Disaccharide analysis of glycosaminoglycan mixtures by ultra-high-performance liquid chromatography–mass spectrometry

Glycosaminoglycans are a family of polysaccharides widely distributed in all eukaryotic cells. These polyanionic, linear chain polysaccharides are composed of repeating disaccharide units that are often differentially substituted with sulfo groups. The diversity of glycosaminoglycan structures in cells, tissues and among different organisms reflect their functional an evolutionary importance. Glycosaminoglycan composition and structure also changes in development, aging and in disease progression, making their accurate and reliable analysis a critical, albeit, challenging endeavor. Quantitative disaccharide compositional analysis is one of the primary ways to characterize glycosaminoglycan composition and structure and has a direct relationship with glycosaminoglycan biological functions. In this study, glycosaminoglycan disaccharides, prepared from heparan sulfate/heparin, chondroitin sulfate/dermatan sulfate and neutral hyaluronic acid using multiple polysaccharide lyases, were fluorescently labeled with 2-aminoacridone, fractionated into 17 well-resolved components by reverse-phase ultra-performance liquid chromatography, and analyzed by electrospray ionization mass spectrometry. This analysis was successfully applied to cell, tissue, and biological fluid samples for the picomole level detection of glycosaminoglycan composition and structure.

► Glycosaminoglycans in biological samples were analyzed.
► These glycosaminoglycans were digested to disaccharides with heparinases.
► The disaccharides were fluorescently labeled by reductive amination.
► The 17 resulting disaccharides were separated by reverse phase HPLC.
► LC–MS analysis was used for picomole quantification of the disaccharide mixture.