An alkyl hydroperoxide reductase from Salmonella typhimurium involved in the defense of DNA against oxidative damage. Purification and properties.

摘要: A peroxide reductase (peroxidase) which converts lipid hydroperoxides and other alkyl to the corresponding alcohols, using either NADH or NADPH as reducing agent, has been identified in both Salmonella typhimurium Escherichia coli. This enzyme is shown play a role protecting against hydroperoxide mutagenesis. To our knowledge this work represents first description of an NAD(P)H peroxidase enteric bacteria reported bacterial exhibit high activity toward hydroperoxides. performance liquid chromatography-based assay for developed by monitoring reduction cumene hydroperoxide, model hydroperoxide. By assay, purified from S. regulatory mutant, oxyR1, overexpresses number proteins involved defenses oxidative damage, contains 20-fold more than wild-type strain. The requires presence two separable components having subunit molecular weights 22,000 57,000. 57-kDa protein bound FAD cofactor can use electron donor direct redox dyes, when combined with 22-kDa protein. may thus serve prokaryotic equivalent glutathione reductase/glutathione system eukaryotes.