Redox proteomic analysis of H2O2 -treated Jurkat cells and effects of bicarbonate and peroxiredoxins 1 and 2

Oxidation of thiol proteins and redox signaling occur in cells exposed to H2O2 but mechanisms are unclear. We used redox proteomics to seek evidence of oxidation of specific proteins either by a mechanism involving reaction of H2O2 with CO2/bicarbonate to give the more reactive peroxymonocarbonate, or via a relay involving peroxiredoxins (Prdx1 or Prdx2). We measured changes in oxidation state of specific Cys-SH residues on treating Jurkat T cells with H2O2,by isotopically labeling reduced thiols and analyzing the tagged peptides by mass spectrometry. Cells treated in the absence and presence of bicarbonate were compared, as well as wildtype cells and cells in which Prdx1 or Prdx2 had been knocked out.