Kinetics of Superoxide Scavenging by Dismutase Enzymes and Manganese MimicsDetermined by Electron Spin Resonance

摘要

This study presents an e.s.r. assay for superoxide dismutase (SOD). Enzymicreactions were studied in which Cu, Zn-SOD, Mn-SOD and Fe-SOD each competed with the spin trap 5,5-dimethyl-1-pyrroline 1-oxide (DPMO) for superoxide anion (O2-) at pH 7.8. O2-from dissolved KO2 (potassium superoxide) in dimethyl sulphoxide was added directly to the enzyme solutions containing DMPO. The results show that, in this competition reaction system, the kinetics of the reactions between