Purification and characterization of galactosyltransferase in human parotid saliva

The galactosyltransferase has been purified from human parotid saliva by ammonium sulfate precipitation (25-70% saturation), followed by repeated affinity chromatography on Sepharose-alpha-lactalbumin. The molecular weight of the enzyme was estimated to be approximately 56,000. The enzyme catalyzes the transfer of galactose from UDP-galactose to the exposed N-acetylglucosamine residues derived from glycoproteins, forming a Gal beta (1-4)GlcNAc linkage.