Involved in the biosynthesis of L2/HNK-1 carbohydrate epitope on both glycolipids and glycoproteins. Substrates include asialo-orosomucoid (ASOR), paragloboside (lacto-N-neotetraosylceramide), Gal-beta-1,4-GlcNAc-beta-1,3-Gal-beta-1,4-Glc-pyridylamine and Gal-beta-1,3-GlcNAc-beta-1,3-Gal-beta-1,4-Glc-pyridylamine