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Query: UNIPROT:P04179 (
MnSOD
)
2,777
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Cu,Zn superoxide dismutase (Cu,Zn-SOD; EC 1.15.1.1) is known to be inhibited slowly by H2O2. Using EPR and the spin traps 5,5-dimethyl-1-pyrroline 1-oxide (DMPO) and N-tert-butyl-alpha-phenylnitrone (PBN), we have shown that Cu,Zn-SOD catalyzes the formation of "free" .OH radicals from H2O2 in pH 7.6 bicarbonate buffer. Supporting evidence includes the following: (i) H2O2 and active Cu,Zn-SOD are required to yield significant signals from spin-trap-OH adducts. (ii) With O2-., Cu,Zn-SOD causes the appearance of intense resonance signals due to DMPO-OH adducts. These signals were inhibited strongly by catalase. (iii) With H2O2, Cu,Zn-SOD, and DMPO, radical scavengers formate and azide, but not ethanol, decrease DMPO-OH signals while causing new intense signals due to their corresponding DMPO-radical adducts. Failure of ethanol to quench DMPO-OH signals is discussed in light of the positively charged active channel of the enzyme. (iv) With PBN as a spin trap, ethanol quenches .OH radical signals and yields PBN-trapped hydroxyethyl radical signals. (v)
Mn-SOD
does not catalyze "free" .OH radical formation and it also exerts no effect on the signals of DMPO-OH adducts when added together with the Cu,Zn-SOD. The capacity of Cu,Zn-SOD to generate "free" .OH radicals from H2O2 may in part explain the biological damage associated with elevated intracellular
SOD
activity.
...
PMID:Copper, zinc superoxide dismutase catalyzes hydroxyl radical production from hydrogen peroxide. 216 16
A sensitive sandwich-type enzyme immunoassay for measurement of human
Mn superoxide dismutase
(Mn
SOD
) was developed using purified antibodies specific to Mn
SOD
. The antisera were raised in rabbits by injecting Mn
SOD
purified from human liver. The antibody IgG, purified by the use of Mn
SOD
-coupled Sepharose, showed a single band on the immunoblotting test with a crude liver extract. The assay system consisted of polystyrene balls with immobilized monospecific antibody F(ab')2 fragments and the same antibody Fab' fragments labeled with beta-D-galactosidase from Escherichia coli. The assay was highly sensitive and the minimum detection limit was 1 pg human Mn
SOD
/assay tube. Serum Mn
SOD
concentrations of healthy adults (77.5 +/- 18.0 ng/ml (1 SD), n = 120, 16-64 yr old) were not related to age or sex. Immunoreactive Mn
SOD
was detectable in most tissues examined except for erythrocytes. The concentrations of immunoreactive Mn
SOD
and Cu/Zn
SOD
in the cerebral cortex were not different among the patients with Alzheimer's disease, and the age matched and young patients without neurological disorders.
...
PMID:Sensitive enzyme immunoassay for human Mn superoxide dismutase. 228 14
We have demonstrated a dramatic induction of manganese superoxide dismutase (Mn-SOD) mRNA levels in response to lipopolysaccharide (LPS), interleukin-1, and tumor necrosis factor in pulmonary epithelial cells. These stimuli had no effect on the corresponding mRNA levels for the copper/zinc (Cu/Zn)-
SOD
. Identical treatments of pulmonary fibroblast cells with LPS showed only minor changes in the Mn-SOD mRNA levels demonstrating a cell type-specific effect for this acute inflammatory mediator. Furthermore, we have shown that hyperoxia has no effect within 24 h on Mn-or Cu/Zn-
SOD mRNA
levels in either fibroblasts or epithelial cells. The induction of Mn-SOD mRNA levels by LPS is completely inhibited by actinomycin. Treatment of cells with cycloheximide causes an induction equal to that for LPS, whereas co-treatment with cycloheximide and LPS resulted in a "super induction." This data is strongly suggestive of an important role for the Mn-SOD in the acute inflammatory response.
...
PMID:Regulation of manganese superoxide dismutase by lipopolysaccharide, interleukin-1, and tumor necrosis factor. Role in the acute inflammatory response. 240 41
Earlier histological studies have demonstrated that copper deficiency results in a selective and progressive atrophy of pancreatic acinar tissue. The present study examined both biochemical and morphological changes of the exocrine pancreas in nutritional copper deficiency. Groups of mature female rats were fed a purified diet either deficient (less than 0.5 micrograms/g) or sufficient (6.2 micrograms/g) in copper for 6 wk. Copper deficiency resulted in distinct ultrastructural changes in acinar cells, including marked variability in zymogen granule content, autophagic vacuoles and dilation of acinar lumen. Pancreatic weight and total DNA, RNA and protein content of the pancreas were similar in both groups of rats, whereas pancreatic amylase, trypsin and chymotrypsin activity was significantly lower in the copper-deficient group. In addition, secretagogue-induced release of these enzymes from dispersed acini isolated from copper-deficient rats was significantly reduced in comparison to enzyme secretion from normal controls. Pancreatic
Cu-Zn
and
Mn superoxide dismutase
activity was also found to be significantly lower in the copper-deficient rats than in normal controls. We conclude that nutritional copper deficiency in adult female rats reduces the responsiveness of the pancreas to secretagogues and may increase the susceptibility of the pancreas to oxidative damage.
...
PMID:Morphological and biochemical changes in the pancreas of the copper-deficient female rat. 247 34
The cellular localization of copper-zinc superoxide dismutase (CuZn
SOD
) mRNA was determined in the human hippocampus by in situ hybridization with a 35S-labelled DNA probe complementary to human CuZn
SOD mRNA
. A positive hybridization signal was detected in pyramidal cell layers CA1-CA4 of Ammon's horn (CA), pyramidal cells of subiculum and in the granule cells of the dentate gyrus. The fact that CuZn
SOD
gene expression is important in neurones which are preferentially vulnerable in neurodegenerative processes such as Alzheimer's disease, suggests a role played by oxygen free radicals in the mechanism of nerve cell death.
...
PMID:Localization of copper-zinc superoxide dismutase mRNA in human hippocampus by in situ hybridization. 248 84
Root resorbing of deciduous teeth is a general phenomenon during eruption of the permanent teeth. In the present study, we tried to clarify the active-oxygen metabolism of root resorped granulated tissues. Granulated tissues were obtained from two fresh mandibles of young bovine about 1 year old undergoing root resorption.
Cu-Zn
-Superoxide dismutase (SOD),
Mn-SOD
, Lactate dehydrogenase (LDH), and concentration of lipid-peroxidated products were determined on the supernatants from homogenized tissues. We obtained the following results. 1) Cytosolic
Cu-Zn
-SOD activity did not elevate as compared to control tissues. 2) Elevation of mitochondrial
Mn-SOD
activity was observed in granulated tissues. 3) LDH activity did not elevate as compared to control tissues. 4) Lipid-peroxidated products in granulated tissues showed high concentration as compared to control tissues. Based on the above, we specurated that the active-oxygen metabolism in the root resorped granulated tissues, at least in mitochondria, was elevated.
...
PMID:[Oxygen metabolism in roots resorbing granulated tissue from bovine deciduous teeth, from the aspects of superoxide dismutase, lactate dehydrogenase, and lipid peroxidation]. 248 84
Lipid peroxide and
SOD
were selected as free radical related substances and system for their elimination, and detection was evaluated. NADPH-Cytochrome c reductase-Neotetrazolium (NT) method (Mic-NT method) and Xanthine oxidase-Nitrotetrazolium Blue method (XOD-NTB method) are current detection methods of
SOD
activities. They are based on the O2-specific reaction. Minimum detectable amount of
SOD
by the Mic-NT method and XOD-NTB method was about 15 ng and 200 ng, respectively. On the other hand, an XOD-NH2OH method which detects
SOD
activities based on the O2-specific oxidation reaction showed the minimum detectable amount of 2.5 ng. Consequently,
SOD
-detecting sensitivity of these methods was found to be in the following order: XOD-NH2OH method greater than Mic-NT method greater than XOD-NTB method. In addition, albumin caused a positive error in all three methods. With a monoclonal antibody-aided
SOD
-analyzing method (EIA method), the minimum detectable amount of
SOD
was 0.2 ng. The isoenzymes of
SOD
(Cu, Zn-
SOD
and
Mn-SOD
) could be detected separately by 1. deactivating Cu, Zn-
SOD
with CN- or H2O2 and regarding the remaining activity as
Mn-SOD
and 2. by deactivating
Mn-SOD
selectively through pretreatment of the sample with SDS and regarding the remaining activity as Cu, Zn-
SOD
. TBA method (Yagi's method) has been used frequently for the measurement of serum lipid peroxide.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:[Detection methods of free radical related substances and the system for their elimination]. 260 53
Lipid peroxidation of the cell membrane is one of the most important factors of reperfusion induced arrhythmia (RIA). To determine the role of lipid peroxidation in RIA, lipid peroxide (LPO) and superoxide dismutase (Total,
Mn-SOD
) were examined in this experiment. Thirty-four male Donryu strain rats (250-350 g body weight) were studied. After left thoracotomy and 5-minute ligature of LAD coronary artery, reperfusion was done under artificial ventilation with room air. The electrocardiogram (ECG) was recorded via standard limb leads. Twenty-four rats were divided into 5 groups and the heart tissue and blood samples were collected 1. preligature 2. after 1-minute ligature 3. after 4-minute ligature 4. 1-minute after declamping and 5. 10-minute after declamping. To examine the correlation between LPO and duration of RIA, samples from another 10 rats were collected as soon as RIA disappeared. LPO,
SOD
, CPK, and MDH (malate dehydrogenase) were measured in all samples. The total
SOD
level in heart tissue decreased after reperfusion (p less than 0.05). The heart tissue LPO (t-LPO) decreased after ligature (p less than 0.05), but each value in 2. to 5. was lower than 1., and no increase was found after reperfusion. A negative correlation of R = 0.87 (p less than 0.01) was found between t-LPO and RIA duration, but a positive correlation of R = 0.79 (p less than 0.01) was found between t-LPO and CPK. Moreover, the LPO level was lower in the RIA occurrence group than in the non-occurrence group (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:[Studies on the behavior of lipid peroxide in reperfusion induced arrhythmia]. 260 63
The genome of Escherichia coli codes for two superoxide dismutases that may contain either iron (FeSOD) or manganese (
MnSOD
) at the active site. The crystal structures of MnSODs from two bacterial sources (but not E. coli) have been completed, and structural comparisons with the crystal structure of the FeSOD from either E. coli or Pseudomonas ovalis have been made. Despite the low degree (less than 50%) of sequence homology between the E. coli enzymes, the two proteins are suggested to be structurally homologous. Nonetheless, these enzymes exhibit absolute metal cofactor specificity in conferring enzymatic activity to the inactive apoenzyme. This observation is surprising considering the identity of the active site ligands and the similarities in their geometry and surrounding environment. Using analytical ultracentrifugation, we have determined that the solution properties of these two proteins are different. Thus dialysis of FeSOD but not of
MnSOD
against phosphate buffer in the presence or absence of EDTA caused dissociation of the
homodimer
. This dissociation appeared to be related to the loss of iron from native FeSOD. Thus, apoFeSOD but not apoMnSOD existed predominantly as a monomer at protein concentrations below 150 micrograms/mL. ApoMnSOD showed no evidence for dissociation under these conditions. Fluorescence data suggest that the tryptophan environments for the two enzymes are also different. The results of these physical measurements lead us to propose that subtle differences, perhaps at the subunit contact faces, exist in the structures of these crystallographically similar proteins.
...
PMID:Differences between the manganese- and the iron-containing superoxide dismutases of Escherichia coli detected through sedimentation equilibrium, hydrodynamic, and spectroscopic studies. 266 53
The synthesis of Cu,Zn
SOD
by rat lung increases spontaneously in the fetus in late gestation and during exposure of neonatal and adult rats to greater than 95% O2. To explore the regulation of these increases, we measured rat lung Cu,Zn
SOD
synthesis and activity. We also cloned and sequenced a rat lung Cu,Zn
SOD
cDNA that was used to measure Cu,Zn
SOD mRNA
concentration. We found that (a) under normal gestational and postgestational conditions the synthesis of this enzyme was regulated pretranslationally; (b) the increased synthesis that occurs under hyperoxia (greater than 95% O2), was pretranslationally mediated in otherwise unmanipulated neonatal rats but translationally controlled in hyperoxic adult rats; and (c) in lungs of rats made tolerant to greater than 95% O2 by allowing 24 h rest in air after an initial 48 h in greater than 95% O2, the increased Cu,Zn
SOD
synthesis that occurred during the second period of hyperoxia was regulated pretranslationally. We conclude Cu,Zn
SOD
gene expression in the lung is developmentally regulated under normal conditions and in response to an oxidant challenge. Tolerance, whether endogenous or induced, appears to require the accumulation of increased amounts of Cu,Zn
SOD mRNA
.
...
PMID:Rat lung Cu,Zn superoxide dismutase. Isolation and sequence of a full-length cDNA and studies of enzyme induction. 270 31
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