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, including the eye. In this study, a recombinant bovine eye 1-Cys peroxiredoxin (BRPrx) was expressed in Escherichia coli (E. coli). The recombinant protein protected glutamine synthetase from oxidative damage caused by a metal ion-catalyzed oxidation system (ascorbate/Fe3+/O2) in the presence of dithiothreitol as an electron donor. The protector activity of BRPrx is attributed to its peroxidase activity exhibited in the presence of dithiothreitol. Both hydrogen peroxide and short chain hydroperoxides are substrates for the protein. Glutathione could not support antioxidant properties of the recombinant protein. The antioxidant activity of BRPrx in the glutamine synthetase protection assay was as high as the activity of catalase and about one order of magnitude lower than that of selenium glutathione peroxidase. These results support the premise that Prx is an important component of the antioxidant defense system in eye tissues.