TPST2, also known as protein-tyrosine sulfotransferase 2, is the enzyme that catalyzes the sulfation reaction of protein tyrosines, a post-translational modification of proteins. This protein is a type II integral membrane protein found in the Golgi body. Compared to TPST1, TPST2 has similar tissue distribution and overlapping substrate specificity. In contrast to TPST1-/- males with normal fertility in mice, TPST2-/- males are infertile due to severe defects in sperm motility. Recombinant human TPST2, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.