Peroxiredoxin

Peroxiredoxin ( detail according to IUBMB: thiol -containing reductant -: hydroperoxide oxidoreductase ) is an enzyme found in all living things. In the collapsed state, it catalyses the reduction of hydroperoxides (R- OOH) to the corresponding alcohol (R- OH), and is itself oxidized to a cysteine ​​residue; in a second step, the initial state for the simultaneous oxidation of a thiol, usually thioredoxin restored. Hydroperoxides are harmful by-products of aerobic respiration and are among the reactive oxygen species; reduced peroxiredoxin therefore acts as an antioxidant. In humans, there are six different known peroxiredoxins which are encoded by the genes to PRDX1 PRDX6, between about 200 and 270 amino acids, and both a monomer, dimer or oligomer may occur.

Catalyzed reaction

Firstly, the hydroperoxide is reduced with concomitant oxidation of the peroxiredoxin. In detail, resulting in a specific cysteine ​​residue of Prx a sulfenic acid, with an additional cysteine ​​residue (located in the same polypeptide or the dimer partners ) elimination of water to a Cys -SS -Cys disulfide bridge connects.

Later Peroxiredoxin is back with reduced thioredoxin, more specifically, the disulfide is reduced to the dithiol. The necessary hydrogen atoms provided by the dithiol of the thioredoxin, which after oxidation, which in turn comprises a disulfide bond.