Several bacterial pathogens possess sodC genes that encode periplasmic or membrane-associated Cu,Zn superoxide dismutases. Since professional phagocytes generate large amounts of reactive oxygen species to control the growth of invading micro-organisms, Cu,Zn superoxide dismutase might protect infectious bacteria from oxy-radical damage and facilitate their survival within the host. This idea h...

Large single crystals of iron-containing superoxide dismutase from Pseudomonas ovalis were prepared from 50% saturated ammonium sulfate solution, at pH 4.5, on gentle evaporation of the solvent at 4 degrees. The crystals were monoclinic, space group P2, with unit cell dimensions a = 81.9 A, b = 49.0 A, c = 61.0 A, and beta = 106 degrees. Considerations of cell volume and protein molecular weig...

Chemical modification of bovine and yeast Cu,Zn superoxide dismutases with phenylglyoxal diminishes the catalytic activities by greater than or equal to 98%, and treatment of these enzymes with butanedione plus borate leads to greater than or equal to 96% inactivation. The activity loss is accompanied by the modification of less than two arginine residues per subunit with no concomitant loss of...

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...

Expression of the SodA superoxide dismutase (MnSOD) in Escherichia coli is regulated by superoxide concentration through the SoxRS system and also by Fur (Ferric uptake regulator) through a mixed incoherent feed forward loop (FFL) containing the RyhB small regulatory RNA. In this work I theoretically analyze the function of this feed forward loop as part of the network controlling expression of...

Pseudomonas aeruginosa is a strict aerobe which is likely exposed to oxygen reduction products including superoxide and hydrogen peroxide during the metabolism of molecular oxygen. To counterbalance the potentially hazardous effects of elevated endogenous levels of superoxide, most aerobic organisms possess one or more superoxide dismutases or compounds capable of scavenging superoxide. We have...

SOD-mimics are small complexes that reproduce the activity of superoxide dismutases, natural proteins that catalytically dismutate the superoxide anion. Activated macrophages, which produce ROS and RNS fluxes, constitute a relevant model to challenge antioxidant activity in a cellular context and were used to test a Mn-complex which was shown to efficiently alter the flow of O(2)(-), ONOO(-) an...