Linkage of cytosolic peroxiredoxin 2 to erythrocyte membrane imposed by hydrogen peroxide-induced oxidative stress

Human erythrocyte peroxiredoxin 2 (Prx2) is a typical 2-cys cytosolic peroxiredoxin with thiol-dependent hydrogen peroxide scavenger activity. In a previous work, we reported Prx2 erythrocyte membrane linkage in some Hereditary Spherocytosis patients and that it seemed to be related to oxidative stress. The aim of the present work was to determine if Prx2 linkage to erythrocyte membrane could be induced by oxidative stress mediated by H₂O₂ and to further understand how and why this process occurs. We performed in vitro assays in which catalase or both Hb autoxidation and catalase were inhibited, under H₂O₂-induced oxidative stress conditions. Erythrocyte membrane linked Prx2 was detected by immunoblotting and quantified by densitometry. As oxidative stress markers, we determined membrane bound hemoglobin and lipid peroxidation, and we found that their values increased with H₂O₂ concentration. Prx2 linkage to the membrane also rose with increasing H₂O₂ concentration, and was only observed when the oxidized form of the enzyme was present in the cytosol. Oxidized Hb and Prx2 membrane linkages appear to be independent processes, although, both result from oxidative stress and may be useful as oxidative stress and/or erythrocyte damage/senescence markers.