PGK2 is a testis-specific form of phosphoglycerate kinase. Initially assumed to be a pseudogene, this protein is actually a functional phosphoglycerate kinase that catalyzes the reversible conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate, during the Embden-Meyerhof-Parnas pathway of glycolysis, in the later stages of spermatogenesis. Recombinant human PGK2 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography.