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 ina...

Superoxide radicals are produced in trace amounts by the mitochondrial respiratory chain. Most are removed rapidly by superoxide dismutase in the matrix. Superoxide is also known to react with glutathione. Reported values of the rate constant for this reaction range from 10(2) to in excess of 10(5) M(-1).s(-1). The magnitude of this rate constant has important physiological implications because...

In this work we report that superoxide dismutase is entrapped in a microbody-like organelle, the glycosome, present in Leishmania spp. Studies on the sensitivity of the enzyme to various inhibitors indicated that glycosomal superoxide dismutase is predominantly of the Cu/Zu type. Localization of superoxide dismutase in glycosomes points to the major importance of this organelle in the survival ...

The intravenous administration of superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1) to animals with induced inflammation suppresses the inflammatory response and inhibits leukocyte infiltration into the challenged site, suggesting that neutrophil-generated superoxide reacts with an extracellular precursor to generate a substance chemotactic for neutrophils. Plasma exposed...

The activity of pea (Pisum sativum L.) Cu/Zn and Mn superoxide dismutase isoforms was evaluated across a range of temperatures from 10 to 45 degrees C. Maximal activity of the Cu/Zn and Mn superoxide dismutase isoforms was observed at 10 degrees C. Both cytoplasmic and chloroplast Cu/Zn superoxide dismutases exhibit a reduction in staining intensity with increasing temperatures. Mn superoxide d...

The major superoxide dismutase ("slow" electromorph) of the fruit fly, Drosophila melanogaster, has been purified to homogeneity. This enzyme contains 2 Cu2+ and 2 Zn2+/molecule. The ultraviolet absorption spectrum indicates a lack of tryptophan. This enzyme has a molecular weight of 32,000 and is composed of two subunits of equal size, which are joined by noncovalent interactions. Cyanide at 1...