Analysis of N-linked oligosaccharides: progress towards the characterisation of glycoprotein-linked carbohydrates

The covalent attachment of carbohydrate to proteins is a very common co- or post-translational event in the biosynthesis of glycoproteins. The type an d heterogeneity of these oligosaccharides can affect a range of physico-che mical and biological properties of a glycoprotein. Thus the development of sensitive, reliable and robust analytical methods for carbohydrate analysis is important in the pharmaceutical industry, especially in the recombinant production of experimental and therapeutic glycoproteins. In this report w e have reviewed methodology for the in-gel enzymatic release of N-linked ol igosaccharides from glycoproteins separated by electrophoresis. These oligo saccharides are derivatised by reductive amination using 3-acetamido-6-amin oacridine (AA-Ac), a novel, highly fluorescent probe. A major advantage of this technique is that glycan derivatives are amenable to analysis by an ar ray of chromatographic and mass spectrometric methods, allowing the resolut ion and characterisation of a wide variety of glycan structures. It is hope d that in due course the methodology described will be applied to proteomic s studies, especially in identifying the role of carbohydrate in protein fu nction and disease. (C) 2001 Elsevier Science BN. All rights reserved.