Recombinant Mouse CHST4 Protein, CF

The mouse CHST family is comprised of 13 enzymes. All members of this family are Golgi-localized type II membrane proteins (1). Only the luminal and enzymatic domain is expressed in each of the 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 (2). This sulfation often creates specific epitopes that can be recognized by extracellular matrix proteins, cell surface receptors and viruses (3). Human CHST4, also known as high endothelial cell N-acetylglucosamine 6-O-sulfotransferase (HEC-GlcNAc6ST) or L‑selectin ligand sulfotransferase (LSST), catalyzes the transfer of sulfate to position 6 of non-reducing GlcNAc residues within mucin-associated glycans that ultimately serve as L‑selectin ligands (4). It has a catalytic preference for core 2-branched mucin-type O‑glycans, but also has activity toward core 3 type of O‑glycans (5). Mouse CHST4 shares 72% amino acid sequence identity with the human ortholog. The enzyme activity was measured using a phosphatase coupled method (6).