Background: Endoparasitoid wasps inject venom proteins at oviposition to alter host immunity. Results: The venom of Leptopilina boulardi but not of a related species contains an active extracellular SOD. Recombinant SODs inhibit the Drosophila host phenoloxidase activity. Conclusion: An extracellular SOD is secreted and active in an insect fluid. Significance: SODs may be used as immune suppres...

Superoxide dismutases are a family of metalloenzymes that catalyze the dismutation of superoxide radicals into molecular oxygen and hydrogen peroxide, and thus represent a primary line of defence against oxidative stress. The iron-containing superoxide dismutases are only found in prokaryotes and plants. The iron superoxide dismutase of Vigna unguiculata (cowpea) consists of two polypeptides of...

The accumulation of dioxygen in Earth's atmosphere allowed for the evolution of aerobic organisms that use O2 as the terminal electron acceptor, thus providing a higher yield of energy compared with fermentation and anaerobic respiration. For example, in aerobic metabolism, the complete breakdown of one molecule of glucose yields a total of 38 molecules of ATP, whereas the anaerobic breakdown o...

To investigate the structural/functional role of the dimeric structure in Cu,Zn superoxide dismutases, we have studied the stability to a variety of agents of the Escherichia coli enzyme, the only monomeric variant of this class so far isolated. Differential scanning calorimetry of the native enzyme showed the presence of two well defined peaks identified as the metal free and holoprotein. Unli...

The incidence of pancreatic cancer is increasing as the population ages but treatment advancements continue to lag far behind. The majority of pancreatic cancer patients have a K-ras oncogene mutation causing a shift in the redox state of the cell, favoring malignant proliferation. This mutation is believed to lead to nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation and su...

Superoxide dismutases (SODs) represent the major antioxidant defense system against superoxide anions (O2 ). Three isoforms of superoxide dismutase have been identified in mammals: copper-zinc SOD (Cu, ZnSOD), manganese SOD (Mn-SOD), and extracellular SOD (ecSOD). Cu, Znand Mn-SOD are localized intracellularly, whereas the last discovered SOD isoform, ecSOD,1 is secreted and bound to heparan su...