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.

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 Absence of the iron-containing superoxide dismutase in mitochondria from mustard (Brassica campestris)

1981 ◽  
Vol 195 (1) ◽  
pp. 229-233 ◽  
Author(s):  
M L Salin ◽  
S M Bridges
Keyword(s):  
Superoxide Dismutase ◽  
Brassica Campestris ◽  
Polyacrylamide Gel ◽  
Superoxide Dismutases ◽  
Intermembrane Space ◽  
Mitochondrial Matrix ◽  
Mature Leaves ◽  
Etiolated Seedlings

Mitochondria were isolated from mature leaves as well as etiolated seedlings of Brassica campestris (mustard), a eukaryote previously shown to possess the iron-containing isoenzyme of superoxide dismutase. On the basis of KCN- and H2O2-sensitivity, and on polyacrylamide-gel analysis, only the cuprozinc and mangano superoxide dismutases were found in mitochondria. The iron-containing enzyme was absent. The mangano enzyme was found in the mitochondrial matrix, whereas the cuprozinc enzyme appeared to be localized in the intermembrane space.

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.

Induction and intracellular localization of the 80-kilodalton heat-shock protein of Neurospora crassa

1992 ◽  
Vol 70 (12) ◽  
pp. 1347-1355 ◽  
Author(s):  
H. S. Roychowdhury ◽  
T. J. MacAlister ◽  
J. W. Costerton ◽  
M. Kapoor
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Neurospora Crassa ◽  
Immunoelectron Microscopy ◽  
Intracellular Localization ◽  
Normal Growth ◽  
Immunogold Labelling ◽  
Subcellular Compartment ◽  
Intracellular Location ◽  
Gold Label

The most abundant heat-shock protein of Neurospora crassa is a multimeric glycoprotein of 80-kilodaltons (i.e., HSP80), induced strongly by hyperthermia and at a lower level by sodium arsenite, ethanol, and carbon source depletion. Immunoelectron microscopy, using indirect immunogold labelling demonstrated that HSP80 was undetectable in mycelium cultured at the normal growth temperature of 28 °C, but it appeared rapidly following the commencement of heat-shock treatment at 48 °C. HSP80, visualized by the gold label, was observed almost exclusively in the cytoplasm, exhibiting a uniform distribution. Association of this protein with cellular membranes and (or) targeting to a particular subcellular compartment or organelle was not apparent.Key words: 80-kilodalton heat-shock protein, Neurospora, intracellular location, immunoelectron microscopy.

Selective induction of manganous superoxide dismutase in human monocytes

1985 ◽  
Vol 249 (5) ◽  
pp. C393-C397 ◽  
Author(s):  
K. Asayama ◽  
R. L. Janco ◽  
I. M. Burr
Keyword(s):  
Superoxide Dismutase ◽  
Muramyl Dipeptide ◽  
Superoxide Production ◽  
Bacterial Lipopolysaccharide ◽  
Culture Period ◽  
Superoxide Dismutases ◽  
Minimal Effect ◽  
Human Monocytes ◽  
Transient Decrease ◽  
Copper Zinc

Radioimmunoassays for both human copper-zinc and manganous superoxide dismutases (Cu-Zn SOD and Mn SOD, respectively) have been developed, validated, and utilized to measure the concentrations of these enzymes in cultured monocytes. Monocyte Mn SOD increased 4.7-fold over basal during 3 days of culture, an increase that was markedly enhanced by stimulation with bacterial lipopolysaccharide (LPS). Cu-Zn SOD showed a transient decrease over the culture period but was unaffected by LPS. Stimulation with muramyl dipeptide had minimal effect on Mn SOD and no effect on Cu-Zn SOD during culture, even at a concentration capable of activating the monocytes, as defined by zymosan-induced superoxide production.

Sign in / Sign up

Export Citation Format

Share Document