Bovine eye 1-Cys peroxiredoxin: Expression in E-coli and antioxidant properties

Peroxiredoxins constitute a molecular family of novel antioxidant proteins and are distributed broadly in non-mammalian and mammalian tissues, includi ng the eye. Ln this study, a recombinant bovine eye 1-Cys peroxiredoxin (BR Prx) was expressed in Escherichia coli (E. coli). The recombinant protein p rotected glutamine synthetase from oxidative damage caused by a metal ion-c atalyzed oxidation system (ascorbate/Fe3+/O-2) in the presence of dithiothr eitol as an electron donor. The protector activity of BRPrx is attributed t o its peroxidase activity exhibited in the presence of dithiothreitol. Both hydrogen peroxide and short chain hydroperoxides are substrates for the pr otein. Glutathione could not support antioxidant propel-ties of the recombi nant protein. The antioxidant activity of BRPrx in the glutamine synthetase protection assay was as high as the activity of catalase and about one ord er of magnitude lower than that of selenium glutathione peroxidase. These r esults support the premise that Prx is an important component of the antiox idant defense system in eye tissues.