 Heparan sulfates are also known to interact with growth factors, cytokines, chemokines, lipid and membrane binding proteins, and adhesion molecules.GSTs catalyze sulfation at the 6-hydroxyl group of galactose, N-acetylgalactosamine, or N-acetylglucosamine.Like heparan sulfotransferases, GSTs are responsible for post-translational protein sulfation that assists in cell-signaling.