Combination of Glycosyltransferases and a Glycosynthase in Sequential and One‐Pot Reactions for the Synthesis of Type 1 and Type 2 N ‐Acetyllactosamine Oligomers

The disaccharide units of N ‐acetyllactosamine (LacNAc) types 1 and 2 and poly‐LacNAc are involved in many biological recognition events. We report the modular design of type 1 (3Galβ1‐3GlcNAcβ1‐; Gal= d ‐galactose, GlcNAc= N ‐acetyl d ‐glucosamine) and type 2 (3Galβ1‐4GlcNAcβ1‐) LacNAc oligomers by combination of two recombinant glycosyltransferases, β1,3‐ N ‐acetylglucosaminyltransferase from Helicobacter pylori and human β1,4‐galactosyltransferase‐1, with galactosynthase His 6 BgaC/Glu233Gly from Bacillus circulans . Combination of His 6 BgaC/Glu233Gly and β1,3‐ N ‐acetylglucosaminyltransferase in sequential or one‐pot mode results in LacNAc type 1 oligomers with up to four LacNAc units. Moreover, sequential use of all three enzymes gives access to a variety of neo‐LacNAc oligomers. We present oligomers composed of alternating type 1 and 2 units and type 1‐terminated LacNAc type 2 oligomers. These glycan structures are valuable compounds for testing carbohydrate–protein interactions.