Rapid analysis of oligosaccharides derived from glycoproteins by microchip electrophoresis

A novel method for fast profiling of complex oligosaccharides released from glycoproteins based on microchip electrophoresis (μ-CE) is presented here. The characterization of separation conditions, i.e., the composition, concentration and pH of running buffer as well as the applied voltage, has been performed using maltose (G2), cellobiose ( G ′ 2 ), maltriose (G3) and panose ( G ′ 3 ) as oligosaccharide isomer models. In μ-CE, much better separation of oligosaccharide isomers and oligosaccharide ladder was obtained in phosphate buffer than in borate buffer over a wide pH range. Under optimal conditions, high-performance separation of the N-linked complex oligosaccharides released from ribonuclease B, fetuin, α1-acid glycoprotein (AGP) and IgG was achieved using polymethylmethacrylate (PMMA) microchips with an effective separation channel of 30 mm. These results represent the first reported analysis of the N-linked oligosaccharides derived from glycoproteins by μ-CE, indicating that the present μ-CE-based method is a promising alternative for characterization of the N-linked oligosaccharides in glycoproteins.