An Assay for 1,6-Fucosyltransferase (FUT8) Activity Based on the HPLC Separation of a Reaction Product with Fluorescence Detection

N-Glycans with an α-fucose unit linked to the 6-position of the innermost GlcNAc are widely distributed among the animal kingdom, from worms and insects to human. This α1,6-linked fucosyl residue, frequently referred to as a core fucose, is formed via the action of an α1,6-fucosyltransferase, the mammalian ortholog which is systematically called FUT8. In mammals, it is well known that the extent of core-fucosylation in cellular and secreted glycoproteins varies, e.g., according to differentiation and carcinogenesis of the cells. This chapter describes a method for the sensitive and quantitative assay of FUT8 activity using a fluorescence-labeled oligosaccharyl asparagine derivative as the glycosyl acceptor substrate.