Peroxiredoxin II (Prdx II; a typical 2‐Cys Prdx) has been originally isolated from erythrocytes, and its structure and peroxidase activity have been adequately studied. Mice absent to Prdx II proteins had heinz bodies in their peripheral blood, and morphologically abnormal cells were detected in the dense red blood cell (RBC) fractions, which contained markedly higher levels of reactive oxygen species (ROS). In this study, a labeling experiment with the thiol‐modifying reagent biotinylated iodoacetamide (BIAM) in Prdx I‒/‒ mice revealed that a variety of RBC proteins were highly oxidized. To identify oxidation‐sensitive proteins in Prdx II‒/‒ mice, we performed RBC comparative proteome analysis in membrane and cytosolic fractions by nano‐UPLC‐MSE shotgun proteomics. We found oxidation‐sensitive 54 proteins from 61 peptides containing cysteine oxidation, and analyzed comparative expression pattern in healthy RBCs of Prdx II+/+ mice, healthy RBCs of Prdx II‒/‒ mice, and abnormal RBCs of Prdx II‒/‒ mice. These proteins belonged to cellular functions related with RBC lifespan maintain, such as cytoskeleton, stress‐induced proteins, metabolic enzymes, signal transduction, and transporters. Furthermore, protein networks among identified oxidation sensitive proteins were analyzed to associate with various diseases. Consequently, we expected that RBC proteome may provide clues to understand redox‐imbalanced diseases.

The objective of this research was to investigate the effect of immersion in Rhus verniciflua Stokes extract (RVSE) on the total reducing ability (TRA), protein oxidation and myoglobin oxidation of beef steak (Hanwoo longissimus muscle) stored with high oxygen-modified-atmosphere packaging (MAP) (HOMAP, 75% O2+20% CO2+5% N2) and low oxygen-MAP (LOMAP, 0% O2+20% CO2+80% N2) at 4℃ for nine days. RVSE induced TRA (p<0.05), metmyoglobin (MetMb) formation, and the CIE Ho value but reduced the carbonyl content and R630-R580, as an index of the intensity of redness by oxymyoglobin, and the CIE L*, a*, and C* values. HOMAP maintained a lower TRA, MetMb concentration, and CIE H° value but had higher R630-R580 and CIE L*, a*, and C* values compared to LOMAP. Therefore, RVSE induced TRA and protein oxidation stability but reduced myoglobin stability in Hanwoo beef steak. In addition, the effects of HOMAP were opposite those of RVSE.