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Query: UNIPROT:P04179 (MnSOD)
 2,777 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Superoxide dismutase (SOD) from anaerobically maintained Porphyromonas gingivalis (anaero-SOD) has the characteristic of Fe-SOD, whereas SOD from aerated cells (aero-SOD) has that of Mn-SOD. However, both types of apoSOD can bind either Fe or Mn. To elucidate the structure relationship between anaero- and aero-SOD, we examined the amino acid sequence of aero-SOD by direct protein analysis. The amino acid sequence of aero-SOD was shown to be identical with that of anaero-SOD determined previously. Our findings support the hypothesis that cambialistic SOD is formed from a single apoprotein in bacterial cells.
Oral Microbiol Immunol 1992 Dec
PMID:Identity of amino acid sequences of superoxide dismutase purified from both anaerobically maintained and aerated Porphyromonas gingivalis. 133 4

Superoxide dismutases are enzymes that defend against oxidative stress through decomposition of superoxide radical. Escherichia coli contains two highly homologous superoxide dismutases, one containing manganese (MnSOD) and the other iron (FeSOD). Although E. coli Mn and FeSOD catalyze the dismutation of superoxide with comparable rate constants, it is not known if they are physiologically equivalent in their protection of cellular targets from oxyradical damage. To address this issue, isogenic strains of E. coli containing either Mn or FeSOD encoded on a plasmid and under the control of tac promoter were constructed. SOD specific activity in the Mn and FeSOD strains could be controlled by the concentration of isopropyl beta-thiogalactoside in the medium. The tolerance of these strains to oxidative stress was compared at equal Mn and FeSOD specific activities. Our results indicate that E. coli Mn and FeSOD are not functionally equivalent. The MnSOD is more effective than FeSOD in preventing damage to DNA, while the FeSOD appears to be more effective in protecting a cytoplasmic superoxide-sensitive enzyme. These data are the first demonstration that Mn and FeSOD are adapted to different antioxidant roles in E. coli.
J Biol Chem 1992 Dec 05
PMID:Functional differences between manganese and iron superoxide dismutases in Escherichia coli K-12. 144 75

A continuous s.c. infusion of (-)deprenyl in young male rats at a dose of 2.0 mg/kg/day for 1 week significantly increased total superoxide dismutase (SOD) activities due to increases in both Cu Zn-SOD and Mn-SOD activities in certain brain regions such as the substantia nitra and striatum, but not in the hippocampus or cerebellum, or in the liver. With continuing infusion, enzyme activities of SOD were further increased in the following weeks, reaching a plateau at 3 weeks. In some cerebral cortices the increase became significant at 3 weeks. In contrast to SOD activities, an increase in catalase (CAT) activity became significant only after 2 weeks of infusion, and only in the brain regions where SOD activities were increased earlier. The delay in the increase in CAT activity following deprenyl infusion suggests that this increased CAT activity is an adaptive response to the earlier increase in deprenyl-induced SOD activities rather than a direct effect of deprenyl on CAT activity, although the latter possibility cannot be excluded.
Biochem Pharmacol 1992 Dec 01
PMID:Sequential changes in activities of superoxide dismutase and catalase in brain regions and liver during (-)deprenyl infusion in male rats. 147 83

Evidence is reported that liver manganese deficiency, whether artificially produced by the administration of a Mn-deficient diet, or physiologically occurring in the neonatal life, in mice and rats respectively, causes the down-regulation of the manganese-containing superoxide dismutase at (pre)-transcriptional level. These observations, in addition to previous data concerning Mn-deficiency and the low level of expression of MnSOD in Morris hepatomas, strongly support the role played by the metal ion in the control of the MnSOD by a mechanism of gene activation. While the molecular events taking place in such regulation are not yet identified, the involvement of reactive oxygen species (ROS) as second messengers in the activation of specific transcription factors is suggested.
Biochem Int 1992 Dec
PMID:Transcriptional regulation of MnSOD by manganese in the liver of manganese-deficient mice and during rat development. 148 98

The effects of phorbol ester (TPA) and other known stimulators such as tumor necrosis factor (TNF), interleukin-1, and lipopolysaccharide on induction of mRNA for manganese-superoxide dismutase (Mn-SOD) were investigated in various cell lines. TPA enhanced Mn-SOD mRNA expression in TNF-resistant cell lines including HeLa cells, in which the other reagents also induced expression of the gene, but did not affect TNF-sensitive cells, in which the other stimulators did not alter expression of the gene. HeLa cells which had been desensitized to TPA by pretreatment with TPA for 24 h expressed Mn-SOD mRNA at a slightly higher level than the cells without TPA treatment. TPA-pretreated cells stimulated with TNF, however, expressed Mn-SOD mRNA at about twice the level of TNF-stimulated, TPA-untreated cells. When protein synthesis was inhibited by cycloheximide during TPA pretreatment, TNF no more enhanced the Mn-SOD mRNA accumulation. These data suggest that at least two separate signal-transducing pathways are involved in expression of this gene. One is triggered by protein kinase C activation itself in the absence of new protein synthesis. The other can be activated by stimulation with TNF, interleukin-1, or lipopolysaccharide and in which a protein factor that can be induced by TPA treatment is involved.
J Biol Chem 1991 Dec 05
PMID:Phorbol ester induces manganese-superoxide dismutase in tumor necrosis factor-resistant cells. 174 13

Several strains of Bacteroides gingivalis had strong activities of superoxide dismutase (SOD) and were markedly tolerant in the presence of oxygen in 13 strains of black-pigmented Bacteroides species tested. Thus, the strains were maintained and incubated in the either anaerobic or aerobic system. It was found that the SOD activity was significantly induced by oxygen, especially in B. gingivalis 381. The SODs, anaero-SOD and aero-SOD from the extracts of B. gingivalis 381 cells, each was purified by hydrophobic chromatography followed by anion exchange chromatography, and then by gel filtration, respectively. Both the purified enzymes having molecular weight of about 46,000 consisted of two subunits of equal sizes. Spectral analysis revealed that anaero-SOD had the characteristic A350 of Fe-SOD, but aero-SOD exhibited A475 of Mn-SOD. Both samples contained three isozymes with identical isoelectric points of 5.25, 5.10 and 5.00. On the basis of inactivation of SOD by H2O2, it was shown that aero-SOD consisted of one Mn-SOD and a small quantity of two Fe-SODs, whereas anaero-SOD contained only Fe-SOD. To ascertain whether or not the apoprotein of aero-SOD is the same as that of anaero-SOD, each apoprotein was prepared by dialysis in guanidinium chloride plus 8-hydroxyquinoline. Only one protein band with the same isoelectric point of 5.30 on an isoelectric focusing gel was obtained in each purified SOD sample. Subsequent reconstitution of both apoenzymes with either Fe (NH4)2 (SO4)2 or MnCl2 significantly restored their activity. These reconstituted SODs showed only one protein band with SOD activity on Native-PAGE. The complete amino acid sequence of anaero-SOD was determined by automated Edman degradation of the protein, Achrombacter protease I, endoproteinase Asp-N and tryptic digestion. The sequence consisted of 191 residues corresponding to a molecular weight of 21,500 per subunit. Furthermore, the first 36 amino acid sequence of aero-SOD was determined following N-terminal analysis. The two enzymes had similar amino acid compositions, and their amino-terminal sequences were identical through the first 36 amino acids in which methionine residue was present at N-terminal. These results suggest the three isozymes of either anaero-SOD or aero-SOD in B. gingivalis 381 may be formed from the same apoprotein.
Osaka Daigaku Shigaku Zasshi 1990 Dec
PMID:[Purification, characterization and induction by oxygen of superoxide dismutase from Bacteroides gingivalis 381]. 196 94

We examined the influence of dehydroepiandrosterone (DHEA), a beta-agonist, and exercise training on enzymes that detoxify toxic oxygen species. Feeding 0.4% DHEA decreased hepatic cytosolic (c) selenium-dependent glutathione peroxidase (GPX), (-26%, P less than 0.0001) and increased hepatic mitochondrial (m) Mn superoxide dismutase (SOD), (+38%, P less than 0.001). DHEA decreased myocardial c-GPX (-21%, P less than 0.05) when compared to a beta-agonist (beta A; L644969 Merck and Co.) fed at 5 ppm but neither differed from the Control (C). In contrast, the beta A increased hepatic m-GPX (+25%, P less than 0.05). In skeletal muscle, DHEA and beta A decreased muscle c-GPX by 20 and 12%, respectively (P less than 0.0009). DHEA increased both muscle (+20%, P less than 0.01) and myocardial (+20%, P less than 0.05) c-glutathione S-transferase (GST) over beta A (+20%, P less than 0.01) but neither was significantly different from C. Similar to DHEA, chronic training (Tr) (1 h/day, 5 days/week at 27 m/min, 15% grade on treadmill) decreased hepatic c-GPX (-16%, P less than 0.003). Tr elevates muscle c-GPX (+36%, P less than 0.05) in C. Tr increased myocardial c-GPX by 28% in the beta A-treated rats, whereas Tr decreased myocardial c-GPX by 22% in the C (P less than 0.05, interaction). One hour of acute exercise (Ex) (70% VO2 max relative work load) decreased hepatic homogenate catalase (-12%, P less than 0.02) and increased hepatic m-Mn SOD (+28%, P less than 0.03). Ex decreased myocardial c-GST (P less than 0.05) only in the DHEA-treated rats. DHEA and Tr may improve efficiency of oxygen utilization at the tissue level with lower antioxidant enzyme activity in liver and locally protective up-regulation in muscle. beta A stresses oxygen utilization systems and liver responds by up-regulation of antioxidant enzymes. The increase in myocardial c-GPX activity in the beta A-treated group may be a protective effect against indirect catecholamine-induced myocardial necrosis which results from free radical generation.
Arch Biochem Biophys 1990 Dec
PMID:Dehydroepiandrosterone and a beta-agonist, energy transducers, alter antioxidant enzyme systems: influence of chronic training and acute exercise in rats. 198 Apr 4

The 2.9 A resolution structure of iron superoxide dismutase (FeSOD) (EC 1.15.1.1) from Pseudomonas ovalis complexed with the inhibitor azide was solved. Comparison of this structure with free enzyme shows that the inhibitor is bound at the open coordination position of the iron, with a bond length of 2.0 A. The metal moves by 0.4 A into the trigonal plane to produce an orthogonal geometry at the iron. Binding of the inhibitor also causes a movement of the axial ligand (histidine 26) away from the metal, a lengthening of the iron-histidine bond, and a rotation of the histidine 74 ring. The inhibitor possesses contacts in the binding pocket with a pair of conserved tryptophan residues and with the side chains of tyrosine 34 and glutamine 70. This glutamine is conserved between all FeSODs, but is absent in MnSOD. Comparisons with MnSOD show that a different glutamine which possesses the same interactions in the active site as Gln70 in FeSOD is conserved at position 154 in the overall SOD sequence, implying that while manganese and FeSODs are structural homologues in a global sense, their functional and evolutionary relationship is that of second-site mutation revertants.
Protein Eng 1990 Dec
PMID:The structure of iron superoxide dismutase from Pseudomonas ovalis complexed with the inhibitor azide. 207 85

Tracheal insufflation of tumor necrosis factor (TNF) enhances pulmonary antioxidant enzyme activities and protects rats against oxygen toxicity (J. Appl. Physiol. 68: 1211-1219, 1990). We now report that tracheal insufflation of TNF selectively induced pulmonary Mn-superoxide dismutase (SOD) mRNA in normoxia- and hyperoxia-exposed rats, leading to increased amounts of Mn-SOD specific protein and enzyme activity. Tracheal insufflation of TNF had no effect on the levels of pulmonary Cu,Zn-SOD mRNA or specific protein. Hyperoxia alone also selectively induced pulmonary Mn-SOD mRNA. However, the hyperoxia-induced increase in Mn-SOD mRNA was not associated with an increase in Mn-SOD specific protein or enzyme activity. The results suggest that the increased pulmonary Mn-SOD in TNF-insufflated rats may contribute to the TNF-induced protection against oxygen toxicity.
Am J Physiol 1990 Dec
PMID:Molecular basis for tumor necrosis factor-induced increase in pulmonary superoxide dismutase activities. 226 Jun 78

Superoxide dismutase (SOD) molecules occur in all cells exposed to an oxygen-containing environment, including retinal pigment epithelial (RPE) cells. Previous studies of nonhuman RPE have either probed specifically for copper-zinc-containing SOD (CuZn-SOD) or have not distinguished between CuZn-SOD and the SOD molecule that contains manganese (Mn-SOD). The authors used specific enzymatic assays and immunologic probes, both in vivo and in vitro, to show that human RPE cells contain both CuZn-SOD and Mn-SOD. The CuZn-SOD had a diffuse cytosolic distribution, whereas the Mn form was located primarily in the mitochondria. The role of SODs in protecting the chorioretinal complex against oxidative damage and with regard to aging processes is not well understood and warrants further investigation, and the two cellular forms of SOD should be considered in future studies.
Invest Ophthalmol Vis Sci 1990 Dec
PMID:Human retinal pigment epithelium contains two distinct species of superoxide dismutase. 226 90


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