Carbohydrate Sulfotransferase 6/CHST6: ProductsThe CHST family is comprised of 14 genes in humans. All members of this family are Golgi-localized type II membrane proteins. Only the luminal and enzymatic domain is expressed in each of R&D Systems recombinant CHST proteins. These enzymes transfer sulfate (i.e., sulfonate) onto the 6-O or 4-O positions of GalNAc, Gal and GlcNAc residues on glycoproteins, proteoglycans and glycolipids. This sulfation often creates specific epitopes that can be recognized by extracellular matrix proteins, cell surface receptors and viruses. CHST6, also designated as corneal N-acetylglucosamine-6-O-sulfotransferase or N-acetylglucosamine 6-O-sulfotransferase 5, transfers sulfate to position 6 of non-reducing GlcNAc residues of keratan sulfate found in the corneal stroma. It also acts on the non-reducing terminal GlcNAc residues of carbohydrate substrates that have poly-N-acetyllactosamine structures. Defects in CHST6 cause macular corneal dystrophy, an autosomal recessive disease characterized by corneal opacities.