Thioredoxin Reductase from Escherichia coli

Thioredoxin Reductase from Escherichia coli can be used in peroxidase-coupled thioredoxin system assay for assessing the peroxidase activitiy of Cys-based thiol peroxidases. The product was used for determining the enzymatic activity of His6-Ahp1p.

Thioredoxin reductase from Escherichia coli has been used in thioredoxin reductase activity and peroxiredoxin assay.
It has also been used to study the synergy between broccoli sprout extract and selenium in the upregulation of thioredoxin reductase in human hepatocytes.

An FAD-containing enzyme involved in the transfer of hydrogen from E. coli thioredoxin to other proteins thus providing a powerful disulfide reductase system.

Thioredoxin reductase is a FAD containing enzyme, which transfers the reducing equivalent from NADPH to the disulphide bond of the enzyme by using FAD moiety within the Cys-Ala-Thr-Cys sequence. It can also reduce Trx-S2 to Trx-(SH)2 by using NADPH.

Thioredoxin reductase (TrxR) is an NADPH-dependent oxidoreductase containing one FAD per subunit that reduces the active site disulfide in oxidised thioredoxin (Trx). The molecular weight of the isozymes from mammalian sources vary between 55-67 kDa as compared with 35 kDa in prokaryotes, plants or yeast. The substrate specificity of the mammalian enzyme is much broader than the prokaryotic enzyme reducing both mammalian and E. coli thioredoxins as well as well as non-disulfide substrates such selenite, lipoic acids, lipid hydroperoxides and hydrogen peroxide.

One unit will cause an increase in absorbance of 1.0 at 412 nm (when measured in a coupled assay with E. coli thioredoxin and DTNB) per min per mL at pH 7.0 at 25 °C.

Suspension in 3.6 M (NH₄)₂SO₄ containing 30 mM potassium phosphate buffer, pH 7.5, and 2 mM EDTA.