GLRX5 is small redox enzymes of approximately one hundred amino-acid residues which uses glutathione as a cofactor. This protein is oxidized by substrates, and reduced non-enzymatically by glutathione. It is involved in the biogenesis of iron-sulfur clusters, which are required for normal iron homeostasis. Recombinant ㅗ human GLRX5 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.