6-Azido d-galactose transfer to N-acetyl-d-glucosamine derivative using commercially available β-1,4-galactosyltransferase

A new strategy to tag glycoproteins carrying terminal GlcNAc was developed using commercially available bovine β-1,4-galactosyltransferase (GalT) and UDP-6-azidogalactose. The azide function was then allowed to react via a biotinylated Staudinger-Bertozzi probe demonstrating the usefulness of such a procedure to tag any glycoprotein possessing a N-acetylglucosamine terminal residue from any type of cell lysate.