Unique cleavage of 2-acetamido-2-deoxy-D-glucose from the reducing end of biantennary complex type oligosaccharides

Basic treatment of a biantennary complex-type sialyloligosaccharide, as well as its asialo form, was found to lead to the specific cleavage of 2-acetamido-2-deoxy-D-glucose (GIcNAc) from the reducing end. The resultant oligosaccharides were identical to those prepared by treatment with endo-beta-glycosidase-M, which cleaves the glycosidic bond between two GIcNAc residues at the reducing end of N-linked oligosaccharides. In addition, mechanistic studies suggested that an elimination reaction in the reducing-end terminal GIcNAc residue causes this specific cleavage reaction. (C) 2010 Elsevier Ltd. All rights reserved.