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Sample records for mn-superoxide dismutase single

  1. Regulation of Cu,Zn- and Mn-superoxide dismutase transcription in Saccharomyces cerevisiae.

    PubMed

    Galiazzo, F; Labbe-Bois, R

    1993-01-01

    The regulation of Cu,Zn- and Mn-superoxide dismutases (SOD) was investigated by Northern blotting and gene fusions of SOD1 and SOD2 promoters with the beta-galactosidase reporter gene. Cu,ZnSOD expression was increased 3-fold under glucose derepressing conditions, and decreased 4- to 6-fold by oxygen or heme deficiency. MnSOD expression was increased 5-fold by glucose derepression, and decreased 8- to 10-fold by anaerobiosis and 4- to 5-fold by heme deficiency. Induction by paraquat was modest, about 50% for SOD1 and 100% for SOD2; it was apparently independent of the respiratory chain function. PMID:8417979

  2. Paradoxical Relationship between Mn Superoxide Dismutase Deficiency and Radiation-Induced Cognitive Defects

    PubMed Central

    Corniola, Rikki; Zou, Yani; Leu, David; Fike, John R.; Huang, Ting-Ting

    2012-01-01

    Radiation therapy of the CNS, even at low doses, can lead to deficits in neurocognitive functions. Reduction in hippocampal neurogenesis is usually, but not always, associated with cognitive deficits resulting from radiation therapy. Generation of reactive oxygen species is considered the main cause of radiation-induced tissue injuries, and elevated levels of oxidative stress persist long after the initial cranial irradiation. Consequently, mutant mice with reduced levels of the mitochondrial antioxidant enzyme, Mn superoxide dismutase (MnSOD or Sod2), are expected to be more sensitive to radiation-induced changes in hippocampal neurogenesis and the related functions. In this study, we showed that MnSOD deficiency led to reduced generation of immature neurons in Sod2−/+ mice even though progenitor cell proliferation was not affected. Compared to irradiated Sod2+/+ mice, which showed cognitive defects and reduced differentiation of newborn cells towards the neuronal lineage, irradiated Sod2−/+ mice showed normal hippocampal-dependent cognitive functions and normal differentiation pattern for newborn neurons and astroglia. However, we also observed a disproportional decrease in newborn neurons in irradiated Sod2−/+ following behavioral studies, suggesting that MnSOD deficiency may render newborn neurons more sensitive to stress from behavioral trainings following cranial irradiation. A positive correlation between normal cognitive functions and normal dendritic spine densities in dentate granule cells was observed. The data suggest that maintenance of synaptic connections, via maintenance of dendritic spines, may be important for normal cognitive functions following cranial irradiation. PMID:23145165

  3. Expression of multiple copies of mitochondrially targeted catalase or genomic Mn superoxide dismutase transgenes does not extend the life span of Drosophila melanogaster

    PubMed Central

    Mockett, Robin J.; Sohal, Barbara H.; Sohal, Rajindar S.

    2010-01-01

    The simultaneous overexpression of multiple copies of Mn superoxide dismutase (SOD) and ectopic catalase (mtCat) transgenes in the mitochondria of the fruit fly, Drosophila melanogaster, was shown previously to diminish the life span. The hypothesis tested in the present study was that this effect was due primarily to the presence of one or the other transgene. An alternative hypothesis was that both transgenes have additive, negative effects. Crosses were performed between five pairs of transgenic lines containing single-copy insertions of either mtCat, Mn SOD, or P element vector control transgenes at unique loci, and the life spans of progeny containing two mtCat, Mn SOD or vector insertions were determined. Increasing amounts of mitochondrial catalase activity tended to be associated with decreases in mean life span. Overexpression of two copies of the genomic Mn SOD transgene had no effect on life span. The results do not support the hypothesis that enhanced mitochondrial SOD or catalase activity promotes longevity in flies. PMID:20923705

  4. Modulation of the Activities of Catalase, Cu-Zn, Mn Superoxide Dismutase, and Glutathione Peroxidase in Adipocyte from Ovariectomised Female Rats with Metabolic Syndrome

    PubMed Central

    Guerra, Rebeca Cambray; Zuñiga-Muñoz, Alejandra; Guarner Lans, Verónica; Díaz-Díaz, Eulises; Tena Betancourt, Carlos Alberto; Pérez-Torres, Israel

    2014-01-01

    The aim of this study was to evaluate the association between estrogen removal, antioxidant enzymes, and oxidative stress generated by obesity in a MS female rat model. Thirty two female Wistar rats were divided into 4 groups: Control (C), MS, MS ovariectomized (Ovx), and MS Ovx plus estradiol (E2). MS was induced by administering 30% sucrose to drinking water for 24 weeks. After sacrifice, intra-abdominal fat was dissected; adipocytes were isolated and lipid peroxidation, non-enzymatic antioxidant capacity, and the activities of Cu-Zn and Mn superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined. There were no significant differences in the activities of Cu-Zn, Mn SOD, CAT, and GPx between the C and MS groups, but in the MS Ovx group there was a statistically significant decrease in the activities of these enzymes when compared to MS and MS Ovx+E2. The increased lipid peroxidation and nonenzymatic antioxidant capacity found in MS Ovx was significantly decreased when compared to MS and MS Ovx+E2. In conclusion, the removal of E2 by ovariectomy decreases the activity of the antioxidant enzymes in the intra-abdominal tissue of MS female rats; this is reflected by increased lipid peroxidation and decreased nonenzymatic antioxidant capacity. PMID:24987414

  5. 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

  6. 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. PMID:27293100

  7. Induced overexpression of mitochondrial Mn-superoxide dismutase extends the life span of adult Drosophila melanogaster.

    PubMed Central

    Sun, Jingtao; Folk, Donna; Bradley, Timothy J; Tower, John

    2002-01-01

    A transgenic system ("FLP-out") based on yeast FLP recombinase allowed induced overexpression of MnSOD enzyme in adult Drosophila melanogaster. With FLP-out a brief heat pulse (HP) of young, adult flies triggered the rearrangement and subsequent expression of a MnSOD transgene throughout the adult life span. Control (no HP) and overexpressing (HP) flies had identical genetic backgrounds. The amount of MnSOD enzyme overexpression achieved varied among six independent transgenic lines, with increases up to 75%. Life span was increased in proportion to the increase in enzyme. Mean life span was increased by an average of 16%, with some lines showing 30-33% increases. Maximum life span was increased by an average of 15%, with one line showing as much as 37% increase. Simultaneous overexpression of catalase with MnSOD had no added benefit, consistent with previous observations that catalase is present in excess in the adult fly with regard to life span. Cu/ZnSOD overexpression also increases mean and maximum life span. For both MnSOD and Cu/ZnSOD lines, increased life span was not associated with decreased metabolic activity, as measured by O2 consumption. PMID:12072463

  8. Induced overexpression of mitochondrial Mn-superoxide dismutase extends the life span of adult Drosophila melanogaster.

    PubMed

    Sun, Jingtao; Folk, Donna; Bradley, Timothy J; Tower, John

    2002-06-01

    A transgenic system ("FLP-out") based on yeast FLP recombinase allowed induced overexpression of MnSOD enzyme in adult Drosophila melanogaster. With FLP-out a brief heat pulse (HP) of young, adult flies triggered the rearrangement and subsequent expression of a MnSOD transgene throughout the adult life span. Control (no HP) and overexpressing (HP) flies had identical genetic backgrounds. The amount of MnSOD enzyme overexpression achieved varied among six independent transgenic lines, with increases up to 75%. Life span was increased in proportion to the increase in enzyme. Mean life span was increased by an average of 16%, with some lines showing 30-33% increases. Maximum life span was increased by an average of 15%, with one line showing as much as 37% increase. Simultaneous overexpression of catalase with MnSOD had no added benefit, consistent with previous observations that catalase is present in excess in the adult fly with regard to life span. Cu/ZnSOD overexpression also increases mean and maximum life span. For both MnSOD and Cu/ZnSOD lines, increased life span was not associated with decreased metabolic activity, as measured by O2 consumption. PMID:12072463

  9. 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

  10. Superoxide dismutase during glucose repression of Hansenula polymorpha CBS 4732.

    PubMed

    Hristozova, Tsonka; Rasheva, Tanya; Nedeva, Trayana; Kujumdzieva, Anna

    2002-01-01

    Hansenula polymorpha CBS 4732 was studied during cultivation on methanol and different glucose concentrations. Activities of Cu/Zn and Mn superoxide dismutase, catalase and methanol oxidase were investigated. During cultivation on methanol, increased superoxide dismutase and catalase activities and an induced methanol oxidase were achieved. Transfer of a methanol grown culture to medium with a high glucose concentration caused growth inhibition, low consumption of carbon, nitrogen and phosphate substrates, methanol oxidase inactivation as well as decrease of catalase activity (21.8 +/- 0.61 deltaE240 x min(-1) x mg protein(-1)). At the same time, a high value for superoxide dismutase enzyme was found (42.9 +/- 0.98 U x mg protein(-1), 25% of which was represented by Mn superoxide dismutase and 75% - by the Cu/Zn type). During derepression methanol oxidase was negligible (0.005 +/- 0.0001 U x mg protein(-1)), catalase tended to be the same as in the repressed culture, while superoxide dismutase activity increased considerably (63.67 +/- 1.72 U x mg protein(-1), 69% belonging to the Cu/Zn containing enzyme). Apparently, the cycle of growth inhibition and reactivation of Hansenula polymorpha CBS 4732 cells is strongly connected with the activity of the enzyme superoxide dismutase. PMID:12064733

  11. 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.

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

    PubMed Central

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

    2005-01-01

    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. PMID:16511113

  13. 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.

  14. 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...

  15. Effects of a single exposure to UVB radiation on the activities and protein levels of copper-zinc and manganese superoxide dismutase in cultured human keratinocytes.

    PubMed

    Sasaki, H; Akamatsu, H; Horio, T

    1997-04-01

    Ultraviolet B irradiation has been believed to decrease or impair the activity of reactive oxygen species (ROS) scavenging enzymes such as superoxide dismutase (SOD) in the skin. It has been recently reported that two isozymes of SOD, namely copper-zinc SOD (Cu-Zn SOD) and manganese SOD (Mn SOD), exist in mammalian cells and that the two enzymes play different roles in living systems. The aim of this study was to investigate changes in SOD activities and protein levels in cultured human keratinocytes after acute UVB irradiation. In addition, the protein levels of Cu-Zn SOD and Mn SOD were quantified separately. A single exposure to UVB irradiation produced an increase in SOD activity and protein level that peaked immediately after UVB irradiation, after which a decline was observed, with subsequent recovery to baseline levels 24 h after irradiation. In individual assays of Mn SOD and Cu-Zn SOD, the amount of Mn SOD protein decreased and then gradually recovered 24 h after irradiation. In contrast, the amount of Cu-Zn SOD protein increased immediately after UVB irradiation, and then gradually declined. To evaluate the mechanisms of these changes, we examined the effects of the cytokines, interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor-alpha (TNF-alpha), which can be secreted from keratinocytes after UVB irradiation, on the SOD activity and protein levels in keratinocytes. Interleukin-1 alpha and TNF-alpha enhanced both the SOD activity and protein level of Mn SOD, while these cytokines had no effect on Cu-Zn SOD protein levels in cultured human keratinocytes after incubation for 24 h. Furthermore, when neutralizing antibodies against IL-1 alpha and TNF-alpha were added separately or together to the culture medium before UVB irradiation, the recovery of total SOD activity and Mn SOD protein level were markedly inhibited 24 h after irradiation. Our results suggest that significant increases in SOD activity and protein level occur as a cutaneous antioxidant

  16. 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.

  17. Manganese accumulation in yeast cells. Electron-spin-resonance characterization and superoxide dismutase activity.

    PubMed

    Galiazzo, F; Pedersen, J Z; Civitareale, P; Schiesser, A; Rotilio, G

    1989-01-01

    Manganese accumulation was studied by room-temperature electron spin resonance (ESR) spectroscopy in Saccharomyces cerevisiae grown in the presence of increasing amounts of MnSO4. Mn2+ retention was nearly linear in intact cells for fractions related to both low-molecular-mass and macromolecular complexes ('free' and 'bound' Mn2+, respectively). A deviation from linearity was observed in cell extracts between the control value and 0.1 mM Mn2+, indicating more efficient accumulation at low Mn2+ concentrations. The difference in slopes between the two straight lines describing Mn2+ retention at concentrations lower and higher than 0.1 mM, respectively, was quite large for the free Mn2+ fraction. Furthermore it was unaffected by subsequent dialyses of the extracts, showing stable retention in the form of low-molecular-mass complexes. In contrast, the slope of the line describing retention of 'bound' Mn2+ at concentrations higher than 0.1 mM became less steep after subsequent dialyses of the cell extracts. This result indicates that the macromolecule-bound Mn2+ was essentially associated with particulate structures. In contrast to Cu2+, Mn2+ had no effect on the major enzyme activities involved in oxygen metabolism except for a slight increase of cyanide-resistant Mn-superoxide dismutase activity, due to dialyzable Mn2+ complexes. PMID:2562042

  18. 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.

  19. Factors Affecting the Enhancement of Oxidative Stress Tolerance in Transgenic Tobacco Overexpressing Manganese Superoxide Dismutase in the Chloroplasts.

    PubMed Central

    Slooten, L.; Capiau, K.; Van Camp, W.; Van Montagu, M.; Sybesma, C.; Inze, D.

    1995-01-01

    Two varieties of tobacco (Nicotiana tabacum var PBD6 and var SR1) were used to generate transgenic lines overexpressing Mn-superoxide dismutase (MnSOD) in the chloroplasts. The overexpressed MnSOD suppresses the activity of those SODs (endogenous MnSOD and chloroplastic and cytosolic Cu/ZnSOD) that are prominent in young leaves but disappear largely or completely during aging of the leaves. The transgenic and control plants were grown at different light intensities and were then assayed for oxygen radical stress tolerance in leaf disc assays and for abundance of antioxidant enzymes and substrates in leaves. Transgenic plants had an enhanced resistance to methylviologen (MV), compared with control plants, only after growth at high light intensities. In both varieties the activities of FeSOD, ascorbate peroxidase, dehydroascorbate reductase, and monodehydroascorbate reductase and the concentrations of glutathione and ascorbate (all expressed on a chlorophyll basis) increased with increasing light intensity during growth. Most of these components were correlated with MV tolerance. It is argued that SOD overexpression leads to enhancement of the tolerance to MV-dependent oxidative stress only if one or more of these components is also present at high levels. Furthermore, the results suggest that in var SR1 the overexpressed MnSOD enhances primarily the stromal antioxidant system. PMID:12228398

  20. Localization of superoxide dismutases in Alzheimer's disease and Down's syndrome neocortex and hippocampus.

    PubMed Central

    Furuta, A.; Price, D. L.; Pardo, C. A.; Troncoso, J. C.; Xu, Z. S.; Taniguchi, N.; Martin, L. J.

    1995-01-01

    Abnormalities in the cellular regulation and expression of antioxidant enzymes may have a role in mechanisms of central nervous system aging and neurodegeneration. We therefore examined, using isozyme-specific antibodies and immunohistochemistry, the localization of copper, zinc-superoxide dismutase and manganese-superoxide dismutase in the frontal and temporal neocortices and hippocampi of aged controls and individuals with Alzheimer's disease or Down's syndrome. Two different antibodies to copper, zinc-superoxide dismutase and one antibody to manganese-superoxide dismutase were evaluated by immunoblotting of homogenates of human brain before use in immunohistochemistry. The copper, zinc-superoxide dismutase antibodies recognized a single band of proteins at 16 kd. The manganese-superoxide dismutase antibody detected a single band of proteins at 25 kd. Immunohistochemically, copper, zinc-superoxide dismutase and manganese-superoxide dismutase immunoreactivities were localized predominantly to neocortical and hippocampal pyramidal neurons and scarcely seen in glial cells in controls. In Alzheimer's disease and Down's syndrome, the distributions and intensities of these two forms of superoxide dismutase immunoreactivities were different as compared with controls. Copper, zinc-superoxide dismutase was enriched in pyramidal neurons undergoing degeneration, whereas manganese-superoxide dismutase was more enriched in reactive astrocytes than in neurons. In senile plaques, copper, zinc-superoxide dismutase-positive globular structures were surrounded by astrocytes highly enriched in manganese-superoxide dismutase. By double label immunohistochemistry, some pyramidal neurons coexpressed superoxide dismutases and tau, and a few copper, zinc-superoxide dismutase-positive structures in senile plaques colocalized with tau. Amyloid cores, diffuse plaques, and microglia scarcely showed colocalization with superoxide dismutase-positive structures. The observed changes in the

  1. 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. PMID:26765960

  2. 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

  3. Preliminary crystallographic analysis of the Megavirus superoxide dismutase.

    PubMed

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

    2012-12-01

    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

  4. 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

  5. Superoxide dismutases of heavy metal resistant streptomycetes.

    PubMed

    Schmidt, Astrid; Schmidt, André; Haferburg, Götz; Kothe, Erika

    2007-02-01

    Heavy metal tolerant and resistant strains of streptomycetes isolated from a former uranium mining site were screened for their superoxide dismutase expression. From the strains tolerating high concentrations of different heavy metals, one was selected for its tolerance of concentrations of heavy metals (Ni, Cu, Cd, Cr, Mn, Zn, Fe). This strain, Streptomyces acidiscabies E13, was chosen for the purpose of superoxide dismutase analysis. Gel electrophoresis and activity staining revealed only one each of a nickel (NiSOD) and an iron (FeZnSOD) containing superoxide dismutase as shown by differential enzymatic repression studies. The gene for nickel containing superoxide dismutase, sodN, was cloned and sequenced from this strain. The genomic sequence shows 92.7% nucleotide identity and 96.1% amino acid identity to sodN of S. coelicolor. Expression can be activated by nickel as well as other heavy metals and active enzyme is produced in media lacking nickel but containing copper, iron or zinc. Thus, the selected strain is well suited for further characterization of the enzyme encoded by sodN. PMID:17304620

  6. 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. PMID:25794772

  7. Superoxide Dismutase in the Symbiont Anabaena azollae Strasb.

    PubMed

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

    1991-09-01

    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. PMID:16668392

  8. 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

  9. Regulation of an in vivo metal-exchangeable superoxide dismutase from Propionibacterium shermanii exhibiting activity with different metal cofactors.

    PubMed Central

    Sehn, A P; Meier, B

    1994-01-01

    The anaerobic, but aerotolerant Propionibacterium freudenreichii sp. shermanii contains a single superoxide dismutase [EC 1.15.1.1.] exhibiting comparable activity with iron or manganese as metal cofactor. The formation of superoxide dismutase is not depending on the supplementation of iron or manganese to the culture medium. Even in the absence of these metals the protein is built in comparable amounts. Bacteria grown in the absence of iron and manganese synthesize a superoxide dismutase with very low activity which had incorporated copper. If the medium was also depleted of copper, cobalt was incorporated, leading to an enzymically inactive form. In the absence of cobalt an enzymically inactive superoxide dismutase was built with unknown metal contents. Upon aeration the amount of superoxide dismutase activity increased continuously up to 9 h, due to a de novo synthesis of the protein. This superoxide dismutase had incorporated iron into the active centre. The superoxide dismutase of Propionibacterium shermanii is able to form a much wider variety of complexes with trace metal ions in vivo than previously recognized, leading to the hypothesis that the original function of these proteins was the binding of cytoplasmic trace metals present in excess. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:7818484

  10. Can superoxide dismutase prevent postburn dermal ischemia?

    PubMed

    Tan, Q; Ma, W X; Wang, L; Chen, H R

    1997-05-01

    Decreasing progressive dermal ischemia after burning could theoretically limit the amount of skin necrosis. It is controversial whether the use of free radical scavengers could prevent the progressive dermal ischemia of the postburn stasis zone. We evaluated the effect of superoxide dismutase (SOD) on preventing postburn dermal ischemia in animal models by the India ink perfusion and skin transparent preparation techniques. The closely clipped backs of guinea-pigs were bathed in 75 degrees C water for 10 s. Within 5 min postburn, SOD-treated groups were administered SOD (10,000 u/kg) intra-peritoneally every 6 h. All animals were perfused with 70 per cent India ink via cervical artery cannula by 16 kPa constant pressure at 0, 8, 16, 24 h postburn, and the skin transparent preparations were made, while the level of malonyl dialdehyde (MDA) in skin tissue was assessed. The results showed that with prolongation of postburn time, the rate of filling of India ink in skin capillary plexuses decreased gradually (p < 0.01). MDA increased continuously, which was related to postburn dermal ischemia (r = 0.689, p < 0.01). Though the level of MDA decreased in SOD-treated groups, the India ink filling rates showed no significant difference between controls and experimental groups (p > 0.05). The results were also confirmed by observation of skin transparent preparations and TEM. This study suggests that superoxide dismutase fails to prevent progressive dermal ischemia after burning. PMID:9232283

  11. Superoxide Dismutase (Sod-1) Null Mutants of Neurospora Crassa: Oxidative Stress Sensitivity, Spontaneous Mutation Rate and Response to Mutagens

    PubMed Central

    Chary, P.; Dillon, D.; Schroeder, A. L.; Natvig, D. O.

    1994-01-01

    Enzymatic superoxide-dismutase activity is believed to be important in defense against the toxic effects of superoxide. Although superoxide dismutases are among the best studied proteins, numerous questions remain concerning the specific biological roles of the various superoxide-dismutase types. In part, this is because the proposed damaging effects of superoxide are manifold, ranging from inactivation of certain metabolic enzymes to DNA damage. Studies with superoxide-deficient mutants have proven valuable, but surprisingly few such studies have been reported. We have constructed and characterized Neurospora crassa mutants that are null for sod-1, the gene that encodes copper-zinc superoxide dismutase. Mutant strains are sensitive to paraquat and elevated oxygen concentrations, and they exhibit an increased spontaneous mutation rate. They appear to have near wild-type sensitivities to near- and far-UV, heat shock and γ-irradiation. Unlike the equivalent Saccharomyces cerevisiae mutant and the sodA sodB double mutant of Escherichia coli, they do not exhibit aerobic auxotrophy. These results are discussed in the context of an attempt to identify consensus phenotypes among superoxide dismutase-deficient mutants. N. crassa sod-1 null mutant strains were also employed in genetic and subcellular fractionation studies. Results support the hypothesis that a single gene (sod-1), located between Fsr-12 and leu-3 on linkage group I, is responsible for most or all CuZn superoxide dismutase activity in this organism. PMID:8088518

  12. Isolation and characterization of Cu/Zn-superoxide dismutase in Fasciola gigantica.

    PubMed

    Lalrinkima, H; Raina, O K; Chandra, Dinesh; Jacob, Siju Susan; Bauri, R K; Chandra, Subhash; Yadav, H S; Singh, M N; Rialch, A; Varghese, A; Banerjee, P S; Kaur, Navneet; Sharma, Arvind

    2015-01-01

    A full-length complementary DNA (cDNA) encoding Cu/Zn-superoxide dismutase was isolated from Fasciola gigantica that on nucleotide sequencing showed a close homology (98.9%) with Cu/Zn-superoxide dismutase (SOD) of the temperate liver fluke, F. hepatica. Expression of the gene was found in all the three developmental stages of the parasite viz. adult, newly excysted juvenile and metacercaria at transcriptional level by reverse transcription-polymerase chain reaction (RT-PCR) and at the protein level by Western blotting. F. gigantica Cu/Zn-SOD cDNA was cloned and expressed in Escherichia coli. Enzyme activity of the recombinant protein was determined by nitroblue tetrazolium (NBT)-polyacrylamide gel electrophoresis (PAGE) and this activity was inactivated by hydrogen peroxide but not by sodium azide, indicating that the recombinant protein is Cu/Zn-SOD. The enzyme activity was relatively stable at a broad pH range of pH 4.0-10.0. Native Cu/Zn-superoxide dismutase protein was detected in the somatic extract and excretory-secretory products of the adult F. gigantica by Western blotting. NBT-PAGE showed a single Cu/Zn-SOD present in the somatic extract while three SODs are released ex vivo by the adult parasite. The recombinant superoxide dismutase did not react with the serum from buffaloes infected with F. gigantica. The role of this enzyme in defense by the parasite against the host reactive oxygen species is discussed. PMID:25655406

  13. 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

  14. 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

  15. 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

  16. Manganese superoxide dismutase: guardian of the powerhouse.

    PubMed

    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

  17. The homopentameric chlorite dismutase from Magnetospirillum sp.

    PubMed

    Freire, Diana M; Rivas, Maria G; Dias, André M; Lopes, Ana T; Costa, Cristina; Santos-Silva, Teresa; Van Doorslaer, Sabine; González, Pablo J

    2015-10-01

    Chlorite dismutase (Cld) is a b-type heme containing enzyme that catalyzes the reduction of chlorite into chloride plus dioxygen. This enzyme has gained attention because it can be used in the development of bioremediation processes, biosensors, and controlled dioxygen production. In the present work, Cld was purified from Magnetospirillum sp. cells cultured anaerobically with acetate/perchlorate until stationary phase. Biochemical, spectroscopic and X-ray crystallography methods showed that Cld from Magnetospirillum sp. is a ~140 kDa homopentamer comprising ~27.8 kDa monomers. Preliminary X-ray crystallography studies confirmed the quaternary structure and the presence of one b-type heme per monomer. The EPR spectroscopic signature of the as-purified Cld samples is affected by the buffer composition used during the purification. Potassium phosphate buffer is the only buffer that affected neither the spectral nor the kinetic properties of Cld. Kinetic studies in solution revealed that Cld from Magnetospirillum sp. decomposes chlorite at high turnover rates with optimal pH6.0. A temperature below 10 °C is required to avoid enzyme inactivation due to cofactor bleaching during turnover, and to achieve full substrate consumption. Cld kinetic parameters were not affected when kinetic assays were performed in the presence of air or under argon atmosphere, but chloride is a weak mixed inhibitor that modifies the EPR signal of as-prepared samples. PMID:26218477

  18. Chemical and physical differentiation of superoxide dismutases in anaerobes.

    PubMed Central

    Gregory, E M; Dapper, C H

    1980-01-01

    Superoxide dismutase activity in crude or partially purified cell extracts from several species and strains of obligate anaerobe Bacteroides was inhibited instantaneously by NaN3 and was inactivated rapidly upon incubation with H2O2. The extent of NaN3 inhibition varied from 41 to 93%, and the half-life of the enzymatic activity in 5 mM H2O2 ranged from 1.2 to 6.1 min, depending upon the organism tests. When grown in a defined medium containing 59Fe, Bacteroides fragilis (VPI 2393) incorporated radiolabel into a 40,000-molecular-weight NaN3- and H2O2-sensitive superoxide dismutase but did not incorporate 54Mn into that protein under similar growth conditions. The anaerobe Actinomyces naeslundii (VPI 9985) incorporated 54Mn but not 59Fe into a NaN3-insensitive and H2O2-resistant superoxide dismutase. The apparent molecular weight of the superoxide dismutase from this and several other Actinomyces spp. was estimated to be 110,000 to 140,000. Comparison of these data with studies of homogeneous metallosuperoxide dismutases suggests that the Bacteroides spp. studied contain a ferrisuperoxide dismutase, whereas Actinomyces spp. contain a managanisuperoxide dismutase. PMID:7440509

  19. 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

  20. Ligand Binding to Chlorite Dismutase from Magnetospirillum sp.

    PubMed

    De Schutter, Amy; Correia, Hugo D; Freire, Diana M; Rivas, María G; Rizzi, Alberto; Santos-Silva, Teresa; González, Pablo J; Van Doorslaer, Sabine

    2015-10-29

    Chlorite dismutase (Cld) catalyzes the reduction of chlorite to chloride and dioxygen. Here, the ligand binding to Cld of Magnetospirillum sp. (MaCld) is investigated with X-ray crystallography and electron paramagnetic resonance (EPR). EPR reveals a large heterogeneity in the structure of wild-type MaCld, showing a variety of low- and high-spin ferric heme forms. Addition of an axial ligand, such as azide or imidazole, removes this heterogeneity almost entirely. This is in line with the two high resolution crystal structures of MaCld obtained in the presence of azide and thiocyanate that show the coordination of the ligands to the heme iron. The crystal structure of the MaCld-azide complex reveals a single well-defined orientation of the azide molecule in the heme pocket. EPR shows, however, a pH-dependent heme structure, probably due to acid-base transitions of the surrounding amino-acid residues stabilizing azide. For the azide and imidazole complex of MaCld, the hyperfine and nuclear quadrupole interactions with the close-by (14)N and (1)H nuclei are determined using pulsed EPR. These values are compared to the corresponding data for the low-spin forms observed in the ferric wild-type MaCld and to existing EPR data on azide and imidazole complexes of other heme proteins. PMID:26287794

  1. Superoxide dismutase is dispensable for normal animal lifespan.

    PubMed

    Van Raamsdonk, Jeremy Michael; Hekimi, Siegfried

    2012-04-10

    Reactive oxygen species (ROS) are toxic oxygen-containing molecules that can damage multiple components of the cell and have been proposed to be the primary cause of aging. The antioxidant enzyme superoxide dismutase (SOD) is the only eukaryotic enzyme capable of detoxifying superoxide, one type of ROS. The fact that SOD is present in all aerobic organisms raises the question as to whether SOD is absolutely required for animal life and whether the loss of SOD activity will result in decreased lifespan. Here we use the genetic model organism Caenorhabditis elegans to generate an animal that completely lacks SOD activity (sod-12345 worms). We show that sod-12345 worms are viable and exhibit a normal lifespan, despite markedly increased sensitivity to multiple stresses. This is in stark contrast to what is observed in other genetic model organisms where the loss of a single sod gene can result in severely decreased survival. Investigating the mechanism underlying the normal lifespan of sod-12345 worms reveals that their longevity results from a balance between the prosurvival signaling and the toxicity of superoxide. Overall, our results demonstrate that SOD activity is dispensable for normal animal lifespan but is required to survive acute stresses. Moreover, our findings indicate that maintaining normal stress resistance is not crucial to the rate of aging. PMID:22451939

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. Cu/Zn superoxide dismutases in developing cotton fibers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. Cloning and differential expression of manganese superoxide dismutase (Mn-SOD) of Trichinella pseudospiralis.

    PubMed

    Wu, W K; Mak, C H; Ko, R C

    2008-01-01

    The complete coding sequence of manganese superoxide dismutase (Mn-SOD) of Trichinella pseudospiralis (Tp) was obtained and characterized for the first time by degenerative reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of complementary DNA ends (RACE) reactions. The open reading frame of Tp Mn-SOD contained 663 nucleotides, encoding 220 amino acid residues. This included the conserved histidine and aspartate residues for metal binding, cysteine residues for disulfide bond formation, and arginine residue for directing the superoxide ion to the protein. The presence of mitochondrial transit peptides and maturation cleavage site suggest that the cloned Tp Mn-SOD gene is a mitochondrial enzyme. It is a single copy gene containing three introns. Northern blotting suggested that the expression level of Mn-SOD is lower than Cu/Zn SOD in infective stage larvae. Semi-quantitative RT-PCR demonstrated that a single dominant transcript of Tp Mn-SOD was highly expressed in the infective-stage larvae but not in adult worms. The information provides a better understanding of the highly compartmentalized superoxide dismutases of adenophorean nematodes. PMID:17955260

  8. Heterodimeric structure of superoxide dismutase in complex with its metallochaperone

    SciTech Connect

    Lamb, A.L.; Torres, A.S.; O'Halloran, T.V.; Rosenzweig, A.C.

    2010-03-08

    The copper chaperone for superoxide dismutase (CCS) activates the eukaryotic antioxidant enzyme copper, zinc superoxide dismutase (SOD1). The 2.9 {angstrom} resolution structure of yeast SOD1 complexed with yeast CCS (yCCS) reveals that SOD1 interacts with its metallochaperone to form a complex comprising one monomer of each protein. The heterodimer interface is remarkably similar to the SOD1 and yCCS homodimer interfaces. Striking conformational rearrangements are observed in both the chaperone and target enzyme upon complex formation, and the functionally essential C-terminal domain of yCCS is well positioned to play a key role in the metal ion transfer mechanism. This domain is linked to SOD1 by an intermolecular disulfide bond that may facilitate or regulate copper delivery.

  9. Superoxide dismutase protects cultured neurons against death by starvation.

    PubMed Central

    Sáez, J C; Kessler, J A; Bennett, M V; Spray, D C

    1987-01-01

    Brief substrate deprivation resulted in high mortality of superior cervical ganglion neurons in culture, assayed 2 hr later by trypan blue exclusion. Involvement of superoxide anions was indicated by several observations. Survival was increased significantly by prior treatment that induced cells to take up superoxide dismutase. During starvation, neurons reduced nitroblue tetrazolium to form the blue precipitate formazan, and the color change was blocked in neurons preloaded with superoxide dismutase. The incidence of staining was comparable to the mortality. In many cells, brief starvation caused the appearance of fluorescence due to oxidation of 2',7'-dichlorofluorescin to dichlorofluorescein, which indicates that oxidants were generated intracellularly. In some cells fluorescence was transient, as would be caused by membrane breakdown, and these cells were then shown to be dead. Superoxide generation caused by substrate deprivation may contribute importantly to cell damage in a variety of pathological conditions. Images PMID:3472251

  10. Cloning, expression, and characterization of thermostable manganese superoxide dismutase from Thermoascus aurantiacus var. levisporus.

    PubMed

    Song, Ning-Ning; Zheng, Yan; E, Shi-Jin; Li, Duo-Chuan

    2009-02-01

    A superoxide dismutase (SOD) gene of Thermoascus aurantiacus var. levisporus, a thermophilic fungus, was cloned, sequenced, and expressed in Pichia pastoris and its gene product was characterized. The coding sequence predicted a 231 residues protein with a unique 35 amino acids extension at the N-terminus indicating a mitochondrial-targeting sequence. The content of Mn was 2.46 microg/mg of protein and Fe was not detected in the purified enzyme. The enzyme was found to be inhibited by NaN(3), but not by KCN or H(2)O(2). These results suggested that the SOD in Thermoascus aurantiacus var. levisporus was the manganese superoxide dismutase type. In comparison with other MnSODs, all manganese-binding sites were also conserved in the sequence (H88, H136, D222, H226). The molecular mass of a single band of the enzyme was estimated to be 21.7 kDa. The protein was expressed in tetramer form with molecular weight of 68.0 kDa. The activity of purified protein was 2,324 U/mg. The optimum temperature of the enzyme was 55 degrees C and it exhibited maximal activity at pH 7.5. The enzyme was thermostable at 50 and 60 degrees C and the half-life at 80 degrees C was approximately 40 min. PMID:19229500

  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. 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

  13. Superoxide dismutase activity in needles of Norwegian spruce trees (Picea abies L. )

    SciTech Connect

    Polle, A.; Krings, B.; Rennenberg, H. Universitaet zu Koeln )

    1989-08-01

    The activity of superoxide dismutase was investigated in needles of spruce trees. To obtain maximum activity, needles were homogenized in the presence of Triton X-100 and polyvinylpyrrolidone. Superoxide dismutase activity was measured in dialyzed extracts with a modified epinephrine assay at pH 10.2. The extracts contained 70 to 120 units of superoxide dismutase per milligram protein. One unit of superoxide dismutase was completely inhibited in the presence of 20 micromolar NaCN. On native polyacrylamide gels three electromorphs were visualized after staining for activity. All three species were sensitive to CN{sup {minus}} and H{sub 2}O{sub 2} and were therefore assumed to be Cu/Zn-superoxide dismutases. Superoxide dismutase activity was dependent on the age of the needles and declined by approximately 25% within 3 to 4 years.

  14. Sources of marine superoxide dismutases: Characteristics and applications.

    PubMed

    Zeinali, Farrokhzad; Homaei, Ahmad; Kamrani, Ehsan

    2015-08-01

    The ability of marine organism to cope with oxidative stress is one of the main factors that influence its survival in the marine environment, when senescence conditions prevail. The antioxidative defense system includes enzymatic and non-enzymatic components. Among the enzymatic system, superoxide dismutases are the first and most important of the antioxidant metalloenzymes. Four different types of metal centers have been detected in SODs, dividing this family into Cu/Zn, Ni, Mn and Fe-SODs. Its use was limited to non-drug applications in humans (include: cosmetic, food, agriculture, and chemical industries) and drug applications in animals. This paper is a review of the recent literatures on sources of marine SODs, the need for SOD and different applications in industry, covering the last decades. The most recent paper, patents and reviews on characterization and application are reviewed. PMID:26047895

  15. 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

  16. 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.

  17. 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. PMID:24283977

  18. 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

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

    PubMed

    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

  20. Effect of the superoxide dismutase inhibitor, diethyldithiocarbamate, on the cytotoxicity of mitomycin antibiotics.

    PubMed

    Pritsos, C A; Keyes, S R; Sartorelli, A C

    1989-10-01

    Mitomycin C (MC) and its structural analogs porfiromycin (PM), BMY-25282 and BL-6783 are toxic to EMT6 cells under aerobic and hypoxic conditions. The mitomycin antibiotics are hypothesized to exert cytotoxicity under hypoxic conditions by cross-linking DNA following reductive activation, while aerobic cytotoxicity may involve DNA cross-linking by these agents and/or damage due to the generation of oxygen radicals. Previous findings (Pritsos and Sartorelli, 1986) indicated that the rank order of cytotoxicity for a series of mitomycins was the same as the rank order for the rate of oxygen consumption induced by these agents. As an additional approach to explore the role of oxygen radicals in the aerobic cytotoxicity of the four agents studied, EMT6 cells were treated with the mitomycins in the presence of the superoxide dismutase inhibitor diethyldithiocarbamate (DETC). DETC, which decreased superoxide dismutase activity in EMT6 cells, increased the cytotoxicity of BMY-25282 and BL-6783 by half an order of magnitude, but did not affect the toxicity of PM or MC to these cells. DNA cross-links, a proposed cytotoxic lesion induced by BMY-25282, however, were not detectably increased in EMT6 cells exposed to this agent in the presence of DETC in spite of the large increase in cytotoxicity under these treatment conditions. No single strand breaks were detected in cells exposed to either BMY-25282 or BMY-25282 plus DETC. The findings support the concept that oxygen radicals may have a role in the aerobic cytotoxicity of some of the mitomycin antibiotics, and that the lesions responsible for cytotoxicity produced by oxygen radicals may not reside entirely at the level of DNA. PMID:2559790

  1. Cobalt substitution studies on bovine erythrocyte superoxide dismutase: evidence for a novel cobalt-superoxide dismutase derivative.

    PubMed

    Salvato, B; Beltramini, M; Ricchelli, F; Tallandini, L

    1989-09-14

    Three cobalt derivatives of bovine erythrocyte superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1) have been prepared under different pH conditions using a cobalt-thiocyanate complex which has already proved to yield specific substitutions on other copper proteins. The cobalt-protein derivatives have been characterized by optical, circular dichroism and fluorescence spectroscopies. One derivative, referred to as Co2Co2-protein, contains Co(II) ions specifically bound at both Zn(II) and Cu(II) sites. On the basis of their spectroscopic properties, the other two derivatives can be referred as E2Co2- and Co2E2-superoxide dismutase, with cobalt substituting, respectively, at the zinc and the copper sites leaving the contiguous site empty (E). The Co2E2-protein complex represents a novel derivative, since it has never been described in literature. The optical spectrum in the visible region of Co2-Co2-protein well corresponds to the sum of the spectra of the other two derivatives. The circular dichroism spectrum of Co2Co2-derivative, however, is not the sum of individual E2Co2- and Co2E2-proteins, suggesting that the presence of Co(II) in one site strongly affects the geometry of the neighbouring site. Some discrepancies between our spectroscopic data and those reported in literature are discussed. The results obtained from fluorescence experiments indicate that Co(II) ions exert a different quenching effect on the tyrosine emission, depending on whether they are located in the Zn(II) or in the Cu(II) site. The fluorescence quenching can be attributed to a 'heavy atom' and 'paramagnetic ion' effect by Co(II) ions. PMID:2790051

  2. An Enzyme-Based Theory of Obligate Anaerobiosis: The Physiological Function of Superoxide Dismutase

    PubMed Central

    McCord, Joe M.; Keele, Bernard B.; Fridovich, Irwin

    1971-01-01

    The distribution of catalase and superoxide dismutase has been examined in various micro-organisms. Strict anaerobes exhibited no superoxide dismutase and, generally, no catalase activity. All aerobic organisms containing cytochrome systems were found to contain both superoxide dismutase and catalase. Aerotolerant anaerobes, which survive exposure to air and metabolize oxygen to a limited extent but do not contain cytochrome systems, were found to be devoid of catalase activity but did exhibit superoxide dismutase activity. This distribution is consistent with the proposal that the prime physiological function of superoxide dismutase is protection of oxygen-metabolizing organisms against the potentially detrimental effects of the superoxide free radical, a biologically produced intermediate resulting from the univalent reduction of molecular oxygen. PMID:4995818

  3. 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.

  4. A novel nickel-containing superoxide dismutase from Streptomyces spp.

    PubMed Central

    Youn, H D; Kim, E J; Roe, J H; Hah, Y C; Kang, S O

    1996-01-01

    A novel type of superoxide dismutase (SOD) was purified to apparent homogeneity from the cytosolic fractions of Streptomyces sp. IMSNU-1 and Strep. coelicolor ATCC 10147 respectively. Both enzymes were composed of four identical subunits of 13.4 kDa, were stable at pH 4.0-8.0 and up to 70 degrees C, and were inhibited by cyanide and H2O2 but little inhibited by azide. The atomic absorption analyses revealed that both enzymes contain 0.74 g-atom of nickel per mol of subunit. Both enzymes were different from iron-containing SOD and manganese-containing SOD from Escherichia coli, and copper- and zinc-containing SODs from Saccharomyces cerevisiae and bovine erythrocytes, with respect to amino acid composition, N-terminal amino acid sequence and cross-reactivity against antibody. The absorption spectra of both enzymes were identical, exhibiting maxima at 276 and 378 nm, and a broad peak at 531 nm. The EPR spectra of both enzymes were almost identical with that of NiIII in a tetragonal symmetry of NiIII-oligopeptides especially containing histidine. The apoenzymes, lacking in nickel, had no ability to mediate the conversion of superoxide anion radical to hydrogen peroxide, strongly indicating that NiIII plays a main role in these enzymes. PMID:8836134

  5. 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

  6. Modifications of Superoxide Dismutase (SOD1) in Human Erythrocytes

    PubMed Central

    Wilcox, Kyle C.; Zhou, Li; Jordon, Joshua K.; Huang, Yi; Yu, Yanbao; Redler, Rachel L.; Chen, Xian; Caplow, Michael; Dokholyan, Nikolay V.

    2009-01-01

    Over 100 mutations in Cu/Zn-superoxide dismutase (SOD1) result in familial amyotrophic lateral sclerosis. Dimer dissociation is the first step in SOD1 aggregation, and studies suggest nearly every amino acid residue in SOD1 is dynamically connected to the dimer interface. Post-translational modifications of SOD1 residues might be expected to have similar effects to mutations, but few modifications have been identified. Here we show, using SOD1 isolated from human erythrocytes, that human SOD1 is phosphorylated at threonine 2 and glutathionylated at cysteine 111. A second SOD1 phosphorylation was observed and mapped to either Thr-58 or Ser-59. Cysteine 111 glutathionylation promotes SOD1 monomer formation, a necessary initiating step in SOD1 aggregation, by causing a 2-fold increase in the Kd. This change in the dimer stability is expected to result in a 67% increase in monomer concentration, 315 nm rather than 212 nm at physiological SOD1 concentrations. Because protein glutathionylation is associated with redox regulation, our finding that glutathionylation promotes SOD1 monomer formation supports a model in which increased oxidative stress promotes SOD1 aggregation. PMID:19299510

  7. 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.

  8. A manganese porphyrin superoxide dismutase mimetic enhances tumor radioresponsiveness

    SciTech Connect

    Moeller, Benjamin J.; Batinic-Haberle, Ines; Spasojevic, Ivan; Rabbani, Zahid N.; Anscher, Mitchell S.; Vujaskovic, Zeljko; Dewhirst, Mark W. D.V.M. . E-mail: dewhirst@radonc.duke.edu

    2005-10-01

    Purpose: To determine the effect of the superoxide dismutase mimetic Mn(III) tetrakis(N-ethylpyridinium-2-yl)porphyrin (MnTE-2-PyP{sup 5+}) on tumor radioresponsiveness. Methods and Materials: Various rodent tumor (4T1, R3230, B16) and endothelial (SVEC) cell lines were exposed to MnTE-2-PyP{sup 5+} and assayed for viability and radiosensitivity in vitro. Next, tumors were treated with radiation and MnTE-2-PyP{sup 5+} in vivo, and the effects on tumor growth and vascularity were monitored. Results: In vitro, MnTE-2-PyP{sup 5+} was not significantly cytotoxic. However, at concentrations as low as 2 {mu}mol/L it caused 100% inhibition of secretion by tumor cells of cytokines protective of irradiated endothelial cells. In vivo, combined treatment with radiation and MnTE-2-PyP{sup 5+} achieved synergistic tumor devascularization, reducing vascular density by 78.7% within 72 h of radiotherapy (p < 0.05 vs. radiation or drug alone). Co-treatment of tumors also resulted in synergistic antitumor effects, extending tumor growth delay by 9 days (p < 0.01). Conclusions: These studies support the conclusion that MnTE-2-PyP{sup 5+}, which has been shown to protect normal tissues from radiation injury, can also improve tumor control through augmenting radiation-induced damage to the tumor vasculature.

  9. 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.

  10. Mice lacking extracellular superoxide dismutase are more sensitive to hyperoxia.

    PubMed Central

    Carlsson, L M; Jonsson, J; Edlund, T; Marklund, S L

    1995-01-01

    Extracellular superoxide dismutase (EC-SOD; superoxide:superoxide oxidoreductase, EC 1.15.1.1) is a secreted Cu- and Zn-containing tetrameric glycoprotein, the bulk of which is bound to heparan sulfate proteoglycans in the interstitium of tissues. To test the function of EC-SOD in vivo, mice carrying a targeted disruption of the EC-SOD gene were generated. The EC-SOD null mutant mice develop normally and remain healthy until at least 14 months of age. No compensatory induction of other SOD isoenzymes or other antioxidant enzymes was observed. When stressed by exposure to > 99% oxygen, the EC-SOD null mutant mice display a considerable reduction in survival time compared to wild-type mice and an earlier onset of severe lung edema. These findings suggest that while under normal physiological conditions other antioxidant systems may substitute for the loss of EC-SOD; when the animal is stressed these systems are unable to provide adequate protection. Images Fig. 1 PMID:7603981

  11. Physical and chemical stability of different formulations with superoxide dismutase.

    PubMed

    Di Mambro, V M; Campos, P M B G Maia; Fonseca, M J V

    2004-10-01

    Topical formulations with superoxide dismutase (SOD), a scavenger of superoxide radicals, have proved to be effective against some skin diseases. Nevertheless, formulations with proteins are susceptible to both chemical and physical instability. Three different formulations (anionic and non-ionic gel and emulsion) were developed and supplemented with SOD in order to determine the most stable formulation that would maintain SOD activity. Physical stability was evaluated by assessing the rheological behavior of the formulations stored at room temperature, 37 and 45 degrees C. Chemical stability was evaluated by the measurement of enzymatic activity in the formulations stored at room temperature and at 45 degrees C. Formulations showed a flow index less than one, characterizing pseudoplastic behavior. There was no significant difference in initial values of flow index, tixotropy or minimum apparent viscosity. Neither gel showed significant changes in minimum apparent viscosity concerning storage time or temperature, as well, SOD presence and its activity. The emulsion showed decreased viscosity by the 28th day, but no significant changes concerning storage temperature or SOD presence, although it showed a decreased activity. The addition of SOD to the formulations studied did not affect their physical stability but gel formulations seem to be better bases for enzyme addition. PMID:15544058

  12. 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

  13. Production of dioxygen in the dark: dismutases of oxyanions.

    PubMed

    DuBois, Jennifer L; Ojha, Sunil

    2015-01-01

    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 (ClO(4)(-) ) 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 O₂generation, as well as the biological and geochemical context of this extraordinary reaction, are described. PMID:25707466

  14. Unexpected superoxide dismutase antioxidant activity of ferric chloride in acetonitrile.

    PubMed

    Foti, Mario C; Ingold, K U

    2003-11-14

    The azobis(isobutyronitrile)-initiated autoxidation of gamma-terpinene in acetonitrile at 50 degrees C yields only p-cymene and hydrogen peroxide (1:1) in a chain reaction carried by the hydroperoxyl radical, HOO. (Foti, M. C.; Ingold, K. U. J. Agric. Food Chem. 2003, 51, 2758-2765). This reaction is retarded by very low (microM) concentrations of FeCl(3) and CuCl(2). The kinetics of the FeCl(3)-inhibited autoxidation are consistent with chain-termination via the following: Fe(3+) + HOO. <==>[Fe(IV)-OOH](3+) and [Fe(IV)-OOH](3+) + HOO. --> Fe(3+) + H2O2 + O2. Thus, FeCl(3) in acetonitrile can be regarded as a very effective (and very simple) superoxide dismutase. The kinetics of the CuCl(2)-inhibited autoxidation indicate that chain transfer occurs and becomes more and more important as the reaction proceeds, i.e., the inhibition is replaced by autocatalysis. These kinetics are consistent withreduction of Cu2+ to Cu+ by HOO. and then the reoxidation of Cu+ to Cu2+ by both HOO.and the H2O2 product. The latter reaction yields HO. radicals which continue the chain. PMID:14604404

  15. Reduction of Renal Superoxide Dismutase in Progressive Diabetic Nephropathy

    PubMed Central

    Fujita, Hiroki; Fujishima, Hiromi; Chida, Shinsuke; Takahashi, Keiko; Qi, Zhonghua; Kanetsuna, Yukiko; Breyer, Matthew D.; Harris, Raymond C.; Yamada, Yuichiro; Takahashi, Takamune

    2009-01-01

    Superoxide excess plays a central role in tissue damage that results from diabetes, but the mechanisms of superoxide overproduction in diabetic nephropathy (DN) are incompletely understood. In the present study, we investigated the enzyme superoxide dismutase (SOD), a major defender against superoxide, in the kidneys during the development of murine DN. We assessed SOD activity and the expression of SOD isoforms in the kidneys of two diabetic mouse models (C57BL/6-Akita and KK/Ta-Akita) that exhibit comparable levels of hyperglycemia but different susceptibility to DN. We observed down-regulation of cytosolic CuZn-SOD (SOD1) and extracellular CuZn-SOD (SOD3), but not mitochondrial Mn-SOD (SOD2), in the kidney of KK/Ta-Akita mice which exhibit progressive DN. In contrast, we did not detect a change in renal SOD expression in DN-resistant C57BL/6-Akita mice. Consistent with these findings, there was a significant reduction in total SOD activity in the kidney of KK/Ta-Akita mice compared with C57BL/6-Akita mice. Finally, treatment of KK/Ta-Akita mice with a SOD mimetic, tempol, ameliorated the nephropathic changes in KK/Ta-Akita mice without altering the level of hyperglycemia. Collectively, these results indicate that down-regulation of renal SOD1 and SOD3 may play a key role in the pathogenesis of DN. PMID:19470681

  16. Purification and characterization of Ag,Zn-superoxide dismutase from Saccharomyces cerevisiae exposed to silver.

    PubMed

    Ciriolo, M R; Civitareale, P; Carrì, M T; De Martino, A; Galiazzo, F; Rotilio, G

    1994-10-14

    Cu,Zn-superoxide dismutase plays an important role in protecting cells from oxygen toxicity by catalyzing the dismutation of superoxide anion into hydrogen peroxide and oxygen. In Saccharomyces cerevisiae Cu,Zn-superoxide dismutase is coregulated with copper-thionein by copper via the transcription factor ACE 1. We demonstrate here that presence of AgNO3 in the culture medium leads to a five times increase of Cu,Zn-superoxide dismutase mRNA, with a concomitant six times decrease of the enzyme activity. Susceptibility of yeast to silver was apparently inversely related to Cu,Zn-superoxide dismutase activity. From silver-treated yeast a Cu,Zn-superoxide dismutase with impaired dismutase function was purified and was shown to contain silver, which was located to the copper site. These data suggest that Cu,Zn-superoxide dismutase may play an additional direct role in the defense of S. cerevisiae against metal stress by functioning as metal chelator. PMID:7929283

  17. Overexpression of Superoxide Dismutase Protects Plants from Oxidative Stress (Induction of Ascorbate Peroxidase in Superoxide Dismutase-Overexpressing Plants).

    PubMed Central

    Gupta, A. S.; Webb, R. P.; Holaday, A. S.; Allen, R. D.

    1993-01-01

    Photosynthesis of leaf discs from transgenic tobacco plants (Nicotiana tabacum) that express a chimeric gene that encodes chloroplast-localized Cu/Zn superoxide dismutase (SOD+) was protected from oxidative stress caused by exposure to high light intensity and low temperature. Under the same conditions, leaf discs of plants that did not express the pea SOD isoform (SOD-) had substantially lower photosynthetic rates. Young plants of both genotypes were more sensitive to oxidative stress than mature plants, but SOD+ plants retained higher photosynthetic rates than SOD- plants at all developmental stages tested. Not surprisingly, SOD+ plants had approximately 3-fold higher SOD specific activity than SOD- plants. However, SOD+ plants also exhibited a 3- to 4-fold increase in ascorbate peroxidase (APX) specific activity and had a corresponding increase in levels of APX mRNA. Dehydroascorbate reductase and glutathione reductase specific activities were the same in both SOD+ and SOD- plants. These results indicate that transgenic tobacco plants that overexpress pea Cu/Zn SOD II can compensate for the increased levels of SOD with increased expression of the H2O2-scavenging enzyme APX. Therefore, the enhancement of the active oxygen-scavenging system that leads to increased oxidative stress protection in SOD+ plants could result not only from increased SOD levels but from the combined increases in SOD and APX activity. PMID:12232001

  18. 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

  19. A non-glycosylated extracellular superoxide dismutase variant.

    PubMed Central

    Edlund, A; Edlund, T; Hjalmarsson, K; Marklund, S L; Sandström, J; Strömqvist, M; Tibell, L

    1992-01-01

    The secretory tetrameric extracellular superoxide dismutase (EC-SOD) is the only glycosylated SOD isoenzyme. The importance of the carbohydrate moiety for the properties of the enzyme is unknown. An expression vector defining nonglycosylated EC-SOD (ngEC-SOD) was constructed by mutagenesis of the codon for Asn-89 into a codon for Gln. The vector was transfected into Chinese hamster ovary DXB-11 cells and ngEC-SOD was isolated to 70% purity from the culture media of selected clones. The absence of glycosylation was established by the lack of affinity for various lectins, the absence of staining with the periodic acid-Schiff reagent, the change in mobility and composition of the tryptic peptide containing the mutated glycosylation site, and the reduction in apparent molecular mass upon SDS/PAGE and size-exclusion chromatography. The tetrameric state was retained. The heparin affinity, a fundamental and distinguishing property of EC-SOD, was found to be slightly increased. The enzymic activity was essentially retained. The major difference from native glycosylated enzyme in physical properties was a marked reduction in solubility. Like glycosylated EC-SOD, ngEC-SOD was, after intravenous injection into rabbits, rapidly sequestered by the vessel endothelium, and was promptly released into plasma after injection of heparin. The only difference from glycosylated EC-SOD in this behaviour, was a slightly more rapid elimination of the mutant enzyme from the vasculature. It is concluded that no specific biological role for the EC-SOD carbohydrate moiety could be revealed. Images Fig. 1. PMID:1463450

  20. 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

  1. Cytosolic superoxide dismutase can provide protection against Fasciola gigantica.

    PubMed

    Jaikua, Wipaphorn; Kueakhai, Pornanan; Chaithirayanon, Kulathida; Tanomrat, Rataya; Wongwairot, Sirima; Riengrojpitak, Suda; Sobhon, Prasert; Changklungmoa, Narin

    2016-10-01

    Superoxide dismutases (SOD), antioxidant metallo-enzymes, are a part of the first line of defense in the trematode parasites which act as the chief scavengers for reactive oxygen species (ROS). A recombinant Fasciola gigantica cytosolic SOD (FgSOD) was expressed in Escherichia coli BL21 (DE3) and used for immunizing rabbits to obtain polyclonal antibodies (anti-rFgSOD). This rabbit anti-rFgSOD reacted with the native FgSOD at a molecular weight of 17.5kDa. The FgSOD protein was expressed at high level in parenchyma, caecal epithelium and egg of the parasite. The rFgSOD reacted with antisera from rabbits infected with F. gigantica metacercariae collected at 2, 5, and 7 weeks after infection, and reacted with sera of infected mice. Anti-rFgSOD exhibited cross reactivity with the other parasites' antigens, including Eurytrema pancreaticum, Cotylophoron cotylophorum, Fischoederius cobboldi, Gastrothylax crumenifer, Paramphistomum cervi, and Setaria labiato papillosa. A vaccination was performed in imprinting control region (ICR) mice by subcutaneous injection with 50μg of rFgSOD combined with Freund's adjuvant. At 2 weeks after the second boost, mice were infected with 15 metacercariae by oral route. IgG1 and IgG2a in the immune sera were determined to indicate Th2 and Th1 immune responses. It was found that the parasite burden was reduced by 45%, and both IgG1 and IgG2a levels showed correlation with the numbers of worm recoveries. PMID:27338185

  2. Extracellular Superoxide Dismutase Regulates Cardiac Function and Fibrosis

    PubMed Central

    Kliment, Corrine R; Suliman, Hagir B; Tobolewski, Jacob M; Reynolds, Crystal M; Day, Brian J; Zhu, Xiaodong; McTiernan, Charles F; McGaffin, Kenneth R; Piantadosi, Claude A; Oury, Tim D

    2009-01-01

    Aims Extracellular superoxide dismutase (EC-SOD) is an antioxidant that protects the heart from ischemia and the lung from inflammation and fibrosis. The role of cardiac EC-SOD under normal conditions and injury remains unclear. Cardiac toxicity, a common side effect of doxorubicin, involves oxidative stress. We hypothesize that EC-SOD is critical for normal cardiac function and protects the heart from oxidant-induced fibrosis and loss of function. Methods C57BL/6 and EC-SOD-null mice were treated with doxorubicin, 15 mg/kg (i.p.). After 15 days, echocardiography was used to assess cardiac function. Left ventricle (LV) tissue was used to assess fibrosis and inflammation by staining, western blot, and hydroxyproline analysis. Results At baseline EC-SOD-null mice have LV wall thinning and increases in LV end diastolic dimensions compared to wild type mice, but have normal cardiac function. After doxorubicin, EC-SOD-null mice have decreases in fractional shortening not apparent in WT mice. Lack of EC-SOD also leads to increases in myocardial apoptosis and significantly more LV fibrosis and inflammatory cell infiltration. Administration of the metalloporphyrin AEOL 10150 abrogates the loss of cardiac function, and potentially fibrosis, associated with doxorubicin treatment in both wild type and EC-SOD KO mice. Conclusions EC-SOD is critical for normal cardiac morphology and protects the heart from oxidant-induced fibrosis, apoptosis and loss of function. The antioxidant metalloporphyrin, AEOL 10150 effectively protects cardiac function from doxorubicin-induced oxidative stress, in vivo. These findings identify targets for the use of antioxidant agents in oxidant-induced cardiac fibrosis. PMID:19695260

  3. 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

  4. 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

  5. Stochastic Formation of Fibrillar and Amorphous Superoxide Dismutase Oligomers Linked to Amyotrophic Lateral Sclerosis.

    PubMed

    Abdolvahabi, Alireza; Shi, Yunhua; Chuprin, Aleksandra; Rasouli, Sanaz; Shaw, Bryan F

    2016-06-15

    Recent reports suggest that the nucleation and propagation of oligomeric superoxide dismutase-1 (SOD1) is effectively stochastic in vivo and in vitro. This perplexing kinetic variability-observed for other proteins and frequently attributed to experimental error-plagues attempts to discern how SOD1 mutations and post-translational modifications linked to amyotrophic lateral sclerosis (ALS) affect SOD1 aggregation. This study used microplate fluorescence spectroscopy and dynamic light scattering to measure rates of fibrillar and amorphous SOD1 aggregation at high iteration (ntotal = 1.2 × 10(3)). Rates of oligomerization were intrinsically irreproducible and populated continuous probability distributions. Modifying reaction conditions to mimic random and systematic experimental error could not account for kinetic outliers in standard assays, suggesting that stochasticity is not an experimental artifact, rather an intrinsic property of SOD1 oligomerization (presumably caused by competing pathways of oligomerization). Moreover, mean rates of fibrillar and amorphous nucleation were not uniformly increased by mutations that cause ALS; however, mutations did increase kinetic noise (variation) associated with nucleation and propagation. The stochastic aggregation of SOD1 provides a plausible statistical framework to rationalize how a pathogenic mutation can increase the probability of oligomer nucleation within a single cell, without increasing the mean rate of nucleation across an entire population of cells. PMID:26979728

  6. 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

  7. The requirement for yeast superoxide dismutase is bypassed through mutations in BSD2, a novel metal homeostasis gene.

    PubMed Central

    Liu, X F; Culotta, V C

    1994-01-01

    Oxygen toxicity in Saccharomyces cerevisiae strains lacking superoxide dismutase can be suppressed through mutations in either the BSD1 or BSD2 gene. In this report, we demonstrate that the BSD2 gene normally functions in the homeostasis of heavy metal ions. A mutation in BSD2 not only reverses the aerobic defects of yeast strains lacking superoxide dismutase but also is associated with an increased sensitivity to copper and cadmium toxicity and an elevation in copper ion accumulation. The BSD2 gene was cloned by functional complementation and is predicted to encode a novel 37.5-kDa protein with three potential transmembrane domains. The mutant bsd2-1 allele was isolated and found to contain a single C-to-T transition changing a centrally located proline to a serine. This substitution results in total inactivation of BSD2, since the bsd2-1 mutation is identical to a bsd2 delta gene deletion in phenotype. BSD2 is expressed in yeast cells as a 1.5-kb mRNA. Although the gene functions in copper detoxification, BSD2 is not induced by copper ions, as is the case with S. cerevisiae metallothioneins. A probable role for copper ions in the bsd2 reversal of oxidative damage is discussed. Images PMID:7935419

  8. Molecular cloning and expression patterns of copper/zinc superoxide dismutase and manganese superoxide dismutase in Musca domestica.

    PubMed

    Tang, Ting; Huang, Da-Wei; Zhou, Chuan-Qi; Li, Xiang; Xie, Qi-Jing; Liu, Feng-Song

    2012-09-01

    Superoxide dismutases (SODs) are metalloenzymes that represent one important line of defense against reactive oxygen species (ROS). In this paper, two novel SOD genes, MdSOD1 and MdSOD2, which putatively encode 261 and 214 amino acid residues respectively were identified and characterized from the housefly Musca domestica. The high similarity of MdSOD1 and MdSOD2 with SODs from other organisms indicated that they should be two new members of the SOD family. qPCR exhibited a universal expression of MdSOD1 and MdSOD2 detected in various tissues of housefly larva, including the fat body, gut, hemocyte and epidermis. Expression profiling reveals that MdSOD1 and MdSOD2 can be induced significantly via not only heat shock and cadmium (Cd) stress but also Escherichia coli and Staphylococcus aureus challenge. The two genes were cloned into the prokaryotic expression vector pET-28a to obtain the fusion proteins rMdSOD1 and rMdSOD2. Between them, the activity of rMdSOD2 was found by visual assay methods. ESI-LC-MS/MS analysis showed that three peptide fragments of the protein rMdSOD2 were identical to the corresponding sequence of M. domestica MdSOD2. MdSOD1 and MdSOD2 in housefly larvae were abrogated by feeding bacteria expressing dsRNA. High mortalities were observed in the larvae treated with dsRNA of SODs at heat shock, Cd stress and bacterial invasion. This phenomenon indicated that MdSOD1 and MdSOD2 are related to the survival of M. domestica under stress. This may provide new insights into the role of the two SOD genes in protecting M. domestica against both stress and bacterial invasion. PMID:22750315

  9. 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.

  10. 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.

  11. Characterization of heparin binding of human extracellular superoxide dismutase.

    PubMed

    Lookene, A; Stenlund, P; Tibell, L A

    2000-01-11

    The C-terminal domain of human extracellular superoxide dismutase (hEC-SOD) plays a crucial role in the protein's interaction with heparin. Here we investigated this interaction in more detail by comparing the heparin-binding characteristics of two variants of hEC-SOD: the two fusion proteins containing the hEC-SOD C-terminal domain and a synthetic peptide homologous to the C-terminal. The interaction studies were performed using a surface plasmon resonance based technique on a BIAcore system. It should be emphasized that this is a model system. However, the kinetic constants, as measured, are valid in a comparative sense. Comparison of affinities for size-fractionated heparins revealed that octa- or decasaccharides are the smallest heparin fragments that can efficiently interact with the C-terminal domain of hEC-SOD. At physiological salt concentration, and pH 7.4, the hEC-SOD/heparin interaction was found to be of a high-affinity type, with an equilibrium dissociation constant, K(d), of 0.12 microM, which is 700 and 10-20 times lower than the K(d) values for the synthetic peptide and the fusion proteins, respectively. However, when an alpha-helical structure was induced in the synthetic peptide, by addition of 10% trifluoroethanol, the K(d) decreased to 0.64 microM. The differences in the K(d) values were mainly governed by differences in the association rate constants (k(ass)). The hEC-SOD/heparin interaction itself was found to have a fairly high dissociation rate constant (0.1 s(-)(1)), and a very high association rate constant (8 x 10(5) M(-)(1) s(-)(1)), suggesting that the interaction is mainly controlled by the association. These results together with circular dichroism spectra of the synthetic peptide suggest that an alpha-helical structure in the C-terminal is essential for optimal binding to heparin and that other parts of hEC-SOD moderate the affinity. Our data also demonstrate that the tetramerization itself does not substantially increase the

  12. 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.

  13. Copper, zinc superoxide dismutase in Escherichia coli: periplasmic localization.

    PubMed

    Benov, L; Chang, L Y; Day, B; Fridovich, I

    1995-06-01

    Cu,ZnSOD purified from Escherichia coli has been used to raise antibodies in rabbits. The resultant antiserum was found to recognize a single band on Western blots of SDS-polyacrylamide gel electropherograms, and that single band coincided with the position of the Cu,ZnSOD. Ultrathin sections of fixed E. coli were treated with the antibody followed by protein A bearing 10-nm gold particles. Electron microscopy revealed that Cu,ZnSOD was largely localized in the periplasm in polar bays. PMID:7786035

  14. 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.

  15. 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

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

    PubMed

    Petrov, Drazen; Daura, Xavier; Zagrovic, Bojan

    2016-04-12

    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

  17. 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) PMID:1877967

  18. 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.

  19. 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

  20. Influence of Catalase and Superoxide Dismutase on Ozone Inactivation of Listeria monocytogenes

    PubMed Central

    Fisher, Christopher W.; Lee, Dongha; Dodge, Beth-Anne; Hamman, Kristen M.; Robbins, Justin B.; Martin, Scott E.

    2000-01-01

    The effects of ozone at 0.25, 0.40, and 1.00 ppm on Listeria monocytogenes were evaluated in distilled water and phosphate-buffered saline. Differences in sensitivity to ozone were found to exist among the six strains examined. Greater cell death was found following exposure at lower temperatures. Early stationary-phase cells were less sensitive to ozone than mid-exponential- and late stationary-phase cells. Ozonation at 1.00 ppm of cabbage inoculated with L. monocytogenes effectively inactivated all cells after 5 min. The abilities of in vivo catalase and superoxide dismutase to protect the cells from ozone were also examined. Three listerial test strains were inactivated rapidly upon exposure to ozone. Both catalase and superoxide dismutase were found to protect listerial cells from ozone attack, with superoxide dismutase being more important than catalase in this protection. PMID:10742219

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

    SciTech Connect

    Bowler, C.; Inze, D.; Van Camp, W.; Kaer, L.V.; Dhaese, P. )

    1990-03-01

    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.

  2. Extraction of Erythrocyte Enzymes for the Preparation of Polyhemoglobin-catalase-superoxide Dismutase

    PubMed Central

    Gu, Jingsong; Chang, Thomas Ming Swi

    2012-01-01

    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. PMID:19229698

  3. Self-Sufficient Formaldehyde-to-Methanol Conversion by Organometallic Formaldehyde Dismutase Mimic.

    PubMed

    van der Waals, Dominic; Heim, Leo E; Vallazza, Simona; Gedig, Christian; Deska, Jan; Prechtl, Martin H G

    2016-08-01

    The catalytic networks of methylotrophic organisms, featuring redox enzymes for the activation of one-carbon moieties, can serve as great inspiration in the development of novel homogeneously catalyzed pathways for the interconversion of C1 molecules at ambient conditions. An imidazolium-tagged arene-ruthenium complex was identified as an effective functional mimic of the bacterial formaldehyde dismutase, which provides a new and highly selective route for the conversion of formaldehyde to methanol in absence of any external reducing agents. Moreover, secondary amines are reductively methylated by the organometallic dismutase mimic in a redox self-sufficient manner with formaldehyde acting both as carbon source and reducing agent. PMID:27380865

  4. 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 (+/+), ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  7. 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...

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

    EPA Science Inventory

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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....

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. 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…

  12. A cambialistic superoxide dismutase in the thermophilic photosynthetic bacterium Chloroflexus aurantiacus.

    PubMed

    Lancaster, Vanessa L; LoBrutto, Russell; Selvaraj, Fabiyola M; Blankenship, Robert E

    2004-06-01

    Superoxide dismutase from the thermophilic anoxygenic photosynthetic bacterium Chloroflexus aurantiacus was cloned, purified, and characterized. This protein is in the manganese- and iron-containing family of superoxide dismutases and is able to use both manganese and iron catalytically. This appears to be the only soluble superoxide dismutase in C. aurantiacus. Iron and manganese cofactors were identified by using electron paramagnetic resonance spectroscopy and were quantified by atomic absorption spectroscopy. By metal enrichment of growth media and by performing metal fidelity studies, the enzyme was found to be most efficient with manganese incorporated, yet up to 30% of the activity was retained with iron. Assimilation of iron or manganese ions into superoxide dismutase was also found to be affected by the growth conditions. This enzyme was also found to be remarkably thermostable and was resistant to H2O2 at concentrations up to 80 mM. Reactive oxygen defense mechanisms have not been previously characterized in the organisms belonging to the phylum Chloroflexi. These systems are of interest in C. aurantiacus since this bacterium lives in a hyperoxic environment and is subject to high UV radiation fluxes. PMID:15150226

  13. 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.

  14. 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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  18. Concerted action of reduced glutathione and superoxide dismutase in preventing redox cycling of dihydroxypyrimidines, and their role in antioxidant defence.

    PubMed

    Winterbourn, C C; Munday, R

    1990-01-01

    Dialuric Acid, the reduced form of the beta-cell toxin alloxan, and the related fava bean derivatives divicine and isouramil, autoxidize rapidly in neutral solution by a radical mechanism. GSH promotes redox cycling of each compound, with concomitant GSH oxidation and H2O2 production. With superoxide dismutase present, there is a lag period in which little oxidation occurs, followed by rapid oxidation. GSH extends this lag and decreases the subsequent rate of oxidation, so that with superoxide dismutase and a sufficient excess of GSH, coupled oxidation of GSH and each pyrimidine is almost completely suppressed. This mechanism may be a means whereby GSH in combination with superoxide dismutase protects against the cytotoxic effects of these reactive pyrimidines. Superoxide dismutase may also protect cells against oxidative stress in other situations where GSH acts as a radical scavenger, and we propose that the concerted action of GSH and superoxide dismutase constitutes an important antioxidant defence. PMID:2354807

  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. Superoxide Dismutase 1 Loss Disturbs Intracellular Redox Signaling, Resulting in Global Age-Related Pathological Changes

    PubMed Central

    2014-01-01

    Aging is characterized by increased oxidative stress, chronic inflammation, and organ dysfunction, which occur in a progressive and irreversible manner. Superoxide dismutase (SOD) serves as a major antioxidant and neutralizes superoxide radicals throughout the body. In vivo studies have demonstrated that copper/zinc superoxide dismutase-deficient (Sod1−/−) mice show various aging-like pathologies, accompanied by augmentation of oxidative damage in organs. We found that antioxidant treatment significantly attenuated the age-related tissue changes and oxidative damage-associated p53 upregulation in Sod1−/− mice. This review will focus on various age-related pathologies caused by the loss of Sod1 and will discuss the molecular mechanisms underlying the pathogenesis in Sod1−/− mice. PMID:25276767

  1. Tissue-specific activity of two manganese superoxide dismutase promoters in transgenic tobacco.

    PubMed Central

    Van Camp, W; Hérouart, D; Willekens, H; Takahashi, H; Saito, K; Van Montagu, M; Inzé, D

    1996-01-01

    In eukaryotes, manganese superoxide dismutase is a nuclear-encoded protein that scavenges superoxide radicals in the mitochondrial matrix. We have isolated two manganese superoxide dismutase genes from Nicotiana plumbaginifolia L. and fused the 5' upstream regulatory region of these genes to the beta-glucuronidase reporter gene. The two gene fusions displayed a differential tissue specificity in transgenic tobacco (Nicotiana tabacum). Promoter activity of the SodA1 gene fusion was found in the pollen, middle layer, and stomium of anthers, but was usually undetectable in vegetative organs of mature plants. The SodA2 gene fusion was expressed in the leaves, stems, roots, and flowers. SodA2 promoter activity was most prominent in the vascular bundles, stomata, axillary buds, pericycle, stomium, and pollen. Histochemical analysis of succinate dehydrogenase activity suggested that the spatial expression of the two gene fusions is generally correlated with mitochondrial respiratory activity. PMID:8883376

  2. Tandem arrangement of photolyase and superoxide dismutase genes in Halobacterium halobium.

    PubMed Central

    Takao, M; Kobayashi, T; Oikawa, A; Yasui, A

    1989-01-01

    A DNA fragment containing the photolyase gene was cloned from Halobacterium halobium. The deduced amino acid sequence is highly similar to those of four known photolyases from eubacteria and a eucaryote. The cloned gene expressed in Escherichia coli cells the survival of UV-irradiated host cells by photoreactivation. These results indicate that photolyases of eucaryotes, eubacteria, and archaebacteria are derived from a common origin. In this cloned DNA fragment, two additional open reading frames (ORFs), ORF 151 and ORF 200, were found in the 5' and 3' adjacent flanking regions of the photolyase gene. ORF 200 shows unequivocal amino acid sequence homology to all known manganese and iron superoxide dismutases. Northern (RNA) hybridization analysis of H. halobium RNA revealed the existence of three transcripts, one of which covered all three ORFs, indicating that photolyase and superoxide dismutase are partly cotranscribed in this bacterium. Images PMID:2681164

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

    PubMed Central

    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.

    2015-01-01

    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. PMID:25961325

  4. Bovine superoxide dismutase and copper ions potentiate the bactericidal effect of autoxidizing cysteine.

    PubMed Central

    Nyberg, G K; Granberg, G P; Carlsson, J

    1979-01-01

    When cysteine is oxidized by oxygen, hydrogen peroxide is formed, and hydrogen peroxide is very toxic to Peptostreptococcus anaerobius VPI 4330-1. Native and inactivated superoxide dismutase increased the rate of oxidation of cysteine and thereby potentiated the toxic effect of cysteine. A similar increase in the rate of oxidation of cysteine and in the toxicity of cysteine was obtained with Cu2+. PMID:573589

  5. Nucleotide sequence, transcription and phylogeny of the gene encoding the superoxide dismutase of Sulfolobus acidocaldarius.

    PubMed

    Klenk, H P; Schleper, C; Schwass, V; Brudler, R

    1993-07-18

    The gene encoding the superoxide dismutase (SOD) of the thermophilic archaeon Sulfolobus acidocaldarius has been isolated and sequenced. Both the start site and the termination sites of the corresponding transcript were mapped. The deduced amino acid sequence of the protein is very similar to the sequence of manganese- or iron-containing SODs. Phylogenetic sequence analysis corroborated the monophyletic nature of the archaeal domain. PMID:8334170

  6. Investigation of ion binding in chlorite dismutases by means of molecular dynamics simulations.

    PubMed

    Sündermann, Axel; Reif, Maria M; Hofbauer, Stefan; Obinger, Christian; Oostenbrink, Chris

    2014-07-29

    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. Inhibition of autoxidation of divicine and isouramil by the combination of superoxide dismutase and reduced glutathione.

    PubMed

    Winterbourn, C C

    1989-06-01

    The effects of GSH on the autoxidation of the fava bean pyrimidine aglycones, divicine and isouramil, and on acid-hydrolyzed vicine (provisional identification 2-amino-4,5,6-trihydroxypyrimidine) have been studied. GSH alone promoted redox cycling of each compound, with concomitant GSH oxidation and H2O2 production. In the presence of superoxide dismutase, there is a lag period during which little pyrimidine oxidation occurs, followed by a period of accelerated oxidation. With the three pyrimidines, increasing concentrations of GSH extended this lag period and progressively decreased subsequent rates of both pyrimidine oxidation and O2 uptake. No GSH oxidation or O2 uptake occurred during the lag. These results show that the combination of GSH and superoxide dismutase is able to inhibit redox cycling of the pyrimidines. With a 10-fold excess of GSH over isouramil or acid-hydrolyzed vicine (20-fold with divicine) this coupled oxidation of GSH and the pyrimidine is almost completely suppressed. This mechanism may be a means whereby GSH in combination with superoxide dismutase protects against the cytotoxic effects of these reactive pyrimidines. PMID:2730000

  8. Superoxide dismutase activity in healthy and inflamed pulp tissues of permanent teeth in children.

    PubMed

    Tulunoglu, O; Alacam, A; Bastug, M; Yavuzer, S

    1998-01-01

    The free radicals play an important role in the tissue damage. Oxygen-derived free radicals are controlled by various cellular defense mechanisms consisting of enzymatic such as superoxide dismutase, catalase, glutathion peroxidase and nonenzymatic scavenger components. Superoxide dismutase (SOD) is responsible for the dismutation of the superoxide radicals into hydrogen peroxide and molecular oxygen. In this study, pulp samples extirpated from the teeth of the 27 children between 10-15 ages which diagnosed to be healthy, reversible pulpitis or symptomatic irreversible pulpitis were evaluated for the activity of superoxide dismutase enzyme. There were statistically significant differences between healthy and reversible pulpitis, and between reversible and symptomatic irreversible pulpitis groups. The SOD activity of the reversible pulpitis group were significantly lower than the irreversible pulpitis and healthy pulp groups. The evaluation of the data revealed that the quantity of SOD as a vitality protector enzyme is low at the beginning of the inflammation as a consequence of rapidly depletion and/or destruction of this enzyme, but as the inflammation proceeds the pulp tissue showed adaptation to this situation. PMID:9796506

  9. 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.

  10. 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.

  11. 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

  12. Superoxide dismutase: correlation with life-span and specific metabolic rate in primate species.

    PubMed Central

    Tolmasoff, J M; Ono, T; Cutler, R G

    1980-01-01

    Much evidence now suggests that superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1) may be a major intracellular protective enzyme against oxygen toxicity by catalyzing the removal of the superoxide radical. We examined the possible role this enzyme may have in determining the life-span of primate species. Superoxide dismutase specific activity levels were measured in cytoplasmic fractions of liver, brain, and heart of 2 rodent and 12 primate species. These species had maximum life-span potentials ranging from 3.5 to 95 years. Liver, brain, and heart had similar specific activity levels for a given species, but the levels for different species varied over 2-fold, with man having the highest level. No general correlation was found in the levels with life-span. However, the ratio of superoxide dismutase specific activity to specific metabolic rate of the tissue or of the whole adult organism was found to increase with increasing maximum lifespan potential for all the species. This correlation suggests that longer-lived species have a higher degree of protection against by-products of oxygen metabolism. PMID:6771758

  13. Wild-type Cu/Zn superoxide dismutase stabilizes mutant variants by heterodimerization.

    PubMed

    Weichert, Anna; Besemer, Anna S; Liebl, Martina; Hellmann, Nadja; Koziollek-Drechsler, Ingrid; Ip, Philbert; Decker, Heinz; Robertson, Janice; Chakrabartty, Avijit; Behl, Christian; Clement, Albrecht M

    2014-02-01

    Mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1) are responsible for a subset of amyotrophic lateral sclerosis cases presumably by the acquisition of as yet unknown toxic properties. Additional overexpression of wild-type SOD1 in mutant SOD1 transgenic mice did not improve but rather accelerated the disease course. Recently, it was documented that the presence of wild-type SOD1 (SOD(WT)) reduced the aggregation propensity of mutant SOD1 by the formation of heterodimers between mutant and SOD1(WT) and that these heterodimers displayed at least a similar toxicity in cellular and animal models. In this study we investigated the biochemical and biophysical properties of obligate SOD1 dimers that were connected by a peptide linker. Circular dichroism spectra indicate an increased number of unstructured residues in SOD1 mutants. However, SOD1(WT) stabilized the folding of heterodimers compared to mutant homodimers as evidenced by an increase in resistance against proteolytic degradation. Heterodimerization also reduced the affinity of mutant SOD1 to antibodies detecting misfolded SOD1. In addition, the formation of obligate dimers resulted in a detection of substantial dismutase activity even of the relatively labile SOD1(G85R) mutant. These data indicate that soluble, dismutase-active SOD1 dimers might contribute at least partially to mutant SOD1 toxicity. PMID:24200866

  14. A multinuclear copper(I) cluster forms the dimerization interface in copper-loaded human copper chaperone for superoxide dismutase.

    PubMed

    Stasser, Jay P; Siluvai, Gnana S; Barry, Amanda N; Blackburn, Ninian J

    2007-10-23

    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. PMID:17902702

  15. 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.

  16. ACE1, a copper-dependent transcription factor, activates expression of the yeast copper, zinc superoxide dismutase gene.

    PubMed Central

    Gralla, E B; Thiele, D J; Silar, P; Valentine, J S

    1991-01-01

    Copper, zinc superoxide dismutase (SOD1 gene product) (superoxide:superoxide oxidoreductase, EC 1.15.1.1) is a copper-containing enzyme that functions to prevent oxygen toxicity. In the yeast Saccharomyces cerevisiae, copper levels exert some control over the level of SOD1 expression. We show that the ACE1 transcriptional activator protein, which is responsible for the induction of yeast metallothionein (CUP1) in response to copper, also controls the SOD1 response to copper. A single binding site for ACE1 is present in the SOD1 promoter region, as demonstrated by DNase I protection and methylation interference experiments, and is highly homologous to a high-affinity ACE1 binding site in the CUP1 promoter. The functional importance of this DNA-protein interaction is demonstrated by the facts that (i) copper induction of SOD1 mRNA does not occur in a strain lacking ACE1 and (ii) it does not occur in a strain containing a genetically engineered SOD1 promoter that lacks a functional ACE1 binding site. Images PMID:1924315

  17. 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.

  18. 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.

  19. Inflammatory cytokines in vitro production are associated with Ala16Val superoxide dismutase gene polymorphism of peripheral blood mononuclear cells.

    PubMed

    Montano, Marco Aurélio Echart; da Cruz, Ivana Beatrice Mânica; Duarte, Marta Maria Medeiros Frescura; Krewer, Cristina da Costa; da Rocha, Maria Izabel de Ugalde Marques; Mânica-Cattani, Maria Fernanda; Soares, Felix Alexandre Antunes; Rosa, Guilherme; Maris, Angélica Francesca; Battiston, Francielle Garghetti; Trott, Alexis; Lera, Juan Pablo Barrio

    2012-10-01

    Obesity is considered a chronic low-grade inflammatory state associated with a chronic oxidative stress caused by superoxide production (O(2)(-)). The superoxide dismutase manganese dependent (SOD2) catalyzes O(2)(-) in H(2)O(2) into mitochondria and is encoded by a single gene that presents a common polymorphism that results in the replacement of alanine (A) with a valine (V) in the 16 codon. This polymorphism has been implicated in a decreased efficiency of SOD2 transport into targeted mitochondria in V allele carriers. Previous studies described an association between VV genotype and metabolic diseases, including obesity and diabetes. However, the causal mechanisms to explain this association need to be more elucidated. We postulated that the polymorphism could influence the inflammatory response. To test our hypothesis, we evaluated the in vitro cytokines production by human peripheral blood mononuclear cells (PBMCs) carrier's different Ala16Val-SOD2 genotypes (IL-1, IL-6, IL-10, TNF-α, IFN-γ). Additionally, we evaluated if the culture medium glucose, enriched insulin, could influence the cytokine production. Higher levels of proinflammatory cytokines were observed in VV-PBMCs when compared to AA-PBMCs. However, the culture medium glucose and enriched insulin did not affect cytokine production. The results suggest that Ala16Val-SOD2 gene polymorphism could trigger the PBMCs proinflammatory cytokines level. However, discerning if a similar mechanism occurs in fat cells is an open question. PMID:22688013

  20. 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.

  1. 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

  2. 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. PMID:25602700

  3. 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

  4. Function of periplasmic copper-zinc superoxide dismutase in Caulobacter crescentus.

    PubMed

    Steinman, H M

    1993-02-01

    Caulobacter crescentus is one of a small number of bacterial species that contain a periplasmic copper-zinc superoxide dismutase (CuZnSOD). A C. crescentus mutant, with the CuZnSOD gene interrupted by a promoterless cat gene, was constructed and characterized to analyze CuZnSOD function. Periplasmic SOD does not protect against oxyradical damage in the cytosol or play a major role in maintaining the integrity of the cell envelope. Studies of the effect of sodium citrate on plating efficiency suggest that CuZnSOD protects a periplasmic or membrane function(s) requiring magnesium or calcium. PMID:8432713

  5. Limitation of dietary copper and zinc decreases superoxide dismutase activity in the onion fly, Delia antiqua.

    PubMed

    Matsuo, T; Ooe, S; Ishikawa, Y

    1997-06-01

    Larvae of the onion fly, Delia antiqua, have lower superoxide dismutase (SOD) activity when they are fed a defined synthetic diet that contains no copper or zinc. SOD activity was rapidly recovered when these larvae were fed onion bulbs. Addition of copper and zinc to the synthetic diet also led to the recovery of SOD activity. Results of an immunoblotting analysis using anti-D. antiqua CuZnSOD mouse monoclonal antibody suggest that this alteration of SOD activity is dependent on the amount of CuZnSOD. PMID:9172377

  6. Activity of Superoxide Dismutase and Catalase in Fenugreek (Trigonella foenum-graecum) in Response to Carbendazim.

    PubMed

    Sangeetha, R

    2010-01-01

    Fenugreek (Trigonella foenum-graecum) is an annual herb, used as a spice and traditionally as medicine. Fenugreek finds its uses in treating hyperglycemia, hyperlipidemia and disorders of gastro-intestinal and cardiovascular systems. Fenugreek cultivation in India is affected by fungal diseases like root-rot and damping-off and fungicides like carbendazim are used to overcome these infections. Fungicides play both positive and negative role in plants; fungicides protect plants from diseases and also exert oxidative stress simultaneously. This report is on the response of antioxidants, superoxide dismutase and catalase in fenugreek seeds and plants treated to different concentrations of carbendazim. PMID:20582202

  7. A new formula to calculate activity of superoxide dismutase in indirect assays.

    PubMed

    Zhang, Chen; Bruins, Marieke E; Yang, Zhi-Qiang; Liu, Shu-Tao; Rao, Ping-Fan

    2016-06-15

    To calculate superoxide dismutase (SOD) activity rapidly and accurately by indirect SOD assays, a formula based on the ratio of the catalytic speed of SOD to the reaction speed of the indicator with superoxide anion was deduced. The accuracy of this formula was compared with the conventional formula based on inhibition in five indirect SOD assays. The new formula was validated in nearly the entire SOD activity range, whereas the conventional formula was validated only during inhibition of 40-60%. This formula might also be used for the assays of other enzymes. PMID:27033009

  8. Human Manganese Superoxide Dismutase Tyrosine 34 Contribution to Structure and Catalysis

    PubMed Central

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

    2009-01-01

    Superoxide dismutase (SOD) enzymes are critical in controlling levels of reactive oxygen species (ROS) that are linked to aging, cancer and neurodegenerative disease. Superoxide (O2 •−) 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 causes a substantial decrease in the catalytic rate constant for the reduction of superoxide. The rate constant for formation of product inhibition complex also decreases but to a much lesser extent, resulting in a net increase in the product inhibition 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 to trap a catalytic intermediate that promises to help elucidate the mechanism of catalysis. PMID:19265433

  9. 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

  10. 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

    2012-01-01

    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. PMID:23096686

  11. Biomimetic superoxide dismutase stabilized by photopolymerization for superoxide anions biosensing and cell monitoring.

    PubMed

    Yuan, Ling; Liu, Suli; Tu, Wenwen; Zhang, Zengsong; Bao, Jianchun; Dai, Zhihui

    2014-05-20

    Photopolymerization strategy, as one of the immobilization methods, has attracted considerable interest because of some advantages, such as easy operation, harmlessness to the biomolecules, and long storage stability. (E)-4-(4-Formylstyryl) pyridine (formylstyrylpyridine) was prepared through Heck reaction and used as a photopolymer material to immobilize biomimetic superoxide dismutase under ultraviolet irradiation (UV) irradiation in a short time. The styrylpyridinium moiety of Formylstyrylpyridine was photoreactive and formed a dimer under UV irradiation. Mn2P2O7 multilayer sheet, a novel superoxide dismutase mimic, was synthesized. The formed photopolymer can immobilize Mn2P2O7 firmly under UV irradiation. On the basis of high catalytic activity of Mn2P2O7 biomimetic enzyme and long-term stability of Mn2P2O7-formylstyrylpyridine film, after introducing multiwalled carbon nanotubes (MWCNTs), a novel electrochemical biosensing platform called MWCNTs/Mn2P2O7-formylstyrylpyridine for superoxide anion (O2(•-)) detection was constructed. The biosensor displayed good performance for O2(•-) detection and provided a reliable platform to adhere living cells directly on the modified electrode surface. Therefore, the biosensor was successfully applied to vitro determination of O2(•-) released from living cells, which had a promising prospect for living cells monitoring and diagnosis of reactive oxygen species-related diseases. PMID:24773067

  12. Mechanism of chlorite degradation to chloride and dioxygen by the enzyme chlorite dismutase.

    PubMed

    Schaffner, Irene; Hofbauer, Stefan; Krutzler, Michael; Pirker, Katharina F; Furtmüller, Paul G; Obinger, Christian

    2015-05-15

    Heme b containing chlorite dismutase (Cld) catalyses the conversion of chlorite to chloride and dioxygen which includes an unusual OO bond formation. This review summarizes our knowledge about the interaction of chlorite with heme enzymes and introduces the biological role, phylogeny and structure of functional chlorite dismutases with differences in overall structure and subunit architecture. The paper sums up the available experimental and computational studies on chlorite degradation by water soluble porphyrin complexes as well as a model based on the active site of Cld. Finally, it reports the available biochemical and biophysical data of Clds from different organisms which allow the presentation of a general reaction mechanism. It includes binding of chlorite to ferric Cld followed by subsequent heterolytic OCl bond cleavage leading to the formation of Compound I and hypochlorite, which finally recombine for production of chloride and O2. The role of the Cld-typical distal arginine in catalysis is discussed together with the pH dependence of the reaction and the role of transiently produced hypochlorite in irreversible inactivation of the enzyme. PMID:25748001

  13. Superoxide dismutase derivative prevents oxidative damage in liver and kidney of rats induced by exhausting exercise.

    PubMed

    Radák, Z; Asano, K; Inoue, M; Kizaki, T; Oh-Ishi, S; Suzuki, K; Taniguchi, N; Ohno, H

    1996-01-01

    To prevent oxidative tissue damage induced by strenuous exercise in the liver and kidney superoxide dismutase derivative (SM-SOD), which circulated bound to albumin with a half-life of 6 h, was injected intraperitoneally into rats. Exhausting treadmill running caused a significant increase in the activities of xanthine oxidase (XO), and glutathione peroxidase (GPX) in addition to concentrations of thiobarbituric acid-reactive substances (TBARS) in hepatic tissue immediately after running. There was a definite increase in the immunoreactive content of mitochondrial superoxide dismutase (Mn-SOD) 1 day after the running. Meanwhile, the TBARS concentration in the kidney was markedly elevated 3 days after running. The activities of GPX, and catalase in the kidney increased significantly immediately and on days 1 and 3 following the test. The immunoreactive content of Mn-SOD also increased 1 day after running. The exercise induced no significant changes in immunoreactive Cu, Zn-SOD content in either tissue. The administration of SM-SOD provided effective protection against lipid peroxidation, and significantly attenuated the alterations in XO and all the anti-oxidant enzymes, measured. In summary, the present data would suggest that exhausting exercise may induce XO-derived oxidative damage in the liver, while the increase in lipid peroxidation in the kidney might be the result of washout-dependent accumulation of peroxidised metabolites. We found that the administration of SM-SOD provided excellent protection against exercise-induced oxidative stress in both liver and kidney. PMID:8820884

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

    PubMed Central

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

    2016-01-01

    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. PMID:26912083

  15. 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. PMID:26912083

  16. Micronutrients and superoxide dismutase in postmenopausal women with chronic periodontitis: a pilot interventional study

    PubMed Central

    2014-01-01

    Purpose The study was aimed at investigating changes in periodontal parameters and superoxide dismutase activity triggered by root surface debridement with and without micronutrient supplementation in postmenopausal women. Methods Forty-three postmenopausal chronic periodontitis patients were divided into two groups: group 1 (n=22) were provided periodontal treatment in the form of scaling and root planing (SRP) and group 2 (n=21) patients received SRP along with systemic administration of micronutrient antioxidants. Patients in both groups were subjected to root surface debridement. Group 2 patients also received adjunctive micronutrient antioxidant supplementation. Serum and salivary superoxide dismutase (SOD) activity along with periodontal parameters were recorded at baseline and 3 months after therapy. Results Salivary and serum SOD values significantly (P<0.05) improved with periodontal treatment. Improvement in systemic enzymatic antioxidant status along with reduction in gingival inflammation and bleeding on probing (%) sites was significantly greater in group 2 as compared to group 1. Conclusions Adjunctive micronutrient supplements reduce periodontal inflammation and improve the status of systemic enzymatic antioxidants in postmenopausal women. Graphical Abstract PMID:25177523

  17. 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.

  18. 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. PMID:26410038

  19. 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. PMID:27190267

  20. 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

  1. 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. J. Cell. Biochem. 117: 1352-1358, 2016. © 2015 Wiley Periodicals, Inc. PMID:26529273

  2. 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

  3. A new strategy for intracellular delivery of enzyme using mesoporous silica nanoparticles: superoxide dismutase.

    PubMed

    Chen, Yi-Ping; Chen, Chien-Tsu; Hung, Yann; Chou, Chih-Ming; Liu, Tsang-Pai; Liang, Ming-Ren; Chen, Chao-Tsen; Mou, Chung-Yuan

    2013-01-30

    We developed mesoporous silica nanoparticle (MSN) as a multifunctional vehicle for enzyme delivery. Enhanced transmembrane delivery of a superoxide dismutase (SOD) enzyme embedded in MSN was demonstrated. Conjugation of the cell-penetrating peptide derived from the human immunodeficiency virus 1 (HIV) transactivator protein (TAT) to mesoporous silica nanoparticle is shown to be an effective way to enhance transmembrane delivery of nanoparticles for intracellular and molecular therapy. Cu,Zn-superoxide dismutase (SOD) is a key antioxidant enzyme that detoxifies intracellular reactive oxygen species, ROS, thereby protecting cells from oxidative damage. In this study, we fused a human Cu,Zn-SOD gene with TAT in a bacterial expression vector to produce a genetic in-frame His-tagged TAT-SOD fusion protein. The His-tagged TAT-SOD fusion protein was expressed in E. coli using IPTG induction and purified using FMSN-Ni-NTA. The purified TAT-SOD was conjugated to FITC-MSN forming FMSN-TAT-SOD. The effectiveness of FMSN-TAT-SOD as an agent against ROS was investigated, which included the level of ROS and apoptosis after free radicals induction and functional recovery after ROS damage. Confocal microscopy on live unfixed cells and flow cytometry analysis showed characteristic nonendosomal distribution of FMSN-TAT-SOD. Results suggested that FMSN-TAT-SOD may provide a strategy for the therapeutic delivery of antioxidant enzymes that protect cells from ROS damage. PMID:23289802

  4. 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. PMID:26960678

  5. Transcript levels of antioxidative genes and oxygen radical scavenging enzyme activities in chilled zucchini squash in response to superatmospheric oxygen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The transcript levels of antioxidative genes including Mn-superoxide dismutase (Mn-SOD), Cu/Zn SOD, ascorbate peroxidise (APX), and catalase (CAT) do not vary significantly during storage at 5 °C with high oxygen treatment in freshly harvested zucchini squash (Cucurbita pepo L. cv. Elite). However, ...

  6. 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.

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

    PubMed Central

    Patil, Naeem K.; Parajuli, Nirmala; Mayeux, Philip R.

    2014-01-01

    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. PMID:24500690

  8. 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

  9. 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. PMID:24500690

  10. Neuronal Uptake of Nanoformulated Superoxide Dismutase and Attenuation of Angiotensin II-Dependent Hypertension Following Central Administration

    PubMed Central

    Savalia, Krupa; Manickam, Devika S.; Rosenbaugh, Erin G.; Tian, Jun; Ahmad, Iman M.; Kabanov, Alexander V.; Zimmerman, Matthew C.

    2014-01-01

    Excessive production of superoxide (O2•−) in the central nervous system has been widely implicated in the pathogenesis of cardiovascular diseases, including chronic heart failure and hypertension. In an attempt to overcome the failed therapeutic impact of currently available antioxidants in cardiovascular disease, we developed a nanomedicine-based delivery system for the O2•− scavenging enzyme, copper/zinc superoxide dismutase (CuZnSOD), in which CuZnSOD protein is electrostatically bound to poly-L-lysine (PLL50)-polyethylene glycol (PEG) block co-polymer to form CuZnSOD nanozyme. Different formulations of CuZnSOD nanozyme are covalently stabilized by either reducible or non-reducible crosslinked bonds between the PLL50-PEG polymers. Herein, we tested the hypothesis that PLL50-PEG CuZnSOD nanozyme delivers active CuZnSOD protein to neurons and decreases blood pressure in a mouse model of AngII-dependent hypertension. As determined by electron paramagnetic resonance (EPR) spectroscopy, nanozymes retain full SOD enzymatic activity as compared to native CuZnSOD protein. Non-reducible CuZnSOD nanozyme delivers active CuZnSOD protein to central neurons in culture (CATH.a neurons) without inducing significant neuronal toxicity. In vivo studies conducted in adult male C57BL/6 mice demonstrate that hypertension established by chronic subcutaneous infusion of AngII is significantly attenuated for up to 7 days following a single intracerebroventricular (ICV) injection of non-reducible nanozyme. These data indicate the efficacy of non-reducible PLL50-PEG CuZnSOD nanozyme in counteracting excessive O2•− and decreasing blood pressure in AngII-dependent hypertensive mice following central administration. Additionally, this study supports the further development of PLL50-PEG CuZnSOD nanozyme as an antioxidant-based therapeutic option for hypertension. PMID:24924945

  11. Cloning and mapping of the manganese superoxide dismutase gene (sodA) of Escherichia coli K-12.

    PubMed Central

    Touati, D

    1983-01-01

    An Escherichia coli gene bank composed of large DNA fragments (about 40 kilobases) was constructed by using the small cosmid pHC79. From it, a clone was isolated for its ability to overproduce superoxide dismutase. The enzyme overproduced was manganese superoxide dismutase, as determined by electrophoresis and antibody precipitation. Maxicell analysis and two-dimensional O'Farrell polyacrylamide gel electrophoresis demonstrated that the structural gene, sodA, of manganese superoxide dismutase was cloned. Subcloning fragments from the original cosmid located the sodA gene within a 4.8-kilobase EcoRI-BamHI fragment. This fragment was inserted into a lambda phage which was deleted for the att region and consequently could only lysogenize by recombination between the cloned bacterial DNA insertion and the bacterial chromosome. Genetic mapping of the prophage in such lysogens indicated that the chromosomal sodA locus lies near 87 min on the E. coli map. Images PMID:6309739

  12. Detection, Distribution and Characterization of Novel Superoxide Dismutases from Yersinia enterocolitica Biovar 1A

    PubMed Central

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

    2013-01-01

    Background 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. Methodology/Principal Findings 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. Conclusions/Significance 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

  13. Changes in Expression of Manganese Superoxide Dismutase, Copper and Zinc Superoxide Dismutase and Catalase in Brachionus calyciflorus during the Aging Process

    PubMed Central

    Yang, Jianghua; Dong, Siming; Jiang, Qichen; Kuang, Tengjiao; Huang, Wenting; Yang, Jiaxin

    2013-01-01

    Rotifers are useful model organisms for aging research, owing to their small body size (0.1–1 mm), short lifespan (6–14 days) and the relative easy in which aging and senescence phenotypes can be measured. Recent studies have shown that antioxidants can extend the lifespan of rotifers. In this paper, we analyzed changes in the mRNA expression level of genes encoding the antioxidants manganese superoxide dismutase (MnSOD), copper and zinc SOD (CuZnSOD) and catalase (CAT) during rotifer aging to clarify the function of these enzymes in this process. We also investigated the effects of common life-prolonging methods [dietary restriction (DR) and resveratrol] on the mRNA expression level of these genes. The results showed that the mRNA expression level of MnSOD decreased with aging, whereas that of CuZnSOD increased. The mRNA expression of CAT did not change significantly. This suggests that the ability to eliminate reactive oxygen species (ROS) in the mitochondria reduces with aging, thus aggravating the damaging effect of ROS on the mitochondria. DR significantly increased the mRNA expression level of MnSOD, CuZnSOD and CAT, which might explain why DR is able to extend rotifer lifespan. Although resveratrol also increased the mRNA expression level of MnSOD, it had significant inhibitory effects on the mRNA expression of CuZnSOD and CAT. In short, mRNA expression levels of CAT, MnSOD and CuZnSOD are likely to reflect the ability of mitochondria to eliminate ROS and delay the aging process. PMID:23451185

  14. Dynamics of hydrogen atoms in superoxide dismutase by quasielastic neutron scattering.

    PubMed Central

    Andreani, C; Filabozzi, A; Menzinger, F; Desideri, A; Deriu, A; Di Cola, D

    1995-01-01

    The low energy dynamic of the enzyme Cu,Zn superoxide dismutase have been investigated by means of quasielastic neutron scattering in the temperature range 4-320 K. Below 200 K the scattering is purely elastic, while above this temperature a pronounced decrease in the elastic intensity is observed, together with the onset of a small quasielastic component. This behavior is similar to that previously observed in other more flexible globular proteins, and can be attributed to transitions between slightly different conformational substates of the protein tertiary structure. The presence of only a small quasielastic component, whose intensity is < or = 25% of the total spectrum, is related to the high structural rigidity of this protein. PMID:7647254

  15. [Catalase and superoxide dismutase in the cells of strictly anaerobic microorganisms].

    PubMed

    Briukhanov, A L; Thauer, R K; Netrusov, A I

    2002-01-01

    Strictly anaerobic microorganisms relating to various physiological groups were screened for catalase and superoxide dismutase (SOD) activity. All of the investigated anaerobes possessed the SOD activity, necessary for protection against toxic products of oxygen reduction. High specific activities of SOD were found in Acetobacterium woodii and Acetobacterium wieringae. Most of the investigated clostridia and acetogens were catalase-negative. A significant activity of catalase was found in Thermohydrogenium kirishiense, in representatives of the genus Desulfotomaculum, and in several methanogens. Methanobrevibacter arboriphilus had an exceptionally high catalase activity after growth in medium supplemented with hemin. Hemin also produced a strong positive effect on the catalase activity in many other anaerobic microorganisms. In methanogens, the activities of the enzymes of antioxidant defense varied in wide ranges depending on the stage of growth and the energy source. PMID:12138753

  16. 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.

  17. Transcriptional Analysis of the Rubrerythrin and Superoxide Dismutase Genes of Clostridium perfringens

    PubMed Central

    Geissmann, Thomas A.; Teuber, Michael; Meile, Leo

    1999-01-01

    We cloned and sequenced a 2.7-kb fragment of chromosomal DNA from Clostridium perfringens containing the superoxide dismutase-encoding gene, sod. Previously, rubrerythrin from C. perfringens had been isolated and its gene (rbr) had been cloned (Y. Lehmann, L. Meile, and M. Teuber, J. Bacteriol. 178:7152–7158, 1996). Northern blot experiments revealed a length of approximately 800 bases for each transcript of rbr and sod of C. perfringens. Thus, rbr and sod each represent a monocistronic operon. Their transcription start points were located by primer extension analyses. sod transcription was shown to depend on the growth phase, and it reached a maximum during the transition from log phase to stationary phase. Neither sod nor rbr transcription was influenced by oxidative stress. PMID:10559182

  18. Redox-activated expression of the cytosolic copper/zinc superoxide dismutase gene in Nicotiana.

    PubMed Central

    Hérouart, D; Van Montagu, M; Inzé, D

    1993-01-01

    Superoxide dismutases (SODs; superoxide: superoxide oxidoreductase, EC 1.15.1.1) play a key role in protection against oxygen radicals, and SOD gene expression is highly induced during environmental stress. To determine the conditions of SOD induction, the promoter of the cytosolic copper/zinc SOD (Cu/ZnSODcyt) gene was isolated in Nicotiana plumbaginifolia and fused to the beta-glucuronidase reporter gene. Oxidative stress is likely to alter the cellular redox in favor of the oxidized status. Surprisingly, the expression of the Cu/ZnSODcyt gene is induced by sulfhydryl antioxidants such as reduced glutathione, cysteine, and dithiothreitol, whereas the oxidized forms of glutathione and cysteine have no effect. It is therefore possible that reduced glutathione directly acts as an antioxidant and simultaneously activates the Cu/ZnSODcyt gene during oxidative stress. Images Fig. 2 PMID:8464930

  19. 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

  20. Molecular cloning of superoxide dismutase (Cu/Zn-SOD) from aquatic molluscs.

    PubMed

    Geret, F; Manduzio, H; Company, R; Leboulenger, F; Bebianno, M J; Danger, J M

    2004-01-01

    The potential of the first line of the active oxygen-scavenging system, partial cDNA encoding Cu/Zn superoxide dismutase (SOD) was isolated in three aquatic mollusc species: Ruditapes decussatus (marine clam), Dreissena polymorpha (continental water mussel) and Bathymodiolus azoricus (hydrothermal vent mussel). These SOD cDNA fragments were amplified by PCR with degenerate oligonucleotide primers derived from the amino acid sequence conserved in the Cu/Zn-SOD from several other organisms. A partial cDNA of CuZn-SOD was obtained for R. decussates (510 bp), D. polymorpha (510 bp) and B. azoricus (195 bp). The deduced amino acid sequence showed high similarity among the three mollusc species (57-63%) and among other species (50-65%). The residues involved in coordinating copper (His-47, 49, 64, 121) and zinc (His-64, 72, 81 and Asp-84) were well conserved among the three Cu/Zn-SOD sequences. PMID:15178089

  1. Superoxide dismutase, catalase and cell dimorphism in Candida albicans cells exposed to methanol and different temperatures.

    PubMed

    Romandini, P; Bonotto, C; Bertoloni, G; Beltramini, M; Salvato, B

    1994-05-01

    The combined effects of methanol and different temperatures on Candida albicans were studied. Growth curve, cell morphology, superoxide dismutase (SOD) and catalase activity levels have been determined. Cell growth in each medium was comparable to 28 degrees C and 37 degrees C. The growth rate was not affected by methanol, in the presence of glucose, while it was much lower in the absence of sugar. Cell dimorphism appeared after thermic stress and it was also dependent on the medium composition. In all media, both SOD and catalase levels were much higher at 37 degrees C. The presence of methanol per se did not affect the enzymatic levels, while the absence of glucose gave higher SOD levels. PMID:8061958

  2. Microencapsulation of superoxide dismutase into poly(epsilon-caprolactone) microparticles by reverse micelle solvent evaporation.

    PubMed

    Youan, Bi-Botti Célestin

    2003-01-01

    The aim of this work was to encapsulate superoxide dismutase (SOD) in poly(epsilon-caprolactone) (PCL) microparticles by reverse micelle solvent evaporation. The concentration of PCL, the hydrophile-lipophile balance (HLB), and concentration of the sucrose ester used as surfactant in the organic phase were investigated as formulation variables. Relatively higher encapsulation efficiency (approximately 48%) and retained enzymatic activity (>90%) were obtained with microparticle formulation made from the 20% (w/v) PCL and 0.05% (w/v) sucrose ester of HLB = 6. This formulation allowed the in vitro release of SOD for at least 72 hr. These results showed that reverse micelle solvent evaporation can be used to efficiently encapsulate SOD in PCL microparticles. Such formulations may improve the bioavailability of SOD. PMID:14612345

  3. MEASUREMENT OF SUPEROXIDE DISMUTASE, CATALASE, AND GLUTATHIONE PEROXIDASE IN CULTURED CELLS AND TISSUE

    PubMed Central

    Weydert, Christine J.; Cullen, Joseph J.

    2010-01-01

    Cells contain a large number of antioxidants to prevent or repair the damage caused by ROS, as well as to regulate redox-sensitive signaling pathways General protocols are described to measure the antioxidant enzyme activity of superoxide dismutase (SOD), catalase, and glutathione peroxidase. The SODs convert superoxide radical into hydrogen peroxide and molecular oxygen, while the catalase and peroxidases convert hydrogen peroxide into water. In this way, two toxic species, superoxide radical and hydrogen peroxide, are converted to the harmless product water. Western blots, activity gels and activity assays are various methods used to determine protein and activity in both cells and tissue depending on the amount of protein needed for each assay. Other techniques including immunohistochemistry and immunogold can further evaluate the levels of the various antioxidant enzymes in tissue and cells. In general, these assays require 24 to 48 hours to complete. PMID:20057381

  4. 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

  5. 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.

  6. 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. PMID:489948

  7. Molecular and biochemical characterization of manganese-containing superoxide dismutase from the silkworm, Bombyx mori.

    PubMed

    Yamamoto, Kohji; Zhang, Pingbo; He, Ningjia; Wang, Yongqiang; Aso, Yoichi; Banno, Yutaka; Fujii, Hiroshi

    2005-12-01

    Superoxide dismutase (SOD) is responsible for the removal of superoxide anion from living organisms. In this study, cDNA encoding the manganese-containing SOD (MnSOD) from the silkworm, Bombyx mori, was isolated by reverse transcriptase-polymerase chain reaction and sequenced. The deduced amino acid sequence of the MnSOD revealed 62% identity to that of the Drosophila melanogaster; both were close to each other in a phylogenetic tree. The MnSOD was overproduced in Escherichia coli and purified. The internal structure of the recombinant MnSOD was confirmed by peptide mass fingerprinting method. The recombinant MnSOD facilitating the reduction reaction of superoxide anion retained 75% of its original activity after incubation at pH 4-11 for 24 h at 4 degrees C. Its activity was never affected by incubation at pH 7 for 30 min below 50 degrees C. PMID:16236537

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

    PubMed

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

    2015-12-01

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

  9. The SODyssey: superoxide dismutases from biochemistry, through proteomics, to oxidative stress, aging and nutraceuticals.

    PubMed

    D'Alessandro, Angelo; Zolla, Lello

    2011-06-01

    A total of 40 years have already passed since the pioneering work of McCord and Fridovich on erythrocuprein superoxide dismutase (SOD) activity. This modern scientific 'Odyssey' has been accompanied by a series of successes in the fields of biochemistry, biomedicine and proteomics. In this article, we resume the main strides in these fields, mainly aiming at delivering an exhaustive portrait of SOD's involvement in several oxidative stress-triggered threats to human health, including neurodegenerative disorders (amyotrophic lateral sclerosis, Alzheimer's, Parkinson's and Huntington's diseases), cardiovascular diseases, cancer and aging. In parallel, food-derived chemical compounds appear to be intertwined with cellular redox poise modulation, as this increasingly emerges from clinical biochemical and proteomic investigations. Thus, we will also consider the involvement of these nutraceuticals in oxidative stress-triggered diseases and SOD activity modulation. Like a modern Ulysses, researchers know that the journey is not yet over. Nevertheless, much information has been gathered over the last four decades. PMID:21679120

  10. 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

  11. 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. PMID:24601674

  12. Cu/Zn superoxide dismutase in yeast mitochondria - a general phenomenon.

    PubMed

    Nedeva, Trayana S; Petrova, Ventzislava Y; Zamfirova, Daniela R; Stephanova, Elena V; Kujumdzieva, Anna V

    2004-01-15

    Fermentative and respiratory yeast strains of genera Saccharomyces, Kluyveromyces, Pichia, Candida and Hansenula have been investigated for mitochondrial localization of Cu/Zn superoxide dismutase (SOD). Pure mitochondrial fractions were obtained and the specific activities of Cu/Zn and Mn SODs were measured in comparison with those in the corresponding cell-free extracts. The Cu/Zn SOD: Mn SOD ratio in mitochondria and crude extracts was calculated and was considered a specific characteristic of all tested strains. Electrophoretical visualization of SOD patterns provided evidence for possible migration of cytosolic Cu/Zn SOD to mitochondria. The characteristic Cu/Zn SOD profile in mitochondria of all tested strains suggested its ubiquity within the fermentative and respiratory yeasts. PMID:14734161

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

    PubMed Central

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

    2012-01-01

    Reduction of superoxide () 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 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 Mn3+. We here propose and compare two hypothetical mechanisms for the mutant yeast enzyme, differing in the structure of the Mn-peroxo complex yet both involving formation of the active six-coordinate Mn3+ 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 Mn2+, six-coordinate Mn3+ species could also actively function in the mechanism of WT yeast MnSODs. PMID:22908245

  14. Aggregation propensities of superoxide dismutase G93 hotspot mutants mirror ALS clinical phenotypes

    PubMed Central

    Pratt, Ashley J.; Shin, David S.; Merz, Gregory E.; Rambo, Robert P.; Lancaster, W. Andrew; Dyer, Kevin N.; Borbat, Peter P.; Poole, Farris L.; Adams, Michael W. W.; Freed, Jack H.; Crane, Brian R.; Tainer, John A.; Getzoff, Elizabeth D.

    2014-01-01

    Protein framework alterations in heritable Cu, Zn superoxide dismutase (SOD) mutants cause misassembly and aggregation in cells affected by the motor neuron disease ALS. However, the mechanistic relationship between superoxide dismutase 1 (SOD1) mutations and human disease is controversial, with many hypotheses postulated for the propensity of specific SOD mutants to cause ALS. Here, we experimentally identify distinguishing attributes of ALS mutant SOD proteins that correlate with clinical severity by applying solution biophysical techniques to six ALS mutants at human SOD hotspot glycine 93. A small-angle X-ray scattering (SAXS) assay and other structural methods assessed aggregation propensity by defining the size and shape of fibrillar SOD aggregates after mild biochemical perturbations. Inductively coupled plasma MS quantified metal ion binding stoichiometry, and pulsed dipolar ESR spectroscopy evaluated the Cu2+ binding site and defined cross-dimer copper–copper distance distributions. Importantly, we find that copper deficiency in these mutants promotes aggregation in a manner strikingly consistent with their clinical severities. G93 mutants seem to properly incorporate metal ions under physiological conditions when assisted by the copper chaperone but release copper under destabilizing conditions more readily than the WT enzyme. Altered intradimer flexibility in ALS mutants may cause differential metal retention and promote distinct aggregation trends observed for mutant proteins in vitro and in ALS patients. Combined biophysical and structural results test and link copper retention to the framework destabilization hypothesis as a unifying general mechanism for both SOD aggregation and ALS disease progression, with implications for disease severity and therapeutic intervention strategies. PMID:25316790

  15. The superoxide dismutase from red claw crayfish, Cherax quadricarinatus: molecular cloning and characterization analysis.

    PubMed

    Gu, Wei; Chen, Jing; Hou, Libo; Huang, Yanqing; Xia, Siyao; Meng, Qingguo; Wang, Wen

    2014-11-01

    In the present study, an extracellular copper-zinc superoxide dismutase (ecCuZnSOD) gene and a mitochondrial manganese superoxide dismutase (mtMnSOD) gene were cloned from hemocytes of red claw crayfish, Cherax quadricarinatus. The open reading frame (ORF) of ecCuZnSOD is 498 bp and encodes a 166 amino acids (aa) protein, whereas the ORF of mtMnSOD is 654 bp and encodes a 218 aa protein. The amino acid sequences of C. quadricarinatus ecCuZnSOD and mtMnSOD showed high similarities with those of ecCuZnSODs and mtMnSODs of other crustaceans, respectively. Both ecCuZnSOD and mtMnSOD of C. quadricarinatus were highly expressed in hepatopancreas, hemocytes, intestine, and gill; low transcript levels were seen in other tissues (heart, muscle, and nerve). The immune responses of ecCuZnSOD and mtMnSOD were studied following inoculation with Spiroplasma eriocheiris and Aeromonas hydrophila. After S. eriocheiris or A. hydrophila challenge, mRNA transcription of ecCuZnSOD and mtMnSOD in hemocytes and gill was upregulated. mRNA transcription of ecCuZnSOD in the hepatopancreas was also upregulated after S. eriocheiris or A. hydrophila inoculation. mtMnSOD in hepatopancreas was upregulated after A. hydrophila inoculation, whereas this was down-regulated after S. eriocheiris challenge. After S. eriocheiris and A. hydrophila challenge, total SOD activity and CuZnSOD activity both increased compared to control group. The results showed that these SODs from C. quadricarinatus likely play an important role in protecting some tissues from reactive oxygen intermediates produced during challenge from S. eriocheiris and A. hydrophila. PMID:25366155

  16. 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.

  17. 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

    2014-01-01

    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. PMID:25501153

  18. 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

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

    PubMed Central

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

    2008-01-01

    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−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 P21212 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. PMID:18678943

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. 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.

  2. 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)

  3. 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

  4. 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

  5. Reaction mechanism of manganese superoxide dismutase studied by combined quantum and molecular mechanical calculations and multiconfigurational methods.

    PubMed

    Srnec, Martin; Aquilante, Francesco; Ryde, Ulf; Rulísek, Lubomír

    2009-04-30

    Manganese superoxide dismutases (MnSODs) are enzymes that convert two molecules of the poisonous superoxide radical into molecular oxygen and hydrogen peroxide. During the reaction, the manganese ion cycles between the Mn(2+) and Mn(3+) oxidation states and accomplishes its enzymatic action in two half-cycles (corresponding to the oxidation and reduction of O(2)(-)). Despite many experimental and theoretical studies dealing with SODs, including quantum chemical active-site-model studies of numerous variants of the reaction mechanisms, several details of MnSOD enzymatic action are still unclear. In this study, we have modeled and compared four reaction pathways (one associative, one dissociative, and two second-sphere) in a protein environment using the QM/MM approach (combined quantum and molecular mechanics calculations) at the density functional theory level. The results were complemented by CASSCF/CASPT2/MM single-point energy calculations for the most plausible models to account properly for the multireference character of the various spin multiplets. The results indicate that the oxidation of O(2)(-) to O(2) most likely occurs by an associative mechanism following a two-state (quartet-octet) reaction profile. The barrier height is estimated to be less than 25 kJ.mol(-1). On the other hand, the conversion of O(2)(-) to H(2)O(2) is likely to take place by a second-sphere mechanism, that is, without direct coordination of the superoxide radical to the manganese center. The reaction pathway involves the conical intersection of two quintet states, giving rise to an activation barrier of approximately 60 kJ.mol(-1). The calculations also indicate that the associative mechanism can represent a competitive pathway in the second half-reaction with the overall activation barrier being only slightly higher than the activation barrier in the second-sphere mechanism. The activation barriers along the proposed reaction pathways are in very good agreement with the

  6. 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

  7. Identification of the residues responsible for the alkaline inhibition of Cu,Zn superoxide dismutase: a site-directed mutagenesis approach.

    PubMed Central

    Polticelli, F.; Battistoni, A.; O'Neill, P.; Rotilio, G.; Desideri, A.

    1996-01-01

    The catalytic rate of wild type, two single (Lys 120-->Leu, Lys 134-->Thr), and one double (Lys 120-->Leu-Lys 134-->Thr) mutants of Xenopus laevis B Cu,Zn superoxide dismutase has been studied by pulse radiolysis as a function of pH. The pH dependence curve of the wild-type enzyme can be deconvoluted by two deprotonation equilibria, at pH 9.3 (pK1) and at pH 11.3 (pK2). Catalytic rate measurements on single and double mutants indicate that pK1 is mainly due to the deprotonation of Lys 120 and Lys 134, with only a minor contribution from other surface basic residues, whereas pK2 is due to titration of the invariant Arg 141, likely coupled to deprotonation of the copper-bound water molecule. Accordingly, Brownian dynamics simulations carried out as a function of pH reproduce well the pH dependence of the catalytic rate, when the experimentally determined pKs are assigned to Lys 120, Lys 134, and Arg 141. PMID:8745402

  8. 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

  9. Two superoxide dismutase prion strains transmit amyotrophic lateral sclerosis-like disease.

    PubMed

    Bidhendi, Elaheh Ekhtiari; Bergh, Johan; Zetterström, Per; Andersen, Peter M; Marklund, Stefan L; Brännström, Thomas

    2016-06-01

    Amyotrophic lateral sclerosis (ALS) is an adult-onset degeneration of motor neurons that is commonly caused by mutations in the gene encoding superoxide dismutase 1 (SOD1). Both patients and Tg mice expressing mutant human SOD1 (hSOD1) develop aggregates of unknown importance. In Tg mice, 2 different strains of hSOD1 aggregates (denoted A and B) can arise; however, the role of these aggregates in disease pathogenesis has not been fully characterized. Here, minute amounts of strain A and B hSOD1 aggregate seeds that were prepared by centrifugation through a density cushion were inoculated into lumbar spinal cords of 100-day-old mice carrying a human SOD1 Tg. Mice seeded with A or B aggregates developed premature signs of ALS and became terminally ill after approximately 100 days, which is 200 days earlier than for mice that had not been inoculated or were given a control preparation. Concomitantly, exponentially growing strain A and B hSOD1 aggregations propagated rostrally throughout the spinal cord and brainstem. The phenotypes provoked by the A and B strains differed regarding progression rates, distribution, end-stage aggregate levels, and histopathology. Together, our data indicate that the aggregate strains are prions that transmit a templated, spreading aggregation of hSOD1, resulting in a fatal ALS-like disease. PMID:27140399

  10. Manganese superoxide dismutase knock-down in 3T3-L1 preadipocytes impairs subsequent adipogenesis.

    PubMed

    Krautbauer, Sabrina; Eisinger, Kristina; Hader, Yvonne; Neumeier, Markus; Buechler, Christa

    2014-08-01

    Adipogenesis is associated with the upregulation of the antioxidative enzyme manganese superoxide dismutase (MnSOD) suggesting a vital function of this enzyme in adipocyte maturation. In the current work, MnSOD was knocked-down with small-interference RNA in preadipocytes to study its role in adipocyte differentiation. In mature adipocytes differentiated from these cells, proteins characteristic for mature adipocytes, which are strongly induced in late adipogenesis like adiponectin and fatty acid-binding protein 4, are markedly reduced. Triglycerides begin to accumulate after about 6 days of the induction of adipogenesis, and are strongly diminished in cells with low MnSOD. Proteins upregulated early during differentiation, like fatty acid synthase and cytochrome C oxidase-4, are not altered. Cell viability, insulin-mediated phosphorylation of Akt, antioxidative capacity (AOC), superoxide levels, and heme oxygenase 1 with the latter being induced upon oxidative stress are not affected. L-Buthionine-(S,R)-sulfoximine (BSO) depletes glutathione and modestly lowers AOC of mature adipocytes. Addition of BSO to 3T3-L1 cells 3 days after the initiation of differentiation impairs triglyceride accumulation and expression of proteins induced in late adipogenesis. Of note, proteins that increased early during adipogenesis are also diminished, suggesting that BSO causes de-differentiation of these cells. Preadipocyte proliferation is not considerably affected by low MnSOD and BSO. These data suggest that glutathione and MnSOD are essential for adipogenesis. PMID:24740755

  11. 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

  12. 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

  13. Accumulation and aggregate formation of mutant superoxide dismutase 1 in canine degenerative myelopathy.

    PubMed

    Nakamae, S; Kobatake, Y; Suzuki, R; Tsukui, T; Kato, S; Yamato, O; Sakai, H; Urushitani, M; Maeda, S; Kamishina, H

    2015-09-10

    Canine degenerative myelopathy (DM) is an adult-onset progressive neurodegenerative disorder that has recently been linked to mutations in the superoxide dismutase 1 (SOD1) gene. We generated a polyclonal antibody against canine SOD1 to further characterize the mutant SOD1 protein and its involvement in DM pathogenesis. This antibody (SYN3554) was highly specific to canine SOD1 and had the ability to reveal distinct cytoplasmic aggregates in cultured cells expressing canine mutant SOD1 and also in the spinal neurons of symptomatic homozygotes. A similar staining pattern was observed in asymptomatic homozygotes. SOD1 aggregates were not detected in the spinal neurons of heterozygotes; the accumulation of SOD1 was also detected in the reactive astrocytes of homozygotes and heterozygotes to a similar extent. Our results support the hypothesis that the cytoplasmic accumulation and aggregate formation of the mutant SOD1 protein, especially in astrocytes, are closely associated with the pathogenesis of DM. Therefore, this disease is regarded as a spontaneous large-animal model of SOD1-mediated amyotrophic lateral sclerosis in humans. PMID:26162235

  14. Differential inhibition of Arabidopsis superoxide dismutases by peroxynitrite-mediated tyrosine nitration

    PubMed Central

    Holzmeister, Christian; Gaupels, Frank; Geerlof, Arie; Sarioglu, Hakan; Sattler, Michael; Durner, Jörg; Lindermayr, Christian

    2015-01-01

    Despite the importance of superoxide dismutases (SODs) in the plant antioxidant defence system little is known about their regulation by post-translational modifications. Here, we investigated the in vitro effects of nitric oxide derivatives on the seven SOD isoforms of Arabidopsis thaliana. S-nitrosoglutathione, which causes S-nitrosylation of cysteine residues, did not influence SOD activities. By contrast, peroxynitrite inhibited the mitochondrial manganese SOD1 (MSD1), peroxisomal copper/zinc SOD3 (CSD3), and chloroplastic iron SOD3 (FSD3), but no other SODs. MSD1 was inhibited by up to 90% but CSD3 and FSD3 only by a maximum of 30%. Down-regulation of these SOD isoforms correlated with tyrosine (Tyr) nitration and both could be prevented by the peroxynitrite scavenger urate. Site-directed mutagenesis revealed that—amongst the 10 Tyr residues present in MSD1—Tyr63 was the main target responsible for nitration and inactivation of the enzyme. Tyr63 is located nearby the active centre at a distance of only 5.26 Å indicating that nitration could affect accessibility of the substrate binding pocket. The corresponding Tyr34 of human manganese SOD is also nitrated, suggesting that this might be an evolutionarily conserved mechanism for regulation of manganese SODs. PMID:25428993

  15. Cloning and expression analysis of Drosophila extracellular Cu Zn superoxide dismutase.

    PubMed

    Blackney, Michael J; Cox, Rebecca; Shepherd, David; Parker, Joel D

    2014-01-01

    In the present study, we cloned and sequenced the mRNAs of the Sod3 [extracellular Cu Zn SOD (superoxide dismutase)] gene in Drosophila and identified two mRNA products formed by alternative splicing. These products code for a long and short protein derived from the four transcripts found in global expression studies (Flybase numbers Dmel\\CG9027, FBgn0033631). Both mRNA process variants contain an extracellular signalling sequence, a region of high homology to the Sod1 (cytoplasmic Cu Zn SOD) including a conserved AUG start, with the longer form also containing a hydrophobic tail. The two fully processed transcripts are homologous to Caenorhabditis elegans Sod3 mRNA showing the same processing pattern. Using an established KG p-element+ insertion line (KG06029), we demonstrate that the Sod3 codes for an active Cu Zn SOD. We found differing expression patterns across sex with higher levels of expression of Sod3 in females. There is a correlation of Sod1 and Sod3 gene expression and activity that can explain why Sod3 was not seen in earlier studies of Sod1. Finally, we found no effect on lifespan with the Sod3 hypomorph mutation (Sod3KG06029) but did observe a significant increase in resistance to paraquat and H2O2 (hydrogen peroxide). PMID:25339624

  16. Manganese superoxide dismutase (Sod2) and redox-control of signaling events that drive metastasis

    PubMed Central

    Hempel, Nadine; Carrico, Pauline M.; Melendez, J. Andres

    2013-01-01

    Manganese superoxide dismutase (Sod2) has emerged as a key enzyme with a dual role in tumorigenic progression. Early studies were primarily directed at defining the tumor suppressive function of Sod2 based on its low level expression in many tumor types. It is now commonly held that loss of Sod2 expression is likely an early event in tumor progression allowing for further propagation of the tumorigenic phenotype resulting from steady state increases in free radical production. Increases in free radical load have also been linked to defects in mitochondrial function and metastatic disease progression. It was initially believed that Sod2 loss may propagate metastatic disease progression, in reality both epidemiologic and experimental evidence indicate that Sod2 levels increase in many tumor types as they progress from early stage non-invasive disease to late stage metastatic disease. Sod2 overexpression in many instances enhances the metastatic phenotype that is reversed by efficient H2O2 scavenging. This review evaluates the many sequelae associated with increases in Sod2 that impinge on the metastatic phenotype. The ability to use Sod2 to modulate the cellular redox-environment has allowed for the identification of redox-responsive signaling events that drive malignancy, such as invasion, migration and prolonged tumor cell survival. Further studies of these redox-driven events will help in the development of targeted therapeutic strategies to efficiently restrict redox-signaling essential for malignant progression. PMID:21434856

  17. 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

  18. Dual gene therapy with extracellular superoxide dismutase and catalase attenuates experimental optic neuritis

    PubMed Central

    Qi, Xiaoping; Hauswirth, William W.

    2007-01-01

    Purpose To ameliorate experimental optic neuritis by combining scavenging of superoxide by germ line increases in the extracellular superoxide dismutase (ECSOD) and hydrogen peroxide by viral-mediated gene transfer of the human catalase gene. Methods The human catalase gene inserted into recombinant adeno-associated virus (rAAV) was injected into the right eyes of transgenic mice overexpressing human ECSOD and wild-type littermates. Animals were simultaneously sensitized for experimental autoimmune encephalomyelitis (EAE) and then sacrificed one month later. The effects of antioxidant genes (ECSOD and catalase) on the histologic lesions of EAE were measured by computerized analysis of myelin area, optic disc area, extent of the cellular infiltrate, cerium derived H2O2 reaction product and extravasation of serum albumin detected by immunogold. Results Combined scavenging of H2O2 and superoxide with ECSOD and catalase suppressed demyelination by 72%, 54% due to catalase, and 19% due to ECSOD. Disruption of the blood-brain barrier was reduced 63% by the combined effects of catalase and ECSOD, 35% due to catalase and 29% due to ECSOD. Conclusions Transgene modulation of antioxidant enzyme defenses against both superoxide and its metabolite H2O2 provide a substantial suppressive effect against EAE in the optic nerve that may be a new therapeutic strategy for suppression of optic neuritis and multiple sclerosis. PMID:17242675

  19. Posttranslational Modifications in Cu,Zn-Superoxide Dismutase and Mutations Associated with Amyotrophic Lateral Sclerosis

    PubMed Central

    FURUKAWA, YOSHIAKI

    2006-01-01

    Activation of the enzyme Cu,Zn-superoxide dismutase (SOD1) involves several posttranslational modifications including copper and zinc binding, as well as formation of the intramolecular disulfide bond. The copper chaperone for SOD1, CCS, is responsible for intracellular copper loading in SOD1 under most physiological conditions. Recent in vitro and in vivo assays reveal that CCS not only delivers copper to SOD1 under stringent copper limitation, but it also facilitates the stepwise conversion of the disulfide-reduced immature SOD1 to the active disulfide-containing enzyme. The two new functions attributed to CCS, (i.e., O2-dependent sulfhydryl oxidase- and disulfide isomerase-like activities) indicate that this protein has attributes of the larger class of molecular chaperones. The CCS-dependent activation of SOD1 is dependent upon oxygen availability, suggesting that the cell only loads copper and activates this enzyme when O2-based oxidative stress is present. Thiol/disulfide status as well as metallation state of SOD1 significantly affects its structure and protein aggregation, which are relevant in pathologies of a neurodegenerative disease, amyotrophic lateral sclerosis (ALS). The authors review here a mechanism for posttranslational activation of SOD1 and discuss models for ALS in which the most immature forms of the SOD1 polypeptide exhibits propensity to form toxic aggregates. PMID:16771675

  20. 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

  1. Catalase and superoxide dismutase activities in a Stenotrophomonas maltophilia WZ2 resistant to herbicide pollution.

    PubMed

    Lü, Zhenmei; Sang, Liya; Li, Zimu; Min, Hang

    2009-01-01

    Quinclorac bensulfuron-methyl is a mixed herbicide widely used on paddy rice field to effectively control barnyard grass and most broad-leaved grasses and sedges. We analyzed superoxide dismutase (SOD) and catalase activities in the quinclorac-highly degrading strain Stenotrophomonas maltophilia WZ2 and Gram-negative standard strain Escherichia coli K12 in an attempt to understand antioxidant enzymes in bacteria are produced in response to quinclorac or bensulfuron-methyl, which increases the virulence of the bacteria. MnSOD and two additional catalase isozymes were induced by quinclorac or bensulfuron-methyl in S. maltophilia WZ2, but not in E. coli K12. Quinclorac turned out to be a more sensitive inducer of SOD, whereas bensulfuron-methyl is a more sensitive one of catalase. A mixture of both has effects similar to quinclorac. Results indicate that catalase has a much weakly role in the defense against quinclorac or bensulfuron-methyl induced oxidative stress, whereas SOD could be critical. PMID:18304632

  2. 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. PMID:25042129

  3. 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. PMID:26207449

  4. Gibbs Energy of Superoxide Dismutase Heterodimerization Accounts for Variable Survival in Amyotrophic Lateral Sclerosis.

    PubMed

    Shi, Yunhua; Acerson, Mark J; Abdolvahabi, Alireza; Mowery, Richard A; Shaw, Bryan F

    2016-04-27

    The exchange of subunits between homodimeric mutant Cu, Zn superoxide dismutase (SOD1) and wild-type (WT) SOD1 is suspected to be a crucial step in the onset and progression of amyotrophic lateral sclerosis (ALS). The rate, mechanism, and ΔG of heterodimerization (ΔGHet) all remain undetermined, due to analytical challenges in measuring heterodimerization. This study used capillary zone electrophoresis to measure rates of heterodimerization and ΔGHet for seven ALS-variant apo-SOD1 proteins that are clinically diverse, producing mean survival times between 2 and 12 years (postdiagnosis). The ΔGHet of each ALS variant SOD1 correlated with patient survival time after diagnosis (R(2) = 0.98), with more favorable ΔGHet correlating with shorter survival by 4.8 years per kJ. Rates of heterodimerization did not correlate with survival time or age of disease onset. Metalation diminished the rate of subunit exchange by up to ∼38-fold but only altered ΔGHet by <1 kJ mol(-1). Medicinal targeting of heterodimer thermodynamics represents a plausible strategy for prolonging life in SOD1-linked ALS. PMID:27054659

  5. 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

  6. Serum Superoxide Dismutase Is Associated with Vascular Structure and Function in Hypertensive and Diabetic Patients.

    PubMed

    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

  7. Homology versus analogy: possible evolutionary relationship of immunoglobulins, cupredoxins, and Cu,Zn-superoxide dismutase.

    PubMed

    Stevens, Fred J

    2008-01-01

    The 'immunoglobulin-like' fold is one of most common structural motifs observed in proteins. This topology is found in more than 80 superfamilies of proteins, including Cu,Zn-superoxide dismutase (SOD) and cupredoxin. Evolutionary relationships have not been identified, but may exist. The challenge remains, therefore, of resolving the issue of whether the diverse distribution of the fold is accounted for by divergent evolution of function or convergent evolution of structure following multiple independent origins of function. Since the early studies that revealed conformational similarity of immunoglobulins and other proteins, the number of primary structures available for comparison has dramatically increased and new computational approaches for analysis of sequences have been developed. It now appears that a hypothesis of a common evolutionary origin for cupredoxins, Cu,Zn-SOD, and immunoglobulins may be credible. The distinction between protein homology and protein analogy is fundamental. The immunoglobulin-like fold may represent a robust system within which to examine again the issue of protein homology versus analogy. PMID:18080994

  8. 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. PMID:24722734

  9. 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.

  10. 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}.

  11. DNA-triggered aggregation of copper, zinc superoxide dismutase in the presence of ascorbate.

    PubMed

    Yin, Jun; Hu, Si; Jiang, Wei; Liu, Liang; Lan, Shemin; Song, Xuegang; Liu, Changlin

    2010-01-01

    The oxidative damage hypothesis proposed for the function gain of copper, zinc superoxide dismutase (SOD1) maintains that both mutant and wild-type (WT) SOD1 catalyze reactions with abnormal substrates that damage cellular components critical for viability of the affected cells. However, whether the oxidative damage of SOD1 is involved in the formation of aggregates rich in SOD1 or not remains elusive. Here, we sought to explore the oxidative aggregation of WT SOD1 exposed to environments containing both ascorbate (Asc) and DNA under neutral conditions. The results showed that the WT SOD1 protein was oxidized in the presence of Asc. The oxidation results in the higher affinity of the modified protein for DNA than that of the unmodified protein. The oxidized SOD1 was observed to be more prone to aggregation than the WT SOD1, and the addition of DNA can significantly accelerate the oxidative aggregation. Moreover, a reasonable relationship can be found between the oxidation, increased hydrophobicity, and aggregation of SOD1 in the presence of DNA. The crucial step in aggregation is neutralization of the positive charges on some SOD1 surfaces by DNA binding. This study might be crucial for understanding molecular forces driving the protein aggregation. PMID:20808835

  12. Manganese superoxide dismutase deficiency triggers mitochondrial uncoupling and the Warburg effect.

    PubMed

    Xu, Y; Miriyala, S; Fang, F; Bakthavatchalu, V; Noel, T; Schell, D M; Wang, C; St Clair, W H; St Clair, D K

    2015-08-01

    Manganese superoxide dismutase (MnSOD) is a mitochondrially localized primary antioxidant enzyme, known to be essential for the survival of aerobic life and to have important roles in tumorigenesis. Here, we show that MnSOD deficiency in skin tissues of MnSOD-heterozygous knockout (Sod2(+/-)) mice leads to increased expresson of uncoupling proteins (UCPs). When MnSOD is deficient, superoxide radical and its resulting reactive oxygen species (ROS) activate ligand binding to peroxisome proliferator-activated receptor alpha (PPARα), suggesting that the activation of PPARα signaling is a major mechanism underlying MnSOD-dependent UCPs expression that consequently triggers the PI3K/Akt/mTOR pathway, leading to increased aerobic glycolysis. Knockdown of UCPs and mTOR suppresses lactate production and increases ATP levels, suggesting that UCPs contribute to increased glycolysis. These results highlight the existence of a free radical-mediated mechanism that activates mitochondria uncoupling to reduce ROS production, which precedes the glycolytic adaptation described as the Warburg Effect. PMID:25362851

  13. 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

  14. Conditional Radioresistance of tet-Inducible Manganese Superoxide Dismutase Bone Marrow Stromal Cell Lines

    PubMed Central

    Epperly, Michael W.; Chaillet, J. Richard; Kalash, Ronny; Shaffer, Ben; Goff, Julie; Franicola, Darcy; Zhang, Xichen; Dixon, Tracy; Houghton, Frank; Wang, Hong; Berhane, Hebist; Romero, Cynthia; Kim, Jee-Hong; Greenberger, Joel S.

    2013-01-01

    Mitochondrial targeted manganese superoxide dismutase is a major antioxidant enzyme, the levels of which modulate the response of cells, tissues and organs to ionizing irradiation. We developed a Tet-regulated MnSOD mouse (MnSODtet) to examine the detailed relationship between cellular MnSOD concentration and radioresistance and carried out in vitro studies using bone marrow culture derived stromal cell lines (mesenchymal stem cells). Homozygous MnSODtet/tet cells had low levels of MnSOD, reduced viability and proliferation, increased radiosensitivity, elevated overall antioxidant stores, and defects in cell proliferation and DNA strand-break repair. Doxycycline (doxy) treatment of MnSODtet/tet cells increased MnSOD levels and radioresistance from ñ of 2.79 ± 1.04 to 8.69 ± 1.09 (P = 0.0060) and normalized other biologic parameters. In contrast, MnSODtet/tet cells showed minimal difference in baseline and radiation induced mRNA and protein levels of TGF-β, Nrf2 and NF-κB and radiation induced cell cycle arrest was not dependent upon MnSOD level. These novel MnSODtet/tet mouse derived cells should be valuable for elucidating several parameters of the oxidative stress response to ionizing radiation. PMID:23862693

  15. Conditional radioresistance of Tet-inducible manganese superoxide dismutase bone marrow stromal cell lines.

    PubMed

    Epperly, Michael W; Chaillet, J Richard; Kalash, Ronny; Shaffer, Ben; Goff, Julie; Franicola, Darcy; Zhang, Xichen; Dixon, Tracy; Houghton, Frank; Wang, Hong; Berhane, Hebist; Romero, Cynthia; Kim, Jee-Hong; Greenberger, Joel S

    2013-08-01

    Mitochondrial targeted manganese superoxide dismutase is a major antioxidant enzyme, the levels of which modulate the response of cells, tissues and organs to ionizing irradiation. We developed a Tet-regulated MnSOD mouse (MnSOD(tet)) to examine the detailed relationship between cellular MnSOD concentration and radioresistance and carried out in vitro studies using bone marrow culture derived stromal cell lines (mesenchymal stem cells). Homozygous MnSOD(tet/tet) cells had low levels of MnSOD, reduced viability and proliferation, increased radiosensitivity, elevated overall antioxidant stores, and defects in cell proliferation and DNA strand-break repair. Doxycycline (doxy) treatment of MnSOD(tet/tet) cells increased MnSOD levels and radioresistance from ñ of 2.79 ± 1.04 to 8.69 ± 1.09 (P = 0.0060) and normalized other biologic parameters. In contrast, MnSOD(tet/tet) cells showed minimal difference in baseline and radiation induced mRNA and protein levels of TGF-β, Nrf2 and NF-κB and radiation induced cell cycle arrest was not dependent upon MnSOD level. These novel MnSOD(tet/tet) mouse derived cells should be valuable for elucidating several parameters of the oxidative stress response to ionizing radiation. PMID:23862693

  16. 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

  17. 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

  18. Two superoxide dismutase prion strains transmit amyotrophic lateral sclerosis–like disease

    PubMed Central

    Bidhendi, Elaheh Ekhtiari; Bergh, Johan; Zetterström, Per; Andersen, Peter M.; Marklund, Stefan L.; Brännström, Thomas

    2016-01-01

    Amyotrophic lateral sclerosis (ALS) is an adult-onset degeneration of motor neurons that is commonly caused by mutations in the gene encoding superoxide dismutase 1 (SOD1). Both patients and Tg mice expressing mutant human SOD1 (hSOD1) develop aggregates of unknown importance. In Tg mice, 2 different strains of hSOD1 aggregates (denoted A and B) can arise; however, the role of these aggregates in disease pathogenesis has not been fully characterized. Here, minute amounts of strain A and B hSOD1 aggregate seeds that were prepared by centrifugation through a density cushion were inoculated into lumbar spinal cords of 100-day-old mice carrying a human SOD1 Tg. Mice seeded with A or B aggregates developed premature signs of ALS and became terminally ill after approximately 100 days, which is 200 days earlier than for mice that had not been inoculated or were given a control preparation. Concomitantly, exponentially growing strain A and B hSOD1 aggregations propagated rostrally throughout the spinal cord and brainstem. The phenotypes provoked by the A and B strains differed regarding progression rates, distribution, end-stage aggregate levels, and histopathology. Together, our data indicate that the aggregate strains are prions that transmit a templated, spreading aggregation of hSOD1, resulting in a fatal ALS-like disease. PMID:27140399

  19. 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.

  20. 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

  1. Superoxide dismutase overexpression protects against glucocorticoid-induced depressive-like behavioral phenotypes in mice.

    PubMed

    Uchihara, Yuki; Tanaka, Ken-ichiro; Asano, Teita; Tamura, Fumiya; Mizushima, Tohru

    2016-01-22

    In the stress response, activation of the hypothalamic-pituitary-adrenal axis, and particularly the release of glucocorticoids, plays a critical role. However, dysregulation of this system and sustained high plasma levels of glucocorticoids can result in depression. Recent studies have suggested the involvement of reactive oxygen species (ROS), such as superoxide anion, in depression. However, direct evidence for a role of ROS in the pathogenesis of this disorder is lacking. In this study, using transgenic mice expressing human Cu/Zn-superoxide dismutase (SOD1), an enzyme that catalyzes the dismutation of superoxide anions, we examined the effect of SOD1 overexpression on depressive-like behavioral phenotypes in mice. Depressive-like behaviors were induced by daily subcutaneous administration of the glucocorticoid corticosterone for 4 weeks, and was monitored with the social interaction test, the sucrose preference test and the forced swim test. These tests revealed that transgenic mice overexpressing SOD1 are more resistant to glucocorticoid-induced depressive-like behavioral disorders than wild-type animals. Furthermore, compared with wild-type mice, transgenic mice showed a reduction in the number of 8-hydroxy-2'-deoxyguanosine (a marker of oxidative stress)-positive cells in the hippocampal CA3 region following corticosterone administration. These results suggest that overexpression of SOD1 protects mice against glucocorticoid-induced depressive-like behaviors by decreasing cellular ROS levels. PMID:26721432

  2. 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

  3. A tandem duplication of manganese superoxide dismutase in Nosema bombycis and its evolutionary origins.

    PubMed

    Xiang, Heng; Pan, Guoqing; Vossbrinck, Charles R; Zhang, Ruizhi; Xu, Jinshan; Li, Tian; Zhou, Zeyang; Lu, Cheng; Xiang, Zhonghuai

    2010-12-01

    Microsporidia are a group of obligate intracellular eukaryotic parasites with small genomes. They infect animals from a wide variety of phyla, including humans. Two manganese superoxide dismutase (MnSOD) genes, designated NbMnSOD1 and NbMnSOD2, were found to be organized in a tandem array within the Nosema bombycis genome. The genes, both 678 bp in length, were found to be more similar to each other than they are to homologous genes of other Microsporidia, suggesting that the tandem duplication occurred subsequent to the development of this lineage. Reverse transcript PCR shows that mRNA for both genes is present in the spores. Analysis of the primary structure, hydrophobic cluster analysis, target signal analysis, and phylogenetic analysis all indicate that NbMnSOD1 is dimeric and targeted to the cytosol. NbMnSOD2 seems to have changed more rapidly and is under less evolutionary constraint than NbMnSOD1 suggesting that NbMnSOD2 may function under different conditions or in different tissues of its host rather than simply resulting in an increase in expression. A phylogenetic analysis of MnSOD sequences from eukaryotes, Archaea, and bacteria shows the microsporidial MnSODs to be grouped with the bacteria suggesting a possible horizontal gene transfer. PMID:20972560

  4. Acetylation at lysine 71 inactivates superoxide dismutase 1 and sensitizes cancer cells to genotoxic agents

    PubMed Central

    Lu, Junyan; Xie, Zuoquan; Sun, Wenyi; Luo, Cheng; Ding, Jian; Yuan, Shengtao; Geng, Meiyu; Huang, Min

    2015-01-01

    Cancer cells are characterized by a high dependency on antioxidant enzymes to cope with the elevated rates of reactive oxygen species (ROS). Impairing antioxidant capacity in cancer cells disturbs the ROS homeostasis and exposes cancer cells to massive oxidative stress. In this study, we have discovered that superoxide dismutase 1 (SOD1), a major player in maintaining the cellular redox status, was acetylated at lysine 71. This acetylation, which was primarily deacetylated by Sirtuin 1 (SIRT1), suppressed the enzymatic activity of SOD1 via disrupting its association with copper chaperone for SOD1 (CCS). More importantly, genotoxic agents, such as camptothecin (CPT), induced SOD1 acetylation by disrupting its binding with SIRT1. CPT-induced SOD1 acetylation was stimulated by its provoked ROS, suggesting a positive feedback loop, in which ROS per se impairs the antioxidative defence of cancer cells and reinforces oxidative stress stimulated by anticancer agents. The intrinsic abundance of SOD1 acetylation varied among cancer cells, and high level of SOD1 acetylation was correlated with elevated sensitivity to CPT. Together, our findings gained mechanistic insights into how cytotoxic agents fine tune the intracellular ROS homeostasis to strengthen their anticancer effects, and suggested SOD1 acetylation as a candidate biomarker for predicting response to CPT-based chemotherapy. PMID:26008972

  5. 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

  6. A Cu/Zn superoxide dismutase from Jatropha curcas enhances salt tolerance of Arabidopsis thaliana.

    PubMed

    Liu, Z B; Zhang, W J; Gong, X D; Zhang, Q; Zhou, L R

    2015-01-01

    Superoxide dismutases (SODs) are involved in protecting plants against diverse biotic and abiotic stresses. In the present study, a novel Cu/Zn-SOD gene (JcCu/Zn-SOD) was cloned from Jatropha curcas L. Quantitative reverse transcription-polymerase chain reaction analysis revealed that JcCu/Zn-SOD is constitutively expressed in different tissues of J. curcas and induced under NaCl treatment. To characterize the function of this gene with respect to salt tolerance, the construct p35S:JcCu/Zn-SOD was developed and transformed into Arabidopsis using Agrobacterium-mediated transformation. Compared with wild-type, transgenic plants over-expressing JcCu/Zn-SOD showed enhanced tolerance to salt stress during germination, seedling establishment, and growth in terms of longer root, larger rosette area, and a larger number of leaves in addition to higher SOD activity levels under NaCl stress. In addition, over-expression of JcCu/Zn-SOD resulted in lower monodialdehyde content in transgenic Arabidopsis compared to wild-type plants under the same NaCl stress. Therefore, JcCu/Zn-SOD can increase a plant salt stress tolerance potentially by reducing oxidant injury. PMID:25867355

  7. Profiling of superoxide dismutase isoenzymes in compartments of the developing bovine antral follicles.

    PubMed

    Combelles, Catherine M H; Holick, Emily A; Paolella, Louis J; Walker, David C; Wu, Qiaqia

    2010-05-01

    The antral follicle constitutes a complex and regulated ovarian microenvironment that influences oocyte quality. Oxidative stress is a cellular state that may play a role during folliculogenesis and oogenesis, although direct supporting evidence is currently lacking. We thus evaluated the expression of the three isoforms (SOD1, SOD2, and SOD3) of the enzymatic antioxidant superoxide dismutase in all the cellular (granulosa cells, cumulus cells, and oocytes) and extracellular (follicular fluid) compartments of the follicle. Comparisons were made in bovine ovaries across progressive stages of antral follicular development. Follicular fluid possessed increased amounts of SOD1, SOD2, and SOD3 in small antral follicles when compared with large antral follicles; concomitantly, total SOD activity was highest in follicular fluids from smaller diameter follicles. SOD1, SOD2, and SOD3 proteins were expressed in granulosa cells without any fluctuations in follicle sizes. All three SOD isoforms were present, but were distributed differently in oocytes from small, medium, or large antral follicles. Cumulus cells expressed high levels of SOD3, some SOD2, but no detectable SOD1. Our studies provide a temporal and spatial expression profile of the three SOD isoforms in the different compartments of the developing bovine antral follicles. These results lay the ground for future investigations into the potential regulation and roles of antioxidants during folliculogenesis and oogenesis. PMID:20197373

  8. Superoxide dismutase activity as a measure of hepatic oxidative stress in cattle following ethionine administration.

    PubMed

    Abd Ellah, Mahmoud R; Okada, Keiji; Goryo, Masanobu; Oishi, Akihiro; Yasuda, Jun

    2009-11-01

    The goal of this study was to assess if oxidative stress, as measured by alterations in the concentrations of antioxidant enzymes in the liver and erythrocytes of cattle, could be induced following dl-ethionine administration. Whole blood, serum and liver biopsy samples were collected 0, 4, 7 and 10 days after intra-peritoneal ethionine administration to five cows. The activities of the antioxidant enzymes copper zinc superoxide dismutase (Cu, Zn SOD) and catalase were assessed in the liver biopsies which were also examined histopathologically. Significant increases in hepatic Cu, Zn SOD concentrations (P<0.01) were noted on days 7 and 10 post-treatment. Hepatic catalase activity decreased significantly (P<0.01) on days 4, 7 and 10 post-treatment and erythrocyte Cu, Zn SOD activity was significantly increased on day 10. Serum biochemical analysis revealed a significant increase (P<0.01) in non-esterified fatty acid concentrations on day 4 and significant decreases in total cholesterol and phospholipid levels on days 4 (P<0.05), 7 (P<0.01) and 10 (P<0.01). In this model system, dl-ethionine administration was effective in inducing oxidative stress particularly reflected in the liver. PMID:18585936

  9. Green tea catechins upregulate superoxide dismutase and catalase in fruit flies.

    PubMed

    Li, Yuk Man; Chan, Ho Yin Edwin; Huang, Yu; Chen, Zhen Yu

    2007-05-01

    Chinese Longjing green tea is an excellent source of polyphenol antioxidants. HPLC analysis revealed that Longjing green tea catechin extract (GTC) contained 62% epigallocatechin gallate (EGCG), 19% epigallocatechin (EGC), 9% epicatechin gallate (ECG), and 7% epicatechin (EC). Investigating the effect of GTC on the lifespan of Drosophila melanogaster, we observed that a 10 mg GTC/mL diet could prolong its 50% survival time by 36% and mean lifespan by 16%. This was consistent with 17% reduction in total body lipid hydroperoxide (LPO) level in GTC-treated flies compared to the control group. Supplementation of 10 mg GTC/mL diet increased the survival time only in wild type Oregon-R-C (OR) but not in two mutant fly lines, SOD(n108)/TM3 (gene for superoxide dismutase (SOD) was knocked out) and Cat(n1)/TM3 (gene for catalase was knocked out), when the flies were challenged with paraquat or hydrogen peroxide. Accordingly, SOD and catalase activities in OR wild type increased by 40 and 19%, respectively. RT-PCR analysis indicated that the genes for copper-zinc containing SOD (CuZnSOD), manganese containing SOD (MnSOD), and catalase were upregulated. It was concluded that prolonging lifespan by GTC in D. melanogaster was influenced, among others, by upregulation of endogenous antioxidant enzymes. PMID:17440995

  10. 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