Production and characterization of active soluble human β1,4-galactosyltransferase in Escherichia coli as a useful catalyst in synthesis of the Gal β1→4 GlcNAc linkage

Abstract An active and soluble human β1,4-galactosyltransferase (β-GT) was produced in Escherichia coli using a maltose-binding protein fusion system. The purified recombinant β-GT has a K m value of 0.035 mM for UDP-galactose and a V max of 643 × 10 3 nmol/mg/h. The enzyme catalyzes the transfer of galactose from UDP-galactose to N -linked oligosaccharides. The properties of the purified enzyme were identical to those of bovine milk β-GT.