacum cultivar W38) plants that overproduce petunia chloroplastic Cu/Zn superoxide dismutase were exposed to ozone dosages that injure control tobacco plants. Based on foliar injury ratings, there was no consistent protection provided to the transgenic plants. These data indicate that an increase in the chloroplastic Cu/Zn superoxide dismutase alone is not sufficient to reduce ozone toxicity. ImagesFigure 1 PMID:16668407

  8. Structure and heme-binding properties of HemQ (chlorite dismutase-like protein) from Listeria monocytogenes

    PubMed Central

    Hofbauer, Stefan; Hagmüller, Andreas; Schaffner, Irene; Mlynek, Georg; Krutzler, Michael; Stadlmayr, Gerhard; Pirker, Katharina F.; Obinger, Christian; Daims, Holger; Djinović-Carugo, Kristina; Furtmüller, Paul G.

    2015-01-01

    Chlorite dismutase-like proteins are structurally closely related to functional chlorite dismutases which are heme b-dependent oxidoreductases capable of reducing chlorite to chloride with simultaneous production of dioxygen. Chlorite dismutase-like proteins are incapable of performing this reaction and their biological role is still under discussion. Recently, members of this large protein family were shown to be involved in heme biosynthesis in Gram-positive bacteria, and thus the protein was renamed HemQ in these organisms. In the present work the structural and heme binding properties of the chlorite dismutase-like protein from the Gram-positive pathogen Listeria monocytogenes (LmCld) were analyzed in order to evaluate its potential role as a regulatory heme sensing protein. The homopentameric crystal structure (2.0 Å) shows high similarity to chlorite-degrading chlorite dismutases with an important difference in the structure of the putative substrate and heme entrance channel. In solution LmCld is a stable hexamer able to bind the low-spin ligand cyanide. Heme binding is reversible with KD-values determined to be 7.2 μM (circular dichroism spectroscopy) and 16.8 μM (isothermal titration calorimetry) at pH 7.0. Both acidic and alkaline conditions promote heme release. Presented biochemical and structural data reveal that the chlorite dismutase-like protein from L. monocytogenes could act as a potential regulatory heme sensing and storage protein within heme biosynthesis. PMID:25602700

  9. Nanovaccine for leishmaniasis: preparation of chitosan nanoparticles containing Leishmania superoxide dismutase and evaluation of its immunogenicity in BALB/c mice

    PubMed Central

    Danesh-Bahreini, Mohammad Ali; Shokri, Javad; Samiei, Afshin; Kamali-Sarvestani, Eskandar; Barzegar-Jalali, Mohammad; Mohammadi-Samani, Soliman

    2011-01-01

    Background: Leishmaniasis is a protozoan disease, affecting 12 million people in different regions of the world with a wide spectrum of diseases. Although several chemotherapeutic agents have been used for treating the disease, long-term therapy, limited efficacy and the development of drug-resistant parasites remain the major limitations. Methods: To develop a new nanovaccine for leishmaniasis, recombinant Leishmania superoxide dismutase (SODB1) was loaded onto chitosan nanoparticles by the ionotropic gelation method. Size and loading efficiency of the nanoparticles were evaluated and optimized, and an immunization study was undertaken on BALB/c mice. The mice received phosphate buffer saline (PBS), superoxide dismutase B1 (SODB1) in PBS and nanoparticles via subcutaneous injection. Soluble Leishmania Antigens (SLA) and complete Freund’s adjuvant (CFA) were also injected subcutaneously three times every three weeks (some groups received only a single dose). Three weeks after the last injection, blood samples were collected and assessed with ELISA to detect IgG2a and IgG1. Results: Immunological analysis showed that in single and triple doses of SODB1 nanoparticles, IgG2a and IgG2a/IgG1 were significantly higher than the other groups (P<0.05). Conclusion: The results revealed that formulations of SODB1 in biodegradable and stable chitosan nanoparticles can increase the immunogenicity toward cell-mediated immunity (TH1 cells producing IgG2a in mice) that is effective in Leishmania eradication and could be presented as a single dose nanovaccine for leishmaniasis. PMID:21589651

  10. Cu,Zn superoxide dismutase from Photobacterium leiognathi is an hyperefficient enzyme.

    PubMed

    Stroppolo, M E; Sette, M; O'Neill, P; Polizio, F; Cambria, M T; Desideri, A

    1998-09-01

    The catalytic rate constant of recombinant Photobacterium leiognathi Cu,Zn superoxide dismutase has been determined as a function of pH by pulse radiolysis. At pH 7 and low ionic strength (I = 0.02 M) the catalytic rate constant is 8.5 x 10(9) M-1 s-1, more than two times the value found for all the native eukaryotic Cu,Zn superoxide dismutases investigated to date. Similarly, Brownian dynamics simulations indicate an enzyme-substrate association rate more than two times higher than that found for bovine Cu,Zn superoxide dismutase. Titration of the paramagnetic contribution to the water proton relaxation rate of the P. leiognathi with increasing concentration of halide ions with different radii indicates that the proteic channel delimiting the active site is wider than 4.4 A. This is at variance with that found on the eukariotic enzymes, and provides a rationale for the high catalytic rate of the bacterial enzyme. Evidence for solvent exposure of the active site different from that observed in the eukaryotic enzyme is suggested from the pH dependence of the water proton relaxation rate and of the EPR spectrum line shape, which indicate the occurrence of a prototropic equilibrium at pH 9.1 and 9.0, respectively. The pH dependence of the P. leiognathi catalytic rate has a trend different from that observed in the bovine enzyme, indicating that groups differently exposed to the solvent are involved in the modulation of the enzyme-substrate encounter.

  11. Bioactivity screening of Pinus brutia bark extracts: superoxide dismutase-like and nitric oxide scavenging effects.

    PubMed

    Cretu, Elena; Miron, S D; Miron, Anca

    2013-01-01

    In the Eastern Mediterranean region the wood of Pinus brutia Ten. is used as building material, the bark being the main waste of the wood production processes. A study was designed to explore possible medicinal applications for the bark waste. This paper reports on the superoxide dismutase-like and NO scavenging effects of bark extracts. Bark extracts (a raw hydromethanolic extract and its fractions) were initially screened regarding their ability to scavenge DPPH radical. The superoxide dismutase-like and NO scavenging effects were further evaluated. Catechin and quercetin were the positive controls in all antioxidant assays. According to the EC50 values, all extracts (11.8 +/- 0.1 - 21.10 +/- 0.05 microg/ml) efficiently scavenged DPPH radical in comparison to quercetin (3.13 +/- 0.05 microg/ml) and catechin (6.36 +/- 0.05 microg/ml). The raw extract, diethyl ether and ethyl acetate fractions (449.46 +/- 1.75, 115.43 +/- 0.25 and 278.3 +/- 2.3 microg/ml, respectively) exhibited higher superoxide dismutase-like effects in comparison to catechin (> 645.1 microg/ml). In NO scavenging assay, the raw extract, ethyl acetate and aqueous fractions (160.63 +/- 0.85, 162.96 +/- 0.52 and 160.23 +/- 2.35 microg/ml, respectively) showed a scavenging ability similar to that of quercetin (156.76 +/- 5.05 microg/ml) and higher than the one developed by catechin (242.66 +/- 7.65 microg/ml). As superoxide anion and NO are important mediators in inflammation, our results support a possible use of Pinus brutia bark waste to develop nutraceuticals with efficiency in disorders involving oxidative and inflammatory stress.

  12. Production of superoxide and activity of superoxide dismutase in rabbit epididymal spermatozoa.

    PubMed

    Holland, M K; Alvarez, J G; Storey, B T

    1982-12-01

    Mature rabbit spermatozoa from the cauda epididymidis suspended in potassium Tris phosphate buffer at 24 degrees C produced O2.-, as measured by reduction of acetylated ferricytochrome c, with an intrinsic rate of 0.20 nmol/min per 10(8) cells. This rate increased to 1.80 nmol/min per 10(8) cells in the presence of 10 mM cyanide. These spermatozoa contain 2.8 units per 10(8) cells of superoxide dismutase activity, 95% of which is sensitive, and 5% of which is insensitive, to cyanide inhibition. These activities correspond to the cytosolic Cu-Zn form and the mitochondrial Mn form of the dismutase, respectively. Only the cyanide-sensitive form is released from the sperm on hypo-osmotic treatment or sonication. Hypo-osmotically treated rabbit epididymal spermatozoa produced O2.- with an intrinsic rate of 0.24 nmol/min per 10(8) cells, which increased to 0.58 nmol/min per 10(8) cells in the presence of 10 mM cyanide. Both intact and hypo-osmotically treated cells react with O2.- in a second order reaction as inferred from the hyperbolic dependence on cell concentration of O2.- production rate in both the absence and presence of cyanide. The second order rate constant for this reaction with intact cells, kS, was calculated to be 22.9 X 10(-8) (cells/ml)-1 min-1 in its absence. For hypo-osmotically treated cells, the values of kS were 10.8 X 10(-8) (cells/ml)-1 min-1 and 8.2 X 10(-8) (cells/ml) -1 min-1, respectively. Since hypo-osmotically treated cells have lost much of their plasma membrane, the lower value of kS for the treated cells implies that this membrane is one site of reaction of O2.- with the cells. The increase in kS in the presence of cyanide, which inhibits superoxide dismutase and so increases O2.- production, suggests that the cells become more reactive with O2.- as its production rate increase, as would be expected for the occurrence of radical chain oxidation. This in turn suggests that superoxide dismutase plays a major role in protecting rabbit sperm

  13. Protection against hyperoxia by serum from endotoxin treated rats: absence of superoxide dismutase induction

    SciTech Connect

    Berg, J.T.; Smith, R.M.

    1988-01-01

    Endotoxin greatly reduces lung injury and pleural effusions in adult rats exposed to normobaric hyperoxia (> 98% oxygen for 60 hours). This study reports that serum from endotoxin treated donor rats protects serum recipients against hyperoxic lung injury without altering lung superoxide dismutase (SOD) activity. Rats pretreated with endotoxin alone were protected and exhibited an increase in lung SOD activity as previously reported by others. Protection by serum was not due to the transfer of residual endotoxin or SOD. These results show, that protection from oxygen toxicity can occur in rats without an increase in lung SOD and suggest that a serum factor may be involved.

  14. Identification, sequencing, and expression of Mycobacterium leprae superoxide dismutase, a major antigen.

    PubMed Central

    Thangaraj, H S; Lamb, F I; Davis, E O; Jenner, P J; Jeyakumar, L H; Colston, M J

    1990-01-01

    The gene encoding a major 28-kilodalton antigen of Mycobacterium leprae has now been sequenced and identified as the enzyme superoxide dismutase (SOD) on the basis of the high degree of homology with known SOD sequences. The deduced amino acid sequence shows 67% homology with a human manganese-utilizing SOD and 55% homology with the Escherichia coli manganese-utilizing enzyme. The gene is not expressed from its own promoter in E. coli but is expressed from its own promoter in Mycobacterium smegmatis. The amino acid sequences of epitopes recognized by monoclonal antibodies against the 28-kilodalton antigen have been determined. Images PMID:1692812

  15. Infrared spectra and normal coordinate analysis of a model compound for superoxide dismutase

    NASA Astrophysics Data System (ADS)

    Yin, Jun; Li, Chongde; Chen, Xianyang; Luo, Qinhui

    1997-10-01

    Infrared spectra have been measured and vibrational assignment are given for a new model compound of superoxide dismutase (SOD): [(tren)CuimZn(tren)](ClO 4) 3·CH 3OH (where tren = tris(2-aminoethyl)amine, im = imidazolate). In order to check the empirical assignment, we have performed a detailed normal coordinate analysis (NCA) based on a Urey-Bradley force field. Due to introducing an appropriate set of internal coordinates and force constants in the course of calculation, the agreement between the experimental and calculated frequencies is satisfactory.

  16. Potentiation of Antibiofilm Activity of Amphotericin B by Superoxide Dismutase Inhibition

    PubMed Central

    De Brucker, Katrijn; Bink, Anna; Meert, Els; Cammue, Bruno P. A.; Thevissen, Karin

    2013-01-01

    This study demonstrates a role for superoxide dismutases (Sods) in governing tolerance of Candida albicans biofilms to amphotericin B (AmB). Coincubation of C. albicans biofilms with AmB and the Sod inhibitors N,N′-diethyldithiocarbamate (DDC) or ammonium tetrathiomolybdate (ATM) resulted in reduced viable biofilm cells and increased intracellular reactive oxygen species levels as compared to incubation of biofilm cells with AmB, DDC, or ATM alone. Hence, Sod inhibitors can be used to potentiate the activity of AmB against C. albicans biofilms. PMID:24078861

  17. Induction of nitric oxide-dependent apoptosis in motor neurons by zinc-deficient superoxide dismutase.

    PubMed

    Estévez, A G; Crow, J P; Sampson, J B; Reiter, C; Zhuang, Y; Richardson, G J; Tarpey, M M; Barbeito, L; Beckman, J S

    1999-12-24

    Mutations in copper, zinc superoxide dismutase (SOD) have been implicated in the selective death of motor neurons in 2 percent of amyotrophic lateral sclerosis (ALS) patients. The loss of zinc from either wild-type or ALS-mutant SODs was sufficient to induce apoptosis in cultured motor neurons. Toxicity required that copper be bound to SOD and depended on endogenous production of nitric oxide. When replete with zinc, neither ALS-mutant nor wild-type copper, zinc SODs were toxic, and both protected motor neurons from trophic factor withdrawal. Thus, zinc-deficient SOD may participate in both sporadic and familial ALS by an oxidative mechanism involving nitric oxide.

  18. Zymography Methods to Simultaneously Analyze Superoxide Dismutase and Catalase Activities: Novel Application for Yeast Species Identification.

    PubMed

    Gamero-Sandemetrio, Esther; Gómez-Pastor, Rocío; Matallana, Emilia

    2017-01-01

    We provide an optimized protocol for a double staining technique to analyze superoxide dismutase enzymatic isoforms Cu-Zn SOD (Sod1) and Mn-SOD (Sod2) and catalase in the same polyacrylamide gel. The use of NaCN, which specifically inhibits yeast Sod1 isoform, allows the analysis of Sod2 isoform while the use of H2O2 allows the analysis of catalase. The identification of a different zymography profiling of SOD and catalase isoforms in different yeast species allowed us to propose this technique as a novel yeast identification and classification strategy.

  19. Engineering a thermo-stable superoxide dismutase functional at sub-zero to >50°C, which also tolerates autoclaving

    PubMed Central

    Kumar, Arun; Dutt, Som; Bagler, Ganesh; Ahuja, Paramvir Singh; Kumar, Sanjay

    2012-01-01

    Superoxide dismutase (SOD) is a critical enzyme associated with controlling oxygen toxicity arising out of oxidative stress in any living system. A hyper-thermostable SOD isolated from a polyextremophile higher plant Potentilla atrosanguinea Lodd. var. argyrophylla (Wall. ex Lehm.) was engineered by mutation of a single amino acid that enhanced the thermostability of the enzyme to twofold. The engineered enzyme was functional from sub-zero temperature to >50°C, tolerated autoclaving (heating at 121°C, at a pressure of 1.1 kg per square cm for 20 min) and was resistant to proteolysis. The present work is the first example to enhance the thermostability of a hyper-thermostable protein and has potential to application to other proteins for enhancing thermostability. PMID:22548128

  20. Isolation, chromosomal localization, and differential expression of mitochondrial manganese superoxide dismutase and chloroplastic copper/zinc superoxide dismutase genes in wheat.

    PubMed

    Wu, G; Wilen, R W; Robertson, A J; Gusta, L V

    1999-06-01

    Superoxide dismutase (SOD) gene expression was investigated to elucidate its role in drought and freezing tolerance in spring and winter wheat (Triticum aestivum). cDNAs encoding chloroplastic Cu/ZnSODs and mitochondrial MnSODs were isolated from wheat. MnSOD and Cu/ZnSOD genes were mapped to the long arms of the homologous group-2 and -7 chromosomes, respectively. Northern blots indicated that MnSOD genes were drought inducible and decreased after rehydration. In contrast, Cu/ZnSOD mRNA was not drought inducible but increased after rehydration. In both spring and winter wheat seedlings exposed to 2 degrees C, MnSOD transcripts attained maximum levels between 7 and 49 d. Transcripts of Cu/ZnSOD mRNA were detected sooner in winter than in spring wheat; however, they disappeared after 21 d of acclimation. Transcripts of both classes of SOD genes increased during natural acclimation in both spring and winter types. Exposure of fully hardened plants to three nonlethal freeze-thaw cycles resulted in Cu/Zn mRNA accumulation; however, MnSOD mRNA levels declined in spring wheat but remained unchanged in winter wheat. The results of the dehydration and freeze-thaw-cycle experiments suggest that winter wheat has evolved a more effective stress-repair mechanism than spring wheat.

  1. A Zostera marina manganese superoxide dismutase gene involved in the responses to temperature stress.

    PubMed

    Liu, Jiao; Tang, Xuexi; Wang, You; Zang, Yu; Zhou, Bin

    2016-01-10

    Superoxide dismutase (SOD) is an essential enzyme playing a pivotal role in the protection mechanism against oxidative stress by reducing superoxide radicals. In the present study, the full-length cDNA sequence of manganese superoxide dismutase was identified from Zostera marina (ZmMnSOD) via raid amplification of cDNA ends (RACE) technique and expressed sequence tags (ESTs) analysis. The open reading frame (ORF) encoded a polypeptide of 254 amino acid residues, which shared 69%-77% similarity with previous identified SODs. Analysis of the deduced amino acid revealed conserved features, including functional domains, signature motifs and metal binding sites. Phylogenetic analysis revealed that ZmMnSOD was closer to the SODs from angiosperm than those from other organisms. The mRNA expression level of ZmMnSOD at different temperatures was investigated using real-time PCR and it was significantly up-regulated from 5°C to 15°C, and then dramatically down-regulated. The recombinant ZmMnSOD protein was purified and exhibited Mn(2+) ions dependency specific enzymatic activity and strong antioxidant activity over a wide temperature range. All these results indicate that ZmMnSOD is an authentic member of the plant SOD family and may play important roles in minimizing the effect of oxidative damage in Z. marina against temperature stress and affect the adaptability of Z. marina to global warming. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Periplasmic superoxide dismutase SodCI of Salmonella binds peptidoglycan to remain tethered within the periplasm.

    PubMed

    Tidhar, Avital; Rushing, Marcus D; Kim, Byoungkwan; Slauch, James M

    2015-09-01

    Salmonellae survive and propagate in macrophages to cause serious systemic disease. Periplasmic superoxide dismutase plays a critical role in this survival by combating phagocytic superoxide. Salmonella Typhimurium strain 14028 produces two periplasmic superoxide dismutases: SodCI and SodCII. Although both proteins are produced during infection, only SodCI is functional in the macrophage phagosome. We have previously shown that SodCI, relative to SodCII, is both protease resistant and tethered within the periplasm and that either of these properties is sufficient to allow a SodC to protect against phagocytic superoxide. Tethering is defined as remaining cell-associated after osmotic shock or treatment with cationic antimicrobial peptides. Here we show that SodCI non-covalently binds peptidoglycan. SodCI binds to Salmonella and Bacillus peptidoglycan, but not peptidoglycan from Staphylococcus. Moreover, binding can be inhibited by a diaminopimelic acid containing tripeptide, but not a lysine containing tripeptide, showing that the protein recognizes the peptide portion of the peptidoglycan. Replacing nine amino acids in SodCII with the corresponding residues from SodCI confers tethering, partially delineating an apparently novel peptidoglycan binding domain. These changes in sequence increase the affinity of SodCII for peptidoglycan fragments to match that of SodCI and allow the now tethered SodCII to function during infection.

  3. Transiently Produced Hypochlorite Is Responsible for the Irreversible Inhibition of Chlorite Dismutase

    PubMed Central

    2014-01-01

    Chlorite dismutases (Clds) are heme b-containing prokaryotic oxidoreductases that catalyze the reduction of chlorite to chloride with the concomitant release of molecular oxygen. Over time, they are irreversibly inactivated. To elucidate the mechanism of inactivation and investigate the role of the postulated intermediate hypochlorite, the pentameric chlorite dismutase of “Candidatus Nitrospira defluvii” (NdCld) and two variants (having the conserved distal arginine 173 exchanged with alanine and lysine) were recombinantly produced in Escherichia coli. Exchange of the distal arginine boosts the extent of irreversible inactivation. In the presence of the hypochlorite traps methionine, monochlorodimedone, and 2-[6-(4-aminophenoxy)-3-oxo-3H-xanthen-9-yl]benzoic acid, the extent of chlorite degradation and release of molecular oxygen is significantly increased, whereas heme bleaching and oxidative modifications of the protein are suppressed. Among other modifications, hypochlorite-mediated formation of chlorinated tyrosines is demonstrated by mass spectrometry. The data obtained were analyzed with respect to the proposed reaction mechanism for chlorite degradation and its dependence on pH. We discuss the role of distal Arg173 by keeping hypochlorite in the reaction sphere for O–O bond formation. PMID:24754261

  4. Chlorite dismutases – a heme enzyme family for use in bioremediation and generation of molecular oxygen

    PubMed Central

    Hofbauer, Stefan; Schaffner, Irene; Furtmüller, Paul G; Obinger, Christian

    2014-01-01

    Chlorite is a serious environmental concern, as rising concentrations of this harmful anthropogenic compound have been detected in groundwater, drinking water, and soil. Chlorite dismutases (Clds) are therefore important molecules in bioremediation as Clds catalyze the degradation of chlorite to chloride and molecular oxygen. Clds are heme b-containing oxidoreductases present in numerous bacterial and archaeal phyla. This review presents the phylogeny of functional Clds and Cld-like proteins, and demonstrates the close relationship of this novel enzyme family to the recently discovered dye-decolorizing peroxidases. The available X-ray structures, biophysical and enzymatic properties, as well as a proposed reaction mechanism, are presented and critically discussed. Open questions about structure-function relationships are addressed, including the nature of the catalytically relevant redox and reaction intermediates and the mechanism of inactivation of Clds during turnover. Based on analysis of currently available data, chlorite dismutase from “Candidatus Nitrospira defluvii” is suggested as a model Cld for future application in biotechnology and bioremediation. Additionally, Clds can be used in various applications as local generators of molecular oxygen, a reactivity already exploited by microbes that must perform aerobic metabolic pathways in the absence of molecular oxygen. For biotechnologists in the field of chemical engineering and bioremediation, this review provides the biochemical and biophysical background of the Cld enzyme family as well as critically assesses Cld's technological potential. PMID:24519858

  5. The induction of manganese superoxide dismutase in response to stress in Nicotiana plumbaginifolia.

    PubMed Central

    Bowler, C; Alliotte, T; De Loose, M; Van Montagu, M; Inzé, D

    1989-01-01

    Superoxide dismutases (SODs) are metalloproteins that catalyse the dismutation of superoxide radicals to oxygen and hydrogen peroxide. The enzyme has been found in all aerobic organisms examined, where it plays a major role in the defence against toxic reduced oxygen species which are generated in many biological oxidations. Here we report the complete primary structure of a plant manganese superoxide dismutase (MnSOD), deduced from a cDNA clone of Nicotiana plumbaginifolia. The plant protein is highly homologous to MnSODs from other organisms and also contains an N-terminal leader sequence resembling a transit peptide for mitochondrial targeting. The location of the mature protein within the mitochondria has been demonstrated by subcellular fractionation experiments. We have analysed the expression profile of this MnSOD and found that it is dramatically induced during stress conditions, most notably in tissue culture as a result of sugar metabolism and also as part of the pathogenesis response of the plant, being induced by ethylene, salicylic acid, and Pseudomonas syringae infection. This induction is always accompanied by an increase in cytochrome oxidase activity, which suggests a specific protective role for MnSOD during conditions of increased mitochondrial respiration. Images PMID:2540959

  6. Featured Article: Effect of copper on nuclear translocation of copper chaperone for superoxide dismutase-1.

    PubMed

    Wang, Lin; Ge, Yan; Kang, Y James

    2016-08-01

    Copper chaperone for superoxide dismutase-1 (CCS-1), facilitating copper insertion into superoxide dismutase 1 (SOD-1), is present in the nucleus. However, it is unknown how CCS-1 is translocated to the nucleus. The present study was undertaken to determine the effect of copper on nuclear translocation of CCS-1. Human umbilical vein endothelial cells (HUVECs) were subjected to hypoxia, causing an increase in both copper and CCS-1 in the nucleus. Treatment with tetraethylenepentamine (TEPA) not only decreased the total cellular concentration and the nuclear translocation of copper, but also completely suppressed the entry of CCS-1 to the nucleus. On the other hand, siRNA targeting CCS-1 neither inhibited the increase in total concentrations nor blocked the nuclear translocation of copper. This study thus demonstrates that under hypoxia condition, both copper and CCS-1 are transported to the nucleus. The nuclear translocation of CCS-1 is copper dependent, but the nuclear translocation of copper could take place alternatively in a CCS-1-independent pathway. © 2016 by the Society for Experimental Biology and Medicine.

  7. Ras Oncogene-Mediated Progressive Silencing of Extracellular Superoxide Dismutase in Tumorigenesis

    PubMed Central

    Cammarota, Francesca; de Vita, Gabriella; Salvatore, Marco; Laukkanen, Mikko O.

    2015-01-01

    Extracellular superoxide dismutase (SOD3) is a secreted enzyme that uses superoxide anion as a substrate in a dismutase reaction that results in the formation of hydrogen peroxide. Both of these reactive oxygen species affect growth signaling in cells. Although SOD3 has growth-supporting characteristics, the expression of SOD3 is downregulated in epithelial cancer cells. In the current work, we studied the mechanisms regulating SOD3 expression in vitro using thyroid cell models representing different stages of thyroid cancer. We demonstrate that a low level of RAS activation increases SOD3 mRNA synthesis that then gradually decreases with increasing levels of RAS activation and the decreasing degree of differentiation of the cancer cells. Our data indicate that SOD3 regulation can be divided into two classes. The first class involves RAS–driven reversible regulation of SOD3 expression that can be mediated by the following mechanisms: RAS GTPase regulatory genes that are responsible for SOD3 self-regulation; RAS-stimulated p38 MAPK activation; and RAS-activated increased expression of the mir21 microRNA, which inversely correlates with sod3 mRNA expression. The second class involves permanent silencing of SOD3 mediated by epigenetic DNA methylation in cells that represent more advanced cancers. Therefore, the work suggests that SOD3 belongs to the group of ras oncogene-silenced genes. PMID:26550576

  8. Extracellular superoxide dismutase is necessary to maintain renal blood flow during sepsis development.

    PubMed

    Constantino, Larissa; Galant, Letícia Selinger; Vuolo, Francieli; Guarido, Karla Lorena; Kist, Luiza Wilges; de Oliveira, Giovanna Medeiros Tavares; Pasquali, Matheus Augusto de Bittencourt; de Souza, Cláudio Teodoro; da Silva-Santos, José Eduardo; Bogo, Maurício Reis; Moreira, José Cláudio Fonseca; Ritter, Cristiane; Dal-Pizzol, Felipe

    2017-12-01

    Extracellular superoxide dismutase (ECSOD) protects nitric oxide (NO) bioavailability by decreasing superoxide levels and preventing peroxynitrite generation, which is important in maintaining renal blood flow and in preventing acute kidney injury. However, the profile of ECSOD expression after sepsis is not fully understood. Therefore, we intended to evaluate the content and gene expression of superoxide dismutase (SOD) isoforms in the renal artery and their relation to renal blood flow. Sepsis was induced in Wistar rats by caecal ligation and perforation. Several times after sepsis induction, renal blood flow (12, 24 and 48 h); the renal arterial content of SOD isoforms, nitrotyrosine, endothelial and inducible nitric oxide synthase (e-NOS and i-NOS), and phosphorylated vasodilator-stimulated phosphoprotein (pVASP); and SOD activity (3, 6 and 12 h) were measured. The influence of a SOD inhibitor was also evaluated. An increase in ECSOD content was associated with decreased 3-nitrotyrosine levels. These events were associated with an increase in pVASP content and maintenance of renal blood flow. Moreover, previous treatment with a SOD inhibitor increased nitrotyrosine content and reduced renal blood flow. ECSOD appears to have a major role in decreasing peroxynitrite formation in the renal artery during the early stages of sepsis development, and its application can be important in renal blood flow control and maintenance during septic insult.

  9. Differential response of maize catalases and superoxide dismutases to the photoactivated fungal toxin cercosporin.

    PubMed

    Williamson, J D; Scandalios, J G

    1992-05-01

    Many fungi of the genus Cercospora produce a light-induced, photoactivated polyketide toxin called cercosporin. In the presence of light an excited form (triplet state) of the toxin molecule is produced which, depending on the reducing potential of the environment, reacts with molecular oxygen to produce singlet oxygen and/or superoxide radicals. In this paper a system is presented for analysis of antioxidant defense gene response using purified cercosporin under conditions demonstrated to favor superoxide formation. Under the assay conditions employed, changes in total catalase activity, as well as individual isozyme protein levels generally mirrored the changes observed in corresponding steady-state RNA levels in response to applied cercosporin. In contrast, while transcript accumulation for most maize superoxide dismutases increased dramatically, both total superoxide dismutase activity and individual isozyme protein levels remained constant in all toxin treatments. In one case, the analyses indicated that there are two distinct transcripts that hybridize with a gene-specific probe for Sod3. These two transcripts responded differentially to applied toxin (levels of the larger transcript increased while the smaller decreased), whereas corresponding steady-state levels for the SOD-3 isozyme proteins remained constant. This suggests that protein turnover might play a role in the response of these SODs to activated oxygen species.

  10. Diversity, Function and Evolution of Genes Coding for Putative Ni-Containing Superoxide Dismutases

    SciTech Connect

    Dupont,C.; Neupane, K.; Shearer, J.; Palenik, B.

    2008-01-01

    We examined the phylogenetic distribution, functionality and evolution of the sodN gene family, which has been shown to code for a unique Ni-containing isoform of superoxide dismutase (Ni-SOD) in Streptomyces. Many of the putative sodN sequences retrieved from public domain genomic and metagenomic databases are quite divergent from structurally and functionally characterized Ni-SOD. Structural bioinformatics studies verified that the divergent members of the sodN protein family code for similar three-dimensional structures and identified evolutionarily conserved amino acid residues. Structural and biochemical studies of the N-terminus 'Ni-hook' motif coded for by the putative sodN sequences confirmed both Ni (II) ligating and superoxide dismutase activity. Both environmental and organismal genomes expanded the previously noted phylogenetic distribution of sodN, and the sequences form four well-separated clusters, with multiple subclusters. The phylogenetic distribution of sodN suggests that the gene has been acquired via horizontal gene transfer by numerous organisms of diverse phylogenetic background, including both Eukaryotes and Prokaryotes. The presence of sodN correlates with the genomic absence of the gene coding for Fe-SOD, a structurally and evolutionarily distinct isoform of SOD. Given the low levels of Fe found in the marine environment from where many sequences were attained, we suggest that the replacement of Fe-SOD with Ni-SOD may be an evolutionary adaptation to reduce iron requirements.

  11. Transient hyperoxic reoxygenation reduces cytochrome C oxidase activity by increasing superoxide dismutase and nitric oxide.

    PubMed

    Arab, Amina; Wang, Jin; Bausch, Kathrin; von Schmädel, Katharina; Bode, Christoph; Hehrlein, Christoph

    2010-04-09

    Oxygen therapies have been shown to be cytoprotective in a dose-dependent fashion. Previously, we have characterized the protective effects of moderate hyperoxia on cell viability of ischemic human cardiomyocytes and their mitochondrial membrane potential by transient addition of oxygenated perfluorocarbons to the cell medium. Now, we report that the activity and expression of cytochrome c oxidase (COX) after prolonged ischemia depend on the amount of oxygen delivered during reoxygenation. Transient hyperoxia during reoxygenation results in a decrease of COX activity by 62 +/- 15% and COX expression by 67 +/- 5%, when hyperoxic tensions of approximately = 300 mm Hg are reached in the cell medium. This decrease in COX expression is prevented by the inhibition of inducible nitric-oxide synthase (iNOS). Immunoblot analysis of ischemic human cardiomyocytes revealed that hyperoxic reoxygenation causes a 2-fold increase of iNOS, leading to a rise in nitric oxide production by 140 +/- 45%. Hyperoxic reoxygenation is further responsible for a 2-fold activation of hydrogen peroxide production and an increase in cytosolic superoxide dismutase expression by 35 +/- 10%. NADPH availability has no effect on the hyperoxia-induced decrease of superoxide. Overall, these results indicate that transient hyperoxic reoxygenation in optimal concentrations increases the level of nitric oxide by activation of iNOS and superoxide dismutase, thereby inducing respiration arrest in mitochondria of ischemic cardiomyocytes.

  12. Chlorite dismutases - a heme enzyme family for use in bioremediation and generation of molecular oxygen.

    PubMed

    Hofbauer, Stefan; Schaffner, Irene; Furtmüller, Paul G; Obinger, Christian

    2014-04-01

    Chlorite is a serious environmental concern, as rising concentrations of this harmful anthropogenic compound have been detected in groundwater, drinking water, and soil. Chlorite dismutases (Clds) are therefore important molecules in bioremediation as Clds catalyze the degradation of chlorite to chloride and molecular oxygen. Clds are heme b-containing oxidoreductases present in numerous bacterial and archaeal phyla. This review presents the phylogeny of functional Clds and Cld-like proteins, and demonstrates the close relationship of this novel enzyme family to the recently discovered dye-decolorizing peroxidases. The available X-ray structures, biophysical and enzymatic properties, as well as a proposed reaction mechanism, are presented and critically discussed. Open questions about structure-function relationships are addressed, including the nature of the catalytically relevant redox and reaction intermediates and the mechanism of inactivation of Clds during turnover. Based on analysis of currently available data, chlorite dismutase from "Candidatus Nitrospira defluvii" is suggested as a model Cld for future application in biotechnology and bioremediation. Additionally, Clds can be used in various applications as local generators of molecular oxygen, a reactivity already exploited by microbes that must perform aerobic metabolic pathways in the absence of molecular oxygen. For biotechnologists in the field of chemical engineering and bioremediation, this review provides the biochemical and biophysical background of the Cld enzyme family as well as critically assesses Cld's technological potential. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Recombinant Mitochondrial Manganese Containing Superoxide Dismutase Protects Against Ochratoxin A-Induced Nephrotoxicity.

    PubMed

    Ciarcia, Roberto; Damiano, Sara; Squillacioti, Caterina; Mirabella, Nicola; Pagnini, Ugo; Florio, Alessia; Severino, Lorella; Capasso, Giovambattista; Borrelli, Antonella; Mancini, Aldo; Boffo, Silvia; Romano, Gaetano; Giordano, Antonio; Florio, Salvatore

    2016-06-01

    Ochratoxin A (OTA) is a natural mycotoxin, involved in the development of important human and animal diseases. In this work we have studied the role of oxidative stress in the development of OTA nephrotoxicity and the effect of a new recombinant mitochondrial manganese containing superoxide dismutase (rMnSOD) to prevent kidney damage induced by OTA. Blood pressure, glomerular filtration rate and renal histology were analyzed in control rats and in OTA treated rats. In addition, lipid peroxidation, catalase and superoxide dismutase productions were measured. Our data showed that animals treated with OTA presented hypertension and reduction of glomerular filtration rate (GFR). These effects are most probably related to an increase in the reactive oxygen species (ROS) productions. In fact, we have shown that treatment with rMnSOD restored the levels of blood pressure and GFR simultaneously. Moreover, we have noted that OTA induced alteration on glomerular and tubular degeneration and interstitial infiltrates and that use of rMnSOD combined with OTA prevent this renal histological damage confirming the potential therapeutic role in the treatment of rMnSOD OTA nephrotoxicity.

  14. Unique Characteristics of Recombinant Hybrid Manganese Superoxide Dismutase from Staphylococcus equorum and S. saprophyticus.

    PubMed

    Retnoningrum, Debbie S; Rahayu, Anis Puji; Mulyanti, Dina; Dita, Astrid; Valerius, Oliver; Ismaya, Wangsa T

    2016-04-01

    A recombinant hybrid of manganese dependent-superoxide dismutase of Staphylococcus equorum and S. saprophyticus has successfully been overexpressed in Escherichia coli BL21(DE3), purified, and characterized. The recombinant enzyme suffered from degradation and aggregation upon storage at -20 °C, but not at room temperature nor in cold. Chromatographic analysis in a size exclusion column suggested the occurrence of dimeric form, which has been reported to contribute in maintaining the stability of the enzyme. Effect of monovalent (Na(+), K(+)), divalent (Ca(2+), Mg(2+)), multivalent (Mn(2+/4+), Zn(2+/4+)) cations and anions (Cl(-), SO4 (2-)) to the enzyme stability or dimeric state depended on type of cation or anion, its concentration, and pH. However, tremendous effect was observed with 50 mM ZnSO4, in which thermostability of both the dimer and monomer was increased. Similar situation was not observed with MnSO4, and its presence was detrimental at 200 mM. Finally, chelating agent appeared to destabilize the dimer around neutral pH and dissociate it at basic pH. The monomer remained stable upon addition of ethylene diamine tetraacetic acid. Here we reported unique characteristics and stability of manganese dependent-superoxide dismutase from S. equorum/saprophyticus.

  15. A biologically effective fullerene (C60) derivative with superoxide dismutase mimetic properties.

    PubMed

    Ali, Sameh S; Hardt, Joshua I; Quick, Kevin L; Kim-Han, Jeong Sook; Erlanger, Bernard F; Huang, Ting-Ting; Epstein, Charles J; Dugan, Laura L

    2004-10-15

    Superoxide, a potentially toxic by-product of cellular metabolism, may contribute to tissue injury in many types of human disease. Here we show that a tris-malonic acid derivative of the fullerene C60 molecule (C3) is capable of removing the biologically important superoxide radical with a rate constant (k(C3)) of 2 x 10(6) mol(-1) s(-1), approximately 100-fold slower than the superoxide dismutases (SOD), a family of enzymes responsible for endogenous dismutation of superoxide. This rate constant is within the range of values reported for several manganese-containing SOD mimetic compounds. The reaction between C3 and superoxide was not via stoichiometric "scavenging," as expected, but through catalytic dismutation of superoxide, indicated by lack of structural modifications to C3, regeneration of oxygen, production of hydrogen peroxide, and absence of EPR-active (paramagnetic) products, all consistent with a catalytic mechanism. A model is proposed in which electron-deficient regions on the C60 sphere work in concert with malonyl groups attached to C3 to electrostatically guide and stabilize superoxide, promoting dismutation. We also found that C3 treatment of Sod2(-/-) mice, which lack expression of mitochondrial manganese superoxide dismutase (MnSOD), increased their life span by 300%. These data, coupled with evidence that C3 localizes to mitochondria, suggest that C3 functionally replaces MnSOD, acting as a biologically effective SOD mimetic.

  16. Featured Article: Effect of copper on nuclear translocation of copper chaperone for superoxide dismutase-1

    PubMed Central

    Wang, Lin; Ge, Yan

    2016-01-01

    Copper chaperone for superoxide dismutase-1 (CCS-1), facilitating copper insertion into superoxide dismutase 1 (SOD-1), is present in the nucleus. However, it is unknown how CCS-1 is translocated to the nucleus. The present study was undertaken to determine the effect of copper on nuclear translocation of CCS-1. Human umbilical vein endothelial cells (HUVECs) were subjected to hypoxia, causing an increase in both copper and CCS-1 in the nucleus. Treatment with tetraethylenepentamine (TEPA) not only decreased the total cellular concentration and the nuclear translocation of copper, but also completely suppressed the entry of CCS-1 to the nucleus. On the other hand, siRNA targeting CCS-1 neither inhibited the increase in total concentrations nor blocked the nuclear translocation of copper. This study thus demonstrates that under hypoxia condition, both copper and CCS-1 are transported to the nucleus. The nuclear translocation of CCS-1 is copper dependent, but the nuclear translocation of copper could take place alternatively in a CCS-1-independent pathway. PMID:27190267

  17. Cloning, Purification, and Characterization of Recombinant Human Extracellular Superoxide Dismutase in SF9 Insect Cells.

    PubMed

    Shrestha, Pravesh; Yun, Ji-Hye; Kim, Woo Taek; Kim, Tae-Yoon; Lee, Weontae

    2016-03-01

    A balance between production and degradation of reactive oxygen species (ROS) is critical for maintaining cellular homeostasis. Increased levels of ROS during oxidative stress are associated with disease conditions. Antioxidant enzymes, such as extracellular superoxide dismutase (EC-SOD), in the extracellular matrix (ECM) neutralize the toxicity of superoxide. Recent studies have emphasized the importance of EC-SOD in protecting the brain, lungs, and other tissues from oxidative stress. Therefore, EC-SOD would be an excellent therapeutic drug for treatment of diseases caused by oxidative stress. We cloned both the full length (residues 1-240) and truncated (residues 19-240) forms of human EC-SOD (hEC-SOD) into the donor plasmid pFastBacHTb. After transposition, the bacmid was transfected into the Sf9-baculovirus expression system and the expressed hEC-SOD purified using FLAG-tag. Western blot analysis revealed that hEC-SOD is present both as a monomer (33 kDa) and a dimer (66 kDa), as detected by the FLAG antibody. A water-soluble tetrazolium (WST-1) assay showed that both full length and truncated hEC-SOD proteins were enzymatically active. We showed that a potent superoxide dismutase inhibitor, diethyldithiocarbamate (DDC), inhibits hEC-SOD activity.

  18. Contribution of human manganese superoxide dismutase tyrosine 34 to structure and catalysis.

    PubMed

    Perry, J Jefferson P; Hearn, Amy S; Cabelli, Diane E; Nick, Harry S; Tainer, John A; Silverman, David N

    2009-04-21

    Superoxide dismutase (SOD) enzymes are critical in controlling levels of reactive oxygen species (ROS) that are linked to aging, cancer, and neurodegenerative disease. Superoxide (O(2)(*-)) produced during respiration is removed by the product of the SOD2 gene, the homotetrameric manganese superoxide dismutase (MnSOD). Here, we examine the structural and catalytic roles of the highly conserved active-site residue Tyr34, based upon structure-function studies of MnSOD enzymes with mutations at this site. Substitution of Tyr34 with five different amino acids retained the active-site protein structure and assembly but caused a substantial decrease in the catalytic rate constant for the reduction of superoxide. The rate constant for formation of the product inhibition complex also decreases but to a much lesser extent, resulting in a net increase in the level of product inhibited form of the mutant enzymes. Comparisons of crystal structures and catalytic rates also suggest that one mutation, Y34V, interrupts the hydrogen-bonded network, which is associated with a rapid dissociation of the product-inhibited complex. Notably, with three of the Tyr34 mutants, we also observe an intermediate in catalysis, which has not been reported previously. Thus, these mutants establish a means of trapping a catalytic intermediate that promises to help elucidate the mechanism of catalysis.

  19. Evolutive and structural characterization of Nostoc commune iron-superoxide dismutase that is fit for modification.

    PubMed

    Ma, Y; Lu, M; Li, J-Y; Qin, Y; Gong, X-G

    2012-10-04

    Superoxide dismutase (SOD) has extensive clinical applications for protecting organisms from toxic oxidation. In this study, the integrated iron-superoxide dismutase gene (fe-sod) coding sequence of Nostoc commune stain CHEN was cloned from genomic DNA and compared to sods from other reported algae. These analyses of immunology and phylogenetics indicated that this Fe-SOD is considerably homologous with SODs from lower prokaryotes (Fe-SOD or Mn-SOD) but not those from higher animals (Cu/Zn-SOD). In addition, the N. commune Fe-SOD shows 67 to 93% protein sequence identity to 10 other algal Fe-SODs (or Mn-SODs) and 69 to 93% gene sequence identity. Rare nonsynonymous substitutions imply that algal SODs are being subjected to strong natural selection. Interestingly, the N. commune Fe-SOD enzyme molecule has a compact active center that is highly conserved (38.1% of residues are absolutely conserved), and 2 loose ends localized outside the molecule and inclined to mutate (only 11.5% of residues are absolutely conserved). Based on associative analyses of evolution, structure, and function, this special phenomenon is attributed to function-dependent evolution through negative natural selection. Under strong natural selection, although the mutation is random on the gene level, the exterior region is inclined to mutate on the protein level owing to more nonsynonymous substitutions in the exterior region, which demonstrates the theoretical feasibility of modifying Fe-SOD on its ends to overcome its disadvantages in clinical applications.

  20. Spectroscopic and molecular modeling studies on the interactions of N-Methylformamide with superoxide dismutase.

    PubMed

    Kalyani, Durai; Jyothi, Kanagaraj; Sivaprakasam, Chinnarasu; Nachiappan, Vasanthi

    2014-04-24

    N-Methylformamide, a polar solvent has a wide industrial applications and it is well-known for hepatotoxicity. The interaction between NMF with superoxide dismutase, an antioxidant defense enzyme has been studied for the first time using spectroscopic methods including Fourier transform infrared (FT-IR) spectroscopy, Circular dichroism (CD) spectroscopy and UV-visible spectroscopy under simulative physiological conditions and also by molecular modelling. Fourier Transform Infra Red analysis showed that the change in peak positions and shapes revealed that the secondary structure of SOD had been changed by the interaction with NMF. The data of CD spectra also confirmed that NMF decreased the degree of secondary structure of SOD, which directly resulted in destabilization of enzyme. We studied the inhibitory effect of NMF on enzyme kinetics by pyrogallol autoxidation revealed that protein-ligand complex caused structural unfolding which resulted in enzymatic inhibition. Thus the spectral behaviour of superoxide dismutase provides data concerning its conformational changes in the presence of NMF. Furthermore, molecular docking was applied to explore the binding mode between the protein-ligand complex. This suggested that Asn54 and Val302 residues of dimeric protein were predicted to interact with NMF. The present study provides direct evidence at a molecular level to show that exposure to NMF cause perturbation in its structure and function.

  1. Superoxide dismutase deficiency impairs olfactory sexual signaling and alters bioenergetic function in mice

    PubMed Central

    Garratt, Michael; Pichaud, Nicolas; Glaros, Elias N.; Kee, Anthony John; Brooks, Robert C.

    2014-01-01

    Oxidative stress (an overproduction of reactive oxygen species in relation to defense mechanisms) may restrict investment in life history traits, such as growth, reproduction, lifespan, and the production of sexual signals to attract mates. The constraint on sexual signaling by oxidative stress is of particular interest because it has been proposed as a mechanism ensuring that only good-quality males produce the most attractive sexual signals. Despite these predictions, evidence supporting this theory is, at best, equivocal. We used a superoxide dismutase knockout mouse to demonstrate that oxidative stress directly impairs investment in morphological (preputial glands) and molecular (major urinary proteins) components of olfactory signaling essential for mate attraction. By maintaining males in a much more competitive environment than usual for mouse laboratory experiments, we also revealed a range of phenotypes of superoxide dismutase deficiency not observed in previous studies of this mouse model. This range included impaired bioenergetic function, which was undetectable in the control environment of this study. We urge further examination of model organisms in seminatural conditions and more competitive laboratory environments, as important phenotypes can be exposed under these more demanding conditions. PMID:24843175

  2. Tempol, a Superoxide Dismutase Mimetic Agent, Ameliorates Cisplatin-Induced Nephrotoxicity through Alleviation of Mitochondrial Dysfunction in Mice

    PubMed Central

    Ahmed, Lamiaa A.; Shehata, Nagwa I.; Abdelkader, Noha F.; Khattab, Mahmoud M.

    2014-01-01

    Background Mitochondrial dysfunction is a crucial mechanism by which cisplatin, a potent chemotherapeutic agent, causes nephrotoxicity where mitochondrial electron transport complexes are shifted mostly toward imbalanced reactive oxygen species versus energy production. In the present study, the protective role of tempol, a membrane-permeable superoxide dismutase mimetic agent, was evaluated on mitochondrial dysfunction and the subsequent damage induced by cisplatin nephrotoxicity in mice. Methods and Findings Nephrotoxicity was assessed 72 h after a single i.p. injection of cisplatin (25 mg/kg) with or without oral administration of tempol (100 mg/kg/day). Serum creatinine and urea as well as glucosuria and proteinuria were evaluated. Both kidneys were isolated for estimation of oxidative stress markers, adenosine triphosphate (ATP) content and caspase-3 activity. Moreover, mitochondrial oxidative phosphorylation capacity, complexes I–IV activities and mitochondrial nitric oxide synthase (mNOS) protein expression were measured along with histological examinations of renal tubular damage and mitochondrial ultrastructural changes. Tempol was effective against cisplatin-induced elevation of serum creatinine and urea as well as glucosuria and proteinuria. Moreover, pretreatment with tempol notably inhibited cisplatin-induced oxidative stress and disruption of mitochondrial function by restoring mitochondrial oxidative phosphorylation, complexes I and III activities, mNOS protein expression and ATP content. Tempol also provided significant protection against apoptosis, tubular damage and mitochondrial ultrastructural changes. Interestingly, tempol did not interfere with the cytotoxic effect of cisplatin against the growth of solid Ehrlich carcinoma. Conclusion This study highlights the potential role of tempol in inhibiting cisplatin-induced nephrotoxicity without affecting its antitumor activity via amelioration of oxidative stress and mitochondrial dysfunction

  3. Cu,Zn superoxide dismutase: cloning and analysis of the Taenia solium gene and Taenia crassiceps cDNA.

    PubMed

    Parra-Unda, Ricardo; Vaca-Paniagua, Felipe; Jiménez, Lucia; Landa, Abraham

    2012-01-01

    Cytosolic Cu,Zn superoxide dismutase (Cu,Zn-SOD) catalyzes the dismutation of superoxide (O(2)(-)) to oxygen and hydrogen peroxide (H(2)O(2)) and plays an important role in the establishment and survival of helminthes in their hosts. In this work, we describe the Taenia solium Cu,Zn-SOD gene (TsCu,Zn-SOD) and a Taenia crassiceps (TcCu,Zn-SOD) cDNA. TsCu,Zn-SOD gene that spans 2.841 kb, and has three exons and two introns; the splicing junctions follow the GT-AG rule. Analysis in silico of the gene revealed that the 5'-flanking region has three putative TATA and CCAAT boxes, and transcription factor binding sites for NF1 and AP1. The transcription start site was a C, located at 22 nucleotides upstream of the translation start codon (ATG). Southern blot analysis showed that TcCu,Zn-SOD and TsCu,Zn-SOD genes are encoded by a single copy. The deduced amino acid sequences of TsCu,Zn-SOD gene and TcCu,Zn-SOD cDNA reveal 98.47% of identity, and the characteristic motives, including the catalytic site and β-barrel structure of the Cu,Zn-SOD. Proteomic and immunohistochemical analysis indicated that Cu,Zn-SOD does not have isoforms, is distributed throughout the bladder wall and is concentrated in the tegument of T. solium and T. crassiceps cysticerci. Expression analysis revealed that TcCu,Zn-SOD mRNA and protein expression levels do not change in cysticerci, even upon exposure to O(2)(-) (0-3.8 nmol/min) and H(2)O(2) (0-2mM), suggesting that this gene is constitutively expressed in these parasites.

  4. Inactivation of renal mitochondrial respiratory complexes and manganese superoxide dismutase during sepsis: mitochondria-targeted antioxidant mitigates injury.

    PubMed

    Patil, Naeem K; Parajuli, Nirmala; MacMillan-Crow, Lee Ann; Mayeux, Philip R

    2014-04-01

    Acute kidney injury (AKI) is a complication of sepsis and leads to a high mortality rate. Human and animal studies suggest that mitochondrial dysfunction plays an important role in sepsis-induced multi-organ failure; however, the specific mitochondrial targets damaged during sepsis remain elusive. We used a clinically relevant cecal ligation and puncture (CLP) murine model of sepsis and assessed renal mitochondrial function using high-resolution respirometry, renal microcirculation using intravital microscopy, and renal function. CLP caused a time-dependent decrease in mitochondrial complex I and II/III respiration and reduced ATP. By 4 h after CLP, activity of manganese superoxide dismutase (MnSOD) was decreased by 50% and inhibition was sustained through 36 h. These events were associated with increased mitochondrial superoxide generation. We then evaluated whether the mitochondria-targeted antioxidant Mito-TEMPO could reverse renal mitochondrial dysfunction and attenuate sepsis-induced AKI. Mito-TEMPO (10 mg/kg) given at 6 h post-CLP decreased mitochondrial superoxide levels, protected complex I and II/III respiration, and restored MnSOD activity by 18 h. Mito-TEMPO also improved renal microcirculation and glomerular filtration rate. Importantly, even delayed therapy with a single dose of Mito-TEMPO significantly increased 96-h survival rate from 40% in untreated septic mice to 80%. Thus, sepsis causes sustained inactivation of three mitochondrial targets that can lead to increased mitochondrial superoxide. Importantly, even delayed therapy with Mito-TEMPO alleviated kidney injury, suggesting that it may be a promising approach to treat septic AKI.

  5. Improvement of superoxide dismutase and catalase in streptozotocin-nicotinamide-induced type 2-diabetes in mice by berberine and glibenclamide.

    PubMed

    Chatuphonprasert, Waranya; Lao-Ong, Thinnakorn; Jarukamjorn, Kanokwan

    2013-11-05

    Abstract Context: Diabetes mellitus (DM) type 2 is a chronic disease characterized by hyperglycemia and insulin resistance. Oxidative stress participates in development and progression of DM, in which changes of superoxide dismutase (SOD) and catalase (CAT) were noted in DM mice. Berberine has been widely used as an alternative medicine and proved to be effective for the treatment of DM and dyslipidemia. Objective: Impacts of berberine on transcriptional regulation of SOD and CAT and their enzyme activities, including the level of malondialdehyde (MDA) formation, were examined in the DM type 2-induced mice to clarify its antioxidation potential, compared with a common hypoglycemic drug, glibenclamide. Materials and methods: Noninsulin-dependent diabetes was induced in mice by a single intraperitoneal streptozotocin-nicotinamide injection. Diabetic mice were treated daily with glibenclamide (10 mg/kg/d) and/or berberine (100 mg/kg/d) for 2 weeks. The fasting blood glucose and the MDA levels in the mouse liver, brain and kidneys were monitored using Glucometer® (Accu-Check® Advantage II Performa kits, Roche Diagnostics, Germany) and thiobarbituric acid substance assay, respectively. The expression of SOD and CAT mRNA were determined in the mouse liver and the activities of SOD and CAT enzymes were determined in mouse liver, brain and kidneys, respectively. Results: Berberine exhibited similar hypoglycemic potential as glibenclamide to lower area under the curve of the fasting blood glucose. In DM type 2 mice, berberine increased the hepatic CuZn-SOD mRNA expression and the kidney SOD and CAT activities to normal levels. Moreover, DM-induced lipid peroxidation by increasing of MDA levels in both the liver and brain and lipid peroxidation status was restored by berberine. Conclusion: Berberine possessed hypoglycemic properties and strong potential to improve the oxidant-antioxidant balance, though the combination treatment of berberine and glibenclamide did not

  6. Unusual stability of manganese superoxide dismutase from a new species, Tatumella ptyseos ct: its gene structure, expression, and enzyme properties.

    PubMed

    Ken, Chuian-Fu; Lee, Chuing-Chi; Duan, Kow-Jen; Lin, Chi-Tsai

    2005-03-01

    A genomic DNA of 1416 bp containing an open reading frame encoding a manganese superoxide dismutase (Mn-SOD) from Tatumella ptyseos ct was cloned. Sequence analysis of this new gene revealed that it translates 205 amino acid residues. The deduced amino acid sequence showed variable identities (41-91%) with sequences of Mn-SODs from other species. The residues required to coordinate the single trivalent manganese ion and the 11 residues putatively involved in the active center are conserved as they are in other reported Mn-SODs. In addition, the gene was introduced into the expression vector, pET-20b(+), and transformed in Escherichia coli BL21(DE3). The Mn-SOD was purified by a His-tag technique. The yield was 0.9 mg from 0.5 L of culture. The specific activity was 6540 U/mg. A dimer is the major form of the enzyme in equilibrium. The half-life of dimer is approximately 50 min and its thermal inactivation rate constant k(d) was 0.015 min(-1) at 80 degrees C. The dimerization of the enzyme was inhibited under an acidic pH (below 4.0), or in the presence of SDS (above 1%) or imidazole (above 0.5 M), whereas it was not affected under an alkaline pH (above 9.0). Furthermore, the dimeric enzyme was much more resistant to proteolytic attack after 3 h of incubation at 37 degrees C with trypsin and chymotrypsin. This unusually stable enzyme can be used as cosmetic to the protection of skin against the unaesthetic effects caused by free radicals.

  7. Cocktail of Superoxide Dismutase and Fasudil Encapsulated in Targeted Liposomes Slows PAH Progression at a Reduced Dosing Frequency.

    PubMed

    Gupta, Nilesh; Rashid, Jahidur; Nozik-Grayck, Eva; McMurtry, Ivan F; Stenmark, Kurt R; Ahsan, Fakhrul

    2017-03-06

    Currently, two or more pulmonary vasodilators are used to treat pulmonary arterial hypertension (PAH), but conventional vasodilators alone cannot reverse disease progression. In this study, we tested the hypothesis that a combination therapy comprising a vasodilator plus a therapeutic agent that slows pulmonary arterial remodeling and right heart hypertrophy is an efficacious alternative to current vasodilator-based PAH therapy. Thus, we encapsulated a cocktail of superoxide dismutase (SOD), a superoxide scavenger, and fasudil, a specific rho-kinase inhibitor, into a liposomal formulation equipped with a homing peptide, CAR. We evaluated the effect of the formulations on pulmonary hemodynamics in monocrotaline-induced PAH rats (MCT-induced PAH) and assessed the formulation's efficacy in slowing the disease progression in Sugen-5416/hypoxia-induced PAH rats (SU/hypoxia-induced PAH). For acute studies, we monitored both mean pulmonary and systemic arterial pressures (mPAP and mSAP) for 2 to 6 h after a single dose of the plain drugs or formulations. In chronic studies, PAH rats received plain drugs every 48 h and the formulations every 72 h for 21 days. In MCT-induced PAH rats, CAR-modified liposomes containing fasudil plus SOD elicited a more pronounced, prolonged, and selective reduction in mPAP than unmodified liposomes and plain drugs did. In SU/hypoxia-induced PAH rats, the formulation produced a >50% reduction in mPAP and slowed right ventricular hypertrophy. When compared with individual plain drugs or combination, CAR-modified-liposomes containing both drugs reduced the extent of collagen deposition, muscularization of arteries, increased SOD levels in the lungs, and decreased the expression of pSTAT-3 and p-MYPT1. Overall, CAR-modified-liposomes of SOD plus fasudil, given every 72 h, was as efficacious as plain drugs, given every 48 h, suggesting that the formulation can reduce the total drug intake, systemic exposures, and dosing frequency.

  8. Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of chlorite dismutase: a detoxifying enzyme producing molecular oxygen

    SciTech Connect

    Geus, Daniël C. de Thomassen, Ellen A. J.; Feltz, Clarisse L. van der; Abrahams, Jan Pieter

    2008-08-01

    Preliminary X-ray data collection and analysis for crystals of chlorite dismutase, a haem-based enzyme that very effectively reduces chlorite to chloride while producing molecular oxygen, is reported to 2.1 Å resolution. Chlorite dismutase, a homotetrameric haem-based protein, is one of the key enzymes of (per)chlorate-reducing bacteria. It is highly active (< 2 kU mg{sup −1}) in reducing the toxic compound chlorite to the innocuous chloride anion and molecular oxygen. Chlorite itself is produced as the intermediate product of (per)chlorate reduction. The chlorite dismutase gene in Azospira oryzae strain GR-1 employing degenerate primers has been identified and the active enzyme was subsequently overexpressed in Escherichia coli. Chlorite dismutase was purified, proven to be active and crystallized using sitting drops with PEG 2000 MME, KSCN and ammonium sulfate as precipitants. The crystals belonged to space group P2{sub 1}2{sub 1}2 and were most likely to contain six subunits in the asymmetric unit. The refined unit-cell parameters were a = 164.46, b = 169.34, c = 60.79 Å. The crystals diffracted X-rays to 2.1 Å resolution on a synchrotron-radiation source and a three-wavelength MAD data set has been collected. Determination of the chlorite dismutase structure will provide insights into the active site of the enzyme, for which no structures are currently available.

  9. Functional and crystallographic characterization of Salmonella typhimurium Cu,Zn superoxide dismutase coded by the sodCI virulence gene.

    PubMed

    Pesce, A; Battistoni, A; Stroppolo, M E; Polizio, F; Nardini, M; Kroll, J S; Langford, P R; O'Neill, P; Sette, M; Desideri, A; Bolognesi, M

    2000-09-15

    The functional and three-dimensional structural features of Cu,Zn superoxide dismutase coded by the Salmonella typhimurium sodCI gene, have been characterized. Measurements of the catalytic rate indicate that this enzyme is the most efficient superoxide dismutase analyzed so far, a feature that may be related to the exclusive association of the sodCI gene with the most pathogenic Salmonella serotypes. The enzyme active-site copper ion is highly accessible to external probes, as indicated by quenching of the water proton relaxation rate upon addition of iodide. The shape of the electron paramagnetic resonance spectrum is dependent on the frozen or liquid state of the enzyme solution, suggesting relative flexibility of the copper ion environment. The crystal structure (R-factor 22.6%, at 2.3 A resolution) indicates that the dimeric enzyme adopts the quaternary assembly typical of prokaryotic Cu,Zn superoxide dismutases. However, when compared to the structures of the homologous enzymes from Photobacterium leiognathi and Actinobacillus pleuropneumoniae, the subunit interface of Salmonella Cu,Zn superoxide dismutase shows substitution of 11 out of 19 interface residues. As a consequence, the network of structural water molecules that fill the dimer interface cavity is structured differently from the other dimeric bacterial enzymes. The crystallographic and functional characterization of this Salmonella Cu,Zn superoxide dismutase indicates that structural variability and catalytic efficiency are higher in prokaryotic than in the eukaryotic homologous enzymes.

  10. Detection, distribution and characterization of novel superoxide dismutases from Yersinia enterocolitica Biovar 1A.

    PubMed

    Dhar, Mahesh Shanker; Gupta, Vatika; Virdi, Jugsharan Singh

    2013-01-01

    Superoxide dismutases (SODs) cause dismutation of superoxide radicals to hydrogen peroxide and oxygen. Besides protecting the cells against oxidative damage by endogenously generated oxygen radicals, SODs play an important role in intraphagocytic survival of pathogenic bacteria. The complete genome sequences of Yersinia enterocolitica strains show presence of three different sod genes. However, not much is known about the types of SODs present in Y. enterocolitica, their characteristics and role in virulence and intraphagocytic survival of this organism. This study reports detection and distribution of the three superoxide dismutase (sodA, sodB and sodC) genes in 59 strains of Y. enterocolitica and related species. The majority (94%) of the strains carried all three genes and constitutive expression of sodA and sodB was detected in 88% of the strains. Expression of sodC was not observed in any of the strains. The sodA, sodB and sodC genes of Y. enterocolitica were cloned in pET28a (+) vector. Recombinant SodA (82 kDa) and SodB (21 kDa) were expressed as homotetramer and monomer respectively, and showed activity over a broad range of pH (3.0-8.0) and temperature (4-70°C). SodA and SodB showed optimal activity at 4°C under acidic pH of 6.0 and 4.0 respectively. The secondary structures of recombinant SodA and SodB were studied using circular dichroism. Production of YeSodC was not observed even after cloning and expression in E. coli BL21(DE3) cells. A SodA(-) SodB(-) Escherichia coli strain which was unable to grow in medium supplemented with paraquat showed normal growth after complementation with Y. enterocolitica SodA or SodB. This is the first report on the distribution and characterization of superoxide dismutases from Y. enterocolitica. The low pH optima of both SodA and SodB encoded by Y. enterocolitica seem to implicate their role in acidic environments such as the intraphagocytic vesicles.

  11. Structure and heme-binding properties of HemQ (chlorite dismutase-like protein) from Listeria monocytogenes.

    PubMed

    Hofbauer, Stefan; Hagmüller, Andreas; Schaffner, Irene; Mlynek, Georg; Krutzler, Michael; Stadlmayr, Gerhard; Pirker, Katharina F; Obinger, Christian; Daims, Holger; Djinović-Carugo, Kristina; Furtmüller, Paul G

    2015-05-15

    Chlorite dismutase-like proteins are structurally closely related to functional chlorite dismutases which are heme b-dependent oxidoreductases capable of reducing chlorite to chloride with simultaneous production of dioxygen. Chlorite dismutase-like proteins are incapable of performing this reaction and their biological role is still under discussion. Recently, members of this large protein family were shown to be involved in heme biosynthesis in Gram-positive bacteria, and thus the protein was renamed HemQ in these organisms. In the present work the structural and heme binding properties of the chlorite dismutase-like protein from the Gram-positive pathogen Listeria monocytogenes (LmCld) were analyzed in order to evaluate its potential role as a regulatory heme sensing protein. The homopentameric crystal structure (2.0Å) shows high similarity to chlorite-degrading chlorite dismutases with an important difference in the structure of the putative substrate and heme entrance channel. In solution LmCld is a stable hexamer able to bind the low-spin ligand cyanide. Heme binding is reversible with KD-values determined to be 7.2μM (circular dichroism spectroscopy) and 16.8μM (isothermal titration calorimetry) at pH 7.0. Both acidic and alkaline conditions promote heme release. Presented biochemical and structural data reveal that the chlorite dismutase-like protein from L. monocytogenes could act as a potential regulatory heme sensing and storage protein within heme biosynthesis. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  12. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Thrombolysis at a controlled pressure prolongs the survival of skin flaps treated with superoxide dismutase.

    PubMed

    Hirigoyen, M B; Prabhat, A; Zhang, W X; Urken, M L; Weinberg, H

    1996-04-01

    The role of thrombolysis in reestablishing patency in the microcirculation following ischemia, and thereby improving the efficacy of agents attenuating reperfusion injury, such as the oxygen free radical scavenger, superoxide dismutase (SOD), was investigated in a rat model. Abdominal skin flaps were subjected to normothermic ischemia induced by complete occlusion of the pedicle for periods of 12, 13, 14, 16, 18, 20, 22, and 24 hr. In Group 1 (n = 64), all animals received flap washout using 100,000U urokinase (manual injection) followed by 7,500 IU SOD given intra-arterially immediately prior to reperfusion. Animals in Group 2 received flap washout consisting of 100,000U urokinase given via a pressurized delivery system, followed by 7,500 IU SOD. Results demonstrated a statistically significant improvement in flap survival in Group 2. The authors concluded that thrombolytic therapy may be useful in improving the delivery of agents, such as SOD, which attenuate reperfusion injury in skin flaps.

  14. Genetics of superoxide dismutase in the forest tent caterpillar and other organisms.

    PubMed

    Lorimer, N

    1979-01-01

    The electrophoretic assay of superoxide dismutase (SOD) in Malacosoma disstria revealed a total of 13 bands arranged in 9 patterns. One locus, composed of bands 28, 32, 36 was polymorphic in some locations. Band frequencies varied by location, but not by generation or by time in the laboratory. Significant interactions between sibling groups and SOD types for development time suggest that selective advantage is a function of genetic background. SOD, an important enzyme protecting diverse organisms against the toxic radicals of oxygen, has been extensively analyzed by biochemists. Geneticists have assayed individuals and populations for the smae enzyme, calling it tetrazolium oxidase (TO). The biochemistry and genetics literatures were reviewed and results from the two disciplines were discussed.

  15. [Free radicals of oxygen and superoxide dismutase. Biological and medical aspects].

    PubMed

    Monte, M; Sacerdote de Lustig, E

    1994-01-01

    Oxygen free radicals (OFR) are very reactive and unstable metabolites capable of altering important biomolecules including proteins, lipids and nucleic acids. OFR are regulated by enzymes such as superoxide dismutases (SOD), catalase, glutation peroxidase and by molecules such as vitamins E, A, C, and K, selenio, cystein and other compounds. Increased OFR levels due to an overproduction of these metabolites or to a failure in the control system, induce cellular and tissue injuries that could lead to diseases such as atherosclerosis, arthritis, fibrosis, lung and heart injuries, neurological disorders and cancer. In this article we consider the use of SOD as therapeutic agents both in human and experimental models. We also refer to the administration of SOD as a protective factor against secondary injuries during radiotherapy and to the determination of SOD as a tumor marker.

  16. Novel inhibitors to Taenia solium Cu/Zn superoxide dismutase identified by virtual screening

    NASA Astrophysics Data System (ADS)

    García-Gutiérrez, P.; Landa-Piedra, A.; Rodríguez-Romero, A.; Parra-Unda, R.; Rojo-Domínguez, A.

    2011-12-01

    We describe in this work a successful virtual screening and experimental testing aimed to the identification of novel inhibitors of superoxide dismutase of the worm Taenia solium ( TsCu/Zn-SOD), a human parasite. Conformers from LeadQuest® database of drug-like compounds were selected and then docked on the surface of TsCu/Zn-SOD. Results were screened looking for ligand contacts with receptor side-chains not conserved in the human homologue, with a subsequent development of a score optimization by a set of energy minimization steps, aimed to identify lead compounds for in vitro experiments. Six out of fifty experimentally tested compounds showed μM inhibitory activity toward TsCu/Zn-SOD. Two of them showed species selectivity since did not inhibit the homologous human enzyme when assayed in vitro.

  17. Novel inhibitors to Taenia solium Cu/Zn superoxide dismutase identified by virtual screening.

    PubMed

    García-Gutiérrez, P; Landa-Piedra, A; Rodríguez-Romero, A; Parra-Unda, R; Rojo-Domínguez, A

    2011-12-01

    We describe in this work a successful virtual screening and experimental testing aimed to the identification of novel inhibitors of superoxide dismutase of the worm Taenia solium (TsCu/Zn-SOD), a human parasite. Conformers from LeadQuest(®) database of drug-like compounds were selected and then docked on the surface of TsCu/Zn-SOD. Results were screened looking for ligand contacts with receptor side-chains not conserved in the human homologue, with a subsequent development of a score optimization by a set of energy minimization steps, aimed to identify lead compounds for in vitro experiments. Six out of fifty experimentally tested compounds showed μM inhibitory activity toward TsCu/Zn-SOD. Two of them showed species selectivity since did not inhibit the homologous human enzyme when assayed in vitro.

  18. N-Glycosylation is essential for the secretion of extracellular superoxide dismutase.

    PubMed

    Ota, Fumi; Kizuka, Yasuhiko; Kitazume, Shinobu; Adachi, Tetsuo; Taniguchi, Naoyuki

    2016-10-01

    Extracellular superoxide dismutase (EC-SOD or SOD3) protects against various oxidative stress-related diseases by scavenging reactive superoxides in the extracellular space. It is the only SOD isozyme that is secreted and glycosylated (at asparagine 89). However, the physiological roles of its glycosylation are poorly understood. In this study, we found that the glycosylation site on EC-SOD is well conserved and that a glycosylation-deficient EC-SOD mutant retains its enzymatic activity, but is not secreted. This impairment in secretion may, in part, be due to the ability of the mutants to form unusual higher order oligomers. Our findings reveal that the glycan modification is a key regulator of EC-SOD secretion and contributes to the understanding of the roles of glycans in EC-SOD-related diseases.

  19. Alterations in superoxide dismutase and catalase in Fusarium oxysporum during starvation-induced differentiation.

    PubMed

    Kono, Y; Yamamoto, H; Takeuchi, M; Komada, H

    1995-07-20

    Vegetative hyphae of Fusarium oxysporum differentiate into chlamydospore by triggering with carbon-starvation. The current changes in the cellular detoxifying defenses against superoxide and hydrogen peroxide: superoxide dismutase (SOD) and catalase, were examined. Although there was a little change in catalase, a dramatic change in SOD was observed during the differentiation. In vegetative hyphae of F. oxysporum f. sp. raphani, three isozymes of SOD, all of which were not inhibited by hydrogen peroxide and cyanide, were present whereas in chlamydospore an isoenzyme, which was inhibited by hydrogen peroxide but not by cyanide, was present. Thus, as differentiation proceeded, Mn-type SOD disappeared and an Fe-type SOD appeared. The results suggest that the Fe-type SOD is specifically expressed during chlamydospore formation and that active intermediates of oxygen and/or its scavenging enzymes participate in the differentiation of Fusarium oxysporum.

  20. Evaluation of Malondialdehyde, Superoxide Dismutase and Catalase Activity in Fetal Cord Blood of Depressed Mothers

    PubMed Central

    Camkurt, Mehmet Akif; Fındıklı, Ebru; Bakacak, Murat; Tolun, Fatma İnanç; Karaaslan, Mehmet Fatih

    2017-01-01

    Objective The umbilical cord consists of two arteries and one vein and it functions in the transport between the maternal and fetal circulation. Biochemical analysis of fetal cord blood (FCB) during delivery could be beneficial in terms of understanding the fetal environment. In this study, we aimed to investigate oxidative parameters like malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) levels in FCB during delivery. Methods We collected FCB samples during caesarean section. Our study included 33 depressed mothers and 37 healthy controls. We investigated MDA, SOD, and CAT levels in FCB samples. Results We found no significant difference between groups in terms of MDA (p=0.625), SOD (p=0.940), and CAT (p=0.413) levels. Conclusion Our study reveals probable protective effects of the placenta from oxidative stress. Future studies should include larger samples. PMID:28138108

  1. Effect of local application of superoxide dismutase on dielectric parameters of cooled skin in rats.

    PubMed

    Paramonov, B A; Turkovski, I I; Doroshkevich, O S; Taranova, V N; Pomorski, K P

    2008-11-01

    The effect of on Changes in dielectric parameters of the skin (modulus of complex dielectric permittivity |e| and dielectric loss tangent tgd) were studied on rats with local surface contact cooling followed by treatment with various cream formulations. Addition of antioxidant superoxide dismutase (SOD) to the cream significantly prevented the shifts in these parameters, which attested to less pronounced changes in the water balance in SOD-treated skin. Application of SOD during the early terms after cooling accelerated wound healing. Histological examination performed on posttraumatic day 60 revealed better integrity of the skin structures (hair follicle, sweat and sebaceous gland), which indicates ability of SOD to prevent and ameliorate the degree of cold-induced damage in the skin.

  2. 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.

  3. Molecular cloning of an Onchocerca volvulus extracellular Cu-Zn superoxide dismutase.

    PubMed Central

    James, E R; McLean, D C; Perler, F

    1994-01-01

    Onchocerca volvulus, a human parasitic nematode, is the third leading cause of preventable blindness worldwide. This study describes the molecular cloning of a novel superoxide dismutase (SOD) from the parasite. This putative O. volvulus extracellular SOD (OvEcSOD) is 628 nucleotides (nt) long, including a 22-nt 5' spliced leader (SL1) and a portion encoding an N-terminal hydrophobic 42-amino-acid signal peptide. The remainder of the cDNA shares 71% identity with an O. volvulus cytosolic SOD sequence and is 3 nt longer. All residues involved in metal ion binding, active site formation, folding, and dimer formation in SODs are conserved. Data indicate the OvEcSOD and O. volvulus cytosolic SOD are separate gene products and that the OvEcSOD appears to possess the characteristics of a membrane-bound or secreted enzyme which may be involved in the parasite defense against phagocyte-generated reactive oxygen species. Images PMID:8300230

  4. Superoxide dismutase and the resistance of Escherichia coli to phagocytic killing by human neutrophils.

    PubMed Central

    Papp-Szabò, E; Sutherland, C L; Josephy, P D

    1993-01-01

    Transformation of Escherichia coli K-12-derived strains with a plasmid carrying the genetic determinants for synthesis of lipopolysaccharide O antigen by Shigella dysenteriae allows the construction of phenotypically smooth derivatives. We show that such E. coli K-12 derivatives are highly resistant to killing by human serum. Isogenic wild-type and sodB mutant (Fe superoxide dismutase-deficient) strains were constructed. The results of experiments on phagocytic killing of these strains by human neutrophils are reported. We observed no difference between the sensitivities of wild-type and sodB mutant strains to phagocytic killing, in contrast to the results reported by other researchers who used species other than E. coli or strains other than K-12. Images PMID:8454348

  5. Endogenous antioxidant defense induction by melon superoxide dismutase reduces cardiac hypertrophy in spontaneously hypertensive rats.

    PubMed

    Carillon, Julie; Rugale, Caroline; Rouanet, Jean-Max; Cristol, Jean-Paul; Lacan, Dominique; Jover, Bernard

    2014-08-01

    We assessed the influence of SODB, a melon superoxide dismutase (SOD), on left ventricular (LV) hypertrophy in SHR. SODB (4 or 40U SOD) was given orally for 4 or 28 days to SHR. For each treatment period, LV weight index (LVWI) and cardiomyocytes size were measured. SOD, glutathione peroxidase (GPx) and catalase expressions, and LV production and presence of superoxide anion were determined. Pro-inflammatory markers were also measured. SODB reduced LVWI and cardiomyocytes size after 4 or 28 days. Cardiac SOD and GPx increased by 30-40% with SODB. The presence but not production of superoxide anion was significantly reduced by SODB. No effect of SODB was detected on inflammatory status in any group. The beneficial effect of SODB on cardiac hypertrophy seems to be related to the stimulation of endogenous antioxidant defense, suggesting that SODB may be of interest as a dietary supplementation during conventional antihypertensive therapy.

  6. Preliminary neutron diffraction analysis of challenging human manganese superoxide dismutase crystals.

    PubMed

    Azadmanesh, Jahaun; Trickel, Scott R; Weiss, Kevin L; Coates, Leighton; Borgstahl, Gloria E O

    2017-04-01

    Superoxide dismutases (SODs) are enzymes that protect against oxidative stress by dismutation of superoxide into oxygen and hydrogen peroxide through cyclic reduction and oxidation of the active-site metal. The complete enzymatic mechanisms of SODs are unknown since data on the positions of hydrogen are limited. Here, methods are presented for large crystal growth and neutron data collection of human manganese SOD (MnSOD) using perdeuteration and the MaNDi beamline at Oak Ridge National Laboratory. The crystal from which the human MnSOD data set was obtained is the crystal with the largest unit-cell edge (240 Å) from which data have been collected via neutron diffraction to sufficient resolution (2.30 Å) where hydrogen positions can be observed.

  7. PEA chloroplasts under clino-rotation: lipid peroxidation and superoxide dismutase activity

    NASA Astrophysics Data System (ADS)

    Baranenko, V. V.

    The lipid peroxidation (LP) intensity and the activity of the antioxidant enzyme superoxide dismutase (SOD) were studied in chloroplasts of pea (Pisum sativum L.) plants grown for 7 and 14 days under clino-rotation. An increase in LP levels in chloroplasts during both terms of clinorotation in comparison with stationary controls was documented. SOD activity increased in chloroplasts of plants that were clino-rotated for seven days. SOD has a significant protective effect by diminishing the availability of O2-. However, under more prolonged clino-rotation (14 days), SOD activity decreased but was still higher than in the control samples. In accordance with Selye's oxidative stress theory (Selye, 1956; modified by Leshem et al., 1998), plants that were clino-rotated for seven days are presumed to be in a stage of resistance while 14-day plants reached a stage of exhaustion.

  8. Superoxide dismutase levels in various radioresistant and radiosensitive tissues of irradiated rats.

    PubMed

    Krízala, J; Kovárová, H; Stoklasová, A; Ledvina, M

    1982-01-01

    The activity of superoxide dismutase (E.C. 1.15.1.1; SOD) was determined in male Wistar rats in order to evaluate the possible relationship between both the enzyme content in tissue and the resistance of this tissue to ionizing radiation (8,0 Gy, 60Co). Our results showed that some non-irradiated radioresistant organs (liver) had a high SOD activity and on the contrary, in some radiosensitive tissue (bone marrow) the SOD content was low. In spite of this observation it is not possible to generalize the statement that the radiosensitivity is directly conditioned by the SOD level without any exception. The SOD content in the spleen was higher than in the brain, but the spleen is remarkably radiosensitive, whereas the brain is not. The radiosensitivity of individual tissues probably reflected the changes of SOD activity after the irradiation.

  9. Overexpressed mutant G93A superoxide dismutase protects calcineurin from inactivation.

    PubMed

    Li, Shipeng; Wang, Xutong; Klee, Claude B; Krieger, Charles

    2004-06-18

    Previous studies have claimed that there is a failure of a mutant form of superoxide dismutase (mSOD) to protect the protein phosphatase, calcineurin (CN), against inactivation in the pathogenesis of amyotrophic lateral sclerosis (ALS), as determined in a murine model of ALS resulting from overexpression of mSOD (G93A). In contrast to previous studies, we find that mice overexpressing G93A mSOD have no statistically significant differences in the expression, or activity, of CN. However, CN from G93A mSOD overexpressing mice is significantly more protected against inactivation than non-transgenic mice that do not overexpress SOD. This reduced inactivation of CN is a consequence of increased expression of G93A mSOD. Thus, like wild-type SOD, G93A mSOD protects CN against inactivation.

  10. Superoxide dismutase 1 acts as a nuclear transcription factor to regulate oxidative stress resistance

    PubMed Central

    Tsang, Chi Kwan; Liu, Yuan; Thomas, Janice; Zhang, Yanjie; Zheng, X. F. Steven

    2015-01-01

    Summary Superoxide dismutase 1 (Sod1) has been known for nearly half a century for catalysis of superoxide to hydrogen peroxide. Here we report a new Sod1 function in oxidative signaling: in response to elevated endogenous and exogenous reactive oxygen species (ROS), Sod1 rapidly relocates into the nucleus, which is important for maintaining genomic stability. Interestingly, H2O2 is sufficient to promote Sod1 nuclear localization, indicating that it is responding to general ROS rather than Sod1 substrate superoxide. ROS signaling is mediated by Mec1/ATM and its effector Dun1/Cds1 kinase, through Dun1 interaction with Sod1 and regulation of Sod1 by phosphorylation at S60, 99. In the nucleus, Sod1 binds to the promoters and regulates the expression of oxidative resistance and repair genes. Altogether, our study unravels an unorthodox function of Sod1 as a transcription factor and elucidates the regulatory mechanism for its localization. PMID:24647101

  11. Copper, Zinc Superoxide Dismutase is Primarily a Cytosolic Protein in Human Cells

    NASA Astrophysics Data System (ADS)

    Crapo, James D.; Oury, Tim; Rabouille, Catherine; Slot, Jan W.; Chang, Ling-Yi

    1992-11-01

    The intracellular localization of human copper, zinc superoxide dismutase (Cu,Zn-SOD; superoxide:superoxide oxidoreductase, EC 1.15.1.1) was evaluated by using EM immunocytochemistry and both isolated human cell lines and human tissues. Eight monoclonal antibodies raised against either native or recombinant human Cu,Zn-SOD and two polyclonal antibodies raised against either native or recombinant human Cu,Zn-SOD were used. Fixation with 2% paraformaldehyde/0.2% glutaraldehyde was found necessary to preserve normal distribution of the protein. Monoclonal antibodies were less effective than polyclonal antibodies in recognizing the antigen after adequate fixation of tissue. Cu,Zn-SOD was found widely distributed in the cell cytosol and in the cell nucleus, consistent with it being a soluble cytosolic protein. Mitochondria and secretory compartments did not label for this protein. In human cells, peroxisomes showed a labeling density slightly less than that of cytoplasm.

  12. 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.

  13. Antidepressants upregulate messenger RNA levels of the neuroprotective enzyme superoxide dismutase (SOD1).

    PubMed Central

    Li, X M; Chlan-Fourney, J; Juorio, A V; Bennett, V L; Shrikhande, S; Bowen, R C

    2000-01-01

    OBJECTIVE: To investigate the effect of amitriptyline, bupropion, doxepin or venlafaxine on the gene expression of the neuroprotective enzyme superoxide dismutase (SOD1) in a catecholamine cell in vitro model. DESIGN: Molecular study of a cultured cell line. INTERVENTIONS: Rat pheochromocytoma (PC12) cells were incubated in 1 and 10 mumol/L of various antidepressant medications for 24 or 48 hours. OUTCOME MEASURES: Northern blot analysis. RESULTS: Amitriptyline up-regulated SOD1 messenger RNA in a time- and dose-dependent manner. The greatest up-regulation was following incubation with 10 mumol/L amitriptyline for 48 hours. The addition of bupropion, doxepin or venlafaxine to PC12 cell cultures also up-regulated SOD1 mRNA. CONCLUSIONS: These findings suggest that some antidepressants have the ability to positively regulate neuroprotective genes. Images Fig. 2 PMID:10721683

  14. Serum levels of manganese superoxide dismutase in patients with localized scleroderma.

    PubMed

    Jinnin, Masatoshi; Ihn, Hironobu; Yazawa, Norihito; Asano, Yoshihide; Yamane, Kenichi; Tamaki, Kunihiko

    2004-06-01

    The objective was to determine the serum levels of manganese superoxide dismutase (Mn SOD) in patients with localized scleroderma and investigate their clinical significance in this disease. Serum samples from 15 patients with localized scleroderma and 20 healthy volunteers were examined by a specific enzyme-linked immunosorbent assay. Serum levels of Mn SOD were significantly higher in patients with generalized morphea than those in healthy individuals. And the patients with elevated serum Mn SOD levels had significantly larger number of sclerotic lesions and significantly higher serum levels of soluble interleukin-2 receptor than those without it. These results suggested that the serum levels of this enzyme may be a serological marker for the disease activity and the extent of skin involvement in this disease.

  15. Preliminary neutron diffraction analysis of challenging human manganese superoxide dismutase crystals

    PubMed Central

    Azadmanesh, Jahaun; Trickel, Scott R.; Borgstahl, Gloria E. O.

    2017-01-01

    Superoxide dismutases (SODs) are enzymes that protect against oxidative stress by dismutation of superoxide into oxygen and hydrogen peroxide through cyclic reduction and oxidation of the active-site metal. The complete enzymatic mechanisms of SODs are unknown since data on the positions of hydrogen are limited. Here, methods are presented for large crystal growth and neutron data collection of human manganese SOD (MnSOD) using perdeuteration and the MaNDi beamline at Oak Ridge National Laboratory. The crystal from which the human MnSOD data set was obtained is the crystal with the largest unit-cell edge (240 Å) from which data have been collected via neutron diffraction to sufficient resolution (2.30 Å) where hydrogen positions can be observed. PMID:28368283

  16. Molecular characterization of a cytosolic manganese superoxide dismutase from the Chinese mitten crab, Eriocheir sinensis.

    PubMed

    Zhao, D X; Chen, L Q; Qin, J G; Qin, C J; Zhang, H; Wu, P; Li, E C

    2014-11-11

    A cytosolic manganese superoxide dismutase gene (Es-cMnSOD) was cloned from the Chinese mitten crab Eriocheir sinensis, using reverse transcription-polymerase chain reaction and the rapid amplification of cDNA ends. The open reading frame of Es-cMnSOD is 867 bp in length and encodes a 288-amino acid protein without a signal peptide. The calculated molecular mass of the translated protein of Es-cMnSOD is 31.43 kDa, with an estimated isoelectric point of 6.30. The deduced amino acid sequence of Es-cMnSOD has similarities of 90, 89, 84, 87, and 81% to those of white shrimp Litopenaeus vannamei MnSOD, black tiger shrimp Penaeus monodon MnSOD, giant freshwater prawn Macrobrachium rosenbergii MnSOD, blue crab Callinectes sapidus MnSOD, and red swamp crayfish Procambarus clarkii MnSOD, respectively. Es-cMnSOD contains a manganese superoxide dismutase domain (DVWEHAYY) and 4 conserved amino acids responsible for binding manganese. Es-cMnSOD was expressed in the hemocytes, eyestalk, muscle, intestine, gill, and hepatopancreas. Es-cMnSOD transcripts in hemocytes of E. sinensis increased at 1.5 and 48 h after injection of Aeromonas hydrophila, indicating that the induction of the SOD system response occurred within a short period of time. This study suggests that MnSOD may play a critical role in crab immunity, allowing efficient activation of an early innate immune response in the crab.

  17. Essential fatty acids alter the activity of manganese-superoxide dismutase in rat heart.

    PubMed

    Phylactos, A C; Harbige, L S; Crawford, M A

    1994-02-01

    The effects of oil-derived dietary essential fatty acids on the activities of mitchondrial Mn-SOD (manganese-superoxide dismutase) and cytosolic cupric zinc-superoxide dismutase (Cu/Zn-SOD) were investigated in rat heart. A control group of rats was fed a stock diet for 29 d, and a second group was fed on a fat-free diet. Three other groups were fed fat-free diets that were supplemented with (i) borage oil, which is rich in linoleic (18:2n-6) and gamma-linolenic (18:3n-6) acids, (ii) fungal oil, which is rich in gamma-linolenic, but low in linoleic acid, or (iii) evening primrose oil, which is rich in linoleic acid and low in gamma-linolenic acid. An increase in the percentage composition of arachidonic acid (20:4n-6) in both the choline and ethanolamine phospholipids, together with a decrease in linoleic acid in ethanolamine phospholipids, were found in heart membranes after feeding the rats with diets containing borage oil or fungal oil as compared to those fed the stock diet. The respective activities of Mn-SOD in rats fed the borage or fungal oil diets were also significantly higher than in rats fed the stock diet alone. No change in cytosolic Cn/Zn-SOD activity was observed. Dietary supply of linoleic acid-rich evening primrose oil resulted in an increased proportion of choline phospholipid linoleic acid without any changes in arachidonic acid content or in the activity of Mn-SOD. By contrast, a reduction in the activity of Mn-SOD was detected in rats fed a fat-free diet.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. The natural compound 7-epiclusianone inhibits superoxide dismutase activity in Schistosoma mansoni.

    PubMed

    Silva, M S; Castro, A P; de Castro, A T; Souza, I M M; Martins-Souza, R L; Colombo, F A; Elias, T C; Santos, M H; Marques, M J

    2017-10-04

    Schistosomiasis - caused by trematodes from the genus Schistosoma - affects more than 200 million people worldwide. Growing resistance to therapy with praziquantel (PZQ) has encouraged the search for novel treatments against this neglected disease. The compound 7-epiclusianone (7-epi) - isolated from 'bacupari' (the fruit of the Gracinia brasiliensis tree) - has promising activity against Schistosoma mansoni in vitro, damaging the parasite's tegument. However, the target and mechanism of action of 7-epi have not been identified. Here, we examined the possibility that 7-epi harms the tegument by inhibiting parasite superoxide dismutase (SOD), which protects the tegument from damage by reactive oxygen species produced by host immune cells. Molecular docking analysis in silico suggested strong interactions between 7-epi and S. mansoni cytosolic superoxide dismutase (SmCtSOD) at allosteric cavities. Schistosoma mansoni couples were cultivated ex vivo with 12.44-198.96 μm 7-epi for 24 h, and then parasite extracts were tested for lipid peroxidation (as a surrogate for oxidative stress), and SOD activity and expression. Lipid peroxidation levels increased after incubation with concentrations ≥99.48 μm 7-epi, and this compound reduced SOD activity at concentrations ≥24.87 μm. However, contact with 7-epi did not alter SOD expression, by quantitative real-time polymerase chain reaction (qRT-PCR). Our results show that the inhibition of SmCtSOD is partly responsible for the tegument detachment observed after incubation with 7-epi, but is not the only cause of the antiparasitic action of this compound in vitro.

  19. The superoxide dismutase mimetic, tempol, blunts right ventricular hypertrophy in chronic hypoxic rats

    PubMed Central

    Elmedal, Britt; de Dam, Mette Y; Mulvany, Michael John; Simonsen, Ulf

    2003-01-01

    The purpose of this study was to investigate whether a membrane-permeable superoxide dismutase mimetic, tempol, added either alone or in combination with the nitric oxide (NO) donor molsidomine, prevents the development of pulmonary hypertension (PH) in chronic hypoxic rats.Chronic hypobaric hypoxia (10% oxygen) for 2 weeks increased the right ventricular systolic pressure (RVSP), right ventricle and lung wet weight. Relaxations evoked by acetylcholine (ACh) and the molsidomine metabolite SIN-1 were impaired in isolated proximal, but not distal pulmonary arteries, from chronic hypoxic rats.Treatment with tempol (86 mg kg−1 day−1 in drinking water) normalized RVSP and reduced right ventricular hypertrophy, while systemic blood pressure, lung and liver weights, and blunted ACh relaxation of pulmonary arteries were unchanged.Treatment with molsidomine (15 mg kg−1 day−1 in drinking water) had the same effects as tempol, except that liver weight was reduced, and potassium and U46619-evoked vasoconstrictions in pulmonary arteries were increased. Combining tempol and molsidomine did not have additional effects compared to tempol alone. ACh relaxation in pulmonary arteries was not normalized by these treatments.The media to lumen diameter ratio of the pulmonary arteries was greater for the hypoxic rats compared to the normoxic rats, and was not reversed by treatment with tempol, molsidomine, or the combination of tempol and molsidomine.We conclude that tempol, like molsidomine, is able to correct RVSP and reduce right ventricular weight in the rat hypoxic model. Functional and structural properties of pulmonary small arteries were little affected. The results support the possibility that superoxide dismutase mimetics may be a useful means for the treatment of PH. PMID:14656807

  20. Six-coordinate manganese(3+) in catalysis by yeast manganese superoxide dismutase

    SciTech Connect

    Sheng, Yuewei; Gralla, Edith Butler; Schumacher, Mikhail; Cascio, Duilio; Cabelli, Diane E.; Valentine, Joan Selverstone

    2012-10-10

    Reduction of superoxide (O{sub 2}{sup -}) by manganese-containing superoxide dismutase occurs through either a 'prompt protonation' pathway, or an 'inner-sphere' pathway, with the latter leading to formation of an observable Mn-peroxo complex. We recently reported that wild-type (WT) manganese superoxide dismutases (MnSODs) from Saccharomyces cerevisiae and Candida albicans are more gated toward the 'prompt protonation' pathway than human and bacterial MnSODs and suggested that this could result from small structural changes in the second coordination sphere of manganese. We report here that substitution of a second-sphere residue, Tyr34, by phenylalanine (Y34F) causes the MnSOD from S. cerevisiae to react exclusively through the 'inner-sphere' pathway. At neutral pH, we have a surprising observation that protonation of the Mn-peroxo complex in the mutant yeast enzyme occurs through a fast pathway, leading to a putative six-coordinate Mn3+ species, which actively oxidizes O{sub 2}{sup -} in the catalytic cycle. Upon increasing pH, the fast pathway is gradually replaced by a slow proton-transfer pathway, leading to the well-characterized five-coordinate Mn{sup 3+}. We here propose and compare two hypothetical mechanisms for the mutant yeast enzyme, diffeeing in the structure of the Mn-peroxo complex yet both involving formation of the active six-coordinate Mn{sup 3+} and proton transfer from a second-sphere water molecule, which has substituted for the -OH of Tyr34, to the Mn-peroxo complex. Because WT and the mutant yeast MnSOD both rest in the 2+ state and become six-coordinate when oxidized up from Mn{sup 2+}, six-coordinate Mn{sup 3+} species could also actively function in the mechanism of WT yeast MnSODs.

  1. Studies on superoxide dismutase activities in virulent and avirulent strains of Agrobacterium tumefaciens and also in normal and crown gall tumor cells of Bryophyllum calycinum.

    PubMed

    Banerjee, D; Basu, M; Choudhury, I; Chatterjee, G C

    1982-01-01

    Superoxide dismutase activity in virulent strains of Agrobacterium tumefaciens was found to be higher than that in avirulent strains. Polyacrylamide gel electrophoresis revealed two isoenzymes in both these strains. These isoenzymes are suggested to be iron and manganese containing superoxide dismutases. Crown gall tumor cells of the plant Bryophyllum calycinum were found to have higher superoxide dismutase activity than the normal plant cells. Polyacrylamide gel electrophoresis revealed two isoenzymes in both normal and crown gall tumor cells. Advantages of the higher superoxide dismutase activities in respect of the survival of virulent strains of A. tumefaciens and crown gall tumor growth have been discussed.

  2. 6-Hydroxydopamine-lesioning of the nigrostriatal pathway in rats alters basal ganglia mRNA for copper, zinc- and manganese-superoxide dismutase, but not glutathione peroxidase.

    PubMed

    Kunikowska, G; Jenner, P

    2001-12-13

    The effects of nigrostriatal pathway destruction on the mRNA levels of copper, zinc-dependent superoxide dismutase (Cu,Zn-SOD), manganese-dependent superoxide dismutase (Mn-SOD), and glutathione peroxidase in basal ganglia of adult rat were investigated using in situ hybridization histochemistry and oligodeoxynucleotide (single-stranded complementary DNA) probes. The 6-hydroxydopamine (6-OHDA)-induced destruction of the nigrostriatal pathway resulted in contralateral rotation to apomorphine and a marked loss of specific [(3)H]mazindol binding in the striatum (93%; P<0.05) and of tyrosine hydroxylase mRNA in substantia nigra pars compacta (SC) (93%; P<0.05) compared with control rats. Levels of Cu,Zn-SOD mRNA were decreased in the striatum, globus pallidus, and SC on the lesioned side of 6-OHDA-lesioned rats compared with sham-lesioned rats (P<0.05). Levels of Mn-SOD mRNA were increased in the nucleus accumbens (P<0.05), but decreased in the SC (P<0.05) on the lesioned side of 6-OHDA-treated rats compared with sham-lesioned rats. Lesioning with 6-OHDA had no effect on glutathione peroxidase mRNA levels in any region of basal ganglia examined. The significant changes in Cu,Zn-SOD and Mn-SOD mRNA indicate that SOD is primarily expressed by dopaminergic neurons of the nigrostriatal pathway, and that the Mn-SOD gene appears to be inducible in rat basal ganglia in response to both physical and chemical damage 5 weeks after 6-OHDA-lesioning. These findings may clarify the status of antioxidant enzymes, particularly Mn-SOD, in patients with Parkinson's disease and their relevance to disease pathogenesis.

  3. Replacement of a cytosolic copper/zinc superoxide dismutase by a novel cytosolic manganese superoxide dismutase in crustaceans that use copper (haemocyanin) for oxygen transport.

    PubMed Central

    Brouwer, Marius; Hoexum Brouwer, Thea; Grater, Walter; Brown-Peterson, Nancy

    2003-01-01

    The blue crab, Callinectes sapidus, which uses the copper-dependent protein haemocyanin for oxygen transport, lacks the ubiquitous cytosolic copper-dependent enzyme copper/zinc superoxide dismutase (Cu,ZnSOD) as evidenced by undetectable levels of Cu,ZnSOD activity, protein and mRNA in the hepatopancreas (the site of haemocyanin synthesis) and gills. Instead, the crab has an unusual cytosolic manganese SOD (cytMnSOD), which is retained in the cytosol, because it lacks a mitochondrial transit peptide. A second familiar MnSOD is present in the mitochondria (mtMnSOD). This unique phenomenon occurs in all Crustacea that use haemocyanin for oxygen transport. Molecular phylogeny analysis suggests the MnSOD gene duplication is as old as the origin of the arthropod phylum. cytMnSOD activity in the hepatopancreas changes during the moulting cycle of the crab. Activity is high in intermoult crabs and non-detectable in postmoult papershell crabs. mtMnSOD is present in all stages of the moulting cycle. Despite the lack of cytCu,ZnSOD, crabs have an extracellular Cu,ZnSOD (ecCu,ZnSOD) that is produced by haemocytes, and is part of a large, approx. 160 kDa, covalently-linked protein complex. ecCu,ZnSOD is absent from the hepatopancreas of intermoult crabs, but appears in this tissue at premoult. However, no ecCu,ZnSOD mRNA can be detected, suggesting that the protein is recruited from the haemolymph. Screening of different taxa of the arthropod phylum for Cu,ZnSOD activity shows that those crustaceans that use haemoglobin for oxygen transport have retained cytCu,ZnSOD. It appears, therefore, that the replacement of cytCu,ZnSOD with cytMnSOD is part of an adaptive response to the dynamic, haemocyanin-linked, fluctuations in copper metabolism that occur during the moulting cycle of the crab. PMID:12769817

  4. Crystal Structure of Cu/Zn Superoxide Dismutase from Taenia Solium Reveals Metal-mediated Self-assembly

    SciTech Connect

    A Hernandez-Santoyo; A Landa; E Gonzalez-Mondragon; M Pedraza-Escalona; R Parra-Unda; A Rodriguez-Romero

    2011-12-31

    Taenia solium is the cestode responsible for porcine and human cysticercosis. The ability of this parasite to establish itself in the host is related to its evasion of the immune response and its antioxidant defence system. The latter includes enzymes such as cytosolic Cu/Zn superoxide dismutase. In this article, we describe the crystal structure of a recombinant T. solium Cu/Zn superoxide dismutase, representing the first structure of a protein from this organism. This enzyme shows a different charge distribution at the entrance of the active channel when compared with human Cu/Zn superoxide dismutase, giving it interesting properties that may allow the design of specific inhibitors against this cestode. The overall topology is similar to other superoxide dismutase structures; however, there are several His and Glu residues on the surface of the protein that coordinate metal ions both intra- and intermolecularly. Interestingly, one of these ions, located on the {beta}2 strand, establishes a metal-mediated intermolecular {beta}-{beta} interaction, including a symmetry-related molecule. The factors responsible for the abnormal protein-protein interactions that lead to oligomerization are still unknown; however, high metal levels have been implicated in these phenomena, but exactly how they are involved remains unclear. The present results suggest that this structure could be useful as a model to explain an alternative mechanism of protein aggregation commonly observed in insoluble fibrillar deposits.

  5. Effect of UV radiation on a thermostable superoxide dismutase purified from a thermophilic bacterium isolated from a sterilization drying oven.

    PubMed

    Monsalves, María T; Amenábar, Maximiliano J; Ollivet-Besson, Gabriela P; Blamey, Jenny M

    2013-07-01

    A thermostable superoxide dismutase from a thermophilic bacterium, called Geobacillus wiegeli (GWE1), isolated from the interior of a sterilization drying oven, was purified by anion-exchange and molecular size-exclusion liquid chromatography. On the basis of SDS-PAGE, the purified enzyme was found to be homogeneous and showed an estimated subunit molecular mass of 23.9 kDa. The holoenzyme is a homotetramer of 97.3 kDa. Superoxide dismutase exhibited maximal activity at pH 8.5 and at temperature around 60 ºC. The enzyme was thermostable maintaining 50% of its activity even after 4.5 hours incubation at 60 ºC and more than 70% of its activity after 30 min at 80 ºC. When the microorganism was irradiated with UVA, an increase in the specific activity of superoxide dismutase was observed which was correlated with decreasing levels of anion superoxide, indicating the direct involvement of this enzyme in the capture of reactive oxygen species. This study reports the effects of UV radiation on a superoxide dismutase from a thermophilic bacterium isolated from an anthropogenic environment.

  6. Crystal structure of Cu / Zn superoxide dismutase from Taenia solium reveals metal-mediated self-assembly.

    PubMed

    Hernández-Santoyo, Alejandra; Landa, Abraham; González-Mondragón, Edith; Pedraza-Escalona, Martha; Parra-Unda, Ricardo; Rodríguez-Romero, Adela

    2011-09-01

    Taenia solium is the cestode responsible for porcine and human cysticercosis. The ability of this parasite to establish itself in the host is related to its evasion of the immune response and its antioxidant defence system. The latter includes enzymes such as cytosolic Cu/Zn superoxide dismutase. In this article, we describe the crystal structure of a recombinant T. solium Cu/Zn superoxide dismutase, representing the first structure of a protein from this organism. This enzyme shows a different charge distribution at the entrance of the active channel when compared with human Cu/Zn superoxide dismutase, giving it interesting properties that may allow the design of specific inhibitors against this cestode. The overall topology is similar to other superoxide dismutase structures; however, there are several His and Glu residues on the surface of the protein that coordinate metal ions both intra- and intermolecularly. Interestingly, one of these ions, located on the β2 strand, establishes a metal-mediated intermolecular β-β interaction, including a symmetry-related molecule. The factors responsible for the abnormal protein-protein interactions that lead to oligomerization are still unknown; however, high metal levels have been implicated in these phenomena, but exactly how they are involved remains unclear. The present results suggest that this structure could be useful as a model to explain an alternative mechanism of protein aggregation commonly observed in insoluble fibrillar deposits.

  7. Involvement of Extracellular Cu/Zn Superoxide Dismutase in Cotton Fiber Primary and Secondary Cell Wall Biosynthesis

    USDA-ARS?s Scientific Manuscript database

    Extracellular Cu/Zn superoxide dismutases (CSDs) that catalyze the conversion of superoxide to hydrogen peroxide have been suggested to be involved in lignification of secondary walls in spinach, pine and aspen. In cotton fibers, hydrogen peroxide was proposed to be involved in the induction of seco...

  8. A pulse-radiolysis study of the catalytic mechanism of the iron-containing superoxide dismutase from Photobacterium leiognathi.

    PubMed

    Lavelle, F; McAdam, M E; Fielden, E M; Roberts, P B

    1977-01-01

    The mechanism of the enzymic reaction of an iron-containing superoxide dismutase purified from the marine bacterium Photobacterium leiognathi was studied by using pulse radiolysis. Measurements of activity were done with two different preparations of enzyme containing either 1.6 or 1.15 g-atom of iron/mol. In both cases, identical values of the second-order rate constant for reaction between superoxide dismutase and the superoxide ion in the pH range 6.2-9.0 (k=5.5 X 10(8) M-1-S-1 at pH 8.0) were found. As with the bovine erythrocuprein, there was no evidence for substrate saturation. The effects of reducing agents (H2O2, sodium ascorbate or CO2 radicals) on the visible and the electron-paramagnetic-resonance spectra of the superoxide dismutase containing 1.6 g-atom of ferric iron/mol indicate that this enzyme contains two different types of iron. Turnover experiments demonstrate that only that fraction of the ferric iron that is reduced by H2O2 is involved in the catalysis, being alternately oxidized and reduced by O2; both the oxidation and the reduction steps have a rate constant equal to that measured under turnover conditions. These results are interpreted by assuming that the superoxide dismutase isolated from the organism contains 1 g-atom of catalytic iron/mol and a variable amount of non-catalytic iron. This interpretation is discused in relation to the stoicheiometry reported for iron-containing superoxide dismutases prepared from several other organisms.

  9. Effects of the angiotensin II type 1 receptor antagonist valsartan on the expression of superoxide dismutase in hypertensive patients.

    PubMed

    Yang, Hung-Yu; Kao, Pai-Feng; Chen, Tso-Hsiao; Tomlinson, Brian; Ko, Wen-Chin; Chan, Paul

    2007-03-01

    The role of oxidative stress in the pathogenesis of vascular diseases such as hypertension has been well recognized. Angiotensin (Ang) II is regarded as a pro-oxidant because it can stimulate the production of reactive oxygen species. The purpose of this study was to evaluate whether treatment with the Ang II type 1 (AT(1)) receptor antagonist valsartan has an antioxidant effect in patients with mild to moderate hypertension. A randomized, double-blind, placebo-controlled study was conducted in 48 stage I and II hypertensive subjects. Patients were followed every 4 weeks for 12 weeks after randomization to valsartan titrated to 80 to 160 mg once or twice daily or matching placebo. The erythrocyte superoxide dismutase (SOD) activity and expression of SOD-mRNA in polymorphonuclear leukocytes were measured before and after treatment. Valsartan showed concentration-dependent inhibition of reactive oxygen species generation in polymorphonuclear leukocytes from hypertensive patients. The erythrocyte superoxide dismutase activity before treatment was more than 2 times higher in hypertensive subjects compared to normal controls. Superoxide dismutase activity decreased significantly after 12 weeks of treatment with valsartan but did not change with placebo. The amount of SOD-mRNA in the polymorphonuclear leukocytes decreased progressively over 3 months in the hypertensive subjects receiving valsartan treatment but did not change in the placebo group. The production of reactive oxygen species is increased in hypertension, and superoxide dismutase activity is increased, presumably as a compensatory mechanism. Treatment with valsartan but not placebo resulted in a progressive down-regulation of SOD-mRNA expression and a reduction in superoxide dismutase activity, suggesting antioxidant activity and a reduction of reactive oxygen species generation. These findings imply that AT(1) receptor antagonists may provide benefits to hypertensive patients beyond blood pressure reduction.

  10. Chlorovirus PBCV-1 Encodes an Active Copper-Zinc Superoxide Dismutase

    PubMed Central

    Kang, Ming; Duncan, Garry A.; Kuszynski, Charles; Oyler, George; Zheng, Jiayin; Becker, Donald F.

    2014-01-01

    ABSTRACT Superoxide dismutases (SODs) are metalloproteins that protect organisms from toxic reactive oxygen species by catalyzing the conversion of superoxide anion to hydrogen peroxide and molecular oxygen. Chlorovirus PBCV-1 encodes a 187-amino-acid protein that resembles a Cu-Zn SOD with all of the conserved amino acid residues for binding copper and zinc (named cvSOD). cvSOD has an internal Met that results in a 165-amino-acid protein (named tcvSOD). Both cvSOD and tcvSOD recombinant proteins inhibited nitroblue tetrazolium reduction of superoxide anion generated in a xanthine-xanthine oxidase system in solution. tcvSOD was chosen for further characterization because it was easier to produce. Recombinant tcvSOD also inhibited a riboflavin photochemical reduction system in a polyacrylamide gel assay, which was blocked by the Cu-Zn SOD inhibitor cyanide but not by azide, which inhibits Fe and Mn SODs. A kcat/Km value for cvSOD was determined by stop-flow spectrophotometry as 1.28 × 108 M−1 s−1, suggesting that cvSOD-catalyzed O2− dismutation was not a diffusion controlled encounter. The cvsod gene was expressed as a late gene, and cvSOD activity was detected in purified virions. Superoxide accumulated rapidly during virus infection, and circumstantial evidence indicates that cvSOD aids its decomposition to benefit virus replication. Cu-Zn SOD homologs have been described to occur in 3 other families of large DNA viruses, poxviruses, baculoviruses, and mimiviruses, which group as a clade. Interestingly, cvSOD does not group in the same clade as the other virus SODs but instead groups in an expanded clade that includes Cu-Zn SODs from many cellular organisms. IMPORTANCE Virus infection often leads to an increase in toxic reactive oxygen species in the host, which can be detrimental to virus replication. Viruses have developed various ways to overcome this barrier. As reported in this article, the chloroviruses often encode and package a functional Cu

  11. How active site protonation state influences the reactivity and ligation of the heme in chlorite dismutase

    PubMed Central

    Streit, Bennett R.; Blanc, Béatrice; Lukat-Rodgers, Gudrun S.; Rodgers, Kenton R.; DuBois, Jennifer L.

    2010-01-01

    Chlorite dismutase catalyzes O2 release from chlorite with exquisite efficiency and specificity. The spectroscopic properties, ligand binding affinities, and steady state kinetics of chlorite dismutase from Dechloromonas aromatica were examined over pH 3–11.5 to gain insight into how the protonation state of the heme environment influences dioxygen formation. An acid/base transition was observed by UV/visible and resonance Raman spectroscopy with a pKa of 8.7, 2–3 pH units below analogous transitions observed in typical His-ligated peroxidases. This transition marks the conversion of a five coordinate high spin Fe(III) to a mixed high/low spin ferric-hydroxide, as confirmed by resonance Raman (rR) spectroscopy. The two Fe–OH stretching frequencies are quite low, consistent with a weak Fe–OH bond, despite the nearly neutral imidazole side chain of the proximal histidine ligand. The hydroxide is proposed to interact strongly with a distal H-bond donor, thereby weakening the Fe–OH bond. The rR spectra of Cld-CO as a function of pH reveal two forms of the complex, one in which there is minimal interaction of distal residues with the carbonyl oxygen and another, acidic form in which the oxygen is under the influence of positive charge. Recent crystallographic data reveal arginine 183 as the lone H-bond donating residue in the distal pocket. It is likely that this Arg is the strong, positively charged H-bond donor implicated by vibrational data to interact with exogenous axial heme ligands. The same Arg in its neutral (pKa ~ 6.5) form also appears to act as the active site base in binding reactions of protonated ligands, such as HCN, to ferric Cld. The steady state profile for the rate of chlorite decomposition is characterized by these same pKas. The 5 coordinate high spin acidic Cld is more active than the alkaline hydroxide-bound form. The acid form decomposes chlorite most efficiently when the distal Arg is protonated/cationic (maximum kcat = 2.0 (±0.6)

  12. Impact of Superoxide Dismutase Mimetic AEOL 10150 on the Endothelin System of Fischer 344 Rats

    PubMed Central

    Ganesh, Devi; Kumarathasan, Prem; Thomson, Errol M.; St-Germain, Carly; Blais, Erica; Crapo, James; Vincent, Renaud

    2016-01-01

    Endothelin-1 is a potent vasoconstrictor and mitogenic peptide involved in the regulation of vasomotor tone and maintenance of blood pressure. Oxidative stress activates the endothelin system, and is implicated in pulmonary and cardiovascular diseases including hypertension, congestive heart failure, and atherosclerosis. Superoxide dismutase mimetics designed with the aim of treating diseases that involve reactive oxygen species in their pathophysiology may exert a hypotensive effect, but effects on the endothelin system are unknown. Our objective was to determine the effect of the superoxide dismutase mimetic AEOL 10150 on the basal endothelin system in vivo. Male Fischer-344 rats were injected subcutaneously with 0, 2 or 5 mg/kg body weight of AEOL 10150 in saline. Plasma oxidative stress markers and endothelins (bigET-1, ET-1, ET-2, ET-3) as well as lung and heart endothelin/nitric oxide system gene expressions were measured using HPLC-Coularray, HPLC-Fluorescence and RT-PCR respectively. AEOL 10150 reduced (p<0.05) the circulating levels of isoprostane (-25%) and 3-nitrotyrosine (-50%) measured in plasma 2h and 24h after treatment, confirming delivery of a physiologically-relevant dose and the potent antioxidant activity of the drug. The reduction in markers of oxidative stress coincided with sustained 24h decrease (p<0.05) of plasma levels of ET-1 (-50%) and ET-3 (-10%). Expression of preproET-1 and endothelin converting enzyme-1 mRNA were not altered significantly in the lungs. However preproET-1 (not significant) and ECE-1 mRNA (p<0.05) were increased (10–25%) in the heart. Changes in the lungs included decrease (p<0.05) of mRNA for the ET-1 clearance receptor ETB and the vasoconstriction-signaling ETA receptor (-30%), and an early surge of inducible nitric oxide synthase expression followed by sustained decrease (-40% after 24 hours). The results indicate that interception of the endogenous physiological flux of reactive nitrogen species and reactive

  13. Human serum albumin nanoparticles for efficient delivery of Cu, Zn superoxide dismutase gene

    PubMed Central

    Mo, Yun; Barnett, Micheal E.; Takemoto, Dolores; Davidson, Harriet

    2007-01-01

    Purpose To assess the potential of human serum albumin nanoparticles (HSA NP) as a nonviral vector for ocular delivery of Cu, Zn superoxide dismutase (SOD1) gene. Methods Cu, Zn superoxide dismutase (SOD1) gene-encapsulated nanoparticles (NP) were developed using human serum albumin (HSA), an endogenous protein, by a desolvation-crosslinking method. The pSOD-loaded HSA NP was evaluated for in vitro release characteristics, stability against DNase I and vitreous humor degradation, cytotoxicity, cellular uptake mechanisms, in vitro transfection efficiency, and in vivo gene expression. In vitro studies employed cultured human retinal pigment epithelial (ARPE-19) cells and in vivo studies employed a mouse model. For cell uptake analysis, fluorescein isothiocyanate (FITC)-labeled human serum albumin (HSA) was used. Results Plasmid containing SOD1 gene was encapsulated in HSA by a desolvation-crosslinking method. Gene-loaded HSA NP has a mean size of 120 nm, zeta potential of -44 mV, and plasmid encapsulation efficiency of 84%. At high crosslinking degree, HSA NP sustained the in vitro release of plasmid over 6 days, and stabilized plasmid DNA against DNase I and vitreous humor degradation. No cytotoxicity was observed in ARPE 19 cells treated with blank HSA NP at concentrations up to 5 mg/ml for 96 h. Cellular uptake of HSA NP was via receptor-mediated endocytosis that involves primarily caveolae-pathways. Confocal analysis indicated rapid endo/lysosomal escape of HSA NP. Further, confocal studies indicated that HSA readily enters the cell nucleus. In vitro, pSOD-HSA NP resulted in more than 80% transfection efficiency in ARPE-19 cells, which was 5 fold higher than Lipofectamine. HSA NP-transfected cells exhibited enhanced SOD1 activity that was 5 fold higher than untreated cells, indicating the overexpression of the functional gene. Intravitreal injection of HSA NP to the mouse eye at a dose of 130 ng of plasmid produced detectable level of fusion protein expression at

  14. Physiological Effects of Superoxide Dismutase on Altered Visual Function of Retinal Ganglion Cells in db/db Mice

    PubMed Central

    Nan, Yan; Zhang, Dongjuan; Chen, Baiyu; Guan, Youfei; Pu, Mingliang

    2012-01-01

    Background The C57BLKS/J db/db (db/db) mouse is a widely used type 2 diabetic animal model, and this model develops early inner retinal neuronal dysfunction beginning at 24 weeks. The neural mechanisms that mediate early stage retinal dysfunction in this model are unknown. We evaluated visual response properties of retinal ganglion cells (RGCs) during the early stage of diabetic insult (8, 12, and 20 wk) in db/db mice and determined if increased oxidative stress plays a role in impaired visual functions of RGCs in 20 wk old db/db mice. Methodology/Principal Findings In vitro extracellular single-unit recordings from RGCs in wholemount retinas were performed. The receptive field size, luminance threshold, and contrast gain of the RGCs were investigated. Although ON- and OFF-RGCs showed a different time course of RF size reduction, by 20 wk, the RF of ON- and OFF-RGCs were similarly affected. The LT of ON-RGCs was significantly elevated in 12 and 20 wk db/db mice compared to the LT of OFF-RGCs. The diabetic injury also affected contrast gains of ON- and OFF-RGCs differently. The generation of reactive oxidative species (ROS) in fresh retina was estimated by dihydroethidium. Superoxide dismutase (SOD) (300 unit/ml) was applied in Ames medium to the retina, and visual responses of RGCs were recorded for five hours. ROS generation in the retinas of db/db mice increased at 8wk and continued to progress at 20 wk of ages. In vitro application of SOD improved visual functions in 20 wk db/db mice but the SOD treatment affected ON- and OFF-RGCs differently in db/m retina. Conclusions/Significance The altered visual functions of RGCs were characterized by the reduced RF center size, elevated LT, and attenuated contrast gain in 12 and 20 wk db/db mice, respectively. These altered visual functions could, at least partly, be due to oxidative stress since in vitro application of SOD effectively improves visual functions. PMID:22272340

  15. Pyrimethamine significantly lowers cerebrospinal fluid Cu/Zn superoxide dismutase in amyotrophic lateral sclerosis patients with SOD1 mutations.

    PubMed

    Lange, Dale J; Shahbazi, Mona; Silani, Vincenzo; Ludolph, Albert C; Weishaupt, Jochen H; Ajroud-Driss, Senda; Fields, Kara G; Remanan, Rahul; Appel, Stanley H; Morelli, Claudia; Doretti, Alberto; Maderna, Luca; Messina, Stefano; Weiland, Ulrike; Marklund, Stefan L; Andersen, Peter M

    2017-06-01

    Cu/Zn superoxide dismutase (SOD1) reduction prolongs survival in SOD1-transgenic animal models. Pyrimethamine produces dose-dependent SOD1 reduction in cell culture systems. A previous phase 1 trial showed pyrimethamine lowers SOD1 levels in leukocytes in patients with SOD1 mutations. This study investigated whether pyrimethamine lowered SOD1 levels in the cerebrospinal fluid (CSF) in patients carrying SOD1 mutations linked to familial amyotrophic lateral sclerosis (fALS/SOD1). A multicenter (5 sites), open-label, 9-month-duration, dose-ranging study was undertaken to determine the safety and efficacy of pyrimethamine to lower SOD1 levels in the CSF in fALS/SOD1. All participants underwent 3 lumbar punctures, blood draw, clinical assessment of strength, motor function, quality of life, and adverse effect assessments. SOD1 levels were measured in erythrocytes and CSF. Pyrimethamine was measured in plasma and CSF. Appel ALS score, ALS Functional Rating Scale-Revised, and McGill Quality of Life Single-Item Scale were measured at screening, visit 6, and visit 9. We enrolled 32 patients; 24 completed 6 visits (18 weeks), and 21 completed all study visits. A linear mixed effects model showed a significant reduction in CSF SOD1 at visit 6 (p < 0.001) with a mean reduction of 13.5% (95% confidence interval [CI] = 8.4-18.5) and at visit 9 (p < 0.001) with a mean reduction of 10.5% (95% CI = 5.2-15.8). Pyrimethamine is safe and well tolerated in ALS. Pyrimethamine is capable of producing a significant reduction in total CSF SOD1 protein content in patients with ALS caused by different SOD1 mutations. Further long-term studies are warranted to assess clinical efficacy. Ann Neurol 2017;81:837-848. © 2017 The Authors. Annals of Neurology published by Wiley Periodicals, Inc. on behalf of American Neurological Association.

  16. Polarizable molecular mechanics studies of Cu(I)/Zn(II) superoxide dismutase: bimetallic binding site and structured waters.

    PubMed

    Gresh, Nohad; El Hage, Krystel; Perahia, David; Piquemal, Jean-Philip; Berthomieu, Catherine; Berthomieu, Dorothée

    2014-11-05

    The existence of a network of structured waters in the vicinity of the bimetallic site of Cu/Zn-superoxide dismutase (SOD) has been inferred from high-resolution X-ray crystallography. Long-duration molecular dynamics (MD) simulations could enable to quantify the lifetimes and possible interchanges of these waters between themselves as well as with a ligand diffusing toward the bimetallic site. The presence of several charged or polar ligands makes it necessary to resort to second-generation polarizable potentials. As a first step toward such simulations, we benchmark in this article the accuracy of one such potential, sum of interactions between fragments Ab initio computed (SIBFA), by comparisons with quantum mechanics (QM) computations. We first consider the bimetallic binding site of a Cu/Zn-SOD, in which three histidines and a water molecule are bound to Cu(I) and three histidines and one aspartate are bound to Zn(II). The comparisons are made for different His6 complexes with either one or both cations, and either with or without Asp and water. The total net charges vary from zero to three. We subsequently perform preliminary short-duration MD simulations of 296 waters solvating Cu/Zn-SOD. Six representative geometries are selected and energy-minimized. Single-point SIBFA and QM computations are then performed in parallel on model binding sites extracted from these six structures, each of which totals 301 atoms including the closest 28 waters from the Cu metal site. The ranking of their relative stabilities as given by SIBFA is identical to the QM one, and the relative energy differences by both approaches are fully consistent. In addition, the lowest-energy structure, from SIBFA and QM, has a close overlap with the crystallographic one. The SIBFA calculations enable to quantify the impact of polarization and charge transfer in the ranking of the six structures. Five structural waters, which connect Arg141 and Glu131, are endowed with very high dipole moments

  17. Differential Expression of Superoxide Dismutase Genes in Aphid-Stressed Maize (Zea mays L.) Seedlings

    PubMed Central

    Sytykiewicz, Hubert

    2014-01-01

    The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB) in seedling leaves of the Zea mays L. Tasty Sweet (susceptible) and Ambrozja (relatively resistant) cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid) or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid). Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl) radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9). However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4) or 24 h (sod9) post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants. PMID:24722734

  18. The Effect of UV-B Radiation on Bufo arenarum Embryos Survival and Superoxide Dismutase Activity

    PubMed Central

    Herkovits, J.; D’Eramo, J. L.; Fridman, O.

    2006-01-01

    The exposure of Bufo arenarum embryos to 300–310 nm UV-B at a dose of 4,104 Joule/m2 resulted in 100% lethality within 24 hr while 820 Joule/m2 was the NOEC value for short-term chronic (10 days) exposure. The dose response curves show that lethal effects are proportional with the dose and achieve its highest value within 48 hr post exposure. The superoxide dismutase (SOD) activity in amphibian embryos for sublethal UV-B exposures was evaluated by means of UV-B treatments with 273 (A), 820(B), 1368(C) and 1915(D) Joule/m2 at 2 and 5 hours post irradiation. The SOD activity in units/mg protein in A, B, C and D at 2 hr after treatments were 80.72 ± 14.29, 74.5 ± 13.19, 39.5 ± 6.99 and 10.7 ± 1.89 respectively while for control embryos it was 10.88 ± 1.31. At 5 hr after treatments the SOD values were similar to those found in control embryos. The results confirm the high susceptibility of amphibian embryos to UV-B and point out that the SOD activity is enhanced by low doses of UV-B irradiation achieving significantly higher values than in control embryos at 2 hr post exposure. PMID:16823076

  19. Inhalation of Talc Induces Infiltration of Macrophages and Upregulation of Manganese Superoxide Dismutase in Rats.

    PubMed

    Shim, Ilseob; Kim, Hyun-Mi; Yang, Sangyoung; Choi, Min; Seo, Gyun-Baek; Lee, Byung-Woo; Yoon, Byung-Il; Kim, Pilje; Choi, Kyunghee

    2015-01-01

    Talc is a mineral that is widely used in cosmetic products, antiseptics, paints, and rubber manufacturing. Although the toxicological effects of talc have been studied extensively, until now no detailed inhalation study of talc focusing on oxidative stress has been done. This repeated 4 weeks whole-body inhalation toxicity study of talc involved Sprague-Dawley rats. Male and female groups of rats were exposed to inhaled talc at 0, 5, 50, and 100 mg/m(3) for 6 hours daily, 5 days/week for 4 weeks. The objective was to identify the 4-week inhalation toxicity of talc and investigate antioxidant activity after exposure to talc. There were no treatment-related symptoms or mortality in rats treated with talc. Glucose (GLU) was decreased significantly in male rats exposed to 50 and 100 mg/m(3) of talc. Histopathological examination revealed infiltration of macrophages on the alveolar walls and spaces near the terminal and respiratory bronchioles. In male and female rats exposed to 100 mg/m(3) talc, expression of superoxide dismutase 2, a typical biological indicator of oxidative damage, was significantly increased. Thus, inhalation of talc induces macrophage aggregations and oxidative damage in the lung.

  20. Effects of copper supplementation on erythrocyte superoxide dismutase activity levels in rheumatoid arthritis patients

    SciTech Connect

    Marten, J.T.; DiSilvestro, R.A. )

    1989-02-09

    Rheumatoid arthritis (RA) patients are reported to possess lower than normal levels of Cu-Zn superoxide dismutase (SOD) activity. The contribution of copper status to these low values has not been examined. To address this issue, blood samples were obtained from 10 RA patients before and after 28 days of daily oral copper supplementation (2 mg/day). All patients were receiving gold therapy. Each RA subject, before supplementation, displayed lower erythrocyte SOD values than any of 25 age matched controls. The mean value for the RA subjects was about 40% lower than the control mean, whether expressed as units per ml packed cells or per mg hemoglobin. Erythrocyte SOD activity levels were increased in all subjects by the 4 week copper supplementation, with 7 of the patients showing at least a 22% increase. Presupplement SOD activities showed no correlation with serum C-reactive protein contents, an indicator of acute phase response. Serum levels of the copper containing acute phase protein ceruloplasmin, showed variable responses to copper supplementation. The studies described here are currently being extended to include RA subjects not being treated with gold and to include supplemented controls.

  1. Molecular Interaction Mechanism between 2-Mercaptobenzimidazole and Copper-Zinc Superoxide Dismutase

    PubMed Central

    Teng, Yue; Zou, Luyi; Huang, Ming; Chen, Yadong

    2014-01-01

    2-Mercaptobenzimidazole (MBI) is widely utilized as a corrosion inhibitor, copper-plating brightener and rubber accelerator. The residue of MBI in the environment is potentially harmful. In the present work, the toxic interaction of MBI with the important antioxidant enzyme copper-zinc superoxide dismutase (Cu/ZnSOD) was investigated using spectroscopic and molecular docking methods. MBI can interact with Cu/ZnSOD to form an MBI-Cu/ZnSOD complex. The binding constant, number of binding sites and thermodynamic parameters were measured, which indicated that MBI could spontaneously bind with Cu/ZnSOD with one binding site through hydrogen bonds and van der Waals forces. MBI bound into the Cu/ZnSOD interface of two subdomains, which caused some microenvironmental and secondary structure changes of Cu/ZnSOD and further resulted in the inhibition of Cu/ZnSOD activity. This work provides direct evidence at a molecular level to show that exposure to MBI could induce changes in the structure and function of the enzyme Cu/ZnSOD. The estimated methods in this work may be applied to probe molecular interactions of biomacromolecules and other pollutants and drugs. PMID:25157630

  2. A plant manganese superoxide dismutase is efficiently imported and correctly processed by yeast mitochondria.

    PubMed Central

    Bowler, C; Alliotte, T; Van den Bulcke, M; Bauw, G; Vandekerckhove, J; Van Montagu, M; Inzé, D

    1989-01-01

    In the plant Nicotiana plumbaginifolia, manganese superoxide dismutase (MnSOD) is synthesized in the cytoplasm as a preprotein and is subsequently translocated to the mitochondrial matrix with corresponding cleavage of an NH2-terminal leader sequence. To determine whether the plant enzyme could replace the endogenous SOD activities of Escherichia coli and yeast, constructions have been made in appropriate vectors for expression of the preprotein and the mature MnSOD. These were introduced into SOD-deficient strains for complementation studies. In E. coli, both forms of the protein were shown to be active and able to complement SOD deficiency to different degrees. Expression of the preprotein in a yeast strain lacking a mitochondrial MnSOD resulted in a restoration of wild-type growth, only possible if the plant protein was being targeted to the mitochondria. Subsequent studies revealed that the protein was processed and that the leader sequence was cleaved at the identical position as recognized by the mitochondrial peptidase of plants. The components mediating mitochondrial import thus appear to be highly conserved between plants and yeast. Images PMID:2654940

  3. Differential regulation of superoxide dismutases in plants exposed to environmental stress.

    PubMed Central

    Tsang, E W; Bowler, C; Hérouart, D; Van Camp, W; Villarroel, R; Genetello, C; Van Montagu, M; Inzé, D

    1991-01-01

    Superoxide dismutases (SODs) are metalloproteins that catalyze the dismutation of superoxide radicals to hydrogen peroxide and oxygen. The enzyme is ubiquitous in aerobic organisms where it plays a major role in defense against oxygen radical-mediated toxicity. In plants, environmental adversity often leads to the increased generation of reduced oxygen species and, consequently, SOD has been proposed to be important in plant stress tolerance. Here we describe the isolation of a cDNA clone encoding a cytosolic copper/zinc SOD from Nicotiana plumbaginifolia. Using this, together with previously isolated cDNAs encoding the mitochondrial manganese SOD and the chloroplastic iron SOD as probes in RNA gel blot analyses, we have studied SOD transcript abundance during different stress conditions: in response to light, during photoinhibitory conditions (light combined with high or low temperatures), and in response to a xenobiotic stress imposed by the herbicide paraquat. Evidence is presented that iron SOD mRNA abundance increases whenever there is a chloroplast-localized oxidative stress, similar to the previous finding that manganese SOD responds to mitochondria-localized events. The diverse effects of the different stress conditions on SOD mRNA abundance thus might provide an insight into the way that each treatment affects the different subcellular compartments. PMID:1820818

  4. Subunit Dissociation and Metal Binding by Escherichia coli apo-Manganese Superoxide Dismutase

    PubMed Central

    Whittaker, Mei M.; Lerch, Thomas F.; Kirillova, Olga; Chapman, Michael S.; Whittaker, James W.

    2010-01-01

    Metal binding by apo-manganese superoxide dismutase (apo-MnSOD) is essential for functional maturation of the enzyme. Previous studies have demonstrated that metal binding by apo-MnSOD is conformationally gated, requiring protein reorganization for the metal to bind. We have now solved the X-ray crystal structure of apo-MnSOD at 1.9 Å resolution. The organization of active site residues is independent of the presence of the metal cofactor, demonstrating that protein itself templates the unusual metal coordination geometry. Electrophoretic analysis of mixtures of apo- and (Mn2)-MnSOD, dye-conjugated protein, or C-terminal Strep-tag II fusion protein reveals a dynamic subunit exchange process associated with cooperative metal binding by the two subunits of the dimeric protein. In contrast, (S126C) (SS) apo-MnSOD, which contains an inter-subunit covalent disulfide crosslink, exhibits anticooperative metal binding. The protein concentration dependence of metal uptake kinetics implies that protein dissociation is involved in metal binding by the wild type apo-protein, although other processes may also contribute to gating metal uptake. Protein concentration dependent small-zone size exclusion chromatography is consistent with apo-MnSOD dimer dissociation at low protein concentration (KD = 1×10−6 M). Studies on metal uptake by apo-MnSOD in Escherichia coli cells show that the protein exhibits similar behavior in vivo and in vitro. PMID:21044611

  5. The role of arsenate reductase and superoxide dismutase in As accumulation in four Pteris species.

    PubMed

    Liu, Y; Wang, H B; Wong, M H; Ye, Z H

    2009-04-01

    Using arsenic (As) hyperaccumulators to extract As from contaminated soils is an effective and low-cost technology. Most of the known As hyperaccumulators belong to Pteris species. The present study aims to explore the responses and role of arsenate reductase (AR) and superoxide dismutase (SOD) in As hyperaccumulating fern species (Pteris vittata, and P. multifida) and non-As hyperaccumulating species (P. ensiformis, and P. semipinnata) when grown in soils added with 0 (control), 100, and 200 mg/kg (dry weight) of arsenic as Na(2)HAsO(4).7H(2)O. The results show that AR activities of roots, SOD activities and As concentrations in both roots and fronds of the four Pteris plants increased when exposed to As-contaminated soils. AR activities of roots were much higher, but SOD activities and As concentrations of roots were lower than those of fronds. It is concluded that AR of roots and SOD of both roots and fronds may play important roles to accumulate and detoxify As in the four Pteris species.

  6. Cu/Zn superoxide dismutase and age-related hearing loss

    PubMed Central

    Keithley, Elizabeth M.; Canto, Cecilia; Zheng, Qing Yin; Wang, Xiaobo; Fischel-Ghodsian, Nathan; Johnson, Kenneth R.

    2010-01-01

    Mice, in which the genetics can be manipulated and the life span is relatively short, enable evaluation of the effects of specific gene expression on cochlear degeneration over time. Antioxidant enzymes such as Cu/Zn superoxide dismutase (SOD1) protect cells from toxic, reactive oxygen species and may be involved in age-related degeneration. The effects of SOD1 deletion and over-expression on the cochlea were examined in Sod1-null mice, Sod1 transgenic mice and in age- and genetics-matched controls. Auditory brainstem responses (ABR) were measured and cochleae were histologically examined. The absence of SOD1 resulted in hearing loss at an earlier age than in wildtype or heterozygous mice. The cochleae of the null mice had severe spiral ganglion cell degeneration at 7–9 months of age. The stria vascularis in the aged, null mice was thinner than in the heterozygous or wildtype mice. Over-expression of SOD1 did not protect against hearing loss except at 24 months of age. In conclusion, SOD1 seems important for survival of cochlear neurons and the stria vascularis, however even half the amount is sufficient and an over abundance does not provide much protection from age-related hearing loss. PMID:16055286

  7. Human extracellular superoxide dismutase (EC-SOD) expression in transgenic chicken

    PubMed Central

    Byun, Sung June; Ji, Mi-Ran; Jang, Ye-Jin; Hwang, A-In; Chung, Hee Kyoung; Kim, Jeom Sun; Kim, Kyung-Woon; Chung, Hak-Jae; Yang, Byoung-Chul; Jeon, Iksoo; Park, Jin-Ki; Yoo, Jae Gyu; Kim, Tae-Yoon

    2013-01-01

    Extracellular superoxide dismutase (EC-SOD) is a metalloprotein and functions as an antioxidant enzyme. In this study, we used lentiviral vectors to generate transgenic chickens that express the human EC-SOD gene. The recombinant lentiviruses were injected into the subgerminal cavity of freshly laid eggs. Subsequently, the embryos were incubated to hatch using phases II and III of the surrogate shell ex vivo culture system. Of 158 injected embryos, 16 chicks (G0) hatched and were screened for the hEC-SOD by PCR. Only 1 chick was identified as a transgenic bird containing the transgene in its germline. This founder (G0) bird was mated with wild-type hens to produce transgenic progeny, and 2 transgenic chicks (G1) were produced. In the generated transgenic hens (G2), the hEC-SOD protein was expressed in the egg white and showed antioxidant activity. These results highlight the potential of the chicken for production of biologically active proteins in egg white. [BMB Reports 2013; 46(8): 404-409] PMID:23977988

  8. Superoxide radical generation and Mn- and Cu-Zn superoxide dismutases activities in human leukemic cells.

    PubMed

    Kato, Masahiko; Minakami, Hisanori; Kuroiwa, Minoru; Kobayashi, Yasuyuki; Oshima, Shigeru; Kozawa, Kunihisa; Morikawa, Akihiro; Kimura, Hirokazu

    2003-03-01

    Mn- and Cu-Zn superoxide dismutase (SOD) activities and generation of superoxide radicals (O(2) (-)) were assessed in leukemic cells from 10 patients with acute myeloid or monocytic leukemia (AML) and 10 patients with acute lymphoblastic leukemia (ALL), using a sensitive, specific chemiluminescence method. Leukemic cells were classified according to the French-American-British classification. M4 AML cells from two patients produced some O(2) (-) upon stimulation with opsonized zymosan (OZ), phorbol myristate acetate (PMA) or N-formyl-methionyl-leucyl-phenylalanine (FMLP), but less than normal granulocytes or monocytes. M5b AML cells from one patient produced as much O(2) (-) in response to these stimulants as normal monocytes. No O(2) (-) generation was induced in other types of leukemic cells. Total SOD activity in AML cells was significantly greater in normal granulocytes, but was only half of the activity in ALL cells. Mn-SOD in AML cells was very low or undetectable. These results suggest that except in M5b cells, decreased O(2) (-) production may contribute to susceptibility to infections in AML patients. Decreased Mn-SOD activity in AML cells may predispose them to oxidative stress. Copyright 2002 John Wiley & Sons, Ltd.

  9. Serum manganese-superoxide dismutase in patients with neuromuscular disorders as judged by an ELISA.

    PubMed

    Yahara, O; Hashimoto, K; Taniguchi, N; Ishikawa, M; Sato, Y; Yamashita, H; Ohno, H

    1991-06-01

    Manganese-superoxide dismutase (Mn-SOD) concentration was measured in sera from 37 healthy controls and 101 patients with 11 forms of neuromuscular diseases including Duchenne muscular dystrophy (DMD) and polymyositis (PMS) by an enzyme-linked immunosorbent assay with the use of a monoclonal antibody against human liver Mn-SOD. Serum from patients with DMD had a significantly (P less than 0.05) lower concentration of Mn-SOD than control serum. On the other hand, the concentration of Mn-SOD was markedly higher in the serum of patients with untreated form of acute PMS. The enzyme appeared to provide a good index for monitoring of responses to treatment of acute PMS. Of other neuromuscular diseases Mn-SOD concentration decreased significantly (P less than 0.05) in Charcot-Marie-Tooth disease and Kennedy-Alter-Sung syndrome but increased significantly (P less than 0.05) in human T-cell lymphotrophic viruses-I-associated myelopathy. This enzyme profile seems to be specific to each neuromuscular disease.

  10. Conformational Disorder of the Most Immature Cu, Zn-Superoxide Dismutase Leading to Amyotrophic Lateral Sclerosis.

    PubMed

    Furukawa, Yoshiaki; Anzai, Itsuki; Akiyama, Shuji; Imai, Mizue; Cruz, Fatima Joy C; Saio, Tomohide; Nagasawa, Kenichi; Nomura, Takao; Ishimori, Koichiro

    2016-02-19

    Misfolding of Cu,Zn-superoxide dismutase (SOD1) is a pathological change in the familial form of amyotrophic lateral sclerosis caused by mutations in the SOD1 gene. SOD1 is an enzyme that matures through the binding of copper and zinc ions and the formation of an intramolecular disulfide bond. Pathogenic mutations are proposed to retard the post-translational maturation, decrease the structural stability, and hence trigger the misfolding of SOD1 proteins. Despite this, a misfolded and potentially pathogenic conformation of immature SOD1 remains obscure. Here, we show significant and distinct conformational changes of apoSOD1 that occur only upon reduction of the intramolecular disulfide bond in solution. In particular, loop regions in SOD1 lose their restraint and become significantly disordered upon dissociation of metal ions and reduction of the disulfide bond. Such drastic changes in the solution structure of SOD1 may trigger misfolding and fibrillar aggregation observed as pathological changes in the familial form of amyotrophic lateral sclerosis. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Localization and distribution of superoxide dismutase-1 in the neural tube morphogenesis of chick embryo.

    PubMed

    Dhage, Prajakta A; Kamble, Lekha K; Bhargava, Shobha Y

    2017-02-01

    Superoxide dismutase 1 (SOD- 1) is an antioxidant enzyme that regulates the levels of Reactive oxygen species (ROS) by catalyzing the conversion of superoxide radical into hydrogen peroxide (H2O2) and oxygen. ROS are known to play a significant role in various cellular processes, via redox modification of a variety of molecules that participate in signaling pathways involved in this processes. As the levels of ROS in cells are controlled by the levels of antioxidant enzymes, thus SOD-1 may be indirectly involved in regulating different cellular processes by maintaining the required levels of H2O2. Therefore, in the present study we have investigated the possible involvement of SOD- 1 in the neurulation during the development of chick embryo. During gastrulation, SOD- 1 immunoreactivity was observed throughout the ectoderm and cauda mesoderm areas, however, its presence during neurulation was restricted to certain areas of neural tube particularly in the dorsal neural tube where neural tube closure takes place. Assaying enzyme activity revealed a significant increase in the SOD activity during neurulation. Further, inhibition of SOD- 1 by Diethyldithiocarbamate (DDC) induced abnormalities in the development of the neural tube. SOD- 1 inhibition specifically affected the closure of neural tube in the anterior region. Thus, here we report the presence of SOD- 1 mainly in the ectoderm and tissues of ectodermal origin during gastrulation to neurulation which suggests that it may be involved in the regulating the cellular processes during neural tube morphogenesis.

  12. Fructose protects baker's yeast against peroxide stress: potential role of catalase and superoxide dismutase.

    PubMed

    Semchyshyn, Halyna M; Lozinska, Liudmyla M

    2012-11-01

    The negative effects of fructose due to its chronic consumption are well documented, while short-term application of fructose is found to protect different types of cells against oxidative stress. Reactive oxygen species (ROS) are suggested to mediate both the cytotoxic and defensive effects. Here, we compare the influence of glucose and fructose on yeast under H(2)O(2)-induced stress. Under control conditions, fructose-grown comparing with glucose-grown yeast demonstrated higher metabolic activity and ROS level. Therefore, fructose was suggested to provoke a mild stress that resulted in the acquisition of cellular resistance to lethal challenges, which explained the higher survival of fructose-grown yeast under H(2)O(2)-induced shock. Exposure to H(2)O(2) increased ROS level in glucose-grown cells, whereas it decreased the ROS level in fructose-grown cells. Hydrogen peroxide activated superoxide dismutase (SOD) and catalase in both the cell types studied, but glucose-grown cells demonstrated a sharp rise of the activities, while cells grown on fructose showed a broad peak of activation. Thus, fructose is likely to protect the antioxidant enzymes against their inactivation by H(2)O(2). Despite a different type of the enzyme activation in both the studied cell types (glucose- and fructose-grown), a strong positive correlation between SOD and catalase was found. The physiological meaning of this relationship and possible mechanisms of the fructose protective effect are discussed.

  13. Superoxide Dismutase 1 Protects Hepatocytes from Type I Interferon-Driven Oxidative Damage

    PubMed Central

    Bhattacharya, Anannya; Hegazy, Ahmed N.; Deigendesch, Nikolaus; Kosack, Lindsay; Cupovic, Jovana; Kandasamy, Richard K.; Hildebrandt, Andrea; Merkler, Doron; Kühl, Anja A.; Vilagos, Bojan; Schliehe, Christopher; Panse, Isabel; Khamina, Kseniya; Baazim, Hatoon; Arnold, Isabelle; Flatz, Lukas; Xu, Haifeng C.; Lang, Philipp A.; Aderem, Alan; Takaoka, Akinori; Superti-Furga, Giulio; Colinge, Jacques; Ludewig, Burkhard; Löhning, Max; Bergthaler, Andreas

    2015-01-01

    Summary Tissue damage caused by viral hepatitis is a major cause of morbidity and mortality worldwide. Using a mouse model of viral hepatitis, we identified virus-induced early transcriptional changes in the redox pathways in the liver, including downregulation of superoxide dismutase 1 (Sod1). Sod1−/− mice exhibited increased inflammation and aggravated liver damage upon viral infection, which was independent of T and NK cells and could be ameliorated by antioxidant treatment. Type I interferon (IFN-I) led to a downregulation of Sod1 and caused oxidative liver damage in Sod1−/− and wild-type mice. Genetic and pharmacological ablation of the IFN-I signaling pathway protected against virus-induced liver damage. These results delineate IFN-I mediated oxidative stress as a key mediator of virus-induced liver damage and describe a mechanism of innate-immunity-driven pathology, linking IFN-I signaling with antioxidant host defense and infection-associated tissue damage. Video Abstract PMID:26588782

  14. Inhibitory effect of alliin from Allium sativum on the glycation of superoxide dismutase.

    PubMed

    Anwar, Shehwaz; Younus, Hina

    2017-10-01

    Inhibition of glycation is an important approach for alleviating diabetic complications. Alliin, the most abundant sulphur compound in garlic has been demonstrated to possess antidiabetic activity. However, there is no scientific evidence supporting its antiglycating activity. The objective of this study was to determine the inhibitory effect of alliin on glucose and methyglyoxal (MG)-induced glycation of an important antioxidant enzyme, superoxide dismutase (SOD). Glycation of SOD resulted in a decrease in enzyme activity, fragmentation/cross-linking, reduced cross-reactivity with anti-SOD antibodies, both tertiary and secondary structural changes, and formation of AGEs and fibrils. Alliin offered protection against glucose or MG induced glycation of SOD. The antiglycating potential of alliin appears to be comparable with that of quercetin which is reported to be a potent natural inhibitor of glycation. Alliin has a good antiglycating effect and hence is expected to have therapeutic potential in the prevention of glycation-mediated diabetic complications. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Extracellular superoxide dismutase is present in secretory vesicles of human neutrophils and released upon stimulation.

    PubMed

    Iversen, Marie B; Gottfredsen, Randi H; Larsen, Ulrike G; Enghild, Jan J; Praetorius, Jeppe; Borregaard, Niels; Petersen, Steen V

    2016-08-01

    Extracellular superoxide dismutase (EC-SOD) is an antioxidant enzyme present in the extracellular matrix (ECM), where it provides protection against oxidative degradation of matrix constituents including type I collagen and hyaluronan. The enzyme is known to associate with macrophages and polymorphonuclear leukocytes (neutrophils) and increasing evidence supports a role for EC-SOD in the development of an inflammatory response. Here we show that human EC-SOD is present at the cell surface of isolated neutrophils as well as stored within secretory vesicles. Interestingly, we find that EC-SOD mRNA is absent throughout neutrophil maturation indicating that the protein is synthesized by other cells and subsequently endocytosed by the neutrophil. When secretory vesicles were mobilized by neutrophil stimulation using formyl-methionyl-leucyl-phenylalanine (fMLF) or phorbol 12-myristate 13-acetate (PMA), the protein was released into the extracellular space and found to associate with DNA released from stimulated cells. The functional consequences were evaluated by the use of neutrophils isolated from wild-type and EC-SOD KO mice, and showed that EC-SOD release significantly reduce the level of superoxide in the extracellular space, but does not affect the capacity to generate neutrophil extracellular traps (NETs). Consequently, our data signifies that EC-SOD released from activated neutrophils affects the redox conditions of the extracellular space and may offer protection against highly reactive oxygen species such as hydroxyl radicals otherwise generated as a result of respiratory burst activity of activated neutrophils.

  16. Effects of catechin and epicatechin on superoxide dismutase and glutathione peroxidase activity, in vivo.

    PubMed

    Simos, Yannis V; Verginadis, Ioannis I; Toliopoulos, Ioannis K; Velalopoulou, Anastasia P; Karagounis, Ilias V; Karkabounas, Spyridon C; Evangelou, Angelos M

    2012-01-01

    The objective of this study was to investigate the effects of catechin and epicatechin on the activity of the endogenous antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) (as well as the total antioxidant capacity (TAC)) of rats after intra-peritoneal (i.p.) administration. Twenty-four Wistar rats were randomly divided into two groups: the experimental group which was administered daily with a 1:1 mixture of epicatechin and catechin at a concentration of 23 mg/kg body weight for 10 days and the control group which was injected daily with an equal amount of saline. Blood and urine samples were collected before and after the administration period, as well as 10 days after (follow-up). Intra-peritoneal administration of catechins led to a potent decrease in GPx levels and a significant increase in SOD levels. TAC was significantly increased in plasma and urine. Malonaldehyde levels in urine remained stable. In the animals treated with catechins, SOD activity showed a moderate negative correlation with GPx activity. Boosting the activity of the antioxidant enzymes could be a potential adjuvant approach for the treatment of the oxidative stress-related diseases.

  17. Effects of salinity change on two superoxide dismutases (SODs) in juvenile marbled eel Anguilla marmorata

    PubMed Central

    2016-01-01

    Salinity is one of the most important factors that affect the fish growth and survival. Superoxide dismutases (SODs), as the primary antioxidant enzymes, play a first role in the process of preventing oxidative stress caused by excessive superoxide anion (O\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${}_{2}^{-}$\\end{document}2−) in living organisms. In the present study, we investigated the effects of salinity on the gene expressions as well as enzymatic activities of MnSOD and Cu/ZnSOD in gill, intestine, kidney, liver and muscle tissues of the marbled eel Anguilla marmorata. We found that the liver might possess stronger redox capacity compared with other tissues. Furthermore, the gene expressions and enzymatic activities of SODs in juvenile marbled eels could be effectively enhanced by low salinity but inhibited when the salinity was higher than the body tolerance. Our findings indicated that MnSOD and Cu/ZnSOD played vital roles in the adaptation of marbled eels to salinity variation, which contributed to the elucidation of physiological adaptation and regulatory mechanism of SODs in eels. PMID:27547518

  18. Blood cell superoxide dismutase and enolase activities as markers of alcoholic and nonalcoholic liver diseases.

    PubMed

    Ledig, M; Doffoel, M; Doffoel, S; Kopp, P; Bockel, R; Mandel, P

    1988-01-01

    Monitoring of chronic alcoholism would be facilitated by using sensitive biochemical markers in blood cells, mainly to detect differences between alcoholic subjects with or without liver injury. We propose two types of markers: the first one is superoxide dismutase (SOD) activity involved in the conversion of superoxide radicals (O2-.) formed during acetaldehyde oxidation by xanthine oxidase after chronic alcohol consumption; the second one is enolase activity with both isoenzyme forms: nonneuronal enolase (NNE) and neuron specific enolase (NSE) which has been shown to be modified in many injuries related to the glycolytic pathways. For SOD activity we found a significant increase in alcoholic patients with liver injury and mainly in cirrhotic patients with ascitis. Both enolase activities were also found to be significantly increased in alcoholic patients with liver injury but NNE activity was also increased in alcoholics without apparent liver disease. Our results suggest that increased activity of SOD and NSE in blood cells may be related to liver injury mainly in alcoholism while increased NNE activity may also be a marker of alcohol abuse without liver injury.

  19. Determination of residual manganese in Mn porphyrin-based superoxide dismutase (SOD) and peroxynitrite reductase mimics

    PubMed Central

    Rebouças, Júlio S.; Kos, Ivan; Batinić-Haberle, Ines

    2009-01-01

    The awareness of the beneficial effects of Mn porphyrin-based superoxide dismutase (SOD) mimics and peroxynitrite scavengers on decreasing oxidative stress injuries has increased the use of these compounds as mechanistic probes and potential therapeutics. Simple Mn2+ salts, however, have SOD-like activity in their own right both in vitro and in vivo. Thus, quantification/removal of residual Mn2+ species in Mn-based therapeutics is critical to an unambiguous interpretation of biological data. Herein we report a simple, sensitive, and specific method to determine residual Mn2+ in Mn-porphyrin preparations that combines a hydrometallurgical approach for separation/speciation of metal compounds with a spectrophotometric strategy for Mn determination. The method requires only common chemicals and a spectrophotometer and is based on the extraction of residual Mn2+ by bis(2-ethylhexyl)hydrogenphosphate (D2EHPA) into kerosene, re-extraction into acid, and neutralization followed by UV-vis determination of the Mn2+ levels via a Cd2+-catalyzed metallation of the H2TCPP4− porphyrin indicator. The overall procedure is simple, sensitive, specific, and amenable to adaptation. This quantification method has been routinely used by us for a large variety of water-soluble porphyrins. PMID:19660888

  20. Effect of Nanoparticles on Modified Screen Printed Inhibition Superoxide Dismutase Electrodes for Aluminum

    PubMed Central

    Barquero-Quirós, Miriam; Arcos-Martínez, María Julia

    2016-01-01

    A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme superoxide dismutase has been developed. The oxidation signal of epinephrine substrate was affected by the presence of Al(III) ions leading to a decrease in its amperometric current. The immobilization of the enzyme was performed with glutaraldehyde on screen-printed carbon electrodes modifiedwith tetrathiofulvalene (TTF) and different types ofnanoparticles. Nanoparticles of gold, platinum, rhodium and palladium were deposited on screen printed carbon electrodes by means of two electrochemical procedures. Nanoparticles were characterized trough scanning electronic microscopy, X-rays fluorescence, and atomic force microscopy. Palladium nanoparticles showed lower atomic force microscopy parameters and higher slope of aluminum calibration curves and were selected to perform sensor validation. The developed biosensor has a detection limit of 2.0 ± 0.2 μM for Al(III), with a reproducibility of 7.9% (n = 5). Recovery of standard reference material spiked to buffer solution was 103.8% with a relative standard deviation of 4.8% (n = 5). Recovery of tap water spiked with the standard reference material was 100.5 with a relative standard deviation of 3.4% (n = 3). The study of interfering ions has also been carried out. PMID:27681735

  1. Aggregation of Copper–Zinc Superoxide Dismutase in Familial and Sporadic ALS

    PubMed Central

    Chattopadhyay, Madhuri

    2009-01-01

    Abstract Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disease characterized by the selective death of motor neurons. While the most common form of ALS is sporadic and has no known cause, a small subset of cases is familial because of underlying genetic mutations. The best-studies example of familial ALS is that caused by mutations in the protein copper–zinc superoxide dismutase. The formation of SOD1-rich inclusions in the spinal cord is an early and prominent feature of SOD1-linked familial ALS in human patients and animal models of this disease. These inclusions have been shown to consist of SOD1-rich fibrils, suggesting that the conversion of soluble SOD1 into amyloid fibrils may play an important role in the etiology of familial ALS. SOD1 is also present in inclusions found in spinal cords of sporadic ALS patients, allowing speculations to arise regarding a possible involvement of SOD1 in the sporadic form of this disease. We here review the recent research on the significance, causes, and mechanisms of SOD1 fibril formation from a biophysical perspective. Antioxid. Redox Signal. 11, 1603–1614. PMID:19271992

  2. [Plasma and red blood cell superoxide dismutase activity in patients with different stages of essential hypertension].

    PubMed

    Simić, Dragan; Perunicić, Jovan; Lasica, Ratko; Ivanović, Branislava; Matić, Danica; Kalimanovska-Ostrić, Dimitra; Vranić, Ivana; Medenica, Miroslav; Mimić-Oka, Jasmina; Simić, Tatjana

    2005-01-01

    It has been suggested that superoxide dismutase (SOD) plays an important role in endothelial dysfunction in essential hypertension (EH), by competing with nitric oxide for superoxide, thus influencing nitric oxide bioavailability. To answer the question of whether endothelial dysfunction is consequence of altered SOD expression we determined SOD activity in patients with different stages of EH. In this study 45 EH patients and 25 normotensive subjects were included. EH patients were divided into the three groups according to the guidelines of European Society of Hypertension. SOD activity was determined spectrophotometrically in RBC and plasma of EH patients and controls. The results obtained have shown that all groups of EH patients exhibit lower SOD activity than control normotensive subjects. Significant correlation between SOD activity and both diastolic (p<0.05, r=-0.394) and systolic blood pressure (p<0.05, r=-0.356) was found. Lowering of SOD activity in patients with different stages of EH leads to inefficient detoxification of superoxide in EH. An excess of superoxide of both cellular and extracellular origin takes part in enhanced degradation of nitric oxide and altered vasodilation, and consequent endothelial dysfunction.

  3. Impact of seminal plasma superoxide dismutase and glutathione peroxidase on cryopreserved buffalo spermatozoa.

    PubMed

    Waheed, M M; Gouda, Eman M; Khalifa, T A A

    2013-11-30

    Fifty semen samples were collected from sixteen buffalo-bulls (4-10 years old) and evaluated before cryopreservation. The activity of superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) as well as the levels of glutathione (GSH) and malondialdehyde (MDA) were assayed in the seminal plasma before freezing. Aspartate aminotransferase (AST) activity and cholesterol content were assayed in seminal plasma before freezing and after thawing. Results revealed the presence of SOD and GPx activities (0.07 ± 0.01 U/ml and 14.59 ± 0.50 nmol/min/ml, respectively) in buffaloes' seminal plasma. SOD activity was positively correlated with both of GSH level and GST activity in seminal plasma, and showed an inverse relationship with both cholesterol efflux and post-thaw abnormal tails of buffalo spermatozoa. A positive correlation was found between GPx activity in seminal plasma and abnormal tails and an inverse relationship with both post-thaw viability indices and increased motility in response to PTx. GST activity showed a positive correlation with the increased motility after addition of PTx and negative correlations with both of cholesterol level and AST activity. MDA levels were negatively correlated with motility after addition of PTx and positive correlations with both post-thaw abnormal acrosomes and tails. Buffalo seminal plasma contains high activities of SOD, GPx and GST enzymes and GSH levels that have an influence on the functional competence of cryopreserved spermatozoa. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Superoxide Dismutase: A Predicting Factor for Boar Semen Characteristics for Short-Term Preservation

    PubMed Central

    Nemec Svete, Alenka

    2014-01-01

    Superoxide dismutase (SOD), total antioxidant capacity (TAC), and thiobarbituric acid reactive substances (TBARS) in seminal plasma were evaluated on the basis of receiver operating characteristics (ROC) analysis as predictors for distinguishing satisfactory from unsatisfactory boar semen samples after storage. SOD on day 0 correlated significantly with progressive motility (r = −0.686; P < 0.05) and viability (r = −0.513; P < 0.05) after storage; TBARS correlated only with motility (r = −0.480; P < 0.05). Semen samples that, after 3 days of storage, fulfilled all criteria for semen characteristics (viability > 85%, motility > 70%, progressive motility > 25%, and normal morphology > 50%) had significantly lower SOD levels on the day 0 than those with at least one criterion not fulfilled (P < 0.05) following storage. SOD levels of less than 1.05 U/mL predicted with 87.5% accuracy that fresh semen will suit the requirements for satisfactory semen characteristics after storage, while semen with SOD levels higher than 1.05 U/mL will not fulfill with 100% accuracy at least one semen characteristic after storage. These results support the proposal that SOD in fresh boar semen can be used as a predictor of semen quality after storage. PMID:24729963

  5. Molecular cloning and characterization of copper/zinc-superoxide dismutase of Paragonimus westermani.

    PubMed

    Li, Ai-Hua; Na, Byoung-Kuk; Kong, Yoon; Cho, Shin-Hyeong; Zhao, Qin-Ping; Kim, Tong-Soo

    2005-04-01

    Superoxide dismutases (SODs; EC 1.15.1.1) play important roles in the protection of the parasites against cellular oxygen-mediated killing of the hosts. A copper/zinc-containing SOD (Cu/Zn-SOD) was identified previously from lung fluke, Paragonimus westermani. To expand our understanding of P. westermani SOD, we isolated a complementary DNA encoding a Cu/Zn-SOD, expressed the active enzyme in Escherichia coli, and characterized its biochemical properties. The deduced amino acid (aa) sequence of the gene shared up to 73.7% identities with Cu/Zn-SODs of other helminths and shared well-conserved characteristic motifs and essential aa residues involved in coordinating copper and zinc enzymatic functions. Recombinant Cu/ Zn-SOD exhibited comparable biochemical properties with that of the native enzyme, including pH optima and potassium cyanide-and hydrogen peroxide-sensitive inhibition profiles. The active enzyme consisted of 2 identical subunits covalently linked by disulfide bonds. The enzyme was constitutively expressed throughout various developmental stages of the parasite. The levels increased as P. westermani matured and plateaued in adult stage. Our result suggests the enzyme might play an important role for parasites to survive in the hosts through its superoxide anion-detoxifying function.

  6. Functional expression and characterization of a cytosolic copper/zinc-superoxide dismutase of Spirometra erinacei.

    PubMed

    Li, Ai-Hua; Na, Byoung-Kuk; Ahn, Sung-Kyu; Cho, Shin-Hyeong; Pak, Jhang-Ho; Park, Yun-Kyu; Kim, Tong-Soo

    2010-02-01

    Spirometra erinacei is a pseudophyllidean tapeworm which inhabits the intestines of cats and dogs. The infections are usually asymptomatic in these animals, but the infection of the plerocercoid larvae of the parasite, spargana, cause sparganosis in other vertebrates, including human. In this study, we identified a gene encoding the copper/zinc-superoxide dismutase of S. erinacei (SeCuZn-SOD) and partially characterized the biochemical and functional properties of the enzyme. The open reading frame of SeCuZnSOD was 465 bp that encodes 154 amino acids. The characteristic amino acid residues and motifs required for coordinating copper and zinc enzymatic function were well conserved. The genomic length of the SeCuZnSOD was 1,985 bp consisting of three exons that are separated by two introns. SeCuZnSOD is a typical cytosolic form which shares similar biochemical properties, including broad pH optima and inhibition profile by KCN and H(2)O(2), with cytosolic Cu/Zn-SODs of other organisms. SeCuZnSOD was functionally expressed in both S. erinacei plerocercoid larvae and adult worms, and its expression level was significantly increased when the plerocercoid larvae were treated with paraquat. The enzyme may play essential roles for survival of the parasite not only by protecting itself from endogenous oxidative stress, but also by detoxifying oxidative killing of the parasite by host immune effector cells.

  7. Nitrite dismutase reaction mechanism: kinetic and spectroscopic investigation of the interaction between nitrophorin and nitrite.

    PubMed

    He, Chunmao; Howes, Barry D; Smulevich, Giulietta; Rumpel, Sigrun; Reijerse, Edward J; Lubitz, Wolfgang; Cox, Nicholas; Knipp, Markus

    2015-04-01

    Nitrite is an important metabolite in the physiological pathways of NO and other nitrogen oxides in both enzymatic and nonenzymatic reactions. The ferric heme b protein nitrophorin 4 (NP4) is capable of catalyzing nitrite disproportionation at neutral pH, producing NO. Here we attempt to resolve its disproportionation mechanism. Isothermal titration calorimetry of a gallium(III) derivative of NP4 demonstrates that the heme iron coordinates the first substrate nitrite. Contrary to previous low-temperature EPR measurements, which assigned the NP4-nitrite complex electronic configuration solely to a low-spin (S = 1/2) species, electronic absorption and resonance Raman spectroscopy presented here demonstrate that the NP4-NO2(-) cofactor exists in a high-spin/low-spin equilibrium of 7:3 which is in fast exchange in solution. Spin-state interchange is taken as evidence for dynamic NO2(-) coordination, with the high-spin configuration (S = 5/2) representing the reactive species. Subsequent kinetic measurements reveal that the dismutation reaction proceeds in two discrete steps and identify an {FeNO}(7) intermediate species. The first reaction step, generating the {FeNO}(7) intermediate, represents an oxygen atom transfer from the iron bound nitrite to a second nitrite molecule in the protein pocket. In the second step this intermediate reduces a third nitrite substrate yielding two NO molecules. A nearby aspartic acid residue side-chain transiently stores protons required for the reaction, which is crucial for NPs' function as nitrite dismutase.

  8. Role of superoxide dismutase in hepatitis B virus-related hepatocellular carcinoma

    PubMed Central

    Zhang, Xiaolian; Lu, Yu; Rong, Chengzhi; Yang, Dongmei; Li, Shan; Qin, Xue

    2016-01-01

    Background: Reactive oxygen species (ROS) play important roles in hepatocarcinogenesis. Superoxide dismutase (SOD) is involved in the repair of ROS. Serum alpha-fetoprotein (AFP) is the “golden marker” for diagnosing hepatocellular carcinoma (HCC), and one major shortcoming of its use is that it is insensitive for the early detection of HCC. Therefore, we evaluated serum SOD levels and their association with AFP in hepatitis B virus (HBV)-related HCC. Materials and Methods: A total of 279 subjects were divided into three groups: 99 HBV patients with HCC, 73 HBV patients without HCC, and 107 sex- and age-matched healthy controls. Serum levels of SOD were assayed using colorimetry, while AFP levels were measured by electrochemiluminescence immunoassay. Results: A highly significant elevation was found in AFP in HBV-with HCC patients compared to HBV-without HCC patients and control subjects (P < 0.001). Alternatively, serum SOD levels were significantly decreased in patients with HCC compared to HBV patients without HCC and healthy controls (P < 0.001). Furthermore, serum SOD was negatively correlated with AFP (r = −0.505, P < 0.001) in HBV-with HCC patients. Conclusion: SOD and AFP might be simultaneously evaluated to improve the HCC detection rate. PMID:28163740

  9. 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.

  10. Formaldehyde dismutase, a novel NAD-binding oxidoreductase from Pseudomonas putida F61.

    PubMed

    Kato, N; Yamagami, T; Shimao, M; Sakazawa, C

    1986-04-01

    A novel enzyme, formaldehyde dismutase, was purified and crystallized from the cell extract of an isolated bacterium, Pseudomonas putida F61. The enzyme catalyzes the dismutation of aldehydes and alcohol:aldehyde oxidoreduction in the absence of an exogenous electron acceptor. The enzyme is composed of four identical subunits with a Mr of 44 000. Each subunit contains 1 mol NAD(H) and 2 mol zinc/mol. The ratio of NAD+ and NADH in a crystalline preparation of the enzyme was about 7:3. The enzyme-bound coenzyme was completely reduced and oxidized on the addition of a large amount of an alcohol and an aldehyde respectively. Both the oxidized and reduced enzymes catalyzed the dismutation reaction to the same extent. Steady-state kinetics of the enzyme were investigated using an oxidoreduction reaction between an alcohol and p-nitroso-N, N-dimethylaniline. The enzyme obeys a ping-pong mechanism and is competitively inhibited by an alcoholic substrate analogue, pyrazole, but not coenzyme analogues, such as AMP, N-methylnicotinamide. These results indicate that NAD(H) binds firmly (but not covalently) at each active site. The enzyme-bound NAD(H) was reduced and oxidized only by the added second substrates, alcohol and aldehyde respectively, and not by exogenous electron acceptors [including NAD(H)].

  11. Purification and properties of Cu-Zn superoxide dismutase extracted from Brucella abortus strain 19

    SciTech Connect

    Tabatabai, L.B. )

    1991-03-11

    Recent work showed that a recombinant 20 kDa protein from Brucella abortus expressed in E. coli is a Cu-Zn superoxide dismutase (SOD). Western blot and ELISA results indicated that cattle with brucellosis have antibody to SOD. Here the authors report the purification and properties of the native B. abortus Cu-Zn SOD. SOD was extracted from methanol-killed Brucella abortus strain 19 with 0.1 M sodium citrate-1.0 M sodium chloride solution. The extract was dialyzed and protein precipitated by ammonium sulfate at 70-100% saturation was collected. The SOD was purified by HPLC anion exchange chromatography. SOD activity was assayed with a coupled enzyme assay using xanthine oxidase-cytochrome C reduction assay. The authors determined that the Brucella SOD is present in two molecular forms both inhibitable with KCN with Ki's of 0.32 mM and 4.98 mM, respectively. No other form of SOD was identified in the extract. Polyclonal antibody to SOD and polyclonal antibody to SOD synthetic peptide residues 134-143 inhibited SOD activity by 50% and 13%, respectively. Both SOD and the synthetic peptide inhibited binding of anti-SOD antibody to SOD by 60% and 20%, respectively. Based on these results the SOD and its amphipathic peptide will be considered as candidates for the design of synthetic multiple peptide vaccines and diagnostic reagents for bovine brucellosis.

  12. Are superoxide dismutase 2 and nitric oxide synthase polymorphisms associated with idiopathic infertility?

    PubMed

    Faure, Celine; Leveille, Pauline; Dupont, Charlotte; Julia, Chantal; Chavatte-Palmer, Pascale; Sutton, Angela; Levy, Rachel

    2014-08-01

    The aim of this study was to investigate in a case-control study the associations between idiopathic infertility and antioxidant gene polymorphisms. One hundred ten infertile subjects (58 women and 52 men) with a history of idiopathic infertility and 69 fertile subjects (35 women and 34 men) with no history of infertility were included by three hospital departments of reproductive biology in the NCT01093378 French government clinical trial. Genotyping was assessed by real-time polymerase chain reaction with TaqMan assay. We examined genetic polymorphisms affecting five antioxidant enzymes: manganese superoxide dismutase (MnSOD), myeloperoxidase (MPO), glutathione peroxidase 1 (GPx1), catalase (CAT), and endothelial nitric oxide synthase (eNOS). The presence of at least 1 Ala-MnSOD allele (rs4880) increased significantly the risk of infertility (odds ratio [OR] 2.94; 95% confidence interval [CI], 1.14, 7.60; p=0.03) in male subjects. Moreover, the presence of 2 G-eNOS allele (rs1799983) increased significantly the risk of infertility in both men and women (OR 1.91; 95% CI, 1.04, 3.54; p=0.04). Our observations lead to the hypothesis that the genetic susceptibility modulating oxidative stress may represent a risk factor for male idiopathic infertility.

  13. Role of Superoxide Dismutase Activity in the Physiology of Porphyromonas gingivalis

    PubMed Central

    Lynch, Michael C.; Kuramitsu, Howard K.

    1999-01-01

    Porphyromonas gingivalis is a gram-negative, obligate anaerobe strongly associated with chronic adult periodontitis. A previous study has demonstrated that this organism requires superoxide dismutase (SOD) for its modest aerotolerance. In this study, we have constructed a mutant deficient in SOD activity by insertional inactivation as well as a sod::lacZ reporter translational fusion construct to study the regulation of expression of this gene. We have confirmed that SOD is essential for tolerance to atmospheric oxygen but does not appear to be protective against hydrogen peroxide or exogenously generated reactive oxygen species. Furthermore, the sod mutant appeared to be no more sensitive to killing by neutrophils than the parental strain 381. SOD appears to be protective against oxygen-dependent DNA damage as measured by increased mutation to rifampin resistance by the sod mutant. Use of the sod::lacZ construct confirmed that SOD expression is maximal at mid-log phase and is influenced by oxygen, temperature, and pH. However, expression does not appear to be significantly affected by iron depletion, osmolarity, or nutrient depletion. The transcription start site of the sod gene was determined to be 315 bp upstream of the sod start codon and to be within an upstream open reading frame. Our studies demonstrate the essential role that SOD plays in aerotolerance of this organism as well as the selective induction of this enzyme by environmental stimuli. PMID:10377114

  14. Kinetics of the Oxidation of Reduced Cu,Zn-Superoxide Dismutase by Peroxymonocarbonate

    PubMed Central

    Ranguelova, Kalina; Ganini, Douglas; Bonini, Marcelo G.; London, Robert E.; Mason, Ronald P.

    2012-01-01

    Kinetic evidence is reported for the role of the peroxymonocarbonate, HOOCO2−, as an oxidant for reduced Cu,Zn-superoxide dismutase-Cu(I) (SOD1) during the peroxidase activity of the enzyme. The formation of this reactive oxygen species results from the equilibrium between hydrogen peroxide and bicarbonate. Recently, peroxymonocarbonate has been proposed to be a key substrate for reduced SOD1 and has been shown to oxidize SOD1-Cu(I) to SOD1-Cu(II) much faster than H2O2. We have reinvestigated the kinetics of the reaction between SOD1-Cu(I) and HOOCO2− by using conventional stopped-flow spectrophotometry and obtained a second-order rate constant of k = 1600 ± 100 M−1s−1 for SOD1-Cu(I) oxidation by HOOCO2−. Our results demonstrate that peroxymonocarbonate oxidizes SOD1-Cu(I) to SOD1-Cu(II) and is in turn reduced to the carbonate anion radical. It is proposed that the dissociation of His61 from the active site Cu(I) in SOD-Cu(I) contributes to this chemistry by facilitating the binding of larger anions, such as peroxymonocarbonate. PMID:22569304

  15. Searching for convergent evolution in manganese superoxidase dismutase using hydrophobic cluster analysis.

    PubMed

    Xiang, Heng; Zhang, Ruizhi; Li, Nengzhang; Vossbrinck, Charles R

    2014-06-01

    There are numerous examples of convergent evolution in nature. Major ecological adaptations such as flight, loss of limbs in vertebrates, pesticide resistance, adaptation to a parasitic way of life, etc., have all evolved more than once, as seen by their analogous functions in separate taxa. But what about protein evolution? Does the environment have a strong enough influence on intracellular processes that enzymes and other functional proteins play, to evolve similar functional roles separately in different organisms? Manganese Superoxide Dismutase (MnSOD) is a manganesedependant metallo-enzyme which plays a crucial role in protecting cells from anti-oxidative stress by eliminating reactive (superoxide) oxygen species. It is a ubiquitous housekeeping enzyme found in nearly all organisms. In this study we compare phylogenies based on MnSOD protein sequences to those based on scores from Hydrophobic Cluster Analysis (HCA). We calculated HCA similarity values for each pair of taxa to obtain a pair-wise distance matrix. A UPGMA tree based on the HCA distance matrix and a common tree based on the primary protein sequence for MnSOD was constructed. Differences between these two trees within animals, enterobacteriaceae, planctomycetes and cyanobacteria are presented and cited as possible examples of convergence. We note that several residue changes result in changes in hydrophobicity at positions which apparently are under the effect of positive selection.

  16. Highly sensitive detection of superoxide dismutase based on an immunoassay with surface-enhanced fluorescence.

    PubMed

    Yang, Xiaoming; Dou, Yao; Zhu, Shanshan

    2013-06-07

    Herein, a novel highly sensitive enhanced-fluorescence immunoassay for detection of superoxide dismutase (SOD) is established by combining surface-enhanced fluorescence (SEF) with immuno-magnetic separation. Based on a sandwich-type immunoassay, analytes in samples are first captured by magnetic beads coated with a monoclonal antibody and then "sandwiched" by another monoclonal antibody on silver nanoparticles labeled with fluorescein-labeled oligonucleotides in the presence of a magnet. Subsequently, the immune complex is enriched by exposure to a magnetic field. Lastly, the fluorescence intensity is measured according to the number of dissociated fluoresceins. The increased fluorescence intensity permits highly sensitive detection of SOD in a linear range of 10-8 × 10(5) pg mL(-1), with a detection limit of 4 pg mL(-1) at a signal-to-noise ratio of 3. Significantly, this method was validated for detection of SOD in human serum, human urine, and cosmetic samples. Moreover, the reliability and accuracy of results obtained by the enhanced-fluorescence method was confirmed by the analysis of high performance liquid chromatography (HPLC).

  17. In vitro antileishmanial activity and iron superoxide dismutase inhibition of arylamine Mannich base derivatives.

    PubMed

    Martin-Montes, Alvaro; Santivañez-Veliz, Mery; Moreno-Viguri, Elsa; Martín-Escolano, Rubén; Jiménez-Montes, Carmen; Lopez-Gonzalez, Catalina; Marín, Clotilde; Sanmartín, Carmen; Gutiérrez Sánchez, Ramón; Sánchez-Moreno, Manuel; Pérez-Silanes, Silvia

    2017-08-09

    Leishmaniasis is one of the world's most neglected diseases, and it has a worldwide prevalence of 12 million. There are no effective human vaccines for its prevention, and treatment is hampered by outdated drugs. Therefore, research aiming at the development of new therapeutic tools to fight leishmaniasis remains a crucial goal today. With this purpose in mind, we present 20 arylaminoketone derivatives with a very interesting in vitro and in vivo efficacy against Trypanosoma cruzi that have now been studied against promastigote and amastigote forms of Leishmania infantum, Leishmania donovani and Leishmania braziliensis strains. Six out of the 20 Mannich base-type derivatives showed Selectivity Index between 39 and 2337 times higher in the amastigote form than the reference drug glucantime. These six derivatives affected the parasite infectivity rates; the result was lower parasite infectivity rates than glucantime tested at an IC25 dose. In addition, these derivatives were substantially more active against the three Leishmania species tested than glucantime. The mechanism of action of these compounds has been studied, showing a greater alteration in glucose catabolism and leading to greater levels of iron superoxide dismutase inhibition. These molecules could be potential candidates for leishmaniasis chemotherapy.

  18. Stress response in Lactococcus lactis: cloning, expression analysis, and mutation of the lactococcal superoxide dismutase gene.

    PubMed Central

    Sanders, J W; Leenhouts, K J; Haandrikman, A J; Venema, G; Kok, J

    1995-01-01

    In an analysis of the stress response of Lactococcus lactis, three proteins that were induced under low pH culture conditions were detected. One of these was identified as the lactococcal superoxide dismutase (SodA) by N-terminal amino acid sequence analysis. The gene encoding this protein, designated sodA, was cloned by the complementation of a sodA sodB Escherichia coli strain. The deduced amino acid sequence of L. lactis SodA showed the highest degree of similarity to the manganese-containing Sod (MnSod) of Bacillus stearothermophilus. A promoter upstream of the sodA gene was identified by primer extension analysis, and an inverted repeat surrounding the -35 hexanucleotide of this promoter is possibly involved in the regulation of the expression of sodA. The expression of sodA was analyzed by transcriptional fusions with a promoterless lacZ gene. The induction of beta-galactosidase activity occurred in aerated cultures. Deletion experiments revealed that a DNA fragment of more than 130 bp surrounding the promoter was needed for the induction of lacZ expression by aeration. The growth rate of an insertion mutant of sodA did not differ from that of the wild type in standing cultures but was decreased in aerated cultures. PMID:7665513

  19. Coxiella burnetii superoxide dismutase gene: cloning, sequencing, and expression in Escherichia coli.

    PubMed Central

    Heinzen, R A; Frazier, M E; Mallavia, L P

    1992-01-01

    A superoxide dismutase (SOD) gene from the obligate intracellular bacterium Coxiella burnetii has been cloned, and its DNA sequence has been determined and expressed in Escherichia coli. The gene was identified on pSJR50, a pHC79-derived genomic clone, by using the polymerase chain reaction with degenerate oligonucleotide primers corresponding to conserved regions of known SODs. Sequences resembling conventional E. coli ribosomal and RNA polymerase-binding sites preceded the C. burnetii 579-bp SOD open reading frame. An E. coli SOD-deficient double mutant (sodA sodB) that carried pSJR50 had growth and survival responses similar to those of the wild type when the transformant was challenged with 0.05 mM paraquat and 5 mM hydrogen peroxide, respectively. These observations indicated that the C. burnetii gene was functionally expressed in E. coli. Staining of native polyacrylamide gels for SOD activity demonstrated that pSJR50 insert DNA codes for an SOD that comigrates with an SOD found in C. burnetii cell lysates. The enzyme was inactivated by 5 mM hydrogen peroxide, which is indicative of an iron-containing SOD. Additionally, the predicted amino acid sequence was significantly more homologous to known iron-containing SODs than to manganese-containing SODs. Isolation of the C. burnetii SOD gene may provide an opportunity to examine its role in the intracellular survival of this rickettsia. Images PMID:1500190

  20. Effects of Greek legume plant extracts on xanthine oxidase, catalase and superoxide dismutase activities.

    PubMed

    Spanou, Chrysoula I; Veskoukis, Aristidis S; Stagos, Dimitrios; Liadaki, Kalliopi; Aligiannis, Nectarios; Angelis, Apostolos; Skaltsounis, Alexios-Leandros; Anastasiadi, Maria; Haroutounian, Serkos A; Kouretas, Dimitrios

    2012-03-01

    Legumes are considered to have beneficial health implications, which have been attributed to their phytochemical content. Polyphenols are considered the most important phytochemical compounds extensively studied for their antioxidant properties. The aim of the present study was to examine the effects of potent antioxidant legume plant extracts on xanthine oxidase (XO), catalase (CAT) and superoxide dismutase (SOD) activities. XO exerts a dual role, as it is the major contributor of free radicals during exercise while it generates uric acid, the most potent antioxidant molecule in plasma. CAT and SOD are two of the main enzymes of the antioxidant defence of tissues. We demonstrate that the majority of the extracts inhibited XO activity, but they had no effect on CAT inhibition and SOD induction when used at low concentrations. These results imply that the tested extracts may be considered as possible source of novel XO inhibitors. However, we have shown that allopurinol administration, a known XO inhibitor, before exercise reduces performance and induces oxidative stress in rats. Considering the fact that the extracts examined had an inhibitory effect on XO activity, possibly posing a restriction in their characterization as antioxidants, phytochemical antioxidant administration before exercise should probably be reconsidered.

  1. Molecular interaction mechanism between 2-mercaptobenzimidazole and copper-zinc superoxide dismutase.

    PubMed

    Teng, Yue; Zou, Luyi; Huang, Ming; Chen, Yadong

    2014-01-01

    2-Mercaptobenzimidazole (MBI) is widely utilized as a corrosion inhibitor, copper-plating brightener and rubber accelerator. The residue of MBI in the environment is potentially harmful. In the present work, the toxic interaction of MBI with the important antioxidant enzyme copper-zinc superoxide dismutase (Cu/ZnSOD) was investigated using spectroscopic and molecular docking methods. MBI can interact with Cu/ZnSOD to form an MBI-Cu/ZnSOD complex. The binding constant, number of binding sites and thermodynamic parameters were measured, which indicated that MBI could spontaneously bind with Cu/ZnSOD with one binding site through hydrogen bonds and van der Waals forces. MBI bound into the Cu/ZnSOD interface of two subdomains, which caused some microenvironmental and secondary structure changes of Cu/ZnSOD and further resulted in the inhibition of Cu/ZnSOD activity. This work provides direct evidence at a molecular level to show that exposure to MBI could induce changes in the structure and function of the enzyme Cu/ZnSOD. The estimated methods in this work may be applied to probe molecular interactions of biomacromolecules and other pollutants and drugs.

  2. Superoxide dismutase in pediatric palatine tonsils and adenoids and its related clinical parameters.

    PubMed

    Park, Shi-Nae; Yeo, Sang W; Park, Kyung-Ho; Chung, Min-Kyo; Lee, Heung-Youp; Chae, Sayong

    2003-01-01

    The objective of this study was to investigate a protective system of pediatric palatine tonsils and adenoids against superoxide radicals (O(2)(-)) and to evaluate the clinical factors including otitis media with effusion that are related to both the expression and activities of copper zinc superoxide dismutases (CuZnSODs). CuZnSODs in the palatine tonsils and adenoids were studied using immunohistochemistry and reverse-transcription polymerase chain reaction. Immunohistochemistry showed that CuZnSODs distribute in the crypt epithelium, mucous membrane, mantle zone, and extrafollicular area of the pediatric adenoids as well as in the palatine tonsils. Otitis media with effusion and paranasal sinusitis were related to CuZnSODs expression in the pediatric adenoids. In addition, the frequency of tonsillitis and presence of recent tonsillitis were significantly related to CuZnSODs expression in the pediatric tonsils (P <.05). In both the pediatric palatine tonsils and adenoids, the mechanism of tissue protection against infection and frequent inflammatory reactions may be closely related to CuZnSODs expression. There may be close relationship between the increased level of O(2)(-) that leads to an increase in CuZnSODs in the pediatric adenoid tissue and the development of otitis media.

  3. Measuring Copper and Zinc Superoxide Dismutase from Spinal Cord Tissue using Electrospray Mass Spectrometry

    PubMed Central

    Rhoads, Timothy W.; Lopez, Nathan I.; Zollinger, Daniel R.; Morre, Jeffrey T.; Arbogast, Brian L.; Maier, Claudia S.; DeNoyer, Linda; Beckman, Joseph S.

    2011-01-01

    Metals are key cofactors for many proteins, yet quantifying the metals bound to specific proteins is a persistent challenge in vivo. We have developed a rapid and sensitive method using electrospray ionization mass spectrometry to measure Cu,Zn superoxide dismutase (SOD1) directly from the spinal cord of SOD1-overexpressing transgenic rats. Metal dyshomeostasis has been implicated in motor neuron death in amyotrophic lateral sclerosis (ALS). Using the assay, SOD1 was directly measured from 100 μg of spinal cord, allowing for anatomical quantitation of apo, metal-deficient, and holo SOD1. SOD1 was bound on a C4 ZipTip® that served as a disposable column, removing interference by physiological salts and lipids. SOD1 was eluted with 30% acetonitrile plus 100 μM formic acid to provide sufficient hydrogen ions to ionize the protein without dislodging metals. SOD1 was quantified by including bovine SOD1 as an internal standard. SOD1 could be measured in subpicomole amounts and resolved to within two Daltons of the predicted parent mass. The methods can be adapted to quantify modifications to other proteins in vivo that can be resolved by mass spectrometry. PMID:21453670

  4. Superoxide dismutase functional regulation in neonatal hypoxia: effect of glucose, oxygen and epinephrine.

    PubMed

    Anju, T R; Babu, Athira; Paulose, C S

    2009-04-01

    Hypoxia is one of the major causes of damage to the fetal and neonatal brain and cardiac functions. In earlier studies, we have reported the brain damage caused by hypoxia and resuscitation with oxygen and epinephrine and have found that glucose treatment to hypoxic rats and hypoxic rats treated with oxygen shows a reversal of brain damage. The neonatal rats are shown to be deficient in free radical scavenging system, which offers a high risk of oxidative stress. In the present study, we induced hypoxia in neonatal Wistar rats and resuscitated with glucose, oxygen and epinephrine. Heart tissue and cerebral cortex were used to study the kinetics of superoxide dismutase activity in experimental groups of rats to assess the free radical status. Results showed that glucose supplementation in hypoxia (Hx + G) and hypoxic + oxygen (Hx + O) had an efficient free radical scavenging capability, compared to all other experimental groups. The observation was ascertained by studying the activity of catalase, another antioxidant enzyme in the body. Our results suggested that in neonatal rats during hypoxic condition, damage to heart and brain was more prominent in all groups, except when supplemented with glucose. These findings may have clinical significance in the proper management of heart and brain function.

  5. Manganese superoxide dismutase expression in endothelial progenitor cells accelerates wound healing in diabetic mice

    PubMed Central

    Marrotte, Eric J.; Chen, Dan-Dan; Hakim, Jeffrey S.; Chen, Alex F.

    2010-01-01

    Amputation as a result of impaired wound healing is a serious complication of diabetes. Inadequate angiogenesis contributes to poor wound healing in diabetic patients. Endothelial progenitor cells (EPCs) normally augment angiogenesis and wound repair but are functionally impaired in diabetics. Here we report that decreased expression of manganese superoxide dismutase (MnSOD) in EPCs contributes to impaired would healing in a mouse model of type 2 diabetes. A decreased frequency of circulating EPCs was detected in type 2 diabetic (db/db) mice, and when isolated, these cells exhibited decreased expression and activity of MnSOD. Wound healing and angiogenesis were markedly delayed in diabetic mice compared with normal controls. For cell therapy, topical transplantation of EPCs onto excisional wounds in diabetic mice demonstrated that diabetic EPCs were less effective than normal EPCs at accelerating wound closure. Transplantation of diabetic EPCs after MnSOD gene therapy restored their ability to mediate angiogenesis and wound repair. Conversely, siRNA-mediated knockdown of MnSOD in normal EPCs reduced their activity in diabetic wound healing assays. Increasing the number of transplanted diabetic EPCs also improved the rate of wound closure. Our findings demonstrate that cell therapy using diabetic EPCs after ex vivo MnSOD gene transfer accelerates their ability to heal wounds in a mouse model of type 2 diabetes. PMID:21060152

  6. Superoxide dismutase and catalase activities in rat hippocampus pretreated with garcinielliptone FC from Platonia insignis.

    PubMed

    da Costa Júnior, Joaquim S; de Almeida, Antonia Amanda C; Costa, Jéssica Pereira; das Graças Lopes Citó, Antonia Maria; Saffi, Jenifer; de Freitas, Rivelilson Mendes

    2012-04-01

    Platonia insignis Mart. (Clusiaceae), commonly known as "bacuri," is a timber and fruit native species of the Brazilian Amazon. Some plants of the Clusiaceae family have their pharmacological properties associated with the presence of xanthone and polycyclic polyprenylated acylphloroglucinols derivatives, which have antioxidant and anticarcinogenic activities. The aim of this study was to assess the in vivo potential of extracts, fractions, and garcinielliptone FC isolated from of Platonia insignis seeds as a natural antioxidant. Male Wistar rats (250-280 g; 2 months old) were treated with Tween 80 0.05% dissolved in 0.9% saline (i.p, vehicle - control group), ethanol extract (EE), hexane extract (HE), dichloromethane fraction (DMF), ethyl acetate fraction (EAF), and garcinielliptone FC (GFC) isolated from P. insignis at doses 2 mg/kg (i.p.). All groups were observed for 24 h after the treatment. The antioxidant enzymatic activities [superoxide dismutase (SOD) and catalase (CAT)] were measured using spectrophotometric methods. There were no marked alterations in SOD and CAT activities in rat hippocampus after pretreatment with EE, HE, DMF, EAF, and GFC. However, the pretreatment with GFC induced a significantly increase of 13, 17, 19, and 13% in SOD activities when compared to EE, HE, DMF, or EAF groups, respectively. Our findings strongly support the hypothesis that GFC isolated from P. insignis has a significant potential to be used as a natural antioxidant agent probably due to the modulation of enzymatic activity of hippocampal SOD.

  7. Diagnosis of superoxide anion radical induced in liquids by atmospheric-pressure plasma using superoxide dismutase

    NASA Astrophysics Data System (ADS)

    Tani, Atsushi; Fukui, Satoshi; Ikawa, Satoshi; Kitano, Katsuhisa

    2015-01-01

    To confirm the formation of the superoxide anion radical (O2-•) in liquids by atmospheric-pressure plasma, we investigated plasma-induced radical species in water using the electron spin resonance (ESR) spin-trapping technique combined with two proteins: superoxide dismutase (SOD), which has enzymatic activity to quench the superoxide anion radical, and bovine serum albumin (BSA), which does not have this enzymatic activity. Different setups of contact and non-contact atmospheric-pressure helium plasma were tested with an additional supply of oxygen gas. For each setup of plasma, no superoxide anion adduct ESR signal was observed in the aqueous solution with SOD, whereas the ESR signal appears in the samples with BSA and without any additive proteins. This means that a superoxide anion radical in the solution is sufficiently quenched by SOD before the formation of the spin adduct. The superoxide anion radical is actually induced in an aqueous solution by atmospheric-pressure plasma when ambient gases contain oxygen.

  8. Enhanced salt tolerance of transgenic poplar plants expressing a manganese superoxide dismutase from Tamarix androssowii.

    PubMed

    Wang, Yu Cheng; Qu, Guan Zheng; Li, Hong Yan; Wu, Ying Jie; Wang, Chao; Liu, Gui Feng; Yang, Chuan Ping

    2010-02-01

    Superoxide dismutases (SODs) play important role in stress tolerance of plants. In this study, an MnSOD gene (TaMnSOD) from Tamarix androssowii, under the control of the CaMV35S promoter, was introduced into poplar (Populus davidiana x P. bolleana). The physiological parameters, including SOD activity, malondialdehyde (MDA) content, relative electrical conductivity (REC) and relative weight gain, of transgenic lines and wild type (WT) plants, were measured and compared. The results showed that SOD activity was enhanced in transgenic plants, and the MDA content and REC were significantly decreased compared to WT plants when exposed to NaCl stress. In addition, the relative weight gains of the transgenic plants were 8- to 23-fold of those observed for WT plants after NaCl stress for 30 days. The data showed that the SOD activities that increased in transgenic lines are 1.3-4-folds of that increased in the WT plant when exposed to NaCl stress. Our analysis showed that increases in SOD activities as low as 0.15-fold can also significantly enhance salt tolerance in transgenic plants, suggesting an important role of increased SOD activity in plant salt tolerance

  9. Superoxide dismutase downregulation in osteoarthritis progression and end-stage disease.

    PubMed

    Scott, Jenny L; Gabrielides, Christos; Davidson, Rose K; Swingler, Tracey E; Clark, Ian M; Wallis, Gillian A; Boot-Handford, Raymond P; Kirkwood, Tom B L; Taylor, Robert W; Talyor, Robert W; Young, David A

    2010-08-01

    Oxidative stress is proposed as an important factor in osteoarthritis (OA). To investigate the expression of the three superoxide dismutase (SOD) antioxidant enzymes in OA. SOD expression was determined by real-time PCR and immunohistochemistry using human femoral head cartilage. SOD2 expression in Dunkin-Hartley guinea pig knee articular cartilage was determined by immunohistochemistry. The DNA methylation status of the SOD2 promoter was determined using bisulphite sequencing. RNA interference was used to determine the consequence of SOD2 depletion on the levels of reactive oxygen species (ROS) using MitoSOX and collagenases, matrix metalloproteinase 1 (MMP-1) and MMP-13, gene expression. All three SOD were abundantly expressed in human cartilage but were markedly downregulated in end-stage OA cartilage, especially SOD2. In the Dunkin-Hartley guinea pig spontaneous OA model, SOD2 expression was decreased in the medial tibial condyle cartilage before, and after, the development of OA-like lesions. The SOD2 promoter had significant DNA methylation alterations in OA cartilage. Depletion of SOD2 in chondrocytes increased ROS but decreased collagenase expression. This is the first comprehensive expression profile of all SOD genes in cartilage and, importantly, using an animal model, it has been shown that a reduction in SOD2 is associated with the earliest stages of OA. A decrease in SOD2 was found to be associated with an increase in ROS but a reduction of collagenase gene expression, demonstrating the complexities of ROS function.

  10. Aqueous two-phase system purification for superoxide dismutase induced by menadione from Phanerochaete chrysosporium.

    PubMed

    Kavakcıoğlu, Berna; Tongul, Burcu; Tarhan, Leman

    2017-03-01

    In the present work, the partitioning behavior of menadione-induced superoxide dismutase (SOD; EC 1.15.1.1), an antioxidant enzyme that has various applications in the medical and cosmetic industries, from the white rot fungus Phanerochaete chrysosporium has been characterized on different types of aqueous two-phase systems (ATPSs) (poly(ethylene glycol)/polypropylene glycol (PEG/PPG)-dextran, PEG-salt and PPG-salt). PEG-salt combinations were found most optimal systems for the purification of SOD. The best partition conditions were found using the PEG-3350 24% and K2HPO4 5% (w/w) with pH 7.0 at 25 °C. The partition coefficient of total SOD activity and total protein concentration observed in this system were 0.17 and 6.65, respectively, with the recovery percentage as 78.90% in the bottom phase and 13.17% in the top phase. The highest purification fold for SOD from P. chrysosporium was found as 6.04 in the bottom phase of PEG 3350%24 - K2HPO4%5 (w/w) system with pH 7.0. SOD purified from P. chrysosporium was determined to be a homodimer in its native state with a molecular weight of 60  ± 4 kDa. Consequently, simple and only one step PEG-salt ATPS system was developed for SOD purification from P. chrysosporium.

  11. Improved three-dimensional growth of manganese superoxide dismutase crystals on the International Space Station.

    PubMed

    Vahedi-Faridi, Ardeschir; Porta, Jason; Borgstahl, Gloria E O

    2003-02-01

    Manganese superoxide dismutase was crystallized in microgravity with 35 PCAM experiments (Protein Crystallization Apparatus for Microgravity) on the ISS (International Space Station) from 5 December 2001 to 19 April 2002. Crystals were very large in size and could easily be seen by eye. Crystals with 0.45 x 0.45 mm cross-sections and of up to 3 mm in length were obtained in several drops: an 80-fold increase in crystal Volume compared with the largest earth-grown crystal. A smaller crystal (0.15 x 0.30 mm in cross-section and 1.6 mm in length) was soaked in cryoprotectant and placed in a cryoloop. Diffraction data were collected at 100 K at the BioCARS bending-magnet beamline. The space group was C222(1), with unit-cell parameters a = 100.64, b = 107.78, c = 179.82 A. Diffraction spots to 1.26 A resolution were observed. Unfortunately, the high-resolution diffraction degraded owing to radiation damage and the resolution limit for the complete data set was 1.35 A. It is anticipated that increasing the crystal Volume and diffraction limit through microgravity crystal growth will enable several types of technically challenging structure determinations.

  12. Cloning, Expression and Characterization of Mitochondrial Manganese Superoxide Dismutase from the Whitefly, Bemisia tabaci

    PubMed Central

    Gao, Xian-Long; Li, Jun-Min; Wang, Yong-Liang; Jiu, Min; Yan, Gen-Hong; Liu, Shu-Sheng; Wang, Xiao-Wei

    2013-01-01

    A mitochondrial manganese superoxide dismutase from an invasive species of the whitefly Bemisia tabaci complex (Bt-mMnSOD) was cloned and analyzed. The full length cDNA of Bt-mMnSOD is 1210 bp with a 675 bp open reading frame, corresponding to 224 amino acids, which include 25 residues of the mitochondrial targeting sequence. Compared with various vertebrate and invertebrate animals, the MnSOD signature (DVWEHAYY) and four conserved amino acids for manganese binding (H54, H102, D186 and H190) were observed in Bt-mMnSOD. Recombinant Bt-mMnSOD was overexpressed in Escherichia coli, and the enzymatic activity of purified mMnSOD was assayed under various temperatures. Quantitative real-time PCR analysis with whiteflies of different development stages showed that the mRNA levels of Bt-mMnSOD were significantly higher in the 4th instar than in other stages. In addition, the in vivo activities of MnSOD in the whitefly were measured under various conditions, including exposure to low (4 °C) and high (40 °C) temperatures, transfer from a favorable to an unfavorable host plant (from cotton to tobacco) and treatment with pesticides. Our results indicate that the whitefly MnSOD plays an important role in cellular stress responses and anti-oxidative processes and that it might contribute to the successful worldwide distribution of the invasive whitefly. PMID:23296268

  13. Cloning, expression and characterization of mitochondrial manganese superoxide dismutase from the Whitefly, Bemisia tabaci.

    PubMed

    Gao, Xian-Long; Li, Jun-Min; Wang, Yong-Liang; Jiu, Min; Yan, Gen-Hong; Liu, Shu-Sheng; Wang, Xiao-Wei

    2013-01-07

    A mitochondrial manganese superoxide dismutase from an invasive species of the whitefly Bemisia tabaci complex (Bt-mMnSOD) was cloned and analyzed. The full length cDNA of Bt-mMnSOD is 1210 bp with a 675 bp open reading frame, corresponding to 224 amino acids, which include 25 residues of the mitochondrial targeting sequence. Compared with various vertebrate and invertebrate animals, the MnSOD signature (DVWEHAYY) and four conserved amino acids for manganese binding (H54, H102, D186 and H190) were observed in Bt-mMnSOD. Recombinant Bt-mMnSOD was overexpressed in Escherichia coli, and the enzymatic activity of purified mMnSOD was assayed under various temperatures. Quantitative real-time PCR analysis with whiteflies of different development stages showed that the mRNA levels of Bt-mMnSOD were significantly higher in the 4th instar than in other stages. In addition, the in vivo activities of MnSOD in the whitefly were measured under various conditions, including exposure to low (4 °C) and high (40 °C) temperatures, transfer from a favorable to an unfavorable host plant (from cotton to tobacco) and treatment with pesticides. Our results indicate that the whitefly MnSOD plays an important role in cellular stress responses and anti-oxidative processes and that it might contribute to the successful worldwide distribution of the invasive whitefly.

  14. Manganese nutrition effects on tomato growth, chlorophyll concentration, and superoxide dismutase activity.

    PubMed

    Shenker, Moshe; Plessner, Ora E; Tel-Or, Elisha

    2004-02-01

    The effects of Mn nutrition of tomato (Lycopersicon esculentum Mill.) seedlings on Mn-, Fe- and CuZn-superoxide dismutase (SOD, EC 1.15.1.1) enzymatic activities, metal translocation, chlorophyll concentration, and plant growth were tested using a bioassay system consisting of chelator-buffered nutrient culture with Mn2+ activities set to pMn (-log activity of Mn2+) of 6.6, 7.6, 8.6, and 9.6. The two middle levels resulted in optimal plant growth, whereas the two extreme levels resulted in a gradual decrease in chlorophyll concentration and slower plant growth. At the end of the experiment, 26 days after transfer to the Mn treatments, significant differences in shoot Mn concentration were manifested, from 10.5 mg kg(-1) in plants grown in pMn 9.6 to 207.4 mg kg(-1) in plants grown in pMn 6.6. Other element concentrations in the leaf suggest that growth inhibition and chlorophyll synthesis were affected primarily by manganese deficiency and excess. Twenty days after transfer of plants to the Mn treatments Mn-, Fe- and CuZn-SOD activities were assayed in young expanded leaf tissues by electrophoresis running gel. Whereas chloroplastic CuZn-SOD activity did not differ among Mn treatments, the cytosolic CuZn-SOD and mitochondrial Mn-SOD activities increased in both Mn-excess and Mn-deficient plants.

  15. Parasitization by Scleroderma guani influences expression of superoxide dismutase genes in Tenebrio molitor.

    PubMed

    Zhu, Jia-Ying; Ze, Sang-Zi; Stanley, David W; Yang, Bin

    2014-09-01

    Superoxide dismutase (SOD) is an antioxidant enzyme involved in detoxifying reactive oxygen species. In this study, we identified genes encoding the extracellular and intracellular copper-zinc SODs (ecCuZnSOD and icCuZnSOD) and a manganese SOD (MnSOD) in the yellow mealworm beetle, Tenebrio molitor. The cDNAs for ecCuZnSOD, icCuZnSOD, and MnSOD, respectively, encode 24.55, 15.81, and 23.14 kDa polypeptides, which possess structural features typical of other insect SODs. They showed 20-94% identity to other known SOD sequences from Bombyx mori, Musca domestica, Nasonia vitripennis, Pediculus humanus corporis, and Tribolium castaneum. Expression of these genes was analyzed in selected tissues and developmental stages, and following exposure to Escherichia coli and parasitization by Scleroderma guani. We recorded expression of all three SODs in cuticle, fat body, and hemocytes and in the major developmental stages. Relatively higher expressions were detected in late-instar larvae and pupae, compared to other developmental stages. Transcriptional levels were upregulated following bacterial infection. Analysis of pupae parasitized by S. guani revealed that expression of T. molitor SOD genes was significantly induced following parasitization. We infer that these genes act in immune response and in host-parasitoid interactions. © 2014 Wiley Periodicals, Inc.

  16. Copper/Zinc-Superoxide Dismutase Is Required for Oxytetracycline Resistance of Saccharomyces cerevisiae

    PubMed Central

    Avery, Simon V.; Malkapuram, Srividya; Mateus, Carolina; Babb, Kimberly S.

    2000-01-01

    Saccharomyces cerevisiae, along with other eukaryotes, is resistant to tetracyclines. We found that deletion of SOD1 (encoding Cu/Zn superoxide dismutase) rendered S. cerevisiae hypersensitive to oxytetracycline (OTC): a sod1Δ mutant exhibited a >95% reduction in colony-forming ability at an OTC concentration of 20 μg ml−1, whereas concentrations of up to 1,000 μg ml−1 had no effect on the growth of the wild type. OTC resistance was restored in the sod1Δ mutant by complementation with wild-type SOD1. The effect of OTC appeared to be cytotoxic and was not evident in a ctt1Δ (cytosolic catalase) mutant or in the presence of tetracycline. SOD1 transcription was not induced by OTC, suggesting that constitutive SOD1 expression is sufficient for wild-type OTC resistance. OTC uptake levels in wild-type and sod1Δ strains were similar. However, lipid peroxidation and protein oxidation were both enhanced during exposure of the sod1Δ mutant, but not the wild type, to OTC. We propose that Sod1p protects S. cerevisiae against a mode of OTC action that is dependent on oxidative damage. PMID:10613865

  17. A novel selenium and copper-containing peptide with both superoxide dismutase and glutathione peroxidase activities.

    PubMed

    Zou, Xian-Feng; Ji, Yue-Tong; Gao, Gui; Zhu, Xue-Jun; Lv, Shao-Wu; Yan, Fei; Han, Si-Ping; Chen, Xing; Gao, Chang-Cheng; Liu, Junqiu; Luo, Gui-Min

    2010-01-01

    Superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) play crucial roles in balancing the production and decomposition of reactive oxygen species (ROS) in living organisms. These enzymes act cooperatively and synergistically to scavenge ROS. In order to imitate the synergism of these enzymes, we designed and synthesized a novel 32-mer peptide (32P) on the basis of the previous 15-mer peptide with GPX activity and a 17-mer peptide with SOD activity. Upon the selenation and chelation of copper, the 32-mer peptide is converted to a new Se- and Cu-containing 32-mer peptide (Se-Cu-32P) and displays both SOD and GPX activities and its kinetics was studied. Moreover, the novel peptide was demonstrated to be able to better protect vero cells from the injury induced by xanthine oxidase (XOD)/xanthine/Fe2+ damage system than its parents. Thus, this bifunctional enzyme imitated the synergism of SOD and GPX and could be a better candidate of therapeutic medicine.

  18. Expression of Nocardia brasiliensis superoxide dismutase during the early infection of murine peritoneal macrophages.

    PubMed

    Revol, Agnès; Espinoza-Ruiz, Marisol; Medina-Villanueva, Igor; Salinas-Carmona, Mario Cesar

    2006-12-01

    Nocardia brasiliensis is the main agent of actinomycetoma in Mexico, but little is known about its virulence and molecular pathogenic pathways. These facultative intracellular bacteria are able to survive and divide within the host phagocytic cells, in part by neutralizing the reactive oxygen intermediates. Superoxide dismutase (SOD) participates in the intracellular survival of several bacterial species and, in particular, constitutes one of Nocardia asteroides virulence factors. To clarify SOD participation in the N. brasiliensis early infective process, we report its isolation and the consequent comparison of its transcript level. A 630 bp polymerase chain reaction fragment that included most of the coding sequence of N. brasiliensis sodA was cloned. A competitive assay was developed, allowing comparison of bacterial sod expression in exponential culture and 1 h after infecting peritoneal macrophages from BALB/c mice. At that time, there were viable bacteria in the macrophages. The intracellular bacteria presented a clear decrease in their sod transcript amount, although their 16S rRNA (used as an internal control) and hsp levels were maintained or slightly increased, respectively. These results indicate that sodA transcription is not maintained within the SOS bacterial response induced by phagosomal conditions. Further kinetics will be necessary to precisely define sod transcriptional regulation during N. brasiliensis intra-macrophage growth.

  19. The effect of UV-B radiation on Bufo arenarum embryos survival and superoxide dismutase activity.

    PubMed

    Herkovits, J; D'Eramo, J L; Fridman, O

    2006-03-01

    The exposure of Bufo arenarum embryos to 300-310 nm UV-B at a dose of 4,104 Joule/m(2) resulted in 100% lethality within 24 hr while 820 Joule/m(2) was the NOEC value for short-term chronic (10 days) exposure. The dose response curves show that lethal effects are proportional with the dose and achieve its highest value within 48 hr post exposure. The superoxide dismutase (SOD) activity in amphibian embryos for sublethal UV-B exposures was evaluated by means of UV-B treatments with 273 (A), 820(B), 1368(C) and 1915(D) Joule/m(2) at 2 and 5 hours post irradiation. The SOD activity in units/mg protein in A, B, C and D at 2 hr after treatments were 80.72 +/- 14.29, 74.5 +/- 13.19, 39.5 +/- 6.99 and 10.7 +/- 1.89 respectively while for control embryos it was 10.88 +/- 1.31. At 5 hr after treatments the SOD values were similar to those found in control embryos. The results confirm the high susceptibility of amphibian embryos to UV-B and point out that the SOD activity is enhanced by low doses of UV-B irradiation achieving significantly higher values than in control embryos at 2 hr post exposure.

  20. Voltage-Induced Misfolding of Zinc-Replete ALS Mutant Superoxide Dismutase-1.

    PubMed

    Shi, Yunhua; Acerson, Mark J; Shuford, Kevin L; Shaw, Bryan F

    2015-10-21

    The monomerization of Cu, Zn superoxide dismutase (SOD1) is an early step along pathways of misfolding linked to amyotrophic lateral sclerosis (ALS). Monomerization requires the reversal of two post-translational modifications that are thermodynamically favorable: (i) dissociation of active-site metal ions and (ii) reduction of intramolecular disulfide bonds. This study found, using amide hydrogen/deuterium (H/D) exchange, capillary electrophoresis, and lysine-acetyl protein charge ladders, that ALS-linked A4V SOD1 rapidly monomerizes and partially unfolds in an external electric field (of physiological strength), without loss of metal ions, exposure to disulfide-reducing agents, or Joule heating. Voltage-induced monomerization was not observed for metal-free A4V SOD1, metal-free WT SOD1, or metal-loaded WT SOD1. Computational modeling suggested a mechanism for this counterintuitive effect: subunit macrodipoles of dimeric SOD1 are antiparallel and amplified 2-fold by metal coordination, which increases torque at the dimer interface as subunits rotate to align with the electric field.

  1. Hydrogen peroxide induce modifications of human extracellular superoxide dismutase that results in enzyme inhibition.

    PubMed

    Gottfredsen, Randi H; Larsen, Ulrike G; Enghild, Jan J; Petersen, Steen V

    2013-01-01

    Superoxide dismutase (EC-SOD) controls the level of superoxide in the extracellular space by catalyzing the dismutation of superoxide into hydrogen peroxide and molecular oxygen. In addition, the enzyme reacts with hydrogen peroxide in a peroxidase reaction which is known to disrupt enzymatic activity. Here, we show that the peroxidase reaction supports a site-specific bond cleavage. Analyses by peptide mapping and mass spectrometry shows that oxidation of Pro112 supports the cleavage of the Pro112-His113 peptide bond. Substitution of Ala for Pro112 did not inhibit fragmentation, indicating that the oxidative fragmentation at this position is dictated by spatial organization and not by side-chain specificity. The major part of EC-SOD inhibited by the peroxidase reaction was not fragmented but found to encompass oxidations of histidine residues involved in the coordination of copper (His98 and His163). These oxidations are likely to support the dissociation of copper from the active site and thus loss of enzymatic activity. Homologous modifications have also been described for the intracellular isozyme, Cu/Zn-SOD, reflecting the almost identical structures of the active site within these enzymes. We speculate that the inactivation of EC-SOD by peroxidase activity plays a role in regulating SOD activity in vivo, as even low levels of superoxide will allow for the peroxidase reaction to occur.

  2. Developing a high performance superoxide dismutase based electrochemical biosensor for radiation dosimetry of thallium 201

    NASA Astrophysics Data System (ADS)

    Salem, Fatemeh; Tavakoli, Hassan; Sadeghi, Mahdi; Riazi, Abbas

    2014-09-01

    To develop a new biosensor for measurement of superoxide free radical generated in radiolysis reaction, three combinations of SOD-based biosensors including Au/Cys/SOD, Au/GNP/Cys/SOD and Au/GNP/Cys/SOD/Chit were fabricated. In these biosensors Au, GNP, Cys, SOD and Chit represent gold electrode, gold nano-particles, cysteine, superoxide dismutase and chitosan, respectively. For biosensors fabrication, SOD, GNP, Cys and Chit were immobilized at the surface of gold electrode. Cyclic voltametry and chronoamperometry were utilized for evaluation of biosensors performances. The results showed that Au/GNP/Cys/SOD/Chit has significantly better responses compared to Au/Cys/SOD and Au/GNP/Cys/SOD. As a result, this biosensor was selected for dosimetry of ionizing radiation. For this purpose, thallium 201 at different volumes was added to buffer phosphate solution in electrochemical cell. To obtain analytical parameters of Au/GNP/Cys/SOD/Chit, calibration curve was sketched. The results showed that this biosensor has a linear response in the range from 0.5 to 4 Gy, detection limit 0.03 μM. It also has a proper sensitivity (0.6038 nA/Gy), suitable long term stability and cost effective as well as high function for radiation dosimetry.

  3. Characterization of superoxide dismutases in anoxia- and hyperoxia-tolerant symbiotic cnidarians.

    PubMed

    Richier, Sophie; Merle, Pierre-Laurent; Furla, Paola; Pigozzi, Delphine; Sola, François; Allemand, Denis

    2003-04-07

    Many cnidarians, such as sea anemones, contain photosynthetic symbiotic dinoflagellates called zooxanthellae. During a light/dark cycle, the intratentacular O(2) state changes in minutes from hypoxia to hyperoxia (3-fold normoxia). To understand the origin of the high tolerance to these unusual oxic conditions, we have characterized superoxide dismutases (SODs) from the three cellular compartments (ectoderm, endoderm and zooxanthellae) of the Mediterranean sea anemone Anemonia viridis. The lowest SOD activity was found in ectodermal cells while endodermal cells and zooxanthellae showed a higher SOD activity. Two, seven and six SOD activity bands were identified on native PAGE in ectoderm, endoderm and zooxanthellae, respectively. A CuZnSOD was identified in both ectodermal and endodermal tissues. MnSODs were detected in all compartments with two different subcellular localizations. One band displays a classical mitochondrial localization, the three others being extramitochondrial. FeSODs present in zooxanthellae also appeared in endodermal host tissue. The isoelectric points of all SODs were distributed between 4 and 5. For comparative study, a similar analysis was performed on the whole homogenate of a scleractinian coral Stylophora pistillata. These results are discussed in the context of tolerance to hyperoxia and to the transition from anoxia to hyperoxia.

  4. Molecular characterization of two CuZn-superoxide dismutases in a sea anemone.

    PubMed

    Plantivaux, Amandine; Furla, Paola; Zoccola, Didier; Garello, Ginette; Forcioli, Didier; Richier, Sophie; Merle, Pierre-Laurent; Tambutté, Eric; Tambutté, Sylvie; Allemand, Denis

    2004-10-15

    Cnidarians living in symbiosis with photosynthetic cells--called zooxanthellae--are submitted to high oxygen levels generated by photosynthesis. To cope with this hyperoxic state, symbiotic cnidarians present a high diversity of superoxide dismutases (SOD) isoforms. To understand better the mechanism of resistance of cnidarian hosts to hyperoxia, we studied copper- and zinc-containing SOD (CuZnSOD) from Anemonia viridis, a temperate symbiotic sea anemone. We cloned two CuZnSOD genes that we call AvCuZnSODa and AvCuZnSODb. Their molecular analysis suggests that the AvCuZnSODa transcript encodes an extracellular form of CuZnSOD, whereas the AvCuZnSODb transcript encodes an intracellular form. Using in situ hybridization, we showed that both AvCuZnSODa and AvCuZnSODb transcripts are expressed in the endodermal and ectodermal cells of the sea anemone, but not in the zooxanthellae. The genomic flanking sequences of AvCuZnSODa and AvCuZnSODb revealed different putative binding sites for transcription factors, suggesting different modes of regulation for the two genes. This study represents a first step in the understanding of the molecular mechanisms of host animal resistance to permanent hyperoxia status resulting from the photosynthetic symbiosis. Moreover, AvCuZnSODa and AvCuZnSODb are the first SODs cloned from a diploblastic animal, contributing to the evolutionary understanding of SODs.

  5. Overproduction of superoxide dismutase and catalase confers cassava resistance to Tetranychus cinnabarinus.

    PubMed

    Lu, Fuping; Liang, Xiao; Lu, Hui; Li, Qian; Chen, Qing; Zhang, Peng; Li, Kaimian; Liu, Guanghua; Yan, Wei; Song, Jiming; Duan, Chunfang; Zhang, Linhui

    2017-01-05

    To explore the role of protective enzymes in cassava (Manihot esculenta Crantz) resistance to mites, transgenic cassava lines overproducing copper/zinc superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) were used to evaluate and molecularly confirm cassava resistance to Tetranychus cinnabarinus. Laboratory evaluation demonstrated that, compared with the control cultivar TMS60444 (wild type, WT), the survival, reproduction, development and activities of SOD and CAT in T. cinnabarinus feeding on transgenic cassava lines SC2, SC4, and SC11 significantly inhibited. Furthermore, the activities of SOD and CAT in transgenic cassava lines SC2, SC4, and SC11 damaged by T. cinnabarinus significantly increased. These findings were similar to the results in the mite-resistant cassava cultivars. Besides, field evaluation indicated that the transgenic cassava lines SC2, SC4, and SC11 were slightly damaged as the highly mite-resistant control C1115, while the highly mite-susceptible WT was severely damaged by T. cinnabarinus. Laboratory and field evaluation demonstrated that transgenic cassava lines were resistant to T. cinnabarinus, which directly confirmed that the increase in SOD and CAT activities was positively related to cassava resistance to T. cinnabarinus. These results will help in understanding the antioxidant defense responses in the cassava-mite interaction and molecular breeding of mite-resistant cassava for effective pest control.

  6. Overproduction of superoxide dismutase and catalase confers cassava resistance to Tetranychus cinnabarinus

    PubMed Central

    Lu, Fuping; Liang, Xiao; Lu, Hui; Li, Qian; Chen, Qing; Zhang, Peng; Li, kaimian; Liu, Guanghua; Yan, Wei; Song, Jiming; Duan, Chunfang; Zhang, Linhui

    2017-01-01

    To explore the role of protective enzymes in cassava (Manihot esculenta Crantz) resistance to mites, transgenic cassava lines overproducing copper/zinc superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) were used to evaluate and molecularly confirm cassava resistance to Tetranychus cinnabarinus. Laboratory evaluation demonstrated that, compared with the control cultivar TMS60444 (wild type, WT), the survival, reproduction, development and activities of SOD and CAT in T. cinnabarinus feeding on transgenic cassava lines SC2, SC4, and SC11 significantly inhibited. Furthermore, the activities of SOD and CAT in transgenic cassava lines SC2, SC4, and SC11 damaged by T. cinnabarinus significantly increased. These findings were similar to the results in the mite-resistant cassava cultivars. Besides, field evaluation indicated that the transgenic cassava lines SC2, SC4, and SC11 were slightly damaged as the highly mite-resistant control C1115, while the highly mite-susceptible WT was severely damaged by T. cinnabarinus. Laboratory and field evaluation demonstrated that transgenic cassava lines were resistant to T. cinnabarinus, which directly confirmed that the increase in SOD and CAT activities was positively related to cassava resistance to T. cinnabarinus. These results will help in understanding the antioxidant defense responses in the cassava–mite interaction and molecular breeding of mite-resistant cassava for effective pest control. PMID:28054665

  7. EPR and O2.- scavenger activity: Cu(II)-peptide complexes as superoxide dismutase models.

    PubMed

    Pogni, R; Baratto, M C; Busi, E; Basosi, R

    1999-03-01

    Several copper(II) complexes with aminoacids and peptides are known to show superoxide dismutase (SOD)-like activity. EPR spectroscopy has proved to be a useful tool for studying the complex equilibria of the copper(II) ion and various ligands of biological importance in solution. In the present work, a variety of copper(II) complexes with di-, tri- and tetra-peptides containing only glycine residues (GG, GGG and GGGG) and others containing a histidyl residue in different positions (HGG, GHG, GGH and GGHG) have been investigated. EPR parameters obtained by extensive use of computer simulation of spectra lead to reliable spin Hamiltonian EPR parameters at both room temperature and in frozen solution. The molecular orbital coefficients computed from the anisotropic EPR data and the d-d electronic energies are used to characterize different arrangements of the complexes. Estimation of the scavenger activity of the complexes due to the particular environment created by the ligands around copper is discussed in the frame of the structure-activity relationship.

  8. Tri-iodothyronine alters superoxide dismutase expression in a teleost Anabas testudineus.

    PubMed

    Sreejith, P; Oommen, O V

    2008-12-01

    The effect of tri-iodothyronine (T3) on superoxide dismutase (SOD) expression was evaluated in a teleost Anabas testudineus (cuthyroid fish) by native gel eletrophoresis and Western blot analysis. SOD is an essential enzyme for the survival of oxygen-utilizing organisms. Its expression is altered by the stress, presumably due to the increase in concentration of superoxide radical in cells. Variations of thyroid honnone levels are the major physiological modulators of cellular oxidative stress. T3 administration generates an oxidative stress, which to some extent is neutralized by the changed activity of enzymes like SOD. T3 treatment decreased CuZn SOD density in liver and brain of A. testudineus. The activity of CuZn SOD in liver and brain was confirmed by native gel analysis. The different physiological states of thyroid influenced the CuZn SOD activity. Western blot analysis further confirmed that liver and brain CuZn SOD decreased after T3 treatment. From these findings, it was clear that T3 treatment in euthyroid fish created an oxidative stress condition and thyroid hormone effectively maintained antioxidant status to overcome this situation in teleosts.

  9. Changes in manganese superoxide dismutase expression after exposure of the retina to intense light.

    PubMed

    Yamamoto, M; Lidia, K; Gong, H; Onitsuka, S; Kotani, T; Ohira, A

    1999-02-01

    Manganese superoxide dismutase (Mn-SOD) is a naturally-occurring scavenger of superoxide, one of several reactive oxygen intermediates. To determine if Mn-SOD expression is enhanced as a defensive mechanism against oxidative challenges, such as intense light exposure, rats were exposed to cyclic light (80 lux) for 2 weeks, intense light (1,800 lux) for 24 h, and then again to cyclic light. Experimental and control (exposed to cyclic light only) eyes were enucleated 3 h, 1, 3, 7, and 14 days after light challenge. Protein expression was examined immunohistochemically using rabbit antisera against rat Mn-SOD. There was no significant difference between the light-exposed and the control groups in the thickness of the outer nuclear layers. Both retinal pigment epithelial cells and photoreceptor inner segments in the normal retina were labeled for Mn-SOD. Mn-SOD labeling was lost 3 h and day 1 after light challenge. It was re-expressed in the retinal pigment epithelial cells 3, 7, and 14 days after the light challenge, and in the photoreceptor inner segments after day 14. These results suggest that the retina might have a protective potential against light damage, in which Mn-SOD may play an important role.

  10. Aggregation of mutant Cu/Zn superoxide dismutase proteins in a culture model of ALS.

    PubMed

    Durham, H D; Roy, J; Dong, L; Figlewicz, D A

    1997-05-01

    Mutations in the Cu/Zn-superoxide dismutase (SOD-1) gene underlie some familial cases of amyotrophic lateral sclerosis (FALS), a neurodegenerative disorder characterized by loss of cortical, brainstem, and spinal motor neurons. To investigate the mechanisms responsible for the toxicity of mutant enzyme, SOD-1 cDNAs bearing mutations found in FALS patients (mSOD) were expressed in cultured spinal motor neurons, dorsal root ganglion (DRG) and hippocampal neurons. Many features of motor neuron disease seen in humans with FALS and in transgenic mouse models were reproduced, including preferential susceptibility of motor neurons to toxicity of mSOD. Abnormal cytoplasmic aggregation of mSOD protein was observed in mSOD-expressing motor neurons, but never in neurons expressing SODwt enzyme, and was followed by evidence of apoptotic cell death. Such aggregates were not observed in nonvulnerable neuronal populations expressing mSOD (DRG or hippocampal neurons). Aggregation of SOD-1 may contribute significantly to the death of motor neurons expressing mutations associated with FALS-1 and the mechanisms leading to aggregation may pertain to the specific vulnerability of motor neurons in this disease.

  11. Neuromuscular dysfunction in the mutant superoxide dismutase mouse model of amyotrophic lateral sclerosis.

    PubMed

    Parkhouse, Wade S; Cunningham, Lori; McFee, Ingrid; Miller, Jennifer M Litt; Whitney, Darryl; Pelech, Steven L; Krieger, Charles

    2008-01-01

    To better understand the interaction between motor neuron dysfunction and denervation in amyotrophic lateral sclerosis (ALS), we have evaluated motor neuron number and the retrograde uptake and transport of fluorogold by motor neurons in mice overexpressing mutant superoxide dismutase (mSOD), and wild-type controls. N-CAM immunoreactivity and protein kinase expression were determined in skeletal muscle during denervation. We found that in severely affected mSOD mice, motor neuron loss is moderate (approximate 40% reduction), whereas retrograde uptake/transport as assessed using fluorogold is profoundly impaired (approximately 90% reduction). The impairment in fluorogold uptake/transport corresponds to measures of progressive muscle denervation such as increased N-CAM immunoreactivity of muscle and increased expression of protein kinase B (PKB) in denervated muscle. These data suggest that the debility in the mSOD mouse model of ALS is produced, in part, by impaired retrograde uptake/transport in motor neuron axons in spite of regenerative support from muscle such as elevated expression of PKB.

  12. Extracellular superoxide dismutase deficiency impairs wound healing in advanced age by reducing neovascularization and fibroblast function

    PubMed Central

    Fujiwara, Toshihiro; Duscher, Dominik; Rustad, Kristine C.; Kosaraju, Revanth; Rodrigues, Melanie; Whittam, Alexander J.; Januszyk, Michael; Maan, Zeshaan N.; Gurtner, Geoffrey C.

    2016-01-01

    Advanced age is characterized by impairments in wound healing, and evidence is accumulating that this may be due in part to a concomitant increase in oxidative stress. Extended exposure to reactive oxygen species (ROS) is thought to lead to cellular dysfunction and organismal death via the destructive oxidation of intra-cellular proteins, lipids and nucleic acids. Extracellular superoxide dismutase (ecSOD/SOD3) is a prime antioxidant enzyme in the extracellular space that eliminates ROS. Here, we demonstrate that reduced SOD3 levels contribute to healing impairments in aged mice. These impairments include delayed wound closure, reduced neovascularization, impaired fibroblast proliferation and increased neutrophil recruitment. We further establish that SOD3 KO and aged fibroblasts both display reduced production of TGF-β1, leading to decreased differentiation of fibroblasts into myofibroblasts. Taken together, these results suggest that wound healing impairments in ageing are associated with increased levels of ROS, decreased SOD3 expression and impaired extracellular oxidative stress regulation. Our results identify SOD3 as a possible target to correct age-related cellular dysfunction in wound healing. PMID:26663425

  13. Kinetics of superoxide scavenging by dismutase enzymes and manganese mimics determined by electron spin resonance.

    PubMed Central

    Gray, B; Carmichael, A J

    1992-01-01

    This study presents an e.s.r. assay for superoxide dismutase (SOD). Enzymic reactions were studied in which Cu,Zn-SOD, Mn-SOD and Fe-SOD each competed with the spin trap 5,5-dimethyl-1-pyrroline 1-oxide (DMPO) for superoxide anion (O2-) at pH 7.8 O2- from dissolved KO2 (potassium superoxide) in dimethyl sulphoxide was added directly to the enzyme solutions containing DMPO. The results show that, in this competition reaction system, the kinetics of the reactions between the enzymes and O2- follow a function y = f[( SOD]0.5). The rate constant, kSOD = 6.4 x 10(9) M-1. S-1, determined for Cu,Zn-SOD is approximately an order of magnitude larger than those for Mn-SOD and Fe-SOD. A comparative study of reported SOD mimics, including Mn2+, MnO2-desferrioxamine mesylate (Desferal) and MnO2-Desferal-ascorbate, was done. The results show that solutions of these complexes are approximately three orders of magnitude less active than Cu,Zn-SOD and approximately two orders of magnitude less active than Mn-SOD or Fe-SOD. The results also suggest that the reactivity toward O2- in solutions of these complexes originates from the Mn2+ present and not from the MnO2-Desferal complexes. PMID:1311175

  14. An alternative Ca2+-dependent mechanism of neuroprotection by the metalloporphyrin class of superoxide dismutase mimetics.

    PubMed

    Tauskela, Joseph S; Brunette, Eric; O'Reilly, Natasha; Mealing, Geoff; Comas, Tanya; Gendron, Tania F; Monette, Robert; Morley, Paul

    2005-10-01

    This study challenges the conventional view that metalloporphyrins protect cultured cortical neurons in models of cerebral ischemia by acting as intracellular catalytic antioxidants [superoxide dismutase (SOD) mimetics]. High SOD-active Mn(III)porphyrins meso-substituted with N,N'-dimethylimidazolium or N-alkylpyridinium groups did not protect neurons against oxygen-glucose deprivation (OGD), although lower SOD-active and -inactive para isomers protected against N-methyl-D-aspartate (NMDA) exposure. Mn(III)meso-tetrakis(4-benzoic acid)porphyrin (Mn(III)TBAP), as well as SOD-inactive metalloTBAPs and other phenyl ring- or beta-substituted metalloporphyrins that contained redox-insensitive metals, protected cultures against OGD and NMDA neurotoxicity. Crucially, neuroprotective metalloporphyrins suppressed OGD- or NMDA-induced rises in intracellular Ca2+ concentration in the same general rank order as observed for neuroprotection. Results from paraquat toxicity, intracellular fluorescence quenching, electrophysiology, mitochondrial Ca2+, and spontaneous synaptic activity experiments suggest a model in which metalloporphyrins, acting at the plasma membrane, protect neurons against OGD by suppressing postsynaptic NMDA receptor-mediated Ca2+ rises, thereby indirectly preventing accumulation of neurotoxic mitochondrial Ca2+ levels. Though neuroprotective in a manner not originally intended, SOD-inactive metalloporphyrins may represent promising therapeutic agents in diseases such as cerebral ischemia, in which Ca2+ toxicity is implicated. Conventional syntheses aimed at improving the catalytic antioxidant capability and/or intracellular access of metalloporphyrins may not yield improved efficacy in some disease models.

  15. Searching for convergent evolution in manganese superoxidase dismutase using hydrophobic cluster analysis

    PubMed Central

    Xiang, Heng; Zhang, Ruizhi; Li, Nengzhang; Vossbrinck, Charles R.

    2014-01-01

    There are numerous examples of convergent evolution in nature. Major ecological adaptations such as flight, loss of limbs in vertebrates, pesticide resistance, adaptation to a parasitic way of life, etc., have all evolved more than once, as seen by their analogous functions in separate taxa. But what about protein evolution? Does the environment have a strong enough influence on intracellular processes that enzymes and other functional proteins play, to evolve similar functional roles separately in different organisms? Manganese Superoxide Dismutase (MnSOD) is a manganesedependant metallo-enzyme which plays a crucial role in protecting cells from anti-oxidative stress by eliminating reactive (superoxide) oxygen species. It is a ubiquitous housekeeping enzyme found in nearly all organisms. In this study we compare phylogenies based on MnSOD protein sequences to those based on scores from Hydrophobic Cluster Analysis (HCA). We calculated HCA similarity values for each pair of taxa to obtain a pair-wise distance matrix. A UPGMA tree based on the HCA distance matrix and a common tree based on the primary protein sequence for MnSOD was constructed. Differences between these two trees within animals, enterobacteriaceae, planctomycetes and cyanobacteria are presented and cited as possible examples of convergence. We note that several residue changes result in changes in hydrophobicity at positions which apparently are under the effect of positive selection. PMID:25071412

  16. Subunit dissociation and metal binding by Escherichia coli apo-manganese superoxide dismutase.

    PubMed

    Whittaker, Mei M; Lerch, Thomas F; Kirillova, Olga; Chapman, Michael S; Whittaker, James W

    2011-01-15

    Metal binding by apo-manganese superoxide dismutase (apo-MnSOD) is essential for functional maturation of the enzyme. Previous studies have demonstrated that metal binding by apo-MnSOD is conformationally gated, requiring protein reorganization for the metal to bind. We have now solved the X-ray crystal structure of apo-MnSOD at 1.9Å resolution. The organization of active site residues is independent of the presence of the metal cofactor, demonstrating that protein itself templates the unusual metal coordination geometry. Electrophoretic analysis of mixtures of apo- and (Mn₂)-MnSOD, dye-conjugated protein, or C-terminal Strep-tag II fusion protein reveals a dynamic subunit exchange process associated with cooperative metal binding by the two subunits of the dimeric protein. In contrast, (S126C) (SS) apo-MnSOD, which contains an inter-subunit covalent disulfide-crosslink, exhibits anti-cooperative metal binding. The protein concentration dependence of metal uptake kinetics implies that protein dissociation is involved in metal binding by the wild type apo-protein, although other processes may also contribute to gating metal uptake. Protein concentration dependent small-zone size exclusion chromatography is consistent with apo-MnSOD dimer dissociation at low protein concentration (K(D)=1×10⁻⁵ M). Studies on metal uptake by apo-MnSOD in Escherichia coli cells show that the protein exhibits similar behavior in vivo and in vitro.

  17. Crystal structure and biochemical characterization of a manganese superoxide dismutase from Chaetomium thermophilum.

    PubMed

    Haikarainen, Teemu; Frioux, Clémence; Zhnag, Li-Qing; Li, Duo-Chuan; Papageorgiou, Anastassios C

    2014-02-01

    A manganese superoxide dismutase from the thermophilic fungus Chaetomium thermophilum (CtMnSOD) was expressed in Pichia pastoris and purified to homogeneity. Its optimal temperature was 60°C with approximately 75% of its activity retained after incubation at 70°C for 60min. Recombinant yeast cells carrying C. thermophilum mnsod gene exhibited higher stress resistance to salt and oxidative stress-inducing agents than control yeast cells. In an effort to provide structural insights, CtMnSOD was crystallized and its structure was determined at 2.0Å resolution. The overall architecture of CtMnSOD was found similar to other MnSODs with highest structural similarities obtained against a MnSOD from the thermotolerant fungus Aspergillus fumigatus. In order to explain its thermostability, structural and sequence analysis of CtMnSOD with other MnSODs was carried out. An increased number of charged residues and an increase in the number of intersubunit salt bridges and the Thr:Ser ratio were identified as potential reasons for the thermostability of CtMnSOD.

  18. Impact of Acinetobacter baumannii superoxide dismutase on motility, virulence, oxidative stress resistance and susceptibility to antibiotics.

    PubMed

    Heindorf, Magdalena; Kadari, Mahendar; Heider, Christine; Skiebe, Evelyn; Wilharm, Gottfried

    2014-01-01

    Acinetobacter baumannii is a Gram-negative bacterium appearing as an opportunistic pathogen in hospital settings. Superoxide dismutase (SOD) contributes to virulence in several pathogenic bacteria by detoxifying reactive oxygen species released in the course of host defense reactions. However, the biological role of SODs in A. baumannii has not yet been elucidated. Here, we inactivated in A. baumannii ATCC 17978 gene A1S_2343, encoding a putative SOD of the Fe-Mn type by transposon insertion, resulting in mutant ATCC 17978 sod2343::Km. The mutation was also introduced in two naturally competent A. baumannii isolates by transformation with chromosomal DNA derived from mutant ATCC 17978 sod2343::Km. We demonstrate that inactivation of sod2343 leads to significant motility defects in all three A. baumannii strains. The mutant strains were more susceptible to oxidative stress compared to their parental strains. Susceptibility to colistin and tetracycline was increased in all mutant strains while susceptibility of the mutants to gentamicin, levofloxacin and imipenem was strain-dependent. In the Galleria mellonella infection model the mutant strains were significantly attenuated. In conclusion, sod2343 plays an important role in motility, resistance to oxidative stress, susceptibility to antibiotics and virulence in A. baumannii.

  19. Impact of Acinetobacter baumannii Superoxide Dismutase on Motility, Virulence, Oxidative Stress Resistance and Susceptibility to Antibiotics

    PubMed Central

    Heider, Christine; Skiebe, Evelyn; Wilharm, Gottfried

    2014-01-01

    Acinetobacter baumannii is a Gram-negative bacterium appearing as an opportunistic pathogen in hospital settings. Superoxide dismutase (SOD) contributes to virulence in several pathogenic bacteria by detoxifying reactive oxygen species released in the course of host defense reactions. However, the biological role of SODs in A. baumannii has not yet been elucidated. Here, we inactivated in A. baumannii ATCC 17978 gene A1S_2343, encoding a putative SOD of the Fe-Mn type by transposon insertion, resulting in mutant ATCC 17978 sod2343::Km. The mutation was also introduced in two naturally competent A. baumannii isolates by transformation with chromosomal DNA derived from mutant ATCC 17978 sod2343::Km. We demonstrate that inactivation of sod2343 leads to significant motility defects in all three A. baumannii strains. The mutant strains were more susceptible to oxidative stress compared to their parental strains. Susceptibility to colistin and tetracycline was increased in all mutant strains while susceptibility of the mutants to gentamicin, levofloxacin and imipenem was strain-dependent. In the Galleria mellonella infection model the mutant strains were significantly attenuated. In conclusion, sod2343 plays an important role in motility, resistance to oxidative stress, susceptibility to antibiotics and virulence in A. baumannii. PMID:25000585

  20. Impaired fertilizing ability of superoxide dismutase 1-deficient mouse sperm during in vitro fertilization.

    PubMed

    Tsunoda, Satoshi; Kawano, Natsuko; Miyado, Kenji; Kimura, Naoko; Fujii, Junichi

    2012-11-01

    The oxidative modification of gametes by a reactive oxygen species is a major deleterious factor that decreases the successful rate of in vitro fertilization. Superoxide dismutase 1 (SOD1) plays a pivotal role in antioxidation by scavenging the superoxide anion, and its deficiency causes infertility in female mice, but the significance of the enzyme in male mice remains unclear. In the present study, we characterized Sod1(-/-) (Sod1-KO) male reproductive organs and compiled the first report of the impaired fertilizing ability of Sod1-KO sperm in in vitro fertilization. Insemination of wild-type oocytes with Sod1-KO sperm exhibited lower rates of fertility compared with insemination by wild-type sperm. The low fertilizing ability found for Sod1-KO sperm was partially rescued by reductant 2-mercaptoethanol, which suggested the oxidative modification of sperm components. The numbers of motile and progressive sperm decreased during the in vitro fertilization process, and a decline in ATP content and elevation in lipid peroxidation occurred in the Sod1-KO sperm in an incubation time-dependent manner. Tyrosine phosphorylation, which is a hallmark for sperm capacitation, was also impaired in the Sod1-KO sperm. These results collectively suggest that machinery involved in sperm capacitation and motility are vulnerable to oxidative damage during the in vitro fertilization process, which could increase the rate of inefficient fertilization.

  1. An iron-based cytosolic catalase and superoxide dismutase mimic complex.

    PubMed

    Horn, Adolfo; Parrilha, Gabrieli L; Melo, Karen V; Fernandes, Christiane; Horner, Manfredo; Visentin, Lorenzo do C; Santos, Jullyane A S; Santos, Monique S; Eleutherio, Elis C A; Pereira, Marcos D

    2010-02-15

    The development of metallodrugs with antioxidant activities is of importance as a way to protect organisms exposed to stressful conditions. Although iron chemistry in the presence of H(2)O(2) is usually associated with pro-oxidant activity, mainly via the Fenton reaction, we found that the mononuclear compound [Fe(HPClNOL)Cl(2)]NO(3) (1; C(15)H(18)Cl(3)FeN(4)O(4), a = 8.7751(3) A, b = 9.0778(4) A, c = 24.3869(10) A, beta = 93.370(2) degrees , monoclinic, P2(1)/c, Z = 4), containing the tripodal ligand 1-[bis(pyridin-2-ylmethyl)amino]-3-chloropropan-2-ol, decomposes hydrogen peroxide and superoxide anion in vitro as well as shows in vivo protection because it prevents the harmful effects promoted by H(2)O(2) on Saccharomyces cerevisiae cells, decreasing the level of lipid peroxidation. This protective effect was observed for wild-type cells, as well as for mutant cells, which do not present the antioxidant metalloenzymes catalase (Ctt1) or copper/zinc superoxide dismutase (Sod1).

  2. Modification and inactivation of Cu,Zn-superoxide dismutase by the lipid peroxidation product, acrolein

    PubMed Central

    Kang, Jung Hoon

    2013-01-01

    Acrolein is the most reactive aldehydic product of lipid peroxidation and is found to be elevated in the brain when oxidative stress is high. The effects of acrolein on the structure and function of human Cu,Zn-superoxide dismutase (SOD) were examined. When Cu,Zn-SOD was incubated with acrolein, the covalent crosslinking of the protein was increased, and the loss of enzymatic activity was increased in a dose-dependent manner. Reactive oxygen species (ROS) scavengers and copper chelators inhibited the acrolein-mediated Cu,Zn-SOD modification and the formation of carbonyl compound. The present study shows that ROS may play a critical role in acrolein-induced Cu,Zn-SOD modification and inactivation. When Cu,Zn-SOD that has been exposed to acrolein was subsequently analyzed by amino acid analysis, serine, histidine, arginine, threonine and lysine residues were particularly sensitive. It is suggested that the modification and inactivation of Cu,Zn-SOD by acrolein could be produced by more oxidative cell environments. [BMB Reports 2013; 46(11): 555-560] PMID:24152914

  3. Oral submucous fibrosis: A quantitative assessment of serum malondialdehyde, superoxide dismutase and correlation with clinical staging

    PubMed Central

    Bale, Ratnakar; Kattappagari, Kiran Kumar; Vidya, Desai; Vuddandi, Sivapradobh; Gummalla, Charani; Baddam, Venkata Ramana Reddy

    2017-01-01

    Background: Oral submucous fibrosis (OSMF) is a progressive disorder affecting the oral mucosa. OSMF predominantly seen in South-east Asian countries. There are some biochemicals parameters which are modify in oral submucous fibrosis; this alteration can be used as a tool for diseases progress and avert malignant transformation. Aims and Objectives: The aim of this study is to evaluate the serum malondialdehyde (malondialdehyde [MDA]), and Superoxide dismutase (SOD) in oral sub mucous fibrosis cases and compare clinical stages. Materials and Methods: Thirty cases of clinical and histopathological established oral submucous fibrosis and thirty cases of nonsymptomatic features of oral submucous fibrosis preferred as controls. Venous blood was collected and separation of serum for estimation of MDA and SOD levels was done using an ultraviolet spectrophotometer. Statistical Analysis: Data were analyzed using SPSS software using Student's t-test and Kruskal–Wallis ANOVA test. Results: Serum MDA levels were elevated when clinical staging increases, where as SOD levels were decreased when clinical stage increases when compared with control cases and it showed stastically significant. Conclusion: Estimation of serum MDA and SOD in patients with OSMF, we can assess the degree of oxidative damage of the disease. This can be used as an early diagnostic tool for preventing malignant transformation of oral submucous fibrosis. PMID:28479685

  4. Oral submucous fibrosis: A quantitative assessment of serum malondialdehyde, superoxide dismutase and correlation with clinical staging.

    PubMed

    Bale, Ratnakar; Kattappagari, Kiran Kumar; Vidya, Desai; Vuddandi, Sivapradobh; Gummalla, Charani; Baddam, Venkata Ramana Reddy

    2017-01-01

    Oral submucous fibrosis (OSMF) is a progressive disorder affecting the oral mucosa. OSMF predominantly seen in South-east Asian countries. There are some biochemicals parameters which are modify in oral submucous fibrosis; this alteration can be used as a tool for diseases progress and avert malignant transformation. The aim of this study is to evaluate the serum malondialdehyde (malondialdehyde [MDA]), and Superoxide dismutase (SOD) in oral sub mucous fibrosis cases and compare clinical stages. Thirty cases of clinical and histopathological established oral submucous fibrosis and thirty cases of nonsymptomatic features of oral submucous fibrosis preferred as controls. Venous blood was collected and separation of serum for estimation of MDA and SOD levels was done using an ultraviolet spectrophotometer. Data were analyzed using SPSS software using Student's t-test and Kruskal-Wallis ANOVA test. Serum MDA levels were elevated when clinical staging increases, where as SOD levels were decreased when clinical stage increases when compared with control cases and it showed stastically significant. Estimation of serum MDA and SOD in patients with OSMF, we can assess the degree of oxidative damage of the disease. This can be used as an early diagnostic tool for preventing malignant transformation of oral submucous fibrosis.

  5. Superoxide Dismutase in Arabidopsis: An Eclectic Enzyme Family with Disparate Regulation and Protein Localization1

    PubMed Central

    Kliebenstein, Daniel J.; Monde, Rita-Ann; Last, Robert L.

    1998-01-01

    A number of environmental stresses can lead to enhanced production of superoxide within plant tissues, and plants are believed to rely on the enzyme superoxide dismutase (SOD) to detoxify this reactive oxygen species. We have identified seven cDNAs and genes for SOD in Arabidopsis. These consist of three CuZnSODs (CSD1, CSD2, and CSD3), three FeSODs (FSD1, FSD2, and FSD3), and one MnSOD (MSD1). The chromosomal location of these seven SOD genes has been established. To study this enzyme family, antibodies were generated against five proteins: CSD1, CSD2, CSD3, FSD1, and MSD1. Using these antisera and nondenaturing-polyacrylamide gel electrophoresis enzyme assays, we identified protein and activity for two CuZnSODs and for FeSOD and MnSOD in Arabidopsis rosette tissue. Additionally, subcellular fractionation studies revealed the presence of CSD2 and FeSOD protein within Arabidopsis chloroplasts. The seven SOD mRNAs and the four proteins identified were differentially regulated in response to various light regimes, ozone fumigation, and ultraviolet-B irradiation. To our knowledge, this is the first report of a large-scale analysis of the regulation of multiple SOD proteins in a plant species. PMID:9765550

  6. Dietary copper supplements modulate aortic superoxide dismutase, nitric oxide and atherosclerosis

    PubMed Central

    Lamb, David J; Tickner, Michelle L; Hourani, Susanna M O; Ferns, Gordon A A

    2005-01-01

    The objective was to test the hypothesis that dietary copper inhibits atherosclerosis by inducing superoxide dismutase (SOD) and potentiating nitric oxide (NO). New Zealand White rabbits were fed either a cholesterol diet (n = 8) or a cholesterol diet containing 0.02% copper acetate (n = 8) for 13 weeks. We found that the intimal area was significantly smaller in the animals supplemented with copper (P < 0.005), although integrated plasma cholesterol levels were not significantly different. This was associated with a significant increase in aortic copper content (P < 0.05), SOD activity (P < 0.05) and Cu/Zn SOD mRNA (P < 0.05) and a significant decrease in nitrotyrosine content (P < 0.05). Furthermore, there was a positive correlation between aortic copper content and SOD activity (P < 0.005, R2 = 0.83) and a negative correlation between aortic superoxide dimutase activity and nitrotyrosine content (P < 0.005, R2 = 0.93). In organ bath experiments, the relaxation of precontracted carotid artery rings to calcium ionophore was greater in animals supplemented with copper. No difference in response to sodium nitroprusside was observed. These data suggest that in the cholesterol-fed rabbit, copper supplements inhibit the progression of atherosclerosis by increasing SOD expression, thereby reducing the interaction of NO with superoxide, and hence potentiating NO-mediated pathways that may protect against atherosclerosis. PMID:16045547

  7. Ultrastructural and chromosomal studies on manganese superoxide dismutase in malignant mesothelioma.

    PubMed

    Kinnula, Vuokko L; Torkkeli, Tuula; Kristo, Paula; Sormunen, Raija; Soini, Ylermi; Pääkkö, Paavo; Ollikainen, Tiina; Kahlos, Katriina; Hirvonen, Ari; Knuutila, Sakari

    2004-08-01

    Mesothelioma represents an aggressive tumor type with high resistance to all treatment modalities. Its pathogenesis is strongly associated with exposure to asbestos fibers and probably with free radicals. One of the most important free radical scavenging enzymes, mitochondrial manganese superoxide dismutase (MnSOD), has been shown to be elevated in mesothelioma (K. Kahlos et al., 1998, Am. J. Respir. Cell Mol. Biol. 18:570-580). In the present study, we could detect intense ultrastructural accumulation of MnSOD in the mitochondrial compartment of malignant mesothelioma cells. There was no association between the immunohistochemical reactivity and the most common and functional polymorphic variant of MnSOD, the Ala to Val amino acid change at 9 position (16th amino acid from the beginning of the signal sequence), in the 31 mesothelioma cases investigated. Comparative genomic hybridization and fluorescence in situ hybridization did not reveal any changes in chromosome 6, where the MnSOD gene is located. Sequencing of the MnSOD promoter region in four mesothelioma cell lines showed similar nucleotide variables in the malignant and nonmalignant cells. Therefore, the intense expression of MnSOD in the mitochondria of mesothelioma cells does not appear be associated with any major chromosomal alterations or the polymorphism of MnSOD gene. Association with oxidative/nitrosative stress in mesothelioma using nitrotyrosine immunostaining pointed to a tendency for more intense reactivity in those mesotheliomas with higher MnSOD expression (P = 0.069).

  8. Two functional variants of the superoxide dismutase genes in Finnish families with asthma.

    PubMed

    Kinnula, V L; Lehtonen, S; Koistinen, P; Kakko, S; Savolainen, M; Kere, J; Ollikainen, V; Laitinen, T

    2004-02-01

    Functional polymorphisms in the genes encoding superoxide dismutases (SOD)-that is, superoxide scavenging antioxidant enzymes-may play an important role in the development of inflammatory airway diseases such as asthma. The allele frequencies of two missense polymorphisms of SOD genes (Ala16Val in MnSOD (SOD2) and Arg213Gly in ECSOD (SOD3)) were investigated in Finnish patients with asthma and compared with family based controls. Both variants have been shown to be functionally interesting in the lung. The polymorphism at the exon-intron 3 boundary of a third SOD, CuZnSOD (SOD1), was also included in the analysis. None of the SOD genetic variants studied appeared to be major genetic regulators in the development of asthma. We could exclude all models of inheritance that increased the risk of asthma more than 1.2 fold for MnSOD*Val (frequency of allele 0.74 in the population) and more than 6.6 fold for ECSOD*Gly213 (frequency of allele 0.03 in the population) compared with non-carriers. For the intronic polymorphism in CuZnSOD, a relative risk of more than 3.3 (frequency of allele 0.10 in the population) could be excluded. It is highly unlikely that the functionally important genetic variants Ala16Val and Arg213Gly of SODs play a major role in the genetic susceptibility of asthma.

  9. Neurodegeneration, myocardial injury, and perinatal death in mitochondrial superoxide dismutase-deficient mice.

    PubMed Central

    Lebovitz, R M; Zhang, H; Vogel, H; Cartwright, J; Dionne, L; Lu, N; Huang, S; Matzuk, M M

    1996-01-01

    Manganese superoxide dismutase (SOD2) converts superoxide to oxygen plus hydrogen peroxide and serves as the primary defense against mitochondrial superoxide. Impaired SOD2 activity in humans has been associated with several chronic diseases, including ovarian cancer and type I diabetes, and SOD2 overexpression appears to suppress malignancy in cultured cells. We have produced a line of SOD2 knockout mice (SOD2m1BCM/SOD2m1BCM) that survive up to 3 weeks of age and exhibit several novel pathologic phenotypes including severe anemia, degeneration of neurons in the basal ganglia and brainstem, and progressive motor disturbances characterized by weakness, rapid fatigue, and circling behavior. In addition, SOD2m1BCM/SOD2m1BCM mice older than 7 days exhibit extensive mitochondrial injury within degenerating neurons and cardiac myocytes. Approximately 10% of SOD2m1BCM/SOD2m1BCM mice exhibit markedly enlarged and dilated hearts. These observations indicate that SOD2 deficiency causes increased susceptibility to oxidative mitochondrial injury in central nervous system neurons, cardiac myocytes, and other metabolically active tissues after postnatal exposure to ambient oxygen concentrations. Our SOD2-deficient mice differ from a recently described model in which homozygotes die within the first 5 days of life with severe cardiomyopathy and do not exhibit motor disturbances, central nervous system injury, or ultrastructural evidence of mitochondrial injury. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8790408

  10. Heat-stable chloroplastic Cu/Zn superoxide dismutase in Chenopodium murale.

    PubMed

    Khanna-Chopra, Renu; Sabarinath, S

    2004-08-06

    Chenopodium murale is a weed species having wide adaptation to different climatic regimes and experiences a temperature range of 5-45 degrees C during its life span. Higher temperatures may result in heat stress, which induces higher ROS production leading to oxidative stress in the plant. Superoxide dismutase enzyme (SOD, EC.1.15.1.1) is ubiquitous, being widely distributed among O(2)(-) consuming organisms and is the first line of defense against oxidative stress. In this study, we have characterized the thermostability of the SOD isozymes from C. murale in vitro. The leaf protein extracts, thylakoidal and stromal fractions were subjected to elevated temperatures ranging from 50 degrees C to boiling and analyzed for activity and isoform pattern of SOD. Out of six SOD isoforms, SOD V showed stability even after boiling the extract for 10min. Under high temperature treatment (>60 degrees C) there was an appearance of a new SOD band with higher electrophoretic mobility. The inhibitor studies and subcellular analysis revealed that the SOD V isoform was a chloroplastic Cu/Zn SOD. The stromal Cu/Zn SOD (SOD V) was more stable than the co-migrating thylakoidal isozyme at 80 degrees C and boiling for 10min. Hence, we report an unusual, constitutive thermostable chloroplastic Cu/Zn SOD from C. murale, which may contribute towards its heat tolerance.

  11. Effects of cadmium on growth and superoxide dismutase activity of the marine microalga Tetraselmis gracilis (Prasinophyceae)

    SciTech Connect

    Okamoto, O.K.; Asano, C.S.; Aidar, E.; Colepicolo, P.

    1996-02-01

    Marine planktonic algae are frequently exposed to metallic contaminants. Because heavy metals can be assimilated and accumulated by algal cells, they can then be transferred to higher trophic levels of food chains. We studied the effects of cadmium on protein production and the growth of the marine prasinophyte Tetraselmis gracilis (Kylin) Butcher. By means of toxicological assays, we estimated the LC{sub 50} of cadmium as 3.2 ppm and 1.8 ppm after 48 h and 96 h of exposure to this heavy metal, respectively. The growth of curves and survival percentages of cell cultures in the presence of cadmium were determined, and a proportional reduction of both parameters with increasing metal concentrations of cadmium, T. gracilis contained high levels of superoxide dismutase (SOD) activity, one of the main enzymes of the cell`s antioxidant defense mechanism. Under these growth conditions, total SOD activity in crude extracts was increased by 41% (at 1.5 ppm) and 107% (at 3.0 ppm). Assays of SOD activity in nondenaturing polyacrylamide gels also showed a similar induction by cadmium. These results show that cadmium has potentially toxic properties since it significantly inhibited the growth of T. gracilis at low concentrations and promoted by induction of SOD activity, suggestive of an oxidative stress state. Besides being the first report of SOD in T. gracilis, this work describes experimental evidence of SOD induction by cadmium in this species. 56 refs., 4 figs., 1 tab.

  12. Environmental genomics reveals a functional chlorite dismutase in the nitrite-oxidizing bacterium 'Candidatus Nitrospira defluvii'.

    PubMed

    Maixner, Frank; Wagner, Michael; Lücker, Sebastian; Pelletier, Eric; Schmitz-Esser, Stephan; Hace, Karin; Spieck, Eva; Konrat, Robert; Le Paslier, Denis; Daims, Holger

    2008-11-01

    Nitrite-oxidizing bacteria of the genus Nitrospira are ubiquitous in natural ecosystems and also in wastewater treatment plants. Nitrospira are members of a distinct phylum, not closely related to other nitrifiers, and no genomic sequences from this genus have been available so far. Here we applied an environmental genomics approach to sequence and assemble a 137 kbp-long genome fragment of 'Candidatus Nitrospira defluvii', which had been enriched from activated sludge and belongs to Nitrospira sublineage I without isolated representatives. The annotation of this contig, which carried the 16S rRNA gene of N. defluvii, offered first insight into the genome of Nitrospira. Surprisingly, we found a gene similar to genes encoding chlorite dismutase (CLD), an enzyme degrading chlorite (ClO(2)(-)) to Cl(-) and O(2). To date, CLDs with high catalytic activity have been found only in perchlorate- and chlorate-reducing bacteria but not in nitrifiers. Heterologous expression in E. coli followed by enzymatic tests confirmed that this gene of Nitrospira encodes a highly active CLD, which is also expressed in situ by Nitrospira, indicating that this nitrite oxidizer might be involved in the bioremediation of perchlorate and chlorite. Phylogenetic analyses showed that CLD and related proteins are widely distributed among the Bacteria and Archaea, and indicated that this enzyme family appeared relatively early in evolution, has been subject to functional diversification and might play yet unknown roles in microbial metabolism.

  13. Aortic ascorbic acid, trace elements, and superoxide dismutase activity in human aneurysmal and occlusive disease.

    PubMed

    Dubick, M A; Hunter, G C; Casey, S M; Keen, C L

    1987-02-01

    Altered trace elements and ascorbic acid metabolism have been implicated in the pathogenesis of atherosclerotic cardiovascular disease. However, their role in the disease process, or the effect of atherosclerosis on their tissue levels within plaque, is poorly understood. The present study analyzes the concentrations of Fe, Cu, Zn, and Mn, and ascorbic acid and superoxide dismutase (SOD) activity in tissue samples from 29 patients with abdominal aortic aneurysms (AAA) and 14 patients with atherosclerotic occlusive disease (AOD). It was observed that the Fe and Mn concentrations in AAA and AOD tissue were higher than the levels in nondiseased control aorta, whereas Cu and Zn levels in AAA and AOD tissue were similar to the levels in controls. The Zn:Cu ratio was significantly lower in the AAA tissue in comparison to both AOD and control tissue. In addition, AAA and AOD tissue had low ascorbic acid levels and low Cu,Zn-SOD activity with Cu,Zn-SOD:Mn-SOD ratios of 0.27 and 0.19, respectively, compared to a ratio of 3.20 in control aorta. These data indicate that aorta affected by aneurysms and occlusive disease have altered trace element and ascorbic acid concentrations, as well as low Cu,Zn-SOD activity. Although these observations do not directly support the hypothesis that AAA is associated with aortic Cu deficiency they do suggest a role for oxygen radicals or increased lipid peroxidation in occlusive and aneurysmal disease of the aorta.

  14. Aortic ascorbic acid, trace elements, and superoxide dismutase activity in human aneurysmal and occlusive disease

    SciTech Connect

    Dubick, M.A.; Hunter, G.C.; Casey, S.M.; Keen, C.L.

    1987-02-01

    Altered trace elements and ascorbic acid metabolism have been implicated in the pathogenesis of atherosclerotic cardiovascular disease. However, their role in the disease process, or the effect of atherosclerosis on their tissue levels within plaque, is poorly understood. The presence study analyzes the concentrations of Fe, Cu, Zn, and Mn, and ascorbic acid and superoxide dismutase (SOD) activity in tissue samples from 29 patients with abdominal aortic aneurysms (AAA) and 14 patients with atherosclerotic occlusive disease (AOD). It was observed that the Fe and Mn concentrations in AAA and AOD tissue were higher than the levels in nondiseased control aorta, whereas Cu and Zn levels in AAA and AOD tissue were similar to the levels in controls. The Zn:Cu ratio was significantly lower in the AAA tissue in comparison to both AOD and control tissue. In addition, AAA and AOD tissue had low ascorbic acid levels and low Cu, Zn-SOD activity with Cu,Zn-SOD:Mn-SOD ratios of 0.27 and 0.19, respectively, compared to a ratio of 3.20 in control aorta. These data indicate that aorta affected by aneurysms and occlusive disease have altered trace element and ascorbic acid concentrations, as well as low Cu,Zn-SOD activity. Although these observations do not directly support the hypothesis that AAA is associated with aortic Cu deficiency they do suggest a role for oxygen radicals or increased lipid peroxidation in occlusive and aneurysmal disease of the aorta.

  15. Kinetic Analysis of the Metal Binding Mechanism of Escherichia coli Manganese Superoxide Dismutase

    PubMed Central

    Whittaker, Mei M.; Mizuno, Kazunori; Bächinger, Hans Peter; Whittaker, James W.

    2006-01-01

    The acquisition of a catalytic metal cofactor is an essential step in the maturation of every metalloenzyme, including manganese superoxide dismutase (MnSOD). In this study, we have taken advantage of the quenching of intrinsic protein fluorescence by bound metal ions to continuously monitor the metallation reaction of Escherichia coli MnSOD in vitro, permitting a detailed kinetic characterization of the uptake mechanism. Apo-MnSOD metallation kinetics are “gated”, zero order in metal ion for both the native Mn2+ and a nonnative metal ion (Co2+) used as a spectroscopic probe to provide greater sensitivity to metal binding. Cobalt-binding time courses measured over a range of temperatures (35–50°C) reveal two exponential kinetic processes (fast and slow phases) associated with metal binding. The amplitude of the fast phase increases rapidly as the temperature is raised, reflecting the fraction of Apo-MnSOD in an “open” conformation, and its temperature dependence allows thermodynamic parameters to be estimated for the “closed” to “open” conformational transition. The sensitivity of the metallated protein to exogenously added chelator decreases progressively with time, consistent with annealing of an initially formed metalloprotein complex (kanneal = 0.4 min−1). A domain-separation mechanism is proposed for metal uptake by apo-MnSOD. PMID:16258041

  16. Differential expression of superoxide dismutase genes in aphid-stressed maize (Zea mays L.) seedlings.

    PubMed

    Sytykiewicz, Hubert

    2014-01-01

    The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB) in seedling leaves of the Zea mays L. Tasty Sweet (susceptible) and Ambrozja (relatively resistant) cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid) or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid). Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl) radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9). However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4) or 24 h (sod9) post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants.

  17. A Printed Superoxide Dismutase Coated Electrode for the Study of Macrophage Oxidative Burst

    PubMed Central

    Hiatt, Leslie A.; McKenzie, Jennifer R.; Deravi, Leila F.; Harry, Reese S.; Wright, David W.; Cliffel, David E.

    2012-01-01

    The miniaturization of electrochemical sensors allows for the minimally invasive and cost effective examination of cellular responses at a high efficacy rate. In this work, an ink-jet printed superoxide dismutase electrode was designed, characterized, and utilized as a novel microfluidic device to examine the metabolic response of a 2D layer of macrophage cells. Since superoxide production is one of the first indicators of oxidative burst, macrophage cells were exposed within the microfluidic device to phorbol myristate acetate (PMA), a known promoter of oxidative burst, and the production of superoxide was measured. A 46 ± 19% increase in current was measured over a 30 min time period demonstrating successful detection of sustained macrophage oxidative burst, which corresponds to an increase in the superoxide production rate by 9 ± 3 attomoles/cell/sec. Linear sweep voltammetry was utilized to show the selectivity of this sensor for superoxide over hydrogen peroxide. This novel controllable microfluidic system can be used to study the impact of multiple effectors from a large number of bacteria or other invaders along a 2D layer of macrophages, providing an in vitro platform for improved electrochemical studies of metabolic responses. PMID:22257735

  18. Effect of Nanoparticles on Modified Screen Printed Inhibition Superoxide Dismutase Electrodes for Aluminum.

    PubMed

    Barquero-Quirós, Miriam; Arcos-Martínez, María Julia

    2016-09-26

    A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme superoxide dismutase has been developed. The oxidation signal of epinephrine substrate was affected by the presence of Al(III) ions leading to a decrease in its amperometric current. The immobilization of the enzyme was performed with glutaraldehyde on screen-printed carbon electrodes modifiedwith tetrathiofulvalene (TTF) and different types ofnanoparticles. Nanoparticles of gold, platinum, rhodium and palladium were deposited on screen printed carbon electrodes by means of two electrochemical procedures. Nanoparticles were characterized trough scanning electronic microscopy, X-rays fluorescence, and atomic force microscopy. Palladium nanoparticles showed lower atomic force microscopy parameters and higher slope of aluminum calibration curves and were selected to perform sensor validation. The developed biosensor has a detection limit of 2.0 ± 0.2 μM for Al(III), with a reproducibility of 7.9% (n = 5). Recovery of standard reference material spiked to buffer solution was 103.8% with a relative standard deviation of 4.8% (n = 5). Recovery of tap water spiked with the standard reference material was 100.5 with a relative standard deviation of 3.4% (n = 3). The study of interfering ions has also been carried out.

  19. Molecular Characterization of a Recombinant Manganese Superoxide Dismutase from Lactococcus lactis M4

    PubMed Central

    Chor Leow, Thean; Foo, Hooi Ling; Abdul Rahim, Raha

    2014-01-01

    A superoxide dismutase (SOD) gene of Lactococcus lactis M4 was cloned and expressed in a prokaryotic system. Sequence analysis revealed an open reading frame of 621 bp which codes for 206 amino acid residues. Expression of sodA under T7 promoter exhibited a specific activity of 4967 U/mg when induced with 1 mM of isopropyl-β-D-thiogalactopyranoside. The recombinant SOD was purified to homogeneity by immobilised metal affinity chromatography and Superose 12 gel filtration chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blot analyses of the recombinant SOD detected a molecular mass of approximately 27 kDa. However, the SOD was in dimer form as revealed by gel filtration chromatography. The purified recombinant enzyme had a pI of 4.5 and exhibited maximal activity at 25°C and pH 7.2. It was stable up to 45°C. The insensitivity of this lactococcal SOD to cyanide and hydrogen peroxide established that it was a MnSOD. Although it has 98% homology to SOD of L. lactis IL1403, this is the first elucidated structure of lactococcal SOD revealing active sites containing the catalytic manganese coordinated by four ligands (H-27, H-82, D-168, and H-172). PMID:24592392

  20. Therapeutic value of oral supplementation with melon superoxide dismutase and wheat gliadin combination.

    PubMed

    Romao, Susana

    2015-03-01

    Dietary antioxidant supplementation has been popular in Western countries. Various supplements have been developed in recent years, and research has been gathered from both animal and clinical research trials. In this review, the therapeutic value of oral administration of a combination of melon superoxide dismutase (SOD) and a vegetable polymer (gliadin) is evaluated. Critical examination of the effects of SOD-gliadin supplementation is carried out, with an emphasis on its impact on oxidative stress levels and on endogenous antioxidant pathways. Overall analysis of peer-reviewed published data suggests that intake of SOD-gliadin might have advantageous health effects. These conclusions are dependent on the condition or pathology under consideration. In general, the authors, who analyzed SOD-gliadin supplementation, support the use of SOD-gliadin supplementation as a complementary treatment rather than a therapeutic treatment. To further clarify the importance of dietary SOD-gliadin administration, additional large-scale clinical trials are recommended. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Copper–zinc superoxide dismutase-mediated redox regulation of bortezomib resistance in multiple myeloma

    PubMed Central

    Salem, Kelley; McCormick, Michael L.; Wendlandt, Erik; Zhan, Fenghuang; Goel, Apollina

    2014-01-01

    Multiple myeloma (MM) is an incurable B-cell malignancy. The proteasome inhibitor bortezomib (BTZ) is a frontline MM drug; however, intrinsic or acquired resistance to BTZ remains a clinical hurdle. As BTZ induces oxidative stress in MM cells, we queried if altered redox homeostasis promotes BTZ resistance. In primary human MM samples, increased gene expression of copper–zinc superoxide dismutase (CuZnSOD or SOD1) correlated with cancer progression, high-risk disease, and adverse overall and event-free survival outcomes. As an in vitro model, human MM cell lines (MM.1S, 8226, U266) and the BTZ-resistant (BR) lines (MM.1SBR, 8226BR) were utilized to determine the role of antioxidants in intrinsic or acquired BTZ-resistance. An up-regulation of CuZnSOD, glutathione peroxidase-1 (GPx-1), and glutathione (GSH) were associated with BTZ resistance and attenuated prooxidant production by BTZ. Enforced overexpression of SOD1 induced BTZ resistance and pharmacological inhibition of CuZnSOD with disulfiram (DSF) augmented BTZ cytotoxicity in both BTZ-sensitive and BTZ-resistant cell lines. Our data validates CuZnSOD as a novel therapeutic target in MM. We propose DSF as an adjuvant to BTZ in MM that is expected to overcome intrinsic and acquired BTZ resistance as well as augment BTZ cytotoxicity. PMID:25485927

  2. Purification of Helicobacter pylori superoxide dismutase and cloning and sequencing of the gene.

    PubMed Central

    Spiegelhalder, C; Gerstenecker, B; Kersten, A; Schiltz, E; Kist, M

    1993-01-01

    The superoxide dismutase (SOD) of Helicobacter pylori, a pathogenic bacterium which colonizes the gastric mucosa, evoking a marked inflammatory response, was purified and characterized, and the N-terminal amino acid sequence was determined. The enzyme consists of two identical subunits each with an apparent molecular weight of 24,000. Analysis of the primary structure and inhibition studies revealed that H. pylori possesses a typical procaryotic iron-containing enzyme. No other isoenzymes could be detected. Indirect gold immunostaining of H. pylori SOD with a polyclonal antibody directed against the iron-containing SOD of Escherichia coli showed a surface-associated localization of the enzyme. The H. pylori SOD gene was cloned by functional complementation of a SOD-deficient E. coli mutant. Sequencing and alignment revealed striking homology to the following facultative intracellular human pathogens: Listeria ivanovii, Listeria monocytogenes, Coxiella burnetti, Porphyromonas gingivalis, Legionella pneumophila, and Entamoeba histolytica. An open reading frame of 642 bp encoding 214 amino acids was determined. There was no leader sequence detectable. Cloning of the H. pylori SOD gene is one of the prerequisites to investigation of its pathophysiological role in the defense against antimicrobial mechanisms of polymorphonuclear granulocytes. Images PMID:8225605

  3. Topical Application of TAT-Superoxide Dismutase in Acupoints LI 20 on Allergic Rhinitis

    PubMed Central

    Zheng, Mei-Feng; Zhou, Jian-Wu; Ke, Li-Jing

    2016-01-01

    Reactive oxygen species are products of cellular metabolism and assigned important roles in biomedical science as deleterious factors in pathologies. In fact, some studies have shown that the therapeutic benefits of taking antioxidants were limited and the potential for therapeutic intervention remains unclear. New evidences showed that ROS have some ability of intercellular transportation. For treating allergic rhinitis, as a novel intracellular superoxide quencher, TAT-SOD applied to acupoints LI 20 instead of directly to nasal cavity can be used to test that. TTA group apply TAT-SOD cream prepared by adding purified TAT-SOD to the vehicle cream to acupoints LI 20, while placebo group used the vehicle cream instead. TTN group applied the same TAT-SOD cream directly to nasal cavity three times daily. Symptom scores were recorded at baseline and days 8 and 15. For the overall efficacy rate, TTA group was 81.0%, while placebo group was 5.9% and TTN was 0%. Malondialdehyde levels decreased observably in TTA group, and superoxide dismutase, catalase, and glutathione peroxidase levels remained basically unaffected. Enzymatic scavenging of the intracellular superoxide at acupoints LI 20 proved to be effective in treating allergic rhinitis, while no improvement was observed with the placebo group and TTN group. PMID:28119757

  4. Cystatin C protects neuronal cells against mutant copper-zinc superoxide dismutase-mediated toxicity

    PubMed Central

    Watanabe, S; Hayakawa, T; Wakasugi, K; Yamanaka, K

    2014-01-01

    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the selective and progressive loss of motor neurons. Cystatin C (CysC), an endogenous cysteine protease inhibitor, is a major protein component of Bunina bodies observed in the spinal motor neurons of sporadic ALS and is decreased in the cerebrospinal fluid of ALS patients. Despite prominent deposition of CysC in ALS, the roles of CysC in the central nervous system remain unknown. Here, we identified the neuroprotective activity of CysC against ALS-linked mutant Cu/Zn-superoxide dismutase (SOD1)-mediated toxicity. We found that exogenously added CysC protected neuronal cells including primary cultured motor neurons. Moreover, the neuroprotective property of CysC was dependent on the coordinated activation of two distinct pathways: autophagy induction through AMPK-mTOR pathway and inhibition of cathepsin B. Furthermore, exogenously added CysC was transduced into the cells and aggregated in the cytosol under oxidative stress conditions, implying a relationship between the neuroprotective activity of CysC and Bunina body formation. These data suggest CysC is an endogenous neuroprotective agent and targeting CysC in motor neurons may provide a novel therapeutic strategy for ALS. PMID:25356866

  5. A Superoxide Dismutase Maquette That Reproduces the Spectroscopic and Functional Properties of the Metalloenzyme

    SciTech Connect

    Shearer,J.; Long, L.

    2006-01-01

    Described herein is a nickel superoxide dismutase (NiSOD) maquette ([Ni(SOD{sup M1})]) based on the first 12 residues from the N-terminal sequence of Streptomyces coelicolor NiSOD. The apopeptide (SOD{sup M1}) was prepared by standard solid-phase Fmoc peptide synthesis. SOD{sup M1} will readily coordinate Ni{sup II} in a 1:1 ratio in slightly basic aqueous sodium phosphate buffer (0.1 M; pH = 7.2) forming a lightly colored beige/pink solution. Unlike NiSOD, which is isolated as a 1:1 mixture of oxidized (Ni{sup III}) and reduced (Ni{sup II}) forms, [Ni(SODM1)] can only be isolated in the NiII oxidation state. The UV/vis, X-ray absorption, and CD spectra of [Ni{sup II}(SOD{sup M1})] correspond well with those reported for the reduced form of NiSOD. Despite the fact that [Ni{sup III}(SOD{sup M1})] is not isolable, [Ni(SOD{sup M1})] has an appropriate redox potential to act as an SOD (E{sub 1/2} = 0.70(2) V vs. Ag/AgCl) and in fact will catalytically disproportionate >40 000 equiv of KO{sub 2}.

  6. Novel autoantibody to Cu/Zn superoxide dismutase in patients with localized scleroderma.

    PubMed

    Nagai, Masaki; Hasegawa, Minoru; Takehara, Kazuhiko; Sato, Shinichi

    2004-03-01

    Abnormal production of reactive oxygen species (ROS) induces tissue damage and superoxide dismutase (SOD) that converts superoxide radicals to hydrogen peroxide functions as defense against ROS. Cu/Zn SOD administration has been shown to be effective for various fibrotic conditions by inhibiting the fibrogenic effects of ROS. We hypothesized that autoimmune background in localized scleroderma induced anti-Cu/Zn SOD autoantibodies that inhibited SOD activity and thereby contributed to fibrosis by increasing ROS. ELISA using human purified Cu/Zn SOD revealed that IgG or IgM anti-Cu/Zn SOD Ab was detected in the serum of 89% of localized scleroderma patients, especially 100% of patients with generalized morphea, the severest form of localized scleroderma, but was positive only in the serum of less than 15% of patients with other autoimmune disorders, including systemic sclerosis, systemic lupus erythematosus, dermatomyositis, and autoimmune bullous disorders. The immunoblotting analysis confirmed the presence of IgG anti-Cu/Zn SOD Ab in sera from localized scleroderma patients. Remarkably, anti-Cu/Zn SOD autoantibody could inhibit Cu/Zn SOD enzymatic activity. Collectively, these results indicate that anti-Cu/Zn SOD Ab is a novel, major autoantibody in localized scleroderma, and also suggest that the autoantibody may play a role in the development of fibrosis by directly inhibiting SOD activity.

  7. Fluorescence assay for monitoring Zn-deficient superoxide dismutase in vitro

    NASA Astrophysics Data System (ADS)

    Martyshkin, D. V.; Mirov, S. B.; Zhuang, Y.-X.; Crow, J. P.; Ermilov, V.; Beckman, J. S.

    2003-11-01

    A method has been developed for selective detection of the zinc-deficient form of Cu, Zn superoxide dismutase (SOD1) in vitro. Zinc-deficient SOD1 mutants have been implicated in the death of motor neurons leading in amyotrophic lateral sclerosis (ALS or Lou Gerhig's disease). Thus, this method may have applicability for detecting zinc-deficient SOD1 mutants in human ALS patients samples as well as in a transgenic mouse model of ALS and in cultured motor neurons. We determined previously that structural analogs of 1,10 phenanthroline, which react specifically with Cu(I), react with the active Cu(I) of SOD1 when zinc is absent, but not when zinc is also bound, as evidenced by the fact that the reaction is inhibited by pretreatment of the enzyme with zinc. We report herein that bathocuproine, or its water-soluble derivative bathocuproine disulfonate, react with zinc-deficient SOD1 to form a complex which fluoresces at 734 nm when excited at 482 nm. Fluorescent intensity is concentration dependent, thus we propose to use fluorescent confocal microscopy to measure intracellular levels of zinc-deficient SOD1 in situ.

  8. Structural basis of heme binding in the Cu,Zn superoxide dismutase from Haemophilus ducreyi.

    PubMed

    Töro, Imre; Petrutz, Cristiana; Pacello, Francesca; D'Orazio, Melania; Battistoni, Andrea; Djinović-Carugo, Kristina

    2009-02-20

    The Cu,Zn superoxide dismutase from Haemophilus ducreyi is characterized by the unique ability to bind heme at its dimer interface. Here we report the high-resolution crystal structures of this protein in the heme-loaded (holo) and heme-free (apo) forms. Heme is asymmetrically bound between the two enzyme subunits, where heme iron is coordinated by two histidine residues, His64 and His 124, provided by the two subunits. Moreover, the binding of heme to the protein is ensured by stabilizing contacts between the prosthetic group and a limited number of other residues, most of which are not present in other bacterial enzyme variants. We show that the introduction of only three mutations at the dimer interface of the enzyme from Haemophilus parainfluenzae, a closely related bacterial species, is sufficient to induce heme-binding ability by this enzyme variant. Heme binding does not alter protein activity. Moreover, the binding of the prosthetic group does not induce any significant structural perturbation at the subunit level and requires only limited local structural rearrangements that widen the cleft at the dimer interface and cause a limited shift in the relative orientation between the subunits. The presence of a preformed heme-binding pocket and the significant solvent exposure of the cofactor to the solvent are compatible with the suggested protective role of the enzyme against heme toxicity or with its involvement in heme trafficking in the periplasmic space.

  9. Trichloroethylene exposure aggravates behavioral abnormalities in mice that are deficient in superoxide dismutase.

    PubMed

    Otsuki, Noriyuki; Homma, Takujiro; Fujiwara, Hiroki; Kaneko, Kenya; Hozumi, Yasukazu; Shichiri, Mototada; Takashima, Mizuki; Ito, Junitsu; Konno, Tasuku; Kurahashi, Toshihiro; Yoshida, Yasukazu; Goto, Kaoru; Fujii, Satoshi; Fujii, Junichi

    2016-08-01

    Trichloroethylene (TCE) has been implicated as a causative agent for Parkinson's disease (PD). The administration of TCE to rodents induces neurotoxicity associated with dopaminergic neuron death, and evidence suggests that oxidative stress as a major player in the progression of PD. Here we report on TCE-induced behavioral abnormality in mice that are deficient in superoxide dismutase 1 (SOD1). Wild-type (WT) and SOD1-deficient (Sod1(-/-)) mice were intraperitoneally administered TCE (500 mg/kg) over a period of 4 weeks. Although the TCE-administrated Sod1(-/-) mice showed marked abnormal motor behavior, no significant differences were observed among the experimental groups by biochemical and histopathological analyses. However, treating mouse neuroblastoma-derived NB2a cells with TCE resulted in the down regulation of the SOD1 protein and elevated oxidative stress under conditions where SOD1 production was suppressed. Taken together, these data indicate that SOD1 plays a pivotal role in protecting motor neuron function against TCE toxicity.

  10. Superoxide dismutase activity in mesocarp tissue from divergent Cucumis melo L. genotypes.

    PubMed

    Lester, Gene E; Jifon, John L; Crosby, Kevin M

    2009-09-01

    Muskmelons (Cucumis melo L.) are well-known as excellent sources of several vitamins, minerals and non-enzymatic antioxidant phytochemicals such as vitamin C and pro-vitamin A. Less well-studied is their potential role as sources of enzymatic antioxidants such as superoxide dismutase (SOD), which have been associated with enhanced reactive oxygen species scavenging capacity in some muskmelon fruits. In this study, we investigated the variability in SOD activities among diverse advanced breeding lines and commercial muskmelon cultivars grown in two different soil types-clay or sandy loam. Specific and total SOD activities varied significantly among the genotypes (P

  11. Cellular distribution of copper to superoxide dismutase involves scaffolding by membranes

    PubMed Central

    Pope, Christopher R.; De Feo, Christopher J.; Unger, Vinzenz M.

    2013-01-01

    Efficient delivery of copper ions to specific intracellular targets requires copper chaperones that acquire metal cargo through unknown mechanisms. Here we demonstrate that the human and yeast copper chaperones (CCS) for superoxide dismutase 1 (SOD1), long thought to exclusively reside in the cytosol and mitochondrial intermembrane space, can engage negatively charged bilayers through a positively charged lipid-binding interface. The significance of this membrane-binding interface is established through SOD1 activity and genetic complementation studies in Saccharomyces cerevisiae, showing that recruitment of CCS to the membrane is required for activation of SOD1. Moreover, we show that a CCS:SOD1 complex binds to bilayers in vitro and that CCS can interact with human high affinity copper transporter 1. Shifting current paradigms, we propose that CCS-dependent copper acquisition and distribution largely occur at membrane interfaces and that this emerging role of the bilayer may reflect a general mechanistic aspect of cellular transition metal ion acquisition. PMID:24297923

  12. Oxygen and the copper chaperone CCS regulate posttranslational activation of Cu,Zn superoxide dismutase.

    PubMed

    Brown, Nina M; Torres, Andrew S; Doan, Peter E; O'Halloran, Thomas V

    2004-04-13

    Oxidative stress leads to the up-regulation of many antioxidant enzymes including Cu,Zn superoxide dismutase (SOD1) via transcriptional mechanisms; however, few examples of posttranslational regulation are known. The copper chaperone for SOD1 (CCS) is involved in physiological SOD1 activation, and its primary function is thought to be delivery of copper to the enzyme. Data presented here are consistent with a previously uncharacterized function for CCS in the SOD1 pathway, namely mediating enzyme activation in response to increases in oxygen tension. Activity assays with pure proteins and cell extracts reveal that O(2) (or superoxide) is required for activation of SOD1 by CCS. Dose-response studies with a translational blocking agent demonstrate that the cellular oxidative response to O(2) is multitiered: existing apo-pools of SOD1 are activated by CCS in the early response, followed by increasing expression of SOD1 protein with persistent oxidative stress. This CCS function provides oxidant-responsive posttranslational regulation of SOD1 activity and may be relevant to a wide array of physiological stresses that involve a sudden elevation of oxygen availability.

  13. Finding Inhibitors of Mutant Superoxide Dismutase-1 for Amyotrophic Lateral Sclerosis Therapy from Traditional Chinese Medicine

    PubMed Central

    Huang, Hung-Jin; Chang, Tung-Ti; Chen, Hsin-Yi; Chen, Calvin Yu-Chian

    2014-01-01

    Superoxide dismutase type 1 (SOD1) mutations cause protein aggregation and decrease protein stability, which are linked to amyotrophic lateral sclerosis (ALS) disease. This research utilizes the world's largest traditional Chinese medicine (TCM) database to search novel inhibitors of mutant SOD1, and molecular dynamics (MD) simulations were used to analyze the stability of protein that interacted with docked ligands. Docking results show that hesperidin and 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside (THSG) have high affinity to mutant SOD1 and then dopamine. For MD simulation analysis, hesperidin and THSG displayed similar value of RMSD with dopamine, and the migration analysis reveals stable fluctuation at the end of MD simulation time. Interestingly, distance between the protein and ligand has distinct difference, and hesperidin changes the position from initial binding site to the other place. In flexibility of residues analysis, the secondary structure among all complexes does not change, indicating that the structure are not affect ligand binding. The binding poses of hesperidin and THSG are similar to dopamine after molecular simulation. Our result indicated that hesperidin and THSG might be potential lead compound to design inhibitors of mutant SOD1 for ALS therapy. PMID:24963318

  14. Brain-Specific Superoxide Dismutase 2 Deficiency Causes Perinatal Death with Spongiform Encephalopathy in Mice.

    PubMed

    Izuo, Naotaka; Nojiri, Hidetoshi; Uchiyama, Satoshi; Noda, Yoshihiro; Kawakami, Satoru; Kojima, Shuji; Sasaki, Toru; Shirasawa, Takuji; Shimizu, Takahiko

    2015-01-01

    Oxidative stress is believed to greatly contribute to the pathogenesis of various diseases, including neurodegeneration. Impairment of mitochondrial energy production and increased mitochondrial oxidative damage are considered early pathological events that lead to neurodegeneration. Manganese superoxide dismutase (Mn-SOD, SOD2) is a mitochondrial antioxidant enzyme that converts toxic superoxide to hydrogen peroxide. To investigate the pathological role of mitochondrial oxidative stress in the central nervous system, we generated brain-specific SOD2-deficient mice (B-Sod2(-/-)) using nestin-Cre-loxp system. B-Sod2(-/-) showed perinatal death, along with severe growth retardation. Interestingly, these mice exhibited spongiform neurodegeneration in motor cortex, hippocampus, and brainstem, accompanied by gliosis. In addition, the mutant mice had markedly decreased mitochondrial complex II activity, but not complex I or IV, in the brain based on enzyme histochemistry. Furthermore, brain lipid peroxidation was significantly increased in the B-Sod2(-/-), without any compensatory alterations of the activities of other antioxidative enzymes, such as catalase or glutathione peroxidase. These results suggest that SOD2 protects the neural system from oxidative stress in the perinatal stage and is essential for infant survival and central neural function in mice.

  15. In vitro inhibition of superoxide anion production and superoxide dismutase activity by zinc in human spermatozoa.

    PubMed

    Gavella, M; Lipovac, V; Vucić, M; Sverko, V

    1999-08-01

    The in vitro effect of zinc on superoxide anion (O2-) generation and on SOD-like activity in spermatozoa of infertile men was investigated. The formation of superoxide anion was stimulated by NADPH and the level of superoxide anion was measured by the reduction of ferricytochrome c. Both Percoll-isolated (n = 14) and washed spermatozoa (n = 14) exposed to 1 mmol/L zinc (60 min, 37 degrees C), released less (p < 0.002 and p < 0.04, respectively) superoxide anions than did zinc-untreated spermatozoa. These results implicate a possible role for zinc as a scavenger of excessive superoxide anions produced by defective spermatozoa in semen after ejaculation. Additionally, zinc was found to dose-dependently inhibit superoxide dismutase (SOD)-like activity of spermatozoa in vitro. The inhibition of SOD-like activity by an equal concentration of zinc (1 mmol/L) was less pronounced in oligospermic (p < 0.002; n = 16) and asthenozoospermic (p < 0.0005; n = 20) than in normozoospermic samples (p < 0.0001; n = 20). This differential ability of zinc to inhibit SOD-like activity may be relevant to the physiological function of spermatozoa in fertilization. The evidence that zinc may elicit an inhibition of both superoxide anion production and SOD-like activity in human spermatozoa, indicate the existence of novel, zinc-related mechanism(s) involved in the oxidative events occurring after ejaculation, with a possible modulatory effect on germ cell function.

  16. Superoxide dismutase activity and gene expression levels in Saudi women with recurrent miscarriage

    PubMed Central

    GHNEIM, HAZEM K.; AL-SHEIKH, YAZEED A.; ALSHEBLY, MASHAEL M.; ABOUL-SOUD, MOURAD A. M.

    2016-01-01

    The antioxidant activities of superoxide dismutase 1 (SOD1) and SOD2, as well as the levels of the oxidant superoxide anion (SOA) and the micronutrients zinc (Zn), copper (Cu) and manganese (Mn), were assayed in plasma, whole blood and placental tissue of non-pregnant (NP), healthy pregnant (HP) women and recurrent miscarriage (RM) patients. The results showed that SOD1 and SOD2 activities and the levels of Zn, Cu and Mn in plasma and whole blood of HP women were slightly, but significantly lower, and even more significantly decreased in RM patients compared to those observed in NP women (P<0.05 and P<0.0001, respectively). Additionally, whereas plasma SOD1 and SOD2 activities and Zn, Cu and Mn levels were significantly lower in RM patients, those of whole blood and placental tissue were significantly lower when compared to HP women (P<0.001 and P<0.0001, respectively). Concurrently, there were consistent increases of equal magnitude and statistical significance in SOA levels in all the assayed samples as identified by a comparison between the subjects. The findings thus supported oxidative metabolism and excessive reactive oxygen species generation. The resultant oxidative stress, identified in whole blood and placental tissues of RM patients, may have been a primary cause of RM. Dietary supplementation of Zn, Cu and Mn may be beneficial to these patients pre- and post-conception. PMID:26821085

  17. Superoxide dismutase: A possible protective agent against sunscald in tomatoes (lycopersicon esculentum mill.).

    PubMed

    Rabinowitch, H D; Sklan, D

    1980-03-01

    Superoxide dismutase (SOD, EC 1.15.1.1) was concentrated from mature-green tomato fruits by gel chromatography. The enzyme was inhibited by cyanide but not by chloroform-ethanol, and appears to contain zinc and lesser amounts of copper. SOD-activity levels were high in immature green fruits, declined to a minimum in the mature-green and breaker stages known to be most susceptible to sunscald damage, increased again until the fruits were pink, and finally decreased through the red-ripe and overripe stages to the level of the mature-green fruit. When tolerance to sunscald damage was induced in mature-green fruits by controlled temperature treatment and samples of the fruits were challenged at various times during this process with a combined heat-and-light treatment known to cause sunscald, SOD activity was found to be inversely related to the susceptibility of the fruit to sunscald damage. It is suggested that superoxide is involved in sunscald injury to tomatoes and that tolerance is acquired through increases in SOD activity. Possibly SOD acts as a general protective agent against photodynamic damage to green tissues in plants that have become conditioned as the result of normal diurnal temperature fluctuations.

  18. Stable Mn(III) porphyrins mimic superoxide dismutase in vitro and substitute for it in vivo.

    PubMed

    Faulkner, K M; Liochev, S I; Fridovich, I

    1994-09-23

    Several manganic porphyrins, with substituents on the methine bridge carbons, were prepared and examined for stability, redox behavior, catalysis of the dismutation of superoxide radical (O2-), and the ability to protect a superoxide dismutase (SOD)-null strain of E. coli against dissolved oxygen and a SOD-competent strain against paraquat. All of the compounds tested exhibited reversible redox behavior and were stable to EDTA in both the oxidized and reduced states, and several were able to catalyze the dismutation of O2- with the rate constants of approximately 10(7) M-1 s-1. The marked protective effects of some of these compounds exceeded that which could be anticipated on the basis of such rate constants. The tetrakis (1-methyl-4-pyridyl) compound was reduced enzymatically at the expense of NADPH and nonenzymatically by GSH and was kept in the reduced state within E. coli. Since the rate constant for reoxidation of the reduced form by O2- is 4 x 10(9) M-1 s-1, it appears that this compound acts in vivo as an NADPH/GSH:O2- oxidoreductase rather than as an SOD mimic. Its ability to facilitate aerobic growth of the SOD-null strain can be explained on this basis.

  19. Identification of a developmentally regulated iron superoxide dismutase of Trypanosoma brucei.

    PubMed Central

    Kabiri, M; Steverding, D

    2001-01-01

    An iron superoxide dismutase (FeSOD) gene of the protozoan parasite Trypanosoma brucei has been cloned and its gene product functionally characterized. The gene encodes a protein of 198 residues which shows 80% identity with FeSODs from other trypanosomatids. Inhibitor studies with purified recombinant FeSOD expressed in Escherichia coli confirmed that the enzyme is an iron-containing SOD. The FeSOD is developmentally regulated in the parasite, expression being lowest in the cell-cycle-arrested, short stumpy bloodstream forms. Differential expression of the FeSOD protein contrasts with only minor quantitative changes in the FeSOD mRNA, indicating post-transcriptional regulation of the enzyme. As the level of FeSOD increases during differentiation of cell-cycle-arrested short stumpy into dividing procyclic forms, it is suggested that the enzyme is only required in proliferating stages of the parasite for the elimination of superoxide radicals which are released during the generation of the iron-tyrosyl free-radical centre in the small subunit of ribonucleotide reductase. PMID:11696005

  20. Activity of superoxide dismutase isoenzymes in the bone marrow of irradiated rabbits.

    PubMed

    Kovárová, H; Stoklasová, A; Ledvina, M

    1992-01-01

    The activities of total, Cu,Zn- and Mn-containing superoxide dismutase were studied in the bone marrow of whole-body irradiated rabbits with 6.0 Gy or 24.0 Gy with local shielding. Irradiation with 6.0 Gy depressed the activities of total and Cu,Zn-SOD on the 8th and 15th days, whereas the activity of Mn-SOD did not change. The exposure to 24.0 Gy with local shielding of head and abdominal region decreased Cu,Zn-SOD activity on the 4th and 60th days after irradiation, Mn-SOD activity was lower nearly at all time intervals investigated. The exposure to 24.0 Gy with shielding of whole body without head region increased markedly Cu,Zn-SOD activity, whereas Mn-SOD activity was diminished on the 8th and 15th days after irradiation in comparison with control group. Mn-SOD activity (U per 10(6) of bone marrow cells) was increased at early time intervals, the changes were not so striking after irradiation of rabbits with 24.0 Gy with shielding of whole body without head region.

  1. Investigation of the Highly Active Manganese Superoxide Dismutase from Saccharomyces cerevisiae

    PubMed Central

    Barnese, Kevin; Sheng, Yuewei; Stich, Troy A.; Gralla, Edith B.; Britt, R. David

    2010-01-01

    Manganese superoxide dismutase (MnSOD) from different species differs in its efficiency in removing high concentrations of superoxide (O2−), due to different levels of product inhibition. Human MnSOD exhibits a substantially higher level of product inhibition than the MnSODs from bacteria. In order to investigate the mechanism of product inhibition and whether it is a feature common to eukaryotic MnSODs, we purified MnSOD from Saccharomyces cerevisiae (ScMnSOD). It was a tetramer with 0.6 equivalents of Mn per monomer. The catalytic activity of ScMnSOD was investigated by pulse radiolysis and compared with human and two bacterial (Escherichia coli and Deinococcus radiodurans) MnSODs. To our surprise, ScMnSOD most efficiently facilitates removal of high concentrations of O2− among these MnSODs. The gating value k2/k3 that characterizes the level of product inhibition scales as ScMnSOD > D. radiodurans MnSOD > E. coli MnSOD > human MnSOD. While most MnSODs rest as the oxidized form, ScMnSOD was isolated in the Mn2+ oxidation state as revealed by its optical and electron paramagnetic resonance spectra. This finding poses the possibility of elucidating the origin of product inhibition by comparing human MnSOD with ScMnSOD PMID:20726524

  2. The Resistance of Esophageal Adenocarcinoma to Bile Salt Insult is Associated with Manganese Superoxide Dismutase Expression

    PubMed Central

    Schiffman, Suzanne C.; Li, Yan; Xiao, Deyi; Li, Xuanshe; Aiyer, Harini S.; Martin, Robert C.G.

    2010-01-01

    BACKGROUND Bile acids are implicated as etiologic agents in esophageal cancer. We sought to analyze the impact of bile acid exposure on esophageal epithelial cells, Barrett’s metaplastic cells (BE), esophageal adenocarcinoma cells (EAC) and esophageal squamous carcinoma cell (ESC). We sought to determine if cellular resistance is related to manganese superoxide dismutase expression. METHODS Cells were exposed to sodium choleate (CA), sodium deoxycholate (DCA), sodium glycocholate (GCA), sodium taurocholate (TCA) or a 1:1 mixture (MIX) of reagents at concentrations ranging 0.2 – 0.8 mM. Cell viability was evaluated by MTT assay. MnSOD expression was analyzed by Western Blot. Statistical analysis was performed using SPSS 17.0. RESULTS Bile salt exposure inhibited cell viability in esophageal squamous cells in time and growth dependent manner. There was a 50% decrease in cell viability from four to 24 hours. BE, EAC and ESC cell lines were more resistant to bile insult. In untreated cell lines, MnSOD expression was significantly decreased in EAC and ESC cell lines as compared to esophageal squamous epithelial cells and BE cells (p=0.002). Exposure of ESC cells to bile salt increased MnSOD expression. DISCUSSION The confirmation of the role of ROS and bile acids in esophageal carcinogenesis has interesting implications for chemoprevention in patients with reflux esophagitis and Barrett’s esophagus. Further studies are necessary to assess the preventative role of antioxidant supplementation PMID:20638682

  3. Investigation of the Highly Active Manganese Superoxide Dismutase from Saccharomyces cerevisiae

    SciTech Connect

    Cabelli, D.E.; Barnese, K.; Sheng, Y.; Stich, T.A.; Gralla, E.B.; Britt, R.D.; Valentine, J.S.

    2010-09-15

    Manganese superoxide dismutase (MnSOD) from different species differs in its efficiency in removing high concentrations of superoxide (O{sub 2}{sup -}), due to different levels of product inhibition. Human MnSOD exhibits a substantially higher level of product inhibition than the MnSODs from bacteria. In order to investigate the mechanism of product inhibition and whether it is a feature common to eukaryotic MnSODs, we purified MnSOD from Saccharomyces cerevisiae (ScMnSOD). It was a tetramer with 0.6 equiv of Mn per monomer. The catalytic activity of ScMnSOD was investigated by pulse radiolysis and compared with human and two bacterial (Escherichia coli and Deinococcus radiodurans) MnSODs. To our surprise, ScMnSOD most efficiently facilitates removal of high concentrations of O{sub 2}{sup -} among these MnSODs. The gating value k{sub 2}/k{sub 3} that characterizes the level of product inhibition scales as ScMnSOD > D. radiodurans MnSOD > E. coli MnSOD > human MnSOD. While most MnSODs rest as the oxidized form, ScMnSOD was isolated in the Mn{sup 2+} oxidation state as revealed by its optical and electron paramagnetic resonance spectra. This finding poses the possibility of elucidating the origin of product inhibition by comparing human MnSOD with ScMnSOD.

  4. Serum Superoxide Dismutase Is Associated with Vascular Structure and Function in Hypertensive and Diabetic Patients

    PubMed Central

    Gómez-Marcos, Manuel A.; Blázquez-Medela, Ana M.; Gamella-Pozuelo, Luis; Recio-Rodriguez, José I.; García-Ortiz, Luis; Martínez-Salgado, Carlos

    2016-01-01

    Oxidative stress is associated with cardiac and vascular defects leading to hypertension and atherosclerosis, being superoxide dismutase (SOD) one of the main intracellular antioxidant defence mechanisms. Although several parameters of vascular function and structure have a predictive value for cardiovascular morbidity-mortality in hypertensive patients, there are no studies on the involvement of SOD serum levels with these vascular parameters. Thus, we assessed if SOD serum levels are correlated with parameters of vascular function and structure and with cardiovascular risk in hypertensive and type 2 diabetic patients. We enrolled 255 consecutive hypertensive and diabetic patients and 52 nondiabetic and nonhypertensive controls. SOD levels were measured with an enzyme-linked immunosorbent assay kit. Vascular function and structure were evaluated by pulse wave velocity, augmentation index, ambulatory arterial stiffness index, and carotid intima-media thickness. We detected negative correlations between SOD and pressure wave velocity, peripheral and central augmentation index and ambulatory arterial stiffness index, pulse pressure, and plasma HDL-cholesterol, as well as positive correlations between SOD and plasma uric acid and triglycerides. Our study shows that SOD is a marker of cardiovascular alterations in hypertensive and diabetic patients, since changes in its serum levels are correlated with alterations in vascular structure and function. PMID:26635913

  5. Expression of human extracellular superoxide dismutase in Chinese hamster ovary cells and characterization of the product

    SciTech Connect

    Tibell, L.; Hjalmarsson, K.; Edlund, T.; Skogman, G.; Engstroem, A.; Marklund, S.L.

    1987-10-01

    A complementary DNA clone from human placenta, encoding human extracellular superoxide dismutase, has recently been isolated and characterized. An expression plasmid, based on the EC-SOD complementary DNA, was transfected into Chinese hamster ovary cells (CHO-K1). The transfected cells secreted human EC-SOD to the culture medium. The secreted recombinant (r) EC-SOD was isolated in high yield with a three-step procedure beginning with immobilized monoclonal anti-EC-SOD antibodies. The properties of the rEC-SOD were compared with native (n) EC-SOD isolated from human umbilical cords. The specific activities and amino-terminal amino acid sequences were identical. The amino acid compositions were virtually identical and very similar to the composition deduced from the complementary DNA sequence. Both rEC-SOD and nEC-SOD contained 4 Cu and 4 Zn atoms per molecule, and the presence of Zn in EC-SOD is thus now established. The rEC-SOD produced is type C, since its affinity for heparin-Sepharose was identical to that of nEC-SOD type C. Both enzymes bound to concanavalin A, lentil lectin, and wheat germ lectin and are thus glycoproteins. rEC-SOD and nEC-SOD seem to have the same subunit structure and composition as analyzed by polyacrylamide gel electrophoresis and gel chromatography.

  6. [Correlation between follicle levels of superoxide dismutase and oocyte quality, fertilization rates and embryo development].

    PubMed

    Kably Ambe, Alberto; Ruiz Anguas, Julián; Carballo Mondragón, Esperanza; Corona de Lau, Clara; Karchmer Krivitsky, Samuel

    2004-07-01

    The intraovarian oxidative balance is important during oocyte development, and fertilization. It has been proposed that one of the most important enzymes in the follicle is the superoxide dismutase (SOD). To correlate levels and percentage of SOD activity in follicular liquid with quality, fertilization and embryo development in a group of patients submitted to in vitro fertilization. We obtained 120 follicular liquids from oocytes aspirated in 41 patients during an IVF program and then we followed the development of each oocyte separately. We measured the activity and concentration of SOD in the follicular liquid, and we evaluated the following variables: quality and maturity in the oocytes, as well as fertilization rate, segmentation rate and pregnancy. The statistical analysis was made with ANOVA test and Pearson test. In the analysis of the results, we observed a higher percentage of activity in the SOD in oocytes with good quality (3 and 4) in comparison with poor quality oocyte (1 and 2) (89 and 82% vs 75 and 61% p<0.05). We observed higher concentrations and activity of SOD in oocytes with a good fertilization rate and segmentation (p<0.05). When we analyzed the variables in function of pregnancy, we observed that the embryos that were transferred and developed pregnancy had higher concentrations and activity of SOD than embryos that did not develop pregnancy. Elevated levels and high percentage in the activity of SOD are associated with a better quality in the oocyte, and a good embryo development, influenced by the oxidative balance.

  7. [Cloning and analysis of promoter of pig copper zinc superoxide dismutase gene (CuZnSOD)].

    PubMed

    Shi, Yuan; Chen, Wei; Zeng, Yongqing; Zhu, Honglei; Xu, Zhenggang; Zhang, Zhe; Yang, Yun; Zhang, Tianyang

    2014-02-01

    Pig copper zinc superoxide dismutase (CuZnSOD) is an important antioxidant enzyme. Some studies focused on the function of CuZnSOD gene, but the transcriptional regulation of the CuZnSOD gene is not yet fully elucidated. Therefore, the aims of the study were to determine the core promoter region and to explore its mechanism of transcriptional regulation. The 853 bp DNA sequence of 5'-flanking promoter was amplified by performing PCR. A series of CuZnSOD promoter fragments with gradually truncated 5'-end were produced by nested PCR and inserted into pGL3-Basic vector. The activities of the promoters were measured by the dual-luciferase assay system after transient transfection into the NIH/3T3 cells. The results demonstrated that there were 2 potential transcription start sites in the regions from initiation codon to -87 bp and -266 bp, respectively. The region from -383 bp to +67 bp in CuZnSOD gene promoter showed higher activity than other regions, and further deletion analysis demonstrated that the region from -75 bp to -32 bp contained an essential promoter sequence for pig CuZnSOD gene transcription. In addition, several potential transcription factor binding sites were predicted with bioinformatics method. These results suggest that these transcription factor binding sites may be involved in the transcriptional regulation of CuZnSOD gene.

  8. Extracellular Superoxide Dismutase Inhibits Innate Immune Responses and Clearance of an Intracellular Bacterial Infection

    PubMed Central

    Break, Timothy J.; Jun, Sujung; Indramohan, Mohanalaxmi; Carr, Karen D.; Sieve, Amy N.; Dory, Ladislav; Berg, Rance E.

    2012-01-01

    Reactive oxygen and nitrogen species (ROS/RNS) play important roles during immune responses to bacterial pathogens. Extracellular superoxide dismutase (ecSOD) regulates extracellular concentrations of ROS/RNS and contributes to tissue protection during inflammatory insults. The participation of ecSOD in immune responses seems therefore intuitive, yet is poorly understood. In the present study, we utilized mice with varying levels of ecSOD activity to investigate the involvement of this enzyme in immune responses against Listeria monocytogenes. Surprisingly, our data demonstrate that, despite enhanced neutrophil recruitment to the liver, ecSOD activity negatively impacted host survival and bacterial clearance. Increased ecSOD activity was accompanied by decreased co-localization of neutrophils with bacteria, as well as increased neutrophil apoptosis, which reduced overall and neutrophil-specific TNF-α production. Liver leukocytes from mice lacking ecSOD produced equivalent nitric oxide (NO·) when compared to mice expressing ecSOD. However, during infection, there were higher levels of peroxynitrite (NO3·−) in livers from mice lacking ecSOD compared to mice expressing ecSOD. Neutrophil depletion studies revealed that high levels of ecSOD activity resulted in neutrophils with limited protective capacity, whereas neutrophils from mice lacking ecSOD provided superior protection compared to neutrophils from wild-type mice. Taken together, our data demonstrate that ecSOD activity reduces innate immune responses during bacterial infection and provides a potential target for therapeutic intervention. PMID:22393157

  9. Modification and inactivation of Cu,Zn-superoxide dismutase by the lipid peroxidation product, acrolein.

    PubMed

    Kang, Jung Hoon

    2013-11-01

    Acrolein is the most reactive aldehydic product of lipid peroxidation and is found to be elevated in the brain when oxidative stress is high. The effects of acrolein on the structure and function of human Cu,Zn-superoxide dismutase (SOD) were examined. When Cu,Zn-SOD was incubated with acrolein, the covalent crosslinking of the protein was increased, and the loss of enzymatic activity was increased in a dose-dependent manner. Reactive oxygen species (ROS) scavengers and copper chelators inhibited the acrolein-mediated Cu,Zn-SOD modification and the formation of carbonyl compound. The present study shows that ROS may play a critical role in acrolein-induced Cu,Zn-SOD modification and inactivation. When Cu,Zn-SOD that has been exposed to acrolein was subsequently analyzed by amino acid analysis, serine, histidine, arginine, threonine and lysine residues were particularly sensitive. It is suggested that the modification and inactivation of Cu,Zn-SOD by acrolein could be produced by more oxidative cell environments.

  10. Scavenging of superoxide anions by lecithinized superoxide dismutase in HL-60 cells.

    PubMed

    Ishihara, Tsutomu; Shibui, Misaki; Hoshi, Takaya; Mizushima, Tohru

    2016-01-01

    Superoxide dismutase covalently bound to four lecithin molecules (PC-SOD) has been found to have beneficial therapeutic effects in animal models of various diseases. However, the mechanism underlying these improved therapeutic effects has not yet been elucidated. It has previously been shown that PC-SOD localizes on the plasma membrane and in the lysosomes of cells. In this study, we evaluated the superoxide anion-scavenging activity of PC-SOD in HL-60 human promyelocytic leukemia cells. Compared to SOD, PC-SOD had only 17% scavenging activity in cell-free systems. Nevertheless, by analyzing enzyme activities in cell suspensions containing PC-SOD or SOD, PC-SOD and SOD showed almost equal activity for scavenging extracellular superoxide anions produced by HL-60 cells. Furthermore, the activity for scavenging extracellular superoxide anions increased with increased amount of PC-SOD on the plasma membrane. Moreover, PC-SOD exhibited no obvious inhibitory effect on the scavenging of intracellular superoxide anions. These results suggested that the association of PC-SOD with the plasma membrane plays a key role in its beneficial therapeutic effects. Thus, this finding may provide a rationale for selecting target diseases for PC-SOD treatment.

  11. Mitochondrial superoxide dismutase deficiency accelerates chronological aging in the fission yeast Schizosaccharomyces pombe.

    PubMed

    Ogata, Toshiya; Senoo, Takanori; Kawano, Shinji; Ikeda, Shogo

    2016-01-01

    A mitochondrial superoxide dismutase (SOD2) is the first line of antioxidant defense against mitochondrial superoxide. Even though the involvement of SOD2 in lifespan has been studied extensively in several organisms, characterization of the aging process has not been performed for the sod2 mutant (sod2Δ) of a prominent model Schizosaccharomyces pombe. In this study, we measured the chronological lifespan of sod2Δ cells by their ability to survive in long-term culture. SOD2 deficiency drastically decreased cell viability in the stationary phase. The mutation frequency of nuclear DNA in sod2Δ was elevated in the stationary phase, and cellular proteins and nuclear DNA were extensively degraded, concurrent with cell death. The sod2 gene in wild-type cells could be induced by an increase in endogenous oxidative stresses, after which, SOD2 activity was substantially elevated during the stationary phase. Culture in a lower glucose concentration (calorie restriction) prominently extended the sod2Δ lifespan. Therefore, S. pombe SOD2 plays a critical role in longevity through its upregulation in the non-dividing phase.

  12. High-efficiency entrapment of superoxide dismutase into cationic liposomes containing synthetic aminoglycolipid.

    PubMed

    Aoki, H; Fujita, M; Sun, C; Fuji, K; Miyajima, K

    1997-08-01

    A monofatty acid ester of glucosamine (PGlcN) was synthesized to provide liposomal membranes with a positive charge, and the trapping efficiency of negatively charged substances (superoxide dismutases, SODs) into cationic liposomes containing PGlcN or stearylamine (SA) prepared by various methods was compared to find the most efficient trapping methods. We demonstrated that cationic liposomes, which were prepared in a buffer of low ionic strength containing sorbitol by a simple hydration method, could entrap a large amount of negatively charged SODs which retained their activity, as compared with cationic liposomes prepared in a buffer of high ionic strength. We also showed a reverse-phase evaporation method entrapped a large amount of SODs. However, SODs were inactivated during the preparation; therefore, this method was not suitable to entrap the enzyme. Freeze-thaw method induced the formation of cationic liposomes which were smaller than extruded liposomes and could entrap the SODs in a buffer of low ionic strength. Dehydration-rehydration method with a buffer of low ionic strength also entrapped a large amount of SODs, indicating that the integrity of liposomes was lost in the lipid bilayer after freeze-drying and the SODs were entrapped in the reconstruction of liposomes during rehydration. These findings showed that the hydration method based on electrostatic attraction with a buffer of low ionic strength was simple and the most effective for entrapping SODs without loss of their activity.

  13. Effects of histone acetylation on superoxide dismutase 1 gene expression in the pathogenesis of senile cataract

    PubMed Central

    Rong, Xianfang; Qiu, Xiaodi; Jiang, Yongxiang; Li, Dan; Xu, Jie; Zhang, Yinglei; Lu, Yi

    2016-01-01

    Histone acetylation plays key roles in gene expression, but its effects on superoxide dismutase 1 (SOD1) expression in senile cataract remains unknown. To address this problem, the study was to investigate the influence of histone acetylation on SOD1 expression and its effects in the pathogenesis of senile cataract. Senile cataract was classified into three types—nuclear cataract (NC), cortical cataract (CC), and posterior subcapsular cataract (SC)—using the Lens Opacities Classification System III. In senile cataracts, SOD1 expression decreased significantly. Both H3 and H4 were deacetylated at −600 bp of the SOD1 promoter of cataract lenses, and hypoacetylated at −1500, −1200, and −900 bp. In hypoacetylated histones, the hypoacetylation pattern differed among the cataracts. In vitro, anacardic acid (AA) significantly reduced H3 and H4 acetylation at the SOD1 promoter, decreased protein expression, and induced cataract formation in rabbits. AA also inhibited HLEC viability and increased cell apoptosis. In contrast, trichostatin A (TSA) was able to efficaciously stop AA’s effects on both rabbit lenses and HLECs. Decreased histone acetylation at the SOD1 promoter is associated with declined SOD1 expression in senile cataracts. Histone acetylation plays an essential role in the regulation of SOD1 expression and in the pathogenesis of senile cataracts. PMID:27703255

  14. Oversynthesis of riboflavin in the yeast Pichia guilliermondii is accompanied by reduced catalase and superoxide dismutases activities.

    PubMed

    Prokopiv, Tetyana M; Fedorovych, Dariya V; Boretsky, Yuriy R; Sibirny, Andriy A

    2013-01-01

    Iron deficiency causes oversynthesis of riboflavin in several yeast species, known as flavinogenic yeasts. Under iron deprivation conditions, Pichia guilliermondii cells increase production of riboflavin and malondialdehyde and the formation of protein carbonyl groups, which reflect increased intracellular content of reactive oxygen species. In this study, we found that P. guilliermondii iron deprived cells showed dramatically decreased catalase and superoxide dismutase activities. Previously reported mutations rib80, rib81, and hit1, which affect repression of riboflavin synthesis and iron accumulation by iron ions, caused similar drops in activities of the mentioned enzymes. These findings could explain the previously described development of oxidative stress in iron deprived or mutated P. guilliermondii cells that overproduce riboflavin. Similar decrease in superoxide dismutase activities was observed in iron deprived cells in the non-flavinogenic yeast Saccharomyces cerevisiae.

  15. [Role of catalase and superoxide dismutase in the yeast Saccharomyces cerevisiae response to hydrogen peroxide in exponential phase of growth].

    PubMed

    Baĭliak, M M; Semchyshyn, H M; Lushchak, V I

    2006-01-01

    The role of catalase and superoxide dismutase (SOD) in response of the yeast Saccharomyces cerevisiae to oxidative stress induced by hydrogen peroxide in the middle-exponential phase has been investigated. It was shown that cell survival is significantly decreased after yeast exposure to hydrogen peroxide in the strains defective in cytosolic or peroxisomal catalases. Treatment of the wild-type cells with 0.5 mM H2O2 for 30 min causes an increase in the activity of catalase and superoxide dismutase, but the effect was not observed in all strains investigated. It was also shown that hydrogen peroxide leads to an increase in the activities of both catalases and Cu,Zn-containing SOD. The effect was cancelled by cycloheximide, an inhibitor of protein synthesis.

  16. The influence of cigarette smoking on blood and salivary super oxide dismutase enzyme levels among smokers and nonsmokers-A cross sectional study.

    PubMed

    Jenifer, Haziel Diana; Bhola, Sarthak; Kalburgi, Veena; Warad, Shivaraj; Kokatnur, Vijayalaxmi M

    2015-04-01

    To determine the influence of smoking on blood and salivary superoxide dismutase enzyme levels among smokers, and to demonstrate the significant alterations in the levels of superoxide dismutase in association with patient age, periodontal disease status, smoking duration, and smoking frequency. This study also aimed to evaluate the use of saliva as a biological fluid for disease diagnosis. Ninety males aged 25-56 years were selected and included 30 smokers, 30 nonsmokers with chronic periodontitis, and 30 healthy controls. Clinical parameters such as the gingival index, pocket depth, and clinical attachment loss were recorded. Blood and saliva samples were collected and superoxide dismutase enzyme levels were analyzed using spectrophotometric assay. Superoxide dismutase enzyme levels in the blood and saliva were significantly higher in smokers than in nonsmokers and the controls (p < 0.05). A significant correlation existed between superoxide dismutase levels and clinical parameters. There was also a significant positive correlation between blood and salivary superoxide dismutase levels among the three groups. Systemic and local antioxidant status is affected by periodontal disease and by the impact of smoking. The increased blood and salivary superoxide dismutase enzyme levels in smokers may be an adaptive defense mechanism to counteract the increased reactive oxygen species production induced by smoking. This study emphasizes the importance of saliva as an easy noninvasive tool in diagnosing patients who are more prone to precancerous lesions and conditions, and its importance in patient education and motivation programs for smoking cessation.

  17. LC-MS/MS Analysis Unravels Deep Oxidation of Manganese Superoxide Dismutase in Kidney Cancer

    PubMed Central

    Zhao, Zuohui; Azadzoi, Kazem M.; Choi, Han-Pil; Jing, Ruirui; Lu, Xin; Li, Cuiling; Wang, Fengqin; Lu, Jiaju; Yang, Jing-Hua

    2017-01-01

    Manganese superoxide dismutase (MNSOD) is one of the major scavengers of reactive oxygen species (ROS) in mitochondria with pivotal regulatory role in ischemic disorders, inflammation and cancer. Here we report oxidative modification of MNSOD in human renal cell carcinoma (RCC) by the shotgun method using data-dependent liquid chromatography tandem mass spectrometry (LC-MS/MS). While 5816 and 5571 proteins were identified in cancer and adjacent tissues, respectively, 208 proteins were found to be up- or down-regulated (p < 0.05). Ontological category, interaction network and Western blotting suggested a close correlation between RCC-mediated proteins and oxidoreductases such as MNSOD. Markedly, oxidative modifications of MNSOD were identified at histidine (H54 and H55), tyrosine (Y58), tryptophan (W147, W149, W205 and W210) and asparagine (N206 and N209) residues additional to methionine. These oxidative insults were located at three hotspots near the hydrophobic pocket of the manganese binding site, of which the oxidation of Y58, W147 and W149 was up-regulated around three folds and the oxidation of H54 and H55 was detected in the cancer tissues only (p < 0.05). When normalized to MNSOD expression levels, relative MNSOD enzymatic activity was decreased in cancer tissues, suggesting impairment of MNSOD enzymatic activity in kidney cancer due to modifications. Thus, LC-MS/MS analysis revealed multiple oxidative modifications of MNSOD at different amino acid residues that might mediate the regulation of the superoxide radicals, mitochondrial ROS scavenging and MNSOD activity in kidney cancer. PMID:28165386

  18. Dimeric chlorite dismutase from the nitrogen-fixing cyanobacterium Cyanothece sp. PCC7425.

    PubMed

    Schaffner, Irene; Hofbauer, Stefan; Krutzler, Michael; Pirker, Katharina F; Bellei, Marzia; Stadlmayr, Gerhard; Mlynek, Georg; Djinovic-Carugo, Kristina; Battistuzzi, Gianantonio; Furtmüller, Paul G; Daims, Holger; Obinger, Christian

    2015-06-01

    It is demonstrated that cyanobacteria (both azotrophic and non-azotrophic) contain heme b oxidoreductases that can convert chlorite to chloride and molecular oxygen (incorrectly denominated chlorite 'dismutase', Cld). Beside the water-splitting manganese complex of photosystem II, this metalloenzyme is the second known enzyme that catalyses the formation of a covalent oxygen-oxygen bond. All cyanobacterial Clds have a truncated N-terminus and are dimeric (i.e. clade 2) proteins. As model protein, Cld from Cyanothece sp. PCC7425 (CCld) was recombinantly produced in Escherichia coli and shown to efficiently degrade chlorite with an activity optimum at pH 5.0 [kcat 1144 ± 23.8 s(-1), KM 162 ± 10.0 μM, catalytic efficiency (7.1 ± 0.6) × 10(6) M(-1) s(-1)]. The resting ferric high-spin axially symmetric heme enzyme has a standard reduction potential of the Fe(III)/Fe(II) couple of -126 ± 1.9 mV at pH 7.0. Cyanide mediates the formation of a low-spin complex with k(on)  = (1.6 ± 0.1) × 10(5) M(-1) s(-1) and k(off) = 1.4 ± 2.9 s(-1) (KD ∼ 8.6 μM). Both, thermal and chemical unfolding follows a non-two-state unfolding pathway with the first transition being related to the release of the prosthetic group. The obtained data are discussed with respect to known structure-function relationships of Clds. We ask for the physiological substrate and putative function of these O2 -producing proteins in (nitrogen-fixing) cyanobacteria. © 2015 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.

  19. Relationship between total superoxide dismutase activity with lipid peroxidation, dynamics and morphological parameters in canine semen.

    PubMed

    Cassani, Paula; Beconi, Martha T; O'Flaherty, Cristian

    2005-03-01

    There is a lack of information regarding biochemical studies on canine semen. The knowledge of canine sperm metabolism is important because this species has differences in fertility among males, but biochemical studies are not well developed in this species. Reactive oxygen species (ROS) are active molecules produced during the oxygen reduction that have been implicated in several deleterious effects on the function and viability of spermatozoa when they are produced at high concentrations. Peroxidation of the plasma membrane phospholipids leads to a loss of motility, viability, and cytosolic elements, metabolic changes and structural alterations in spermatozoa. The most important antioxidant enzyme involved in ROS detoxification in mammalian spermatozoa is superoxide dismutase (SOD). The aims of the present study were to determine the presence of SOD-like activity in different fractions of canine semen, and to determine the relationship between SOD-like activity and different morphological, dynamical and biochemical parameters in canine spermatozoa. We demonstrated the presence of SOD-like activity in canine seminal plasma and spermatozoa; the negative correlation between SOD-like activity and lipid peroxidation concentrations in spermatozoa suggests a protective effect of this enzymatic activity against the potential oxidative stress in canine spermatozoa. A significant negative correlation between percentage of abnormal spermatozoa, and the percentage of progressive motility or vigor was found. Abnormal spermatozoa not only showed a deformed shape, moreover there was an energetic motility system failure. The presence of SOD-like activity in seminal plasma, spermatic, and postspermatic fractions of canine semen was demonstrated for the first time.

  20. Epigenetic regulation of human buccal mucosa mitochondrial superoxide dismutase gene expression by diet.

    PubMed

    Thaler, Roman; Karlic, Heidrun; Rust, Petra; Haslberger, Alexander G

    2009-03-01

    The impact of nutrition on the epigenetic machinery has increasingly attracted interest. The aim of the present study was to demonstrate the effects of various diets on methylation and gene expression. The antioxidative enzyme mitochondrial superoxide dismutase (MnSOD) was chosen as the model system because epigenetic regulation has been previously shown in cell lines for this gene. Promoter methylation and gene expression of MnSOD in buccal swabs from three sample groups were analysed. The three groups included: (1) forty vegetarians (aged 20-30 years); (2) age-matched omnivores; (3) elderly omnivores (aged>85 years). A 3-fold increase in the expression of the MnSOD gene was associated with decreased CpG methylation of the analysed promoter region in the vegetarian group compared with the age-matched omnivores group. Expression and promoter methylation of the MnSOD gene in elderly omnivores showed no significant differences compared with younger omnivores. In accordance with previous findings in various tissues, DNA global methylation was found to be significantly higher (30 %) in buccal swabs of younger subjects (independent of the diet), than in those of elderly omnivores. In the control experiment which was designed to verify the findings of the human buccal swab studies, the Caco-2 cell line was treated with zebularine. Results of the control study showed a 6-fold increase of MnSOD expression, an approximately 40 % decreased methylation of specified CpG in the MnSOD promoter and a 50 % reduction of global DNA methylation. These results indicate that diet affects the epigenetic regulation of human MnSOD.

  1. The role of a cytosolic superoxide dismutase in barley-pathogen interactions.

    PubMed

    Lightfoot, Damien J; Mcgrann, Graham R D; Able, Amanda J

    2017-04-01

    Reactive oxygen species (ROS), including superoxide ( O2·-/ HO2·) and hydrogen peroxide (H2 O2 ), are differentially produced during resistance responses to biotrophic pathogens and during susceptible responses to necrotrophic and hemi-biotrophic pathogens. Superoxide dismutase (SOD) is responsible for the catalysis of the dismutation of O2·-/ HO2· to H2 O2 , regulating the redox status of plant cells. Increased SOD activity has been correlated previously with resistance in barley to the hemi-biotrophic pathogen Pyrenophora teres f. teres (Ptt, the causal agent of the net form of net blotch disease), but the role of individual isoforms of SOD has not been studied. A cytosolic CuZnSOD, HvCSD1, was isolated from barley and characterized as being expressed in tissue from different developmental stages. HvCSD1 was up-regulated during the interaction with Ptt and to a greater extent during the resistance response. Net blotch disease symptoms and fungal growth were not as pronounced in transgenic HvCSD1 knockdown lines in a susceptible background (cv. Golden Promise), when compared with wild-type plants, suggesting that cytosolic O2·-/ HO2· contributes to the signalling required to induce a defence response to Ptt. There was no effect of HvCSD1 knockdown on infection by the hemi-biotrophic rice blast pathogen Magnaporthe oryzae or the biotrophic powdery mildew pathogen Blumeria graminis f. sp. hordei, but HvCSD1 also played a role in the regulation of lesion development by methyl viologen. Together, these results suggest that HvCSD1 could be important in the maintenance of the cytosolic redox status and in the differential regulation of responses to pathogens with different lifestyles.

  2. The Phylogeny and Active Site Design of Eukaryotic Copper-only Superoxide Dismutases

    SciTech Connect

    Peterson, Ryan L.; Galaleldeen, Ahmad; Villarreal, Johanna; Taylor, Alexander B.; Cabelli, Diane E.; Hart, P. John; Culotta, Valeria C.

    2016-08-17

    In eukaryotes the bimetallic Cu/Zn superoxide dismutase (SOD) enzymes play important roles in the biology of reactive oxygen species by disproportionating superoxide anion. We reported that the fungal pathogen Candida albicans expresses a novel copper-only SOD, known as SOD5, that lacks the zinc cofactor and electrostatic loop (ESL) domain of Cu/Zn-SODs for substrate guidance. In spite of these abnormalities, C. albicans SOD5 can disproportionate superoxide at rates limited only by diffusion. Here we demonstrate that this curious copper-only SOD occurs throughout the fungal kingdom as well as in phylogenetically distant oomycetes or “pseudofungi” species. It is the only form of extracellular SOD in fungi and oomycetes, in stark contrast to the extracellular Cu/Zn-SODs of plants and animals. Through structural biology and biochemical approaches we demonstrate that these copper-only SODs have evolved with a specialized active site consisting of two highly conserved residues equivalent to SOD5 Glu-110 and Asp-113. The equivalent positions are zinc binding ligands in Cu/Zn-SODs and have evolved in copper-only SODs to control catalysis and copper binding in lieu of zinc and the ESL. Similar to the zinc ion in Cu/Zn-SODs, SOD5 Glu-110 helps orient a key copper-coordinating histidine and extends the pH range of enzyme catalysis. Furthermore, SOD5 Asp-113 connects to the active site in a manner similar to that of the ESL in Cu/Zn-SODs and assists in copper cofactor binding. Copper-only SODs are virulence factors for certain fungal pathogens; thus this unique active site may be a target for future anti-fungal strategies.

  3. Extracellular superoxide dismutase is important for hippocampal neurogenesis and preservation of cognitive functions after irradiation.

    PubMed

    Zou, Yani; Corniola, Rikki; Leu, David; Khan, Aslam; Sahbaie, Peyman; Chakraborti, Ayanabha; Clark, David J; Fike, John R; Huang, Ting-Ting

    2012-12-26

    Cranial irradiation is widely used in cancer therapy, but it often causes cognitive defects in cancer survivors. Oxidative stress is considered a major cause of tissue injury from irradiation. However, in an earlier study mice deficient in the antioxidant enzyme extracellular superoxide dismutase (EC-SOD KO) showed reduced sensitivity to radiation-induced defects in hippocampal functions. To further dissect the role of EC-SOD in neurogenesis and in response to irradiation, we generated a bigenic EC-SOD mouse model (OE mice) that expressed high levels of EC-SOD in mature neurons in an otherwise EC-SOD-deficient environment. EC-SOD deficiency was associated with reduced progenitor cell proliferation in the subgranular zone of dentate gyrus in KO and OE mice. However, high levels of EC-SOD in the granule cell layer supported normal maturation of newborn neurons in OE mice. Following irradiation, wild-type mice showed reduced hippocampal neurogenesis, reduced dendritic spine densities, and defects in cognitive functions. OE and KO mice, on the other hand, were largely unaffected, and the mice performed normally in neurocognitive tests. Although the resulting hippocampal-related functions were similar in OE and KO mice following cranial irradiation, molecular analyses suggested that they may be governed by different mechanisms: whereas neurotrophic factors may influence radiation responses in OE mice, dendritic maintenance may be important in the KO environment. Taken together, our data suggest that EC-SOD plays an important role in all stages of hippocampal neurogenesis and its associated cognitive functions, and that high-level EC-SOD may provide protection against irradiation-related defects in hippocampal functions.

  4. Nitric oxide activates superoxide dismutase and ascorbate peroxidase to repress the cell death induced by wounding.

    PubMed

    Lin, Chih-Ching; Jih, Pei-Ju; Lin, Hsin-Hung; Lin, Jeng-Shane; Chang, Ling-Lan; Shen, Yu-Hsing; Jeng, Shih-Tong

    2011-10-01

    Wounding caused by rain, wind, and pathogen may lead plants to onset defense response. Previous studies indicated that mechanical wounding stimulates plants to generate nitric oxide (NO) and hydrogen peroxide (H(2)O(2)). In this study, the functions of NO and H(2)O(2) after wounding in sweet potato (Ipomoea batatas cv. Tainung 57) was further analyzed. Mechanical wounding damaged cells and resulted in necrosis, but the presence of NO donors or NO scavenger might reduce or enhance the cell death caused by wounding, respectively. The amount of H(2)O(2) induced by wounding was also decreased or increased when plants were incubated with NO donors or NO scavenger, individually. These results indicate that NO may regulate H(2)O(2) generation to affect cell death. NO-induced proteins isolated from two-dimensional electrophoresis were identified to be Copper/Zinc superoxide dismutases (CuZnSODs). The activities of CuZnSODs and ascorbate peroxidase (APX) could be enhanced by NO. In addition, the expression of CuZnSOD and APX was induced by wounding via NO, and their expression was further stimulated by NO through the generation of cGMP. The influx of calcium ions and the activity of NADPH oxidase were also involved in the NO signal transduction pathway inducing APX expression. Collectively, the generation of H(2)O(2) in wounded plants might trigger cell death. Meanwhile, the production of NO induced by wounding stimulated signal transducers including cGMP, calcium ions, and H(2)O(2) to activate CuZnSOD and APX, which further decreased H(2)O(2) level and reduced the cell death caused by wounding.

  5. NFAT is required for spontaneous pulmonary hypertension in superoxide dismutase 1 knockout mice

    PubMed Central

    Ramiro-Diaz, Juan Manuel; Nitta, Carlos H.; Maston, Levi D.; Codianni, Simon; Giermakowska, Wieslawa; Resta, Thomas C.

    2013-01-01

    Elevated reactive oxygen species are implicated in pulmonary hypertension (PH). Superoxide dismutase (SOD) limits superoxide bioavailability, and decreased SOD activity is associated with PH. A decrease in SOD activity is expected to increase superoxide and reduce hydrogen peroxide levels. Such an imbalance of superoxide/hydrogen peroxide has been implicated as a mediator of nuclear factor of activated T cells (NFAT) activation in epidermal cells. We have shown that NFATc3 is required for chronic hypoxia-induced PH. However, it is unknown whether NFATc3 is activated in the pulmonary circulation in a mouse model of decreased SOD1 activity and whether this leads to PH. Therefore, we hypothesized that an elevated pulmonary arterial superoxide/hydrogen peroxide ratio activates NFATc3, leading to PH. We found that SOD1 knockout (KO) mice have elevated pulmonary arterial wall superoxide and decreased hydrogen peroxide levels compared with wild-type (WT) littermates. Right ventricular systolic pressure (RVSP) was elevated in SOD1 KO and was associated with pulmonary arterial remodeling. Vasoreactivity to endothelin-1 was also greater in SOD1 KO vs. WT mice. NFAT activity and NFATc3 nuclear localization were increased in pulmonary arteries from SOD1 KO vs. WT mice. Administration of A-285222 (selective NFAT inhibitor) decreased RVSP, arterial wall thickness, vasoreactivity, and NFAT activity in SOD1 KO mice to WT levels. The SOD mimetic, tempol, also reduced NFAT activity, NFATc3 nuclear localization, and RVSP to WT levels. These findings suggest that an elevated superoxide/hydrogen peroxide ratio activates NFAT in pulmonary arteries, which induces vascular remodeling and increases vascular reactivity leading to PH. PMID:23475768

  6. The Phylogeny and Active Site Design of Eukaryotic Copper-only Superoxide Dismutases.

    PubMed

    Peterson, Ryan L; Galaleldeen, Ahmad; Villarreal, Johanna; Taylor, Alexander B; Cabelli, Diane E; Hart, P John; Culotta, Valeria C

    2016-09-30

    In eukaryotes the bimetallic Cu/Zn superoxide dismutase (SOD) enzymes play important roles in the biology of reactive oxygen species by disproportionating superoxide anion. Recently, we reported that the fungal pathogen Candida albicans expresses a novel copper-only SOD, known as SOD5, that lacks the zinc cofactor and electrostatic loop (ESL) domain of Cu/Zn-SODs for substrate guidance. Despite these abnormalities, C. albicans SOD5 can disproportionate superoxide at rates limited only by diffusion. Here we demonstrate that this curious copper-only SOD occurs throughout the fungal kingdom as well as in phylogenetically distant oomycetes or "pseudofungi" species. It is the only form of extracellular SOD in fungi and oomycetes, in stark contrast to the extracellular Cu/Zn-SODs of plants and animals. Through structural biology and biochemical approaches we demonstrate that these copper-only SODs have evolved with a specialized active site consisting of two highly conserved residues equivalent to SOD5 Glu-110 and Asp-113. The equivalent positions are zinc binding ligands in Cu/Zn-SODs and have evolved in copper-only SODs to control catalysis and copper binding in lieu of zinc and the ESL. Similar to the zinc ion in Cu/Zn-SODs, SOD5 Glu-110 helps orient a key copper-coordinating histidine and extends the pH range of enzyme catalysis. SOD5 Asp-113 connects to the active site in a manner similar to that of the ESL in Cu/Zn-SODs and assists in copper cofactor binding. Copper-only SODs are virulence factors for certain fungal pathogens; thus this unique active site may be a target for future anti-fungal strategies. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Water restriction increases renal inner medullary manganese superoxide dismutase (MnSOD).

    PubMed

    Zhou, Xiaoming; Burg, Maurice B; Ferraris, Joan D

    2012-09-01

    Oxidative stress damages cells. NaCl and urea are high in renal medullary interstitial fluid, which is necessary to concentrate urine, but which causes oxidative stress by elevating reactive oxygen species (ROS). Here, we measured the antioxidant enzyme superoxide dismutases (SODs, MnSOD, and Cu/ZnSOD) and catalase in mouse kidney that might mitigate the oxidative stress. MnSOD protein increases progressively from the cortex to the inner medulla, following the gradient of increasing NaCl and urea. MnSOD activity increases proportionately, but MnSOD mRNA does not. Water restriction, which elevates renal medullary NaCl and urea, increases MnSOD protein, accompanied by a proportionate increase in MnSOD enzymatic activity in the inner medulla, but not in the cortex or the outer medulla. In contrast, Cu/ZnSOD and TNF-α (an important regulator of MnSOD) do not vary between the regions of the kidney, and expression of catalase protein actually decreases from the cortex to the inner medulla. Water restriction increases activity of mitochondrial enzymes that catalyze production of ROS in the inner medulla, but reduces NADPH oxidase activity there. We also examined the effect of high NaCl and urea on MnSOD in Madin-Darby canine kidney (MDCK) cells. High NaCl and high urea both increase MnSOD in MDCK cells. This increase in MnSOD protein apparently depends on the elevation of ROS since it is eliminated by the antioxidant N-acetylcysteine, and it occurs without raising osmolality when ROS are elevated by antimycin A or xanthine oxidase plus xanthine. We conclude that ROS, induced by high NaCl and urea, increase MnSOD activity in the renal inner medulla, which moderates oxidative stress.

  8. Immunohistochemical assessment of mitochondrial superoxide dismutase (MnSOD) in colorectal premalignant and malignant lesions

    PubMed Central

    Piecuch, Adam; Dziewit, Bartosz; Segiet, Oliwia; Kurek, Józef; Kowalczyk-Ziomek, Grażyna; Wojnicz, Romuald; Helewski, Krzysztof

    2016-01-01

    Introduction It is generally accepted that mitochondria are a primary source of intracellular reactive oxygen species (ROS). Under physiological circumstances they are permanently formed as by-products of aerobic metabolism in the mitochondria. To counter the harmful effect of ROS, cells possess an antioxidant defence system to detoxify ROS and avert them from accumulation at high concentrations. Mitochondria-located manganese superoxide dismutase (MnSOD, SOD2) successfully converts superoxide to the less reactive hydrogen peroxide (H2O2). To the best of our knowledge, there are no available data regarding immunohistochemical expression of MnSOD in colorectal neoplastic tissues. Aim To investigate the immunohistochemical expression status of MnSOD in colorectal premalignant and malignant lesions. Material and methods This study was performed on resected specimens obtained from 126 patients who had undergone surgical resection for primary sporadic colorectal cancer, and from 114 patients who had undergone colonoscopy at the Municipal Hospital in Jaworzno (Poland). Paraffin-embedded, 4-µm-thick tissue sections were stained for rabbit polyclonal anti SOD2 antibody obtained from GeneTex (clone TF9-10-H10 from America Diagnostica). Results Results of our study demonstrated that the development of colorectal cancer is connected with increased expression of MnSOD both in adenoma and adenocarcinoma stages. Samples of adenocarcinoma with G2 and G3 grade showed significantly higher levels of immunohistochemical expression of this antioxidant enzyme. Moreover, patients with the presence of lymphovascular invasion and higher degree of regional lymph node status have been also characterised by higher levels of MnSOD expression. The samples of adenoma have been characterised by higher levels of MnSOD expression in comparison to normal mucosa as well. Interestingly, there was no significant correlation between expression and histological type of adenoma. Conclusions Development

  9. Age-associated intracellular superoxide dismutase deficiency potentiates dermal fibroblast dysfunction during wound healing.

    PubMed

    Fujiwara, Toshihiro; Dohi, Teruyuki; Maan, Zeshaan N; Rustad, Kristine C; Kwon, Sun Hyung; Padmanabhan, Jagannath; Whittam, Alexander J; Suga, Hirotaka; Duscher, Dominik; Rodrigues, Melanie; Gurtner, Geoffrey C

    2017-07-04

    Reactive oxygen species (ROS) impair wound healing through destructive oxidation of intracellular proteins, lipids and nucleic acids. Intracellular superoxide dismutase (SOD1) regulates ROS levels and plays a critical role in tissue homoeostasis. Recent evidence suggests that age-associated wound healing impairments may partially result from decreased SOD1 expression. We investigated the mechanistic basis by which increased oxidative stress links to age-associated impaired wound healing. Fibroblasts were isolated from unwounded skin of young and aged mice, and myofibroblast differentiation was assessed by measuring α-smooth muscle actin and collagen gel contraction. Excisional wounds were created on young and aged mice to study the healing rate, ROS levels and SOD1 expression. A mechanistic link between oxidative stress and fibroblast function was explored by assessing the TGF-β1 signalling pathway components in young and aged mice. Age-related wounds displayed reduced myofibroblast differentiation and delayed wound healing, consistent with a decrease in the in vitro capacity for fibroblast-myofibroblast transition following oxidative stress. Young fibroblasts with normal SOD1 expression exhibited increased phosphorylation of ERK in response to elevated ROS. In contrast, aged fibroblasts with reduced SOD1 expression displayed a reduced capacity to modulate intracellular ROS. Collectively, age-associated wound healing impairments are associated with fibroblast dysfunction that is likely the result of decreased SOD1 expression and subsequent dysregulation of intracellular ROS. Strategies targeting these mechanisms may suggest a new therapeutic approach in the treatment of chronic non-healing wounds in the aged population. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Direct evidence for interaction between nano-anatase and superoxide dismutase from rat erythrocytes

    NASA Astrophysics Data System (ADS)

    Ma, Linglan; Ze, Yuguang; Liu, Jie; Liu, Huiting; Liu, Chao; Li, Zhongrui; Zhao, Jinfang; Yan, Jinying; Duan, Yanmei; Xie, Yaning; Hong, Fashui

    2009-07-01

    Nano-TiO2 and superoxide dismutase (SOD, EC 1.15.1.1) have been added to cosmetics and used to prevent injury of skin from UV-radiation, which might be related to the decrease of oxidative damage of skin. In previous studies we had proven that nano-anatase could increase the activity of SOD and decrease the oxidative damage in vivo. The mechanisms by which nano-anatase promoted SOD activity, however, are still not clearly understood. In the present work, nano-anatase in various concentrations was added to SOD from rat erythrocytes in vitro to gain insight into the mechanism of molecular interactions between nano-anatase and SOD by various spectral methods, suggesting that the reaction between SOD and nano-anatase was two-order, which meant that the SOD activity was greatly increased by low concentration of nano-anatase and inhibited by high concentration of nano-anatase. The spectroscopic assays suggested that the nano-anatase was determined to directly bind to SOD; the binding site of nano-anatase to SOD was 0.256 and the binding constants were 6.54 × 105 and 3.6 × 105 L mol-1; Ti was bound with three oxygen or nitrogen atoms and a sulfur atoms of amino acid residues at the Ti-O(N) and Ti-S bond lengths of 1.86 and 2.37 Å, respectively, the binding nano-anatase entirely altered the secondary structure of SOD. It implied that the nano-anatase coordination created a new metal ion-active site form in SOD, thus leading to an enhancement in SOD activity.

  11. Redox-Modulated Phenomena and Radiation Therapy: The Central Role of Superoxide Dismutases

    PubMed Central

    Holley, Aaron K.; Miao, Lu; St. Clair, Daret K.

    2014-01-01

    Abstract Significance: Ionizing radiation is a vital component in the oncologist's arsenal for the treatment of cancer. Approximately 50% of all cancer patients will receive some form of radiation therapy as part of their treatment regimen. DNA is considered the major cellular target of ionizing radiation and can be damaged directly by radiation or indirectly through reactive oxygen species (ROS) formed from the radiolysis of water, enzyme-mediated ROS production, and ROS resulting from altered aerobic metabolism. Recent Advances: ROS are produced as a byproduct of oxygen metabolism, and superoxide dismutases (SODs) are the chief scavengers. ROS contribute to the radioresponsiveness of normal and tumor tissues, and SODs modulate the radioresponsiveness of tissues, thus affecting the efficacy of radiotherapy. Critical Issues: Despite its prevalent use, radiation therapy suffers from certain limitations that diminish its effectiveness, including tumor hypoxia and normal tissue damage. Oxygen is important for the stabilization of radiation-induced DNA damage, and tumor hypoxia dramatically decreases radiation efficacy. Therefore, auxiliary therapies are needed to increase the effectiveness of radiation therapy against tumor tissues while minimizing normal tissue injury. Future Directions: Because of the importance of ROS in the response of normal and cancer tissues to ionizing radiation, methods that differentially modulate the ROS scavenging ability of cells may prove to be an important method to increase the radiation response in cancer tissues and simultaneously mitigate the damaging effects of ionizing radiation on normal tissues. Altering the expression or activity of SODs may prove valuable in maximizing the overall effectiveness of ionizing radiation. Antioxid. Redox Signal. 20, 1567–1589. PMID:24094070

  12. Superoxide dismutase gene expression in skeletal muscle: fiber-specific adaptation to endurance training.

    PubMed

    Hollander, J; Fiebig, R; Gore, M; Bejma, J; Ookawara, T; Ohno, H; Ji, L L

    1999-09-01

    The effects of endurance training on the enzyme activity, protein content, and mRNA abundance of Mn and CuZn superoxide dismutase (SOD) were studied in various phenotypes of rat skeletal muscle. Female Sprague-Dawley rats were randomly divided into trained (T, n = 8) and untrained (U, n = 8) groups. Training, consisting of treadmill running at 27 m/min and 12% grade for 2 h/day, 5 days/wk for 10 wk, significantly increased citrate synthase activity (P < 0. 01) in the type I (soleus), type IIa (deep vastus lateralis, DVL), and mixed type II (plantaris) muscles but not in type IIb (superficial vastus lateralis, SVL) muscle. Mitochondrial (Mn) SOD activity was elevated by 80% (P < 0.05) with training in DVL. SVL and plantaris muscle in T rats showed 54 and 42% higher pooled immunoreactive Mn SOD protein content, respectively, than those in U rats. However, no change in Mn SOD mRNA level was found in any of the muscles. CuZn SOD activity, protein content, and mRNA level in general were not affected by training, except for a 160% increase in pooled CuZn SOD protein in SVL. Training also significantly increased glutathione peroxidase and catalase activities (P < 0.05), but only in DVL muscle. These data indicate that training adaptations of Mn SOD and other antioxidant enzymes occur primarily in type IIa fibers, probably as a result of enhanced free radical generation and modest antioxidant capacity. Differential training responses of mRNA, enzyme protein, and activity suggest that separate cellular signals may control pre- and posttranslational regulation of SOD.

  13. In vitro preparation of iron-substituted human manganese superoxide dismutase: possible toxic properties for mitochondria.

    PubMed

    Yamakura, Fumiyuki; Kobayashi, Kazuo; Furukawa, Satoshi; Suzuki, Yasunori

    2007-08-01

    We prepared an iron-substituted form of recombinant human manganese superoxide dismutase (MnSOD) by using guanidine hydrochloride for the first time as a model of iron-misincorporated MnSOD, the formation of which has been reported by M. Yang et al. upon disruption of mitochondrial metal homeostasis in yeast (Yang et al. 2006, EMBO J. 25, 1775-1783). The iron-substituted enzyme contained 0.79 g atoms of Fe/mol of subunits and had a specific activity of 80 units/mg protein/g atom of Fe/mol of subunit, which was less than 3% of the activity of the purified MnSOD. Fe-substituted MnSOD (Fe-MnSOD) showed the same absorption spectrum as that of bacterial Fe-MnSODs reported, a similar pH-dependent change of the enzymatic activity, and a similar electron paramagnetic resonance spectrum. Fe-MnSOD showed more thermal stability than native MnSOD. The Fe-substituted enzyme showed a hydrogen-peroxide-mediated radical-generating activity, which was monitored by a cation radical of 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate) formation similar to that of Cu,ZnSOD, but native human MnSOD and FeSOD showed no radical-generation ability. This evidence suggests that a substitution of Mn to Fe in human MnSOD in mitochondria may produce a disadvantage for oxidative stress in three ways: loss of the enzymatic activity, increase of stability, and gain of radical-generating ability.

  14. A Manganese-rich Environment Supports Superoxide Dismutase Activity in a Lyme Disease Pathogen, Borrelia burgdorferi*

    PubMed Central

    Aguirre, J. Dafhne; Clark, Hillary M.; McIlvin, Matthew; Vazquez, Christine; Palmere, Shaina L.; Grab, Dennis J.; Seshu, J.; Hart, P. John; Saito, Mak; Culotta, Valeria C.

    2013-01-01

    The Lyme disease pathogen Borrelia burgdorferi represents a novel organism in which to study metalloprotein biology in that this spirochete has uniquely evolved with no requirement for iron. Not only is iron low, but we show here that B. burgdorferi has the capacity to accumulate remarkably high levels of manganese. This high manganese is necessary to activate the SodA superoxide dismutase (SOD) essential for virulence. Using a metalloproteomic approach, we demonstrate that a bulk of B. burgdorferi SodA directly associates with manganese, and a smaller pool of inactive enzyme accumulates as apoprotein. Other metalloproteins may have similarly adapted to using manganese as co-factor, including the BB0366 aminopeptidase. Whereas B. burgdorferi SodA has evolved in a manganese-rich, iron-poor environment, the opposite is true for Mn-SODs of organisms such as Escherichia coli and bakers' yeast. These Mn-SODs still capture manganese in an iron-rich cell, and we tested whether the same is true for Borrelia SodA. When expressed in the iron-rich mitochondria of Saccharomyces cerevisiae, B. burgdorferi SodA was inactive. Activity was only possible when cells accumulated extremely high levels of manganese that exceeded cellular iron. Moreover, there was no evidence for iron inactivation of the SOD. B. burgdorferi SodA shows strong overall homology with other members of the Mn-SOD family, but computer-assisted modeling revealed some unusual features of the hydrogen bonding network near the enzyme's active site. The unique properties of B. burgdorferi SodA may represent adaptation to expression in the manganese-rich and iron-poor environment of the spirochete. PMID:23376276

  15. Superoxide dismutase enhances tolerance of freezing stress in transgenic alfalfa (Medicago sativa L.).

    PubMed Central

    McKersie, B D; Chen, Y; de Beus, M; Bowley, S R; Bowler, C; Inzé, D; D'Halluin, K; Botterman, J

    1993-01-01

    Activated oxygen or oxygen free radicals have been implicated in a number of physiological disorders in plants including freezing injury. Superoxide dismutase (SOD) catalyzes the dismutation of superoxide into O2 and H2O2 and thereby reduces the titer of activated oxygen molecules in the cell. To further examine the relationship between oxidative and freezing stresses, the expression of SOD was modified in transgenic alfalfa (Medicago sativa L.). The Mn-SOD cDNA from Nicotiana plumbaginifolia under the control of the cauliflower mosaic virus 35S promoter was introduced into alfalfa using Agrobacterium tumefaciens-mediated transformation. Two plasmid vectors, pMitSOD and pChlSOD, contained a chimeric Mn-SOD construct with a transit peptide for targeting to the mitochondria or one for targeting to the chloroplast, respectively. The putatively transgenic plants were selected for resistance to kanamycin and screened for neomycin phosphotransferase activity and the presence of an additional Mn-SOD isozyme. Detailed analysis of a set of four selected transformants indicated that some had enhanced SOD activity, increased tolerance to the diphenyl ether herbicide, acifluorfen, and increased regrowth after freezing stress. The F1 progeny of one line, RA3-ChlSOD-30, were analyzed by SOD isozyme activity, by polymerase chain reaction for the Mn-SOD gene, and by polymerase chain reaction for the neo gene. RA3-ChlSOD-30 had three sites of insertion of pChlSOD, but only one gave a functional Mn-SOD isozyme; the other two were apparently partial insertions. The progeny with a functional Mn-SOD transgene had more rapid regrowth following freezing stress than those progeny lacking the functional Mn-SOD transgene, suggesting that Mn-SOD serves a protective role by minimizing oxygen free radical production after freezing stress. PMID:8290627

  16. Extracellular superoxide dismutase increased the therapeutic potential of human mesenchymal stromal cells in radiation pulmonary fibrosis.

    PubMed

    Wei, Li; Zhang, Jing; Yang, Zai-Liang; You, Hua

    2017-05-01

    Pulmonary fibrosis induced by irradiation is a significant problem of radiotherapy in cancer patients. Extracellular superoxide dismutase (SOD3) is found to be predominantly and highly expressed in the extracellular matrix of lung and plays a pivotal role against oxidative damage. Early administration of mesenchymal stromal cells (MSCs) has been demonstrated to reduce fibrosis of damaged lung. However, injection of MSCs at a later stage would be involved in fibrosis development. The present study aimed to determine whether injection of human umbilical cord-derived MSCs (UC-MSCs) over-expressing SOD3 at the established fibrosis stage would have beneficial effects in a mice model of radiation pulmonary fibrosis. Herein, pulmonary fibrosis in mice was induced using Cobalt-60 ((60)Co) irradiator with 20 Gy, followed by intravenous injection of UC-MSCs, transduced or not to express SOD3 at 2 h (early delivery) and 60 day (late delivery) post-irradiation, respectively. Our results demonstrated that the early administration of UC-MSCs could attenuate the microscopic damage, reduce collagen deposition, inhibit (myo)fibroblast proliferation, reduce inflammatory cell infiltration, protect alveolar type II (AE2) cell injury, prevent oxidative stress and increase antioxidant status, and reduce pro-fibrotic cytokine level in serum. Furthermore, the early treatment with SOD3-infected UC-MSCs resulted in better improvement. However, we failed to observe the therapeutic effects of UC-MSCs, transduced to express SOD3, during established fibrosis. Altogether, our results demonstrated that the early treatment with UC-MSCs alone significantly reduced radiation pulmonary fibrosis in mice through paracrine effects, with further improvement by administration of SOD3-infected UC-MSCs, suggesting that SOD3-infected UC-MSCs may be a potential cell-based gene therapy to treat clinical radiation pulmonary fibrosis. Copyright © 2017 International Society for Cellular Therapy. Published by

  17. Histidinyl radical formation in the self-peroxidation reaction of bovine copper-zinc superoxide dismutase.

    PubMed

    Gunther, Michael R; Peters, J Andrew; Sivaneri, Meena K

    2002-03-15

    In the absence of suitable oxidizable substrates, the peroxidase reaction of copper-zinc superoxide dismutase (SOD) oxidizes SOD itself, ultimately resulting in its inactivation. A SOD-centered free radical adduct of 2-methyl-2-nitrosopropane (MNP) was detected upon incubation of SOD with the spin trap and a hydroperoxide (either H(2)O(2) or peracetic acid). Proteolysis by Pronase converted the anisotropic electron paramagnetic resonance (EPR) spectrum of MNP/(center dot)SOD to a nearly isotropic spectrum with resolved hyperfine couplings to several atoms with non-zero nuclear spin. Authentic histidinyl radical (from histidine + HO(center dot)) formed a MNP adduct with a very similar EPR spectrum to that of the Pronase-treated MNP/(center dot)SOD, suggesting that the latter was centered on a histidine residue. An additional hyperfine coupling was detected when histidine specifically (13)C-labeled at C-2 of the imidazole ring was used, providing evidence for trapping at that atom. All of the experimental spectra were convincingly simulated assuming hyperfine couplings to 2 nearly equivalent nitrogen atoms and 2 different protons, also consistent with trapping at C-2 of the imidazole ring. Free histidinyl radical consumed oxygen, implying peroxyl radical formation. MNP-inhibitable oxygen consumption was also observed when cuprous SOD but not cupric SOD was added to a H(2)O(2) solution. Formation of 2-oxohistidine, the stable product of the SOD-hydroperoxide reaction, required oxygen and was inhibited by MNP. These results support formation of a transient SOD-peroxyl radical.

  18. Calcium Ions Promote Superoxide Dismutase 1 (SOD1) Aggregation into Non-fibrillar Amyloid

    PubMed Central

    Leal, Sónia S.; Cardoso, Isabel; Valentine, Joan S.; Gomes, Cláudio M.

    2013-01-01

    Imbalance in metal ion homeostasis is a hallmark in neurodegenerative conditions involving protein deposition, and amyotrophic lateral sclerosis (ALS) is no exception. In particular, Ca2+ dysregulation has been shown to correlate with superoxide dismutase-1 (SOD1) aggregation in a cellular model of ALS. Here we present evidence that SOD1 aggregation is enhanced and modulated by Ca2+. We show that at physiological pH, Ca2+ induces conformational changes that increase SOD1 β-sheet content, as probed by far UV CD and attenuated total reflectance-FTIR, and enhances SOD1 hydrophobicity, as probed by ANS fluorescence emission. Moreover, dynamic light scattering analysis showed that Ca2+ boosts the onset of SOD1 aggregation. In agreement, Ca2+ decreases SOD1 critical concentration and nucleation time during aggregation kinetics, as evidenced by thioflavin T fluorescence emission. Attenuated total reflectance FTIR analysis showed that Ca2+ induced aggregates consisting preferentially of antiparallel β-sheets, thus suggesting a modulation effect on the aggregation pathway. Transmission electron microscopy and analysis with conformational anti-fibril and anti-oligomer antibodies showed that oligomers and amyloidogenic aggregates constitute the prevalent morphology of Ca2+-induced aggregates, thus indicating that Ca2+ diverts SOD1 aggregation from fibrils toward amorphous aggregates. Interestingly, the same heterogeneity of conformations is found in ALS-derived protein inclusions. We thus hypothesize that transient variations and dysregulation of cellular Ca2+ levels contribute to the formation of SOD1 aggregates in ALS patients. In this scenario, Ca2+ may be considered as a pathogenic effector in the formation of ALS proteinaceous inclusions. PMID:23861388

  19. Copper and Zinc Metallation Status of Copper Zinc Superoxide Dismutase form Amyotrophic Lateral Sclerosis Transgenic Mice

    SciTech Connect

    Lelie, H.L.; Miller, L.; Liba, A.; Bourassa, M.W.; Chattopadhyay, M.; Chan, P.K.; Gralla, E.B.; Borchelt, D.R.; et al

    2010-09-24

    Mutations in the metalloenzyme copper-zinc superoxide dismutase (SOD1) cause one form of familial amyotrophic lateral sclerosis (ALS), and metals are suspected to play a pivotal role in ALS pathology. To learn more about metals in ALS, we determined the metallation states of human wild-type or mutant (G37R, G93A, and H46R/H48Q) SOD1 proteins from SOD1-ALS transgenic mice spinal cords. SOD1 was gently extracted from spinal cord and separated into insoluble (aggregated) and soluble (supernatant) fractions, and then metallation states were determined by HPLC inductively coupled plasma MS. Insoluble SOD1-rich fractions were not enriched in copper and zinc. However, the soluble mutant and WT SOD1s were highly metallated except for the metal-binding-region mutant H46R/H48Q, which did not bind any copper. Due to the stability conferred by high metallation of G37R and G93A, it is unlikely that these soluble SOD1s are prone to aggregation in vivo, supporting the hypothesis that immature nascent SOD1 is the substrate for aggregation. We also investigated the effect of SOD1 overexpression and disease on metal homeostasis in spinal cord cross-sections of SOD1-ALS mice using synchrotron-based x-ray fluorescence microscopy. In each mouse genotype, except for the H46R/H48Q mouse, we found a redistribution of copper between gray and white matters correlated to areas of high SOD1. Interestingly, a disease-specific increase of zinc was observed in the white matter for all mutant SOD1 mice. Together these data provide a picture of copper and zinc in the cell as well as highlight the importance of these metals in understanding SOD1-ALS pathology.

  20. Cu,Zn-Superoxide Dismutase without Zn is Folded but Catalytically Inactive

    PubMed Central

    Nedd, Sean; Redler, Rachel L.; Proctor, Elizabeth A.; Dokholyan, Nikolay V.; Alexandrova, Anastassia N.

    2014-01-01

    Amyotrophic Lateral Sclerosis has been linked to the gain of aberrant function of superoxide dismutase, Cu,Zn-SOD1 upon protein misfolding. The mechanism of SOD1 misfolding is thought to involve mutations leading to the loss of Zn, followed by protein unfolding, and aggregation. We show that the removal of Zn from SOD1 may not lead to an immediate unfolding, but immediately deactivates the enzyme through a combination of subtle structural and electronic effects. Using Quantum Mechanics/Discrete Molecular Dynamics, we showed that Zn-less wild type SOD1 and its D124N mutant that does not bind Zn both have at least metastable folded states. In those states, the reduction potential of Cu increases, leading to the presence of detectable amounts of Cu(I) instead of Cu(II) in the active site, as confirmed experimentally. The Cu(I) protein cannot participate in the catalytic Cu(I) – Cu(II) cycle. However, even without the full reduction to Cu(I), the Cu site in the Zn-less variants of SOD1 is shown to be catalytically incompetent: unable to bind superoxide in a way comparable to the wild type SOD1. The changes are more radical and different in the D124N Zn-less mutant than in the Zn-less wild type SOD1, suggesting D124N being perhaps not the most adequate model for Zn-less SOD1. Overall, Zn in SOD1 appears to be influencing the Cu site directly by adjusting its reduction potential and geometry. Thus, the role of Zn in SOD1 is not just structural, as was previously thought; it is a vital part of the catalytic machinery. PMID:25083917

  1. Superoxide dismutase and taurine supplementation improves in vitro blastocyst yield from poor-quality feline oocytes.

    PubMed

    Ochota, Małgorzata; Pasieka, Anna; Niżański, Wojciech

    2016-03-15

    Blastocyst production in vitro seems to be crucial part of assisted reproduction techniques in feline species. However, the results of cats' oocyte maturation and embryo development are still lower than those in other species. The aim of this study was to evaluate whether the supplementation with superoxide dismutase (SOD) and taurine during maturation or culture would improve the blastocyst yield obtained from lower grades of oocytes, that are usually discarded, as not suitable for further in vitro purposes. To investigate the effect of antioxidants' addition, the good- and poor-quality oocytes, were cultured with the addition of 10-mmol taurine and 600 UI/mL SOD. The nuclear maturity, embryo development, and blastocyst quality were subsequently assessed. In control group, without antioxidant supplementation, significantly less poor-quality oocytes matured (42% vs. 62%) and more degenerated (35% vs. 20%), comparing to the experimental group supplemented with SOD and taurine. The amount of obtained blastocyst was much higher, when poor quality oocytes were supplemented with SOD and taurine (supplementation to IVM-4%; supplementation to IVC-5.5%; supplementation to IVM and IVC-5.9% of blastocyst), comparing to not supplemented control group (1.3%). The best blastocysts were obtained when poor oocytes had antioxidants added only during embryo culture (185 ± 13.4 blastomeres vs. 100 ± 1.5 in control). In the present study, we reported that the lower grades of oocytes can better mature and form significantly more blastocysts with better quality, when cultured with addition of SOD and taurine.

  2. Identification and Analysis of the Role of Superoxide Dismutases Isoforms in the Pathogenesis of Paracoccidioides spp.

    PubMed

    Tamayo, Diana; Muñoz, José F; Lopez, Ángela; Urán, Martha; Herrera, Juan; Borges, Clayton L; Restrepo, Ángela; Soares, Celia M; Taborda, Carlos P; Almeida, Agostinho J; McEwen, Juan G; Hernández, Orville

    2016-03-01

    The ability of Paracoccidioides to defend itself against reactive oxygen species (ROS) produced by host effector cells is a prerequisite to survive. To counteract these radicals, Paracoccidioides expresses, among different antioxidant enzymes, superoxide dismutases (SODs). In this study, we identified six SODs isoforms encoded by the Paracoccidioides genome. We determined gene expression levels of representative isolates of the phylogenetic lineages of Paracoccidioides spp. (S1, PS2, PS3 and Pb01-like) using quantitative RT-PCR. Assays were carried out to analyze SOD gene expression of yeast cells, mycelia cells, the mycelia-to-yeast transition and the yeast-to-mycelia germination, as well as under treatment with oxidative agents and during interaction with phagocytic cells. We observed an increased expression of PbSOD1 and PbSOD3 during the transition process, exposure to oxidative agents and interaction with phagocytic cells, suggesting that these proteins could assist in combating the superoxide radicals generated during the host-pathogen interaction. Using PbSOD1 and PbSOD3 knockdown strains we showed these genes are involved in the response of the fungus against host effector cells, particularly the oxidative stress response, and in a mouse model of infection. Protein sequence analysis together with functional analysis of knockdown strains seem to suggest that PbSOD3 expression is linked with a pronounced extracellular activity while PbSOD1 seems more related to intracellular requirements of the fungus. Altogether, our data suggests that P. brasiliensis actively responds to the radicals generated endogenously during metabolism and counteracts the oxidative burst of immune cells by inducing the expression of SOD isoforms.

  3. Identification and Analysis of the Role of Superoxide Dismutases Isoforms in the Pathogenesis of Paracoccidioides spp.

    PubMed Central

    Tamayo, Diana; Muñoz, José F.; Lopez, Ángela; Urán, Martha; Herrera, Juan; Borges, Clayton L.; Restrepo, Ángela; Soares, Celia M.; Taborda, Carlos P.; Almeida, Agostinho J.; McEwen, Juan G.; Hernández, Orville

    2016-01-01

    The ability of Paracoccidioides to defend itself against reactive oxygen species (ROS) produced by host effector cells is a prerequisite to survive. To counteract these radicals, Paracoccidioides expresses, among different antioxidant enzymes, superoxide dismutases (SODs). In this study, we identified six SODs isoforms encoded by the Paracoccidioides genome. We determined gene expression levels of representative isolates of the phylogenetic lineages of Paracoccidioides spp. (S1, PS2, PS3 and Pb01-like) using quantitative RT-PCR. Assays were carried out to analyze SOD gene expression of yeast cells, mycelia cells, the mycelia-to-yeast transition and the yeast-to-mycelia germination, as well as under treatment with oxidative agents and during interaction with phagocytic cells. We observed an increased expression of PbSOD1 and PbSOD3 during the transition process, exposure to oxidative agents and interaction with phagocytic cells, suggesting that these proteins could assist in combating the superoxide radicals generated during the host-pathogen interaction. Using PbSOD1 and PbSOD3 knockdown strains we showed these genes are involved in the response of the fungus against host effector cells, particularly the oxidative stress response, and in a mouse model of infection. Protein sequence analysis together with functional analysis of knockdown strains seem to suggest that PbSOD3 expression is linked with a pronounced extracellular activity while PbSOD1 seems more related to intracellular requirements of the fungus. Altogether, our data suggests that P. brasiliensis actively responds to the radicals generated endogenously during metabolism and counteracts the oxidative burst of immune cells by inducing the expression of SOD isoforms. PMID:26963091

  4. Acceleration of diabetic renal injury in the superoxide dismutase knockout mouse: effects of tempol.

    PubMed

    DeRubertis, Frederick R; Craven, Patricia A; Melhem, Mona F

    2007-09-01

    Indices of renal injury and oxidative stress were examined in mice with deficiency of cytosolic Cu(2+)/Zn(2+) superoxide dismutase (SOD1-/-, KO) and their wild-type (WT) littermates with streptozotocin-induced diabetes. After 5 weeks of diabetes, KO diabetic (D) but not WT-D mice developed marked albuminuria, increases in glomerular content of transforming growth factor beta, collagen alpha1(IV), and nitrotyrosine, and higher glomerular superoxide compared with corresponding values in nondiabetics. After 5 months of diabetes, increases in these parameters, mesangial matrix expansion, renal cortical malondialdehyde content, and severity of tubulointerstitial injury were all significantly greater, whereas cortical glutathione was lower, in KO-D than in WT-D. In contrast to WT-D, after 4 weeks of diabetes, KO-D mice did not develop the increase in inulin clearance (C(In)) characteristic of early diabetes. The nitric oxide synthase inhibitor N(omega)-nitro-l-arginine methylester suppressed C(In) in WT-D, but had no effect on C(In) in KO-D. Treatment of KO-D with the SOD mimetic tempol for 4 weeks suppressed albuminuria, increases in glomerular transforming growth factor beta, collagen alpha1(IV), nitrotyrosine, and glomerular superoxide, and concurrently increased C(In). The latter action of tempol in KO-D was blocked by the N(omega)-nitro-l-arginine methylester. The findings provide support for a role for superoxide and its metabolism by SOD1 in the pathogenesis of renal injury in diabetes in vivo, and implicate increased interaction of superoxide with nitric oxide as a pathogenetic factor.

  5. The iron-dependent mitochondrial superoxide dismutase SODA promotes Leishmania virulence.

    PubMed

    Mittra, Bidyottam; Laranjeira-Silva, Maria Fernanda; Miguel, Danilo Ciccone; Perrone Bezerra de Menezes, Juliana; Andrews, Norma W

    2017-07-21

    Leishmaniasis is one of the leading globally neglected diseases, affecting millions of people worldwide. Leishmania infection depends on the ability of insect-transmitted metacyclic promastigotes to invade mammalian hosts, differentiate into amastigotes, and replicate inside macrophages. To counter the hostile oxidative environment inside macrophages, these protozoans contain anti-oxidant systems that include iron-dependent superoxide dismutases (SODs) in mitochondria and glycosomes. Increasing evidence suggests that in addition to this protective role, Leishmania mitochondrial SOD may also initiate H2O2-mediated redox signaling that regulates gene expression and metabolic changes associated with differentiation into virulent forms. To investigate this hypothesis, we examined the specific role of SODA, the mitochondrial SOD isoform in Leishmania amazonensis Our inability to generate L. amazonensis SODA null mutants and the lethal phenotype observed following RNAi-mediated silencing of the Trypanosoma brucei SODA ortholog suggests that SODA is essential for trypanosomatid survival. L. amazonensis metacyclic promastigotes lacking one SODA allele failed to replicate in macrophages and were severely attenuated in their ability to generate cutaneous lesions in mice. Reduced expression of SODA also resulted in mitochondrial oxidative damage and failure of SODA/ΔsodA promastigotes to differentiate into axenic amastigotes. SODA expression above a critical threshold was also required for the development of metacyclic promastigotes, as SODA/ΔsodA cultures were strongly depleted in this infective form and more susceptible to reactive oxygen species (ROS)-induced stress. Collectively, our data suggest that SODA promotes Leishmania virulence by protecting the parasites against mitochondrion-generated oxidative stress and by initiating ROS-mediated signaling mechanisms required for the differentiation of infective forms. © 2017 by The American Society for Biochemistry and

  6. Changes in nitric oxide level and superoxide dismutase activity during antimanic treatment.

    PubMed

    Gergerlioglu, H Serdar; Savas, Haluk A; Bulbul, Feridun; Selek, Salih; Uz, Efkan; Yumru, Mehmet

    2007-04-13

    Oxidant nitric oxide (NO) and antioxidant superoxide dismutase (SOD) have been implicated to play a role in the pathogenesis of bipolar disorders. This is the first prospective study aimed to evaluate NO levels and SOD activity in bipolar disorder (type I manic episode) (BD-ME). 29 inpatient subjects with BD-ME and 30 healthy controls were included. Serum NO levels and SOD activity have been studied at 1st (NO [1st] and SOD [1st] respectively) and 30th days (NO [30th] and SOD [30th] respectively) after treatment. The clinical outcome was measured by Bech-Rafaelson Mania Scale (BRMS). The mean NO [1st] (p<.001) and NO [30th] levels (p<.001) were higher than controls, but SOD [1st] (p<.001) and SOD [30th] (p<.001) activities in BD-ME were lower than controls. SOD(1) activity was higher than SOD [30th] (p<.001), while there was no significance in comparison between NO [1st] and NO [30th] (p>.05). SOD [30th] activity is negatively correlated with the number of previous manic attacks and NO [1st] was negatively correlated with sleep item score of BRMS at first day. Also there was a significant correlation between NO [1st] levels and with the existence of a delusion. NO and SOD appear to play a role in the pathophysiological events occurring in BD, especially in BD-ME. This study for the first time showed the possible role of NO on sleep and the generation of delusions in the pathophysiology of BD. In the light of literature, induced glutamate pathway might be responsible for delusions in BD. The results of this research need further investigation to understand the oxidative vs antioxidative process in BD.

  7. FUsed in Sarcoma Is a Novel Regulator of Manganese Superoxide Dismutase Gene Transcription

    PubMed Central

    Dhar, Sanjit Kumar; Zhang, Jiayu; Gal, Jozsef; Xu, Yong; Miao, Lu; Lynn, Bert C.; Zhu, Haining; Kasarskis, Edward J.

    2014-01-01

    Abstract Aims: FUsed in sarcoma (FUS) is a multifunctional DNA/RNA-binding protein that possesses diverse roles, such as RNA splicing, RNA transport, DNA repair, translation, and transcription. The network of enzymes and processes regulated by FUS is far from being fully described. In this study, we have focused on the mechanisms of FUS-regulated manganese superoxide dismutase (MnSOD) gene transcription. Results: Here we demonstrate that FUS is a component of the transcription complex that regulates the expression of MnSOD. Overexpression of FUS increased MnSOD expression in a dose-dependent manner and knockdown of FUS by siRNA led to the inhibition of MnSOD gene transcription. Reporter analyses, chromatin immunoprecipitation assay, electrophoretic mobility shift assay, affinity chromatography, and surface plasmon resonance analyses revealed the far upstream region of MnSOD promoter as an important target of FUS-mediated MnSOD transcription and confirmed that FUS binds to the MnSOD promoter and interacts with specificity protein 1 (Sp1). Importantly, overexpression of familial amyotropic lateral sclerosis (fALS)-linked R521G mutant FUS resulted in a significantly reduced level of MnSOD expression and activity, which is consistent with the decline in MnSOD activity observed in fibroblasts from fALS patients with the R521G mutation. R521G-mutant FUS abrogates MnSOD promoter-binding activity and interaction with Sp1. Innovation and Conclusion: This study identifies FUS as playing a critical role in MnSOD gene transcription and reveals a previously unrecognized relationship between MnSOD and mutant FUS in fALS. Antioxid. Redox Signal. 20, 1550–1566. PMID:23834335

  8. 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.

  9. Superoxide dismutase type 1 in monocytes of chronic kidney disease patients.

    PubMed

    Scholze, Alexandra; Krueger, Katharina; Diedrich, Madeleine; Räth, Christine; Torges, Anja; Jankowski, Vera; Maier, Alexandra; Thilo, Florian; Zidek, Walter; Tepel, Martin

    2011-07-01

    We analyzed proteomic profiles in monocytes of chronic kidney disease (CKD) patients and healthy control subjects. Two-dimensional electrophoresis (2-DE) and silver staining indicated differences in protein pattern. Among the analyzed proteins, superoxide dismutase type 1 (SOD1), which was identified both by MS/MS mass-spectrometry and immunoblotting, was reduced in kidney disease. We characterized SOD1 protein amount, using quantitative in-cell Western assay and immunostaining of 2-DE gel blots, and SOD1 gene expression, using quantitative real-time polymerase chain reaction (PCR), in 98 chronic hemodialysis (HD) and 211 CKD patients, and 34 control subjects. Furthermore, we showed that different SOD1 protein species exist in human monocytes. SOD1 protein amount was significantly lower in HD (normalized SOD1 protein, 27.2 ± 2.8) compared to CKD patients (34.3 ± 2.8), or control subjects (48.0 ± 8.6; mean ± SEM; P < 0.05). Analysis of SOD1 immunostaining showed significantly more SOD1 protein in control subjects compared to patients with CKD or HD (P < 0.0001, analysis of main immunoreactive protein spot). SOD1 gene expression was significantly higher in HD (normalized SOD1 gene expression, 17.8 ± 2.3) compared to CKD patients (9.0 ± 0.7), or control subjects (5.5 ± 1.0; P < 0.0001). An increased SOD1 gene expression may indicate increased protein degradation in patients with CKD and compensatory increase of SOD1 gene expression. Taken together, we show reduced SOD1 protein amount in monocytes of CKD, most pronounced in HD patients, accompanied by increased SOD1 gene expression.

  10. Evaluation of Serum Superoxide Dismutase Activity, Malondialdehyde, and Zinc and Copper Levels in Patients With Keratoconus.

    PubMed

    Kılıç, Raşit; Bayraktar, Aslhan Cavunt; Bayraktar, Serdar; Kurt, Ali; Kavutçu, Mustafa

    2016-12-01

    The aim of this study was to evaluate the relationship between antioxidant superoxide dismutase (SOD) enzyme activity, malondialdehyde (MDA) as a lipid peroxidation marker, and some trace elements such as zinc (Zn) and copper (Cu) levels in patients with keratoconus. A total of 58 patients with keratoconus and 53 control subjects with similar age and sex were evaluated in this study. The modified Krumeich keratoconus classification was used to divide the patients into 4 stages. Serum SOD activity, MDA, and zinc and copper levels were compared between the patient and control groups. The median serum SOD activity, MDA, and Zn and Cu levels were 27.2 (42.4-13.7) U/mL, 10.2 (11.9-8.5) nmol/mL, 87.9 (104.6-76.5) μmol/L, and 103.2 (117.9-90.3) μmol/L in the keratoconus group and 26.2 (32.5-14.4) U/mL, 8.8 (11.4-7.1) nmol/mL, 100.5 (121.1-81.8) μmol/L, and 98.4 (120.3-83.4) μmol/L in the control group, respectively. There was a statistically significant difference between the MDA and Zn levels of the keratoconus group and control subjects but not between the respective SOD activities or Cu levels (P = 0.016, P = 0.031, P = 0.440, and P = 0.376, respectively). We found no significant difference between the keratoconus group stages for serum SOD activity, serum MDA, and Zn and Cu levels (P > 0.05), and there was also no significant correlation between the keratoconus group stages and serum SOD activity, serum MDA, and Zn and Cu levels (P > 0.05). There is imbalance in the systemic oxidant/antioxidant status where Zn deficiency also plays a role in patients with keratoconus.

  11. Peroxisomal copper, zinc superoxide dismutase. Characterization of the isoenzyme from watermelon cotyledons.

    PubMed Central

    Bueno, P; Varela, J; Gimeénez-Gallego, G; del Río, L A

    1995-01-01

    The biochemical and immunochemical characterization of a superoxide dismutase (SOD, EC 1.15.1.1) from peroxisomal origin has been carried out. The enzyme is a Cu,Zn-containing SOD (CuZn-SOD) located in the matrix of peroxisomes from watermelon (Citrullus vulgaris Schrad.) cotyledons (L.M. Sandalio and L.A. del Río [1988] Plant Physiol 88: 1215-1218). The amino acid composition of the enzyme was determined. Analysis by reversed-phase high-performance liquid chromatography of the peroxisomal CuZn-SOD incubated with 6 M guanidine-HCl indicated that this enzyme contained a noncovalently bound chromophore group that was responsible for the absorbance peak of the native enzyme at 260 nm. The amino acid sequence of the peroxisomal CuZn-SOD was determined by Edman degradation. Comparison of its sequence with those reported for other plant SODs revealed homologies of about 70% with cytosolic CuZn-SODs and of 90% with chloroplastic CuZn-SODs. The peroxisomal SOD has a high thermal stability and resistance to inactivation by hydrogen peroxide. A polyclonal antibody was raised against peroxisomal CuZn-SOD, and by western blotting the antibody cross-reacted with plant CuZn-SODs but did not recognize either plant Mn-SOD or bacterial Fe-SOD. The antiSOD-immunoglobulin G showed a weak cross-reaction with bovine erythrocytes and liver CuZn-SODs, and also with cell-free extracts from trout liver. The possible function of this CuZn-SOD in the oxidative metabolism of peroxisomes is discussed. PMID:7630940

  12. Over-expression of superoxide dismutase exhibits lignification of vascular structures in Arabidopsis thaliana.

    PubMed

    Gill, Tejpal; Sreenivasulu, Yelam; Kumar, Sanjay; Ahuja, Paramvir Singh

    2010-06-15

    The present study demonstrated that over-expression of copper-zinc superoxide dismutase (Cu/Zn-SOD), an important enzyme scavenging reactive oxygen species, improved vascular structures through lignification and imparted tolerance to salt stress (NaCl) in Arabidopsis thaliana (Arabidopsis; accession Col-0). Transgenic plants of Arabidopsis were developed by over-expressing cytosolic Cu/Zn-SOD from Potentilla atrosanguinea under CaMV35S promoter via Agrobacterium tumefaciens mediated transformation. Homozygous T(3) lines were analyzed for morphological, anatomical and molecular differences in response to salt stress. The transgenic plants showed higher germination and survival percentage, larger root length, larger rosette area and the higher number of leaves as compared to the wild type (WT) under NaCl stress. Anatomical studies of the inflorescence stem revealed significant thickening of inter-vesicular cambium in transgenics under NaCl stress as compared to the (i) WT and the transgenics raised in the absence of NaCl stress, as well as (ii) WT raised under NaCl stress. This thickening was possibly due to lignification as evidenced by the confocal microscopy. Also, the up-regulation of transcripts of critical genes of lignin biosynthesis, phenylalanine ammonia-lyase1 (PAL1) and peroxidase (PRXR9GE) in the transgenics supported lignification of vascular tissue under the above stated conditions. Results have been discussed on the possible implication of over-expression of PaSOD in lignification of vascular structure under NaCl stress in Arabidopsis. Copyright 2010 Elsevier GmbH. All rights reserved.

  13. Superoxide dismutase reduces the impairment of endothelium-dependent relaxation in the spontaneously hypertensive rat aorta.

    PubMed

    Sekiguchi, Fumiko; Yanamoto, Aiko; Sunano, Satoru

    2004-04-01

    The involvement of the superoxide anion in endothelium-dependent relaxation (EDR) was examined in noradrenaline-contracted aortic smooth muscle preparations isolated from normotensive Wistar Kyoto rats (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP). Acetylcholine (ACh, 10(-9)-10(-5) M) induced EDR in both WKY and SHRSP preparations in a concentration-dependent manner, but with a significantly smaller amplitude in those from SHRSP than in those from WKY. The ACh-induced EDR was inhibited by N(omega)-nitro-L-arginine (L-NOARG), in a concentration-dependent manner, both in WKY and SHRSP. The EDR produced in WKY in the presence of 3 x 10(-6) M L-NOARG was similar in magnitude to that produced in SHRSP in the absence of L-NOARG. Superoxide dismutase (SOD, 300 units/ml) increased the amplitude of EDR in SHRSP but not in WKY, with no alteration of the threshold or of the maximal amplitude. The maximal amplitude of EDR produced in SHRSP in the presence of SOD was still smaller than that in WKY. In WKY, a possible involvement of superoxide in the EDR was examined in aortae whose EDR was partially inhibited by treatment with a subthreshold concentration (3 x 10 (-6) M) of L-NOARG. In the L-NOARG-conditioned aorta, the reduced EDR was partially but significantly recovered by SOD. These results suggest that the impaired EDR in aortae of SHRSP may be causally related to a higher production of superoxide. The L-NOARG-induced inhibition of EDR in WKY may be produced, in part, by the reduction of effective NO due to its destruction by superoxide.

  14. Glycation in Demetalated Superoxide Dismutase 1 Prevents Amyloid Aggregation and Produces Cytotoxic Ages Adducts

    PubMed Central

    Sirangelo, Ivana; Vella, Filomena M.; Irace, Gaetano; Manco, Giuseppe; Iannuzzi, Clara

    2016-01-01

    Superoxide dismutase 1 (SOD1) has been implicated with familial amyotrophic lateral sclerosis (fALS) through accumulation of protein amyloid aggregates in motor neurons of patients. Amyloid aggregates and protein inclusions are a common pathological feature of many neurological disorders in which protein aggregation seems to be directly related to neurotoxicity. Although, extensive studies performed on the aggregation process of several amyloidogenic proteins in vitro allowed the identification of many physiological factors involved, the molecular mechanisms underlying the formation of amyloid aggregates in vivo and in pathological conditions are still poorly understood. Post-translational modifications are known to affect protein structure and function and, recently, much attention has been devoted to the role played by non-enzymatic glycation in stimulating amyloid aggregation and cellular toxicity. In particular, glycation seems to have a determining role both in sporadic and familial forms of ALS and SOD1 has been shown to be glycated in vivo The aim of this study was to investigate the role of glycation on the amyloid aggregation process of both wild-type SOD1 and its ALS-related mutant G93A. To this aim, the glycation kinetics of both native and demetalated SOD have been followed using two different glycating agents, i.e., D-ribose and methylglyoxal. The effect of glycation on the structure and the amyloid aggregation propensity of native and ApoSOD has been also investigated using a combination of biophysical and biochemical techniques. In addition, the effect of SOD glycated species on cellular toxicity and reactive oxygen species (ROS) production has been evaluated in different cellular models. The results provided by this study contribute to clarify the role of glycation in amyloid aggregation and suggest a direct implication of glycation in the pathology of fALS. PMID:27695694

  15. A computational combinatorial approach identifies a protein inhibitor of superoxide dismutase 1 misfolding, aggregation, and cytotoxicity.

    PubMed

    Banerjee, Victor; Oren, Ofek; Ben-Zeev, Efrat; Taube, Ran; Engel, Stanislav; Papo, Niv

    2017-09-22

    Molecular agents that specifically bind and neutralize misfolded and toxic superoxide dismutase 1 (SOD1) mutant proteins may find application in attenuating the disease progression of familial amyotrophic lateral sclerosis. However, high structural similarities between the wild-type and mutant SOD1 proteins limit the utility of this approach. Here we addressed this challenge by converting a promiscuous natural human IgG-binding domain, the hyperthermophilic variant of protein G (HTB1), into a highly specific aggregation inhibitor (designated HTB1M) of two familial amyotrophic lateral sclerosis-linked SOD1 mutants, SOD1(G93A) and SOD1(G85R) We utilized a computational algorithm for mapping protein surfaces predisposed to HTB1 intermolecular interactions to construct a focused HTB1 library, complemented with an experimental platform based on yeast surface display for affinity and specificity screening. HTB1M displayed high binding specificity toward SOD1 mutants, inhibited their amyloid aggregation in vitro, prevented the accumulation of misfolded proteins in living cells, and reduced the cytotoxicity of SOD1(G93A) expressed in motor neuron-like cells. Competition assays and molecular docking simulations suggested that HTB1M binds to SOD1 via both its α-helical and β-sheet domains at the native dimer interface that becomes exposed upon mutated SOD1 misfolding and monomerization. Our results demonstrate the utility of computational mapping of the protein-protein interaction potential for designing focused protein libraries to be used in directed evolution. They also provide new insight into the mechanism of conversion of broad-spectrum immunoglobulin-binding proteins, such as HTB1, into target-specific proteins, thereby paving the way for the development of new selective drugs targeting the amyloidogenic proteins implicated in a variety of human diseases. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. 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 μM) 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.

  17. Complete Amino Acid Sequence of a Copper/Zinc-Superoxide Dismutase from Ginger Rhizome.

    PubMed

    Nishiyama, Yuki; Fukamizo, Tamo; Yoneda, Kazunari; Araki, Tomohiro

    2017-04-01

    Superoxide dismutase (SOD) is an antioxidant enzyme protecting cells from oxidative stress. Ginger (Zingiber officinale) is known for its antioxidant properties, however, there are no data on SODs from ginger rhizomes. In this study, we purified SOD from the rhizome of Z. officinale (Zo-SOD) and determined its complete amino acid sequence using N terminal sequencing, amino acid analysis, and de novo sequencing by tandem mass spectrometry. Zo-SOD consists of 151 amino acids with two signature Cu/Zn-SOD motifs and has high similarity to other plant Cu/Zn-SODs. Multiple sequence alignment showed that Cu/Zn-binding residues and cysteines forming a disulfide bond, which are highly conserved in Cu/Zn-SODs, are also present in Zo-SOD. Phylogenetic analysis revealed that plant Cu/Zn-SODs clustered into distinct chloroplastic, cytoplasmic, and intermediate groups. Among them, only chloroplastic enzymes carried amino acid substitutions in the region functionally important for enzymatic activity, suggesting that chloroplastic SODs may have a function distinct from those of SODs localized in other subcellular compartments. The nucleotide sequence of the Zo-SOD coding region was obtained by reverse-translation, and the gene was synthesized, cloned, and expressed. The recombinant Zo-SOD demonstrated pH stability in the range of 5-10, which is similar to other reported Cu/Zn-SODs, and thermal stability in the range of 10-60 °C, which is higher than that for most plant Cu/Zn-SODs but lower compared to the enzyme from a Z. officinale relative Curcuma aromatica.

  18. Association of the Metabolic Syndrome with Antioxidant Defense and Outstanding Superoxide Dismutase Activity in Mexican Subjects.

    PubMed

    Baez-Duarte, Blanca G; Zamora-Ginez, Irma; De Jésus, Karina Luna; Torres-Rasgado, Enrique; González-Mejía, M Elba; Porchia, Leonardo; Ruiz-Vivanco, Guadalupe; Pérez-Fuentes, Ricardo

    2016-04-01

    Metabolic syndrome (MetS) is considered a public health problem worldwide. Recently, oxidative stress (OS) has been proposed as a factor related with the genesis of MetS. Different studies have reported decreased antioxidant defense, such as superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRed) activities, and reduced glutathione (GSH) concentration, and, on the other hand, an increase in nitrotyrosine concentration in MetS patients. However, it is not known whether there is a direct association of antioxidant defense with MetS in a Mexican population. The aim of the study was to determine the relationship between antioxidant defense and MetS in Mexican subjects. The subjects were Mexican mestizos, who were anthropometrically, biochemically, and clinically characterized. MetS was diagnosed by National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III)-modified criteria. Antioxidant defense was determined by activity of SOD, GPx, GRed, and GSH concentrations; as a marker of OS, nitrotyrosine concentration was determined. The study included 376 subjects, among whom 152 subjects had MetS and 224 were assigned to the non-MetS group. Statistical association was found between MetS and SOD activity (Odds ratio: 167.1; P < 0.01; adjusted by age, gender, and waist circumference). It is noteworthy that a significant correlation between antioxidant defense (SOD and GPx activities, and GSH) and different MetS components was found and between MetS and nitrotyrosine concentration (P < 0.05). The results indicate that SOD activity is associated with MetS in Mexican subjects, allowing us to suggest that this enzyme plays an important role in the pathophysiology of MetS.

  19. Formation of high-order oligomers by a hyperthemostable Fe-superoxide dismutase (tcSOD).

    PubMed

    Wang, Sha; Dong, Zhi-Yang; Yan, Yong-Bin

    2014-01-01

    Hyperthermostable proteins are highly resistant to various extreme conditions. Many factors have been proposed to contribute to their ultrahigh structural stability. Some thermostable proteins have larger oligomeric size when compared to their mesophilic homologues. The formation of compact oligomers can minimize the solvent accessible surface area and increase the changes of Gibbs free energy for unfolding. Similar to mesophilic proteins, hyperthermostable proteins also face the problem of unproductive aggregation. In this research, we investigated the role of high-order oligomerization in the fight against aggregation by a hyperthermostable superoxide dismutase identified from Tengchong, China (tcSOD). Besides the predominant tetramers, tcSOD could also form active high-order oligomers containing at least eight subunits. The dynamic equilibrium between tetramers and high-order oligomers was not significantly affected by pH, salt concentration or moderate temperature. The secondary and tertiary structures of tcSOD remained unchanged during heating, while cross-linking experiments showed that there were conformational changes or structural fluctuations at high temperatures. Mutational analysis indicated that the last helix at the C-terminus was involved in the formation of high-order oligomers, probably via domain swapping. Based on these results, we proposed that the reversible conversion between the active tetramers and high-order oligomers might provide a buffering system for tcSOD to fight against the irreversible protein aggregation pathway. The formation of active high-order oligomers not only increases the energy barrier between the native state and unfolded/aggregated state, but also provides the enzyme the ability to reproduce the predominant oligomers from the active high-order oligomers.

  20. The Phylogeny and Active Site Design of Eukaryotic Copper-only Superoxide Dismutases

    SciTech Connect

    Peterson, Ryan L.; Galaleldeen, Ahmad; Villarreal, Johanna; Taylor, Alexander B.; Cabelli, Diane E.; Hart, P. John; Culotta, Valeria C.

    2016-08-17

    In eukaryotes the bimetallic Cu/Zn superoxide dismutase (SOD) enzymes play important roles in the biology of reactive oxygen species by disproportionating superoxide anion. We reported that the fungal pathogen Candida albicans expresses a novel copper-only SOD, known as SOD5, that lacks the zinc cofactor and electrostatic loop (ESL) domain of Cu/Zn-SODs for substrate guidance. In spite of these abnormalities, C. albicans SOD5 can disproportionate superoxide at rates limited only by diffusion. Here we demonstrate that this curious copper-only SOD occurs throughout the fungal kingdom as well as in phylogenetically distant oomycetes or “pseudofungi” species. It is the only form of extracellular SOD in fungi and oomycetes, in stark contrast to the extracellular Cu/Zn-SODs of plants and animals. Through structural biology and biochemical approaches we demonstrate that these copper-only SODs have evolved with a specialized active site consisting of two highly conserved residues equivalent to SOD5 Glu-110 and Asp-113. The equivalent positions are zinc binding ligands in Cu/Zn-SODs and have evolved in copper-only SODs to control catalysis and copper binding in lieu of zinc and the ESL. Similar to the zinc ion in Cu/Zn-SODs, SOD5 Glu-110 helps orient a key copper-coordinating histidine and extends the pH range of enzyme catalysis. Furthermore, SOD5 Asp-113 connects to the active site in a manner similar to that of the ESL in Cu/Zn-SODs and assists in copper cofactor binding. Copper-only SODs are virulence factors for certain fungal pathogens; thus this unique active site may be a target for future anti-fungal strategies.

  1. Functional characterization and expression of a cytosolic iron-superoxide dismutase from cowpea root nodules.

    PubMed

    Moran, Jose F; James, Euan K; Rubio, Maria C; Sarath, Gautam; Klucas, Robert V; Becana, Manuel

    2003-10-01

    An iron-superoxide dismutase (FeSOD) with an unusual subcellular localization, VuFeSOD, has been purified from cowpea (Vigna unguiculata) nodules and leaves. The enzyme has two identical subunits of 27 kD that are not covalently bound. Comparison of its N-terminal sequence (NVAGINLL) with the cDNA-derived amino acid sequence showed that VuFeSOD is synthesized as a precursor with seven additional amino acids. The mature protein was overexpressed in Escherichia coli, and the recombinant enzyme was used to generate a polyclonal monospecific antibody. Phylogenetic and immunological data demonstrate that there are at least two types of FeSODs in plants. An enzyme homologous to VuFeSOD is present in soybean (Glycine max) and common bean (Phaseolus vulgaris) nodules but not in alfalfa (Medicago sativa) and pea (Pisum sativum) nodules. The latter two species also contain FeSODs in the leaves and nodules, but the enzymes are presumably localized to the chloroplasts and plastids. In contrast, immunoblots of the soluble nodule fraction and immunoelectron microscopy of cryo-processed nodule sections demonstrate that VuFeSOD is localized to the cytosol. Immunoblot analysis showed that the content of VuFeSOD protein increases in senescent nodules with active leghemoglobin degradation, suggesting a direct or indirect (free radical-mediated) role of the released Fe in enzyme induction. Therefore, contrary to the widely held view, FeSODs in plants are not restricted to the chloroplasts and may become an important defensive mechanism against the oxidative stress associated with senescence.

  2. The Phylogeny and Active Site Design of Eukaryotic Copper-only Superoxide Dismutases

    DOE PAGES

    Peterson, Ryan L.; Galaleldeen, Ahmad; Villarreal, Johanna; ...

    2016-08-17

    In eukaryotes the bimetallic Cu/Zn superoxide dismutase (SOD) enzymes play important roles in the biology of reactive oxygen species by disproportionating superoxide anion. We reported that the fungal pathogen Candida albicans expresses a novel copper-only SOD, known as SOD5, that lacks the zinc cofactor and electrostatic loop (ESL) domain of Cu/Zn-SODs for substrate guidance. In spite of these abnormalities, C. albicans SOD5 can disproportionate superoxide at rates limited only by diffusion. Here we demonstrate that this curious copper-only SOD occurs throughout the fungal kingdom as well as in phylogenetically distant oomycetes or “pseudofungi” species. It is the only form ofmore » extracellular SOD in fungi and oomycetes, in stark contrast to the extracellular Cu/Zn-SODs of plants and animals. Through structural biology and biochemical approaches we demonstrate that these copper-only SODs have evolved with a specialized active site consisting of two highly conserved residues equivalent to SOD5 Glu-110 and Asp-113. The equivalent positions are zinc binding ligands in Cu/Zn-SODs and have evolved in copper-only SODs to control catalysis and copper binding in lieu of zinc and the ESL. Similar to the zinc ion in Cu/Zn-SODs, SOD5 Glu-110 helps orient a key copper-coordinating histidine and extends the pH range of enzyme catalysis. Furthermore, SOD5 Asp-113 connects to the active site in a manner similar to that of the ESL in Cu/Zn-SODs and assists in copper cofactor binding. Copper-only SODs are virulence factors for certain fungal pathogens; thus this unique active site may be a target for future anti-fungal strategies.« less

  3. Superoxide dismutase SodB is a protective antigen against Campylobacter jejuni colonisation in chickens

    PubMed Central

    Chintoan-Uta, Cosmin; Cassady-Cain, Robin L.; Al-Haideri, Halah; Watson, Eleanor; Kelly, Dav