CONVERSION OF GALNAC-BETA(1-4)GLCNAC-BETA-OME INTO GALNAC-BETA(1-4)-[FUC-ALPHA(1-3)]GLCNAC-BETA-OME USING HUMAN-MILK ALPHA-3/4-FUCOSYL-TRANSFERASE - SYNTHESIS OF A NOVEL TERMINAL ELEMENT IN GLYCOPROTEIN GLYCANS

Incubation of GalNAcbeta(1-4)GlcNAcbeta-OMe with GDP-Fuc in the presence of human milk alpha3/4-fucosyltransferase resulted in the formation of GalNAcbeta(1-4)[Fucalpha(1-3)]GlcNAcbeta-OMe. Under conditions that led to complete alpha3-fucosylation of Galbeta(1-4)GlcNAcbeta-OEt, GalNAcbeta(1-4)GlcNAcbeta-OMe was fucosylated for more than 85%. For the identification of the isolated fucosylated products one- and two-dimensional H-1-NMR spectroscopy was applied. In vacuo molecular dynamics simulations of Galbeta(1-4)[Fucalpha(1-3)]GlcNAcbeta-OEt and GalNAcbeta(1-4)[Fucalpha(1-3)]GlcNAcbeta-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.