Conversion of GalNAcβ(1-4)GlcNAcβ-OMe into GalNAcβ(1-4)[Fucα(1-3)]GlcNAcβ-OMe using human milk α3/4-fucosyltransferase. Synthesis of a novel terminal element in glycoprotein glycans

Abstract

Incubation of GalNAc beta(1-4)GlcNAc beta-OMe with GDP-Fuc in the presence of human milk alpha3/4-fucosyltransferase resulted in the formation of GalNAc beta(1-4)[Fuc( alpha1-3)]GlcNAc beta-OMe. Under conditions that led to complete alpha3-fucosylation of Gal beta(1-4)GlcNAc beta-OEt, GalNAc beta(1-4)GlcNAc beta-OMe was fucosylated for more than 85%. For the identification of the isolated fucosylated products one- and two- dimensional 1H-NMR spectroscopy was applied. In vacuo molecular dynamics simulations of Gal beta(1-4)[Fuc alpha(1-3)]GlcNAc beta-OEt and GalNAc beta(1-4)[Fuc alpha(1-3)]GlcNAc beta-OMe using the CHARMm based force field CHEAT, demonstrated only small differences between the conformations of these compounds. This illustrates the minor conformational influence of the substituent at C-2', i.e. a hydroxyl function versus a N-acetyl group.