Thiol-specific peroxidase that catalyzes the reduction of hydrogen peroxide and organic hydroperoxides to water and alcohols, respectively. Plays a role in cell protection against oxidative stress by detoxifying peroxides. [thioredoxin]-dithiol + a hydroperoxide = [thioredoxin]-disulfide + an alcohol + H2O Homodimer. On the 2D-gel the determined pI of this protein is: 4.6, its MW is: 20.2 kDa. Belongs to the peroxiredoxin family. Tpx subfamily.