One-pot enzymatic production of 2-acetamido-2-deoxy- d-galactose (GalNAc) from 2-acetamido-2-deoxy- d-glucose (GlcNAc)

2-Acetamido-2-deoxy- d-galactose (GalNAc) is a common monosaccharide found in biologically functional sugar chains, but its availability is often limited due to the lack of abundant natural sources. In order to produce GalNAc from abundantly available sugars, 2-acetamido-2-deoxy- d-glucose (GlcNAc) was converted to GalNAc by a one-pot reaction using three enzymes involved in the galacto- N-biose/lacto- N-biose I pathway of bifidobacteria. Starting the reaction with 600 mM GlcNAc, 170 mM GalNAc was produced at equilibrium in the presence of catalytic amounts of ATP and UDP-Glc under optimized conditions. GalNAc was separated from GlcNAc using water-eluting cation-exchange chromatography with a commonly available cation-exchange resin.