Elucidation of the Binding Mechanism of Anionic Phospholipids to Antioxidant Protein Peroxiredoxin 2.

Peroxiredoxins (Prxs) belong to a family of ubiquitously expressed peroxidases that detoxify reactive oxygen species. In addition to their enzymatic function, Prxs also function as molecular chaperones. This functional switch is related to their degree of oligomerization. We have previously revealed that Prx2 interacts with anionic phospholipids and that the anionic phospholipid-containing Prx2 oligomer forms a high molecular weight (HMW) complex in a nucleotide-dependent manner. However, the detailed mechanism of the oligomer and HMW complex formation remains unclear. In this study, we investigated the anionic phospholipid binding site in Prx2 using site-directed mutagenesis to understand the mechanism of the oligomer formation. Our findings demonstrated that six binding site residues in Prx2 are important for the binding of anionic phospholipids.