Combination of Glycosyltransferases and a Glycosynthase in Sequential and One-Pot Reactions for the Synthesis of Type1 and Type2 N-Acetyllactosamine Oligomers

The disaccharide units of N-acetyllactosamine (LacNAc) types1 and 2 and poly-LacNAc are involved in many biological recognition events. We report the modular design of type1 (3Gal beta 1-3GlcNAc beta 1-; Gal=d-galactose, GlcNAc=N-acetyl D-glucosamine) and type2 (3Gal beta 1-4GlcNAc beta 1-) LacNAc oligomers by combination of two recombinant glycosyltransferases, beta 1,3-N-acetylglucosaminyltransferase from Helicobacter pylori and human beta 1,4-galactosyltransferase-1, with galactosynthase His(6)BgaC/Glu233Gly from Bacillus circulans. Combination of His(6)BgaC/Glu233Gly and beta 1,3-N-acetylglucosaminyltransferase in sequential or one-pot mode results in LacNAc type1 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 type1 and 2 units and type1-terminated LacNAc type2 oligomers. These glycan structures are valuable compounds for testing carbohydrate-protein interactions.