Peroxiredoxin 2: An Important Element of the Antioxidant Defense of the Erythrocyte

Abstract

Peroxiredoxin 2 (Prdx2) is the third most abundant erythrocyte protein. It was known previously as calpromotin since its binding to the membrane stimulates the calcium-dependent potassium channel. Prdx2 is present mostly in cytosol in the form of non-covalent dimers but may associate into doughnut-like decamers and other oligomers. Prdx2 reacts rapidly with hydrogen peroxide (k > 107 M−1 s−1). It is the main erythrocyte antioxidant that removes hydrogen peroxide formed endogenously by hemoglobin autoxidation. Prdx2 also reduces other peroxides including lipid, urate, amino acid, and protein hydroperoxides and peroxynitrite. Oxidized Prdx2 can be reduced at the expense of thioredoxin but also of other thiols, especially glutathione. Further reactions of Prdx2 with oxidants lead to hyperoxidation (formation of sulfinyl or sulfonyl derivatives of the peroxidative cysteine). The sulfinyl derivative can be reduced by sulfiredoxin. Circadian oscillations in the level of hyperoxidation of erythrocyte Prdx2 were reported. The protein can be subject to post-translational modifications; some of them, such as phosphorylation, nitration, and acetylation, increase its activity. Prdx2 can also act as a chaperone for hemoglobin and erythrocyte membrane proteins, especially during the maturation of erythrocyte precursors. The extent of Prdx2 oxidation is increased in various diseases and can be an index of oxidative stress.

Catalase, Glutathione Peroxidase, and Peroxiredoxin 2 in Erythrocyte Cytosol and Membrane in Hereditary Spherocytosis, Sickle Cell Disease, and β-Thalassemia

“…The MBH and membrane LPO levels were significantly increased compared to controls; however, compared to the other NIHAs, they presented some of the lowest values (specially LPO), which could be associated with the significant increases in CAT and Prx2 linked to the membrane ( Table 1 or Figure 1 ). Our data are in accordance with other studies [ 10 , 55 , 56 ] suggesting that CAT and Prx2 might confer protection to the RBC membrane in these patients. In addition, this hypothesis is further supported by the positive correlations we found between membrane LPO with both CAT ( r = 0.44) and Prx2 amounts ( r = 0.76), and between MBH and CAT amount ( r = 0.53) ( Table 2 and Figure 2 ).…”

“…Therefore, both LPO and MBH appear to be membrane OS biomarkers; moreover, these biomarkers were correlated with the (increased) amount of CAT ( r = 0.53, for both) and of Prx2 in the membrane ( r = 0.44 for both) ( Table 2 ), suggesting that the linkage of these enzymes might be a physiological response to counteract oxidative injuries. In fact, other studies have proposed that Prx2 and CAT binding might be involved in the protection of the RBC membrane against LPO [ 10 , 55 , 56 ].…”

The mammosphere-derived epithelial cell secretome modulates neutrophil functions in the bovine model

“…As described above, we first evaluated neutrophil ROS in the absence and presence of PMA in either MDEC CM or medium with the addition of recombinant SOD, PII, and CAT, alone or in combination (triple recombinant), using protein concentrations recommended in other studies ( 87 , 88 ). As expected, unstimulated or PMA-stimulated neutrophils in MDEC CM showed a significant reduction of ROS when compared to those in the medium controls (p = 0.0107, p = 0.0044 respectively) [ Figure 7A (i, ii)].…”

Sickle Cell Disease: Current Drug Treatments and Functional Foods with Therapeutic Potential

“…Increasing antioxidant intake may help SCD patients by supporting cellular renewal and promoting the formation of red blood cells [ 75 ]. For example, significant components in vegetables, phenolics have promising impact on human health.…”