In the present study, we investigated whetherPlasmodium falciparum1-Cys peroxiredoxin (Prx) (Pf1-Cys-Prx), a cytosolic protein expressed at high lev-els during the haem-digesting stage, can act as an antioxidant to cope with the oxidative burden of haem (ferriprotoporphyrin IX; FP). Recombinant Pf1-Cys-Prx protein (rPf1-Cys-Prx) competed with glutathione (GSH) for FP and inhibited FP degradation by GSH. When rPf1-Cys-Prx was added to GSH-mediated FP degradation, the amount of iron released was reduced to 23% of the reaction without the protein (P.
