Glycosylation is one of the most common post-translational modifications, and approximately 50% of all proteins are presumed to be glycosylated in eukaryotes. Branched N-glycans, such as bisecting GlcNAc,b-1,6-GlcNAc and core fucose (a-1,6-fucose), are enzymatic products of N-acetylglucos-aminyltransferase III,N-acetylglucosaminyltransferase V and a-1,6-fucosyl-transferase, respectively.