scholarly journals Polarographic assay and intracellular distribution of superoxide dismutase in rat liver.

1975 ◽  
Vol 147 (3) ◽  
pp. 493-504 ◽  
Author(s):  
D D Tyler
Keyword(s):  
Superoxide Dismutase ◽  
Rat Liver ◽  
Total Activity ◽  
Intracellular Distribution ◽  
Superoxide Dismutase Activity ◽  
Intermembrane Space ◽  
Matrix Space ◽  
Intracellular Location ◽  
H2o2 Formation ◽  
Mitochondrial Intermembrane Space

1. A polarographic assay of superoxide (O2-) dismutase (EC 1.15.1.1) activity is described, in which the ability of the enzyme to inhibit O2-dependent sulphite oxidation, initiated by xanthine oxidase activity, is measured. The assay was used in a study of the intracellular distribution of superoxide dismutase in rat liver. Both cyanide-sensitive cupro-zinc dismutase (92% of the total activity) and cyanide-insensitive mangano-dismutase (8%) were measured. 2. Rat liver homogenates contained both particulate (16%y and soluble (84%) dismutase activity. The particulate activity contained both types of dismutase, whereas nearly all the soluble dismutase was a cupro-zinc enzymes. The distribution pattern of mangano-dismutase was similar to that of cytochrome oxidase and glutamate dehydrogenase, indicating that the enzyme was probably present exclusively in the mitochondria. 3. Superoxide dismutase activity in the heavy-mitochondrial (M) fraction was latent and was activated severalfold and largely solubilized by sonication. Treatment of the M fraction with digitonin or a hypo-osmotic suspending medium indicated that most of the cupro-zinc dismutase was located in the mitochondrial intermembrane space, whereas the mangano-enzyme was located in the inner-membrane and matrix space. 4. A small amount of dismutase activity appeared to be present in the nuclei and microsomal fraction, but little or no activity in the lysosomes or peroxisomes. 5. The results are discussed in relation to the intracellular location of known O2-generating enzymes, the possible role of superoxide dismutase activity in intracellular H2O2 formation, and to current views on the physiological function of the enzyme.

scholarly journals Subcellular localization of superoxide dismutase in rat liver

1975 ◽  
Vol 150 (1) ◽  
pp. 31-39 ◽  
Author(s):  
C Peeters-Joris ◽  
A M Vandevoorde ◽  
P Baudhuin
Keyword(s):  
Superoxide Dismutase ◽  
Subcellular Localization ◽  
Rat Liver ◽  
Specific Activity ◽  
Osmotic Shock ◽  
Superoxide Dismutase Activity ◽  
Mitochondrial Activity ◽  
Intermembrane Space ◽  
Matrix Space ◽  
The Matrix

The subcellular localization of superoxide dismutase was investigated in rat liver homogenates. Most of the superoxide dismutase activity is present in the soluble fraction (84%), the rest being associated with mitochondria. No indications for the occurrence of superoxide dismutase in other subcellular structures, particularly in peroxisomes, was found. Mitochondrial activity is not due to adsorption, since the sedimentable activity is essentially latent. Subfractionation of mitochondria by hypo-osmotic shock and sonication shows that half of the mitochondrial superoxide dismutase activity is localized in the intermembrane space, the rest of the enzyme being a component of the matrix space. In non-ionic media the matrix enzyme is, however, adsorbed to the inner membrane, from which it can be desorbed by low (0.04M) concentration of KCl. Superoxide dismutase activity was found in all rat organs investigated. Maximal activity of the enzyme is observed in liver, adrenals and kidney. In adrenals, the highest specific activity is associated with the medulla.

scholarly journals Intracellular localization, isolation and characterization of two distinct varieties of superoxide dismutase from Neurospora crassa

1980 ◽  
Vol 187 (2) ◽  
pp. 321-328 ◽  
Author(s):  
Landis E. A. Henry ◽  
Richard Cammack ◽  
Jean-Paul Schwitzguebel ◽  
John M. Palmer ◽  
David O. Hall
Keyword(s):  
Superoxide Dismutase ◽  
Neurospora Crassa ◽  
Analytical Ultracentrifugation ◽  
Intracellular Localization ◽  
Total Activity ◽  
Superoxide Dismutases ◽  
Intermembrane Space ◽  
Matrix Space ◽  
Isolation And Characterization ◽  
High Yields

1. Neurospora crassa was found to contain two distinct superoxide dismutases. 2. Most of the activity is associated with the cytosolic fraction and was shown to be the Cu/Zn-containing form of the protein. 3. Mitochondria isolated from Neurospora crassa showed two distinct superoxide dismutases: a cyanide-sensitive Cu/Zn-containing protein and a cyanide-insensitive form which probably contains manganese. 4. Localization experiments, using selective marker enzymes and digitonin fractionation, indicated that the cyanide-sensitive form is localized in the intermembrane space, whereas the cyanide-insensitive form is confined to the mitochondrial matrix space. 5. The cytosolic Cu/Zn-containing superoxide dismutase was isolated in high yields and extensively characterized by using e.p.r. spectroscopy, isoelectric focusing and analytical ultracentrifugation. 6. E.p.r. spectroscopy was used to monitor changes in the copper environment of the native protein after the addition of a number of potential inhibitors and after high-pH treatment. 7. Both of the cyanide-sensitive Cu/Zn-containing enzymes (cytosolic and mitochondrial) appeared to have identical properties which in turn were different from the cyanide-insensitive enzyme. 8. It is probable that the cyanide-insensitive enzyme was not previously detected, owing to its low amount (less than 10% of the total activity), greater lability than the cyanide-sensitive enzyme and the necessity of obtaining a mitochondrial-enriched fraction before its isolation.

Effects of estradiol benzoate and progesterone on superoxide dismutase activity in the rat liver

1997 ◽  
Vol 20 (4) ◽  
pp. 203-206 ◽  
Author(s):  
J. Kasapović ◽  
S. B. Pajović ◽  
D. T. Kanazir ◽  
J. V. Martinović
Keyword(s):  
Superoxide Dismutase ◽  
Rat Liver ◽  
Estradiol Benzoate ◽  
Superoxide Dismutase Activity

Influence of adrenalectomy and dexamethasone on rat liver metallothionein and superoxide dismutase activity

1984 ◽  
Vol 91 (2) ◽  
pp. L21-L22 ◽  
Author(s):  
Linda L. Hutchings ◽  
Diane M. Scholler ◽  
Joan S. Valentine ◽  
Mavis R. Swerdel ◽  
Kenneth R. Etzel ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Rat Liver ◽  
Superoxide Dismutase Activity

scholarly journals Mitochondrial Protein Oxidation in Yeast Mutants Lacking Manganese-(MnSOD) or Copper- and Zinc-containing Superoxide Dismutase (CuZnSOD)

2004 ◽  
Vol 279 (50) ◽  
pp. 51817-51827 ◽  
Author(s):  
Kristin M. O'Brien ◽  
Reinhard Dirmeier ◽  
Marcella Engle ◽  
Robert O. Poyton
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Stationary Phases ◽  
Mitochondrial Protein ◽  
Protein Carbonylation ◽  
Intermembrane Space ◽  
Flight Mass Spectrometry ◽  
Specific Proteins ◽  
Mitochondrial Intermembrane Space ◽  
Yeast Mutants

Saccharomyces cerevisiaeexpresses two forms of superoxide dismutase (SOD): MnSOD, encoded bySOD2, which is located within the mitochondrial matrix, and CuZnSOD, encoded bySOD1, which is located in both the cytosol and the mitochondrial intermembrane space. Because two different SOD enzymes are located in the mitochondrion, we examined the relative roles of each in protecting mitochondria against oxidative stress. Using protein carbonylation as a measure of oxidative stress, we have found no correlation between overall levels of respiration and the level of oxidative mitochondrial protein damage in either wild type orsodmutant strains. Moreover, mitochondrial protein carbonylation levels insod1,sod2, andsod1sod2mutants are not elevated in cells harvested from mid-logarithmic and early stationary phases, suggesting that neither MnSOD nor CuZnSOD is required for protecting the majority of mitochondrial proteins from oxidative damage during these early phases of growth. During late stationary phase, mitochondrial protein carbonylation increases in all strains, particularly insod1andsod1sod2mutants. By using matrix-assisted laser desorption ionization time-of-flight mass spectrometry, we have found that specific proteins become carbonylated insod1andsod2mutants. We identified six mitochondrial protein spots representing five unique proteins that become carbonylated in asod1mutant and 19 mitochondrial protein spots representing 11 unique proteins that become carbonylated in asod2mutant. Although some of the same proteins are carbonylated in both mutants, other proteins are not. These findings indicate that MnSOD and CuZnSOD have both unique and overlapping functions in the mitochondrion.

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