Peroxiredoxin-6 (human, recombinant)

Peroxiredoxin-6 (Prx6) is a 1-Cys-containing Prx that is involved in the maintenance of cellular thiol redox homeostasis and phospholipid metabolism. It exists as a homodimer and is composed of a thioredoxin fold-containing catalytic domain, which contains a peroxidatic cysteine (Cp), and a C-terminal arm. Unlike 2-Cys-containing Prxs, Prx6 does not contain a resolving cysteine (Cr) and uses glutathione (GSH) instead. Prx6 is ubiquitously expressed and localizes to the cytosol, nucleus, mitochondria, and plasma membrane. It has three enzymatic activities: glutathione peroxidase (GPX), acidic calcium-independent phospholipase A2 (aiPLA2), and lysophosphatidylcholine acyltransferase (LPCAT). The LPCAT activity, which selectively uses palmitoyl-CoA as a substrate, is coupled to the aiPLA2 activity and is selective for lysophosphatidylcholine over lysophosphatidylethanolamine, lysophosphatidylglycerol, lysophosphatidylinositol, and lysophosphatidylserine. These activities, coupled with the GPX activity, provide Prx6 the ability to repair oxidized cell membranes. Prx6 is also involved in the activation of NADPH oxidase 2 (NOX2). Tumor levels of Prx6 are increased in patients with non-small cell lung cancer (NSCLC) and serum levels of Prx6 are decreased in patients with asthma. Cayman's Peroxiredoxin-6 (human, recombinant) protein consists of 235 amino acids and has a calculated molecular weight of approximately 25 kDa. By SDS-PAGE, under reducing conditions, the apparent molecular mass of the protein is 26. kDa.. Protein function: Thiol-specific peroxidase that catalyzes the reduction of hydrogen peroxide and organic hydroperoxides to water and alcohols, respectively (PubMed:9497358, PubMed:10893423). Can reduce H(2)O(2) and short chain organic, fatty acid, and phospholipid hydroperoxides (PubMed:10893423). Also has phospholipase activity, can therefore either reduce the oxidized sn-2 fatty acyl group of phospholipids (peroxidase activity) or hydrolyze the sn-2 ester bond of phospholipids (phospholipase activity) (PubMed:10893423, PubMed:26830860). These activities are dependent on binding to phospholipids at acidic pH and to oxidized phospholipds at cytosolic pH (PubMed:10893423). Plays a role in cell protection against oxidative stress by detoxifying peroxides and in phospholipid homeostasis (PubMed:10893423). Exhibits acyl-CoA-dependent lysophospholipid acyltransferase which mediates the conversion of lysophosphatidylcholine (1-acyl-sn-glycero-3- phosphocholine or LPC) into phosphatidylcholine (1,2-diacyl-sn-glycero- 3-phosphocholine or PC) (PubMed:26830860). Shows a clear preference for LPC as the lysophospholipid and for palmitoyl CoA as the fatty acyl substrate (PubMed:26830860). [The UniProt Consortium]