Separation of glycans and monosaccharides

Glycosylation is the most common form of posttranslational modification found on proteins and is critical for wide range of functions, including cell–cell interaction, ligand–receptor interactions, immune defense, protein secretion and transport, inflammation, and disease progression. Many biopharmaceuticals are glycosylated, so it is imperative to identify the glycosylation attributes that are critical for drug safety and efficacy and to monitor these throughout the drug’s life cycle. Full structural analysis of glycans involves identifying both the sequence and linkages of the monosaccharides in each glycan as small changes can affect the activity or immunogenicity of the glycoprotein. Fluorescent labeling allows for quantitative detection at femtomole levels for glycan and monosaccharide analysis, followed by separation by liquid chromatography (LC). Hyphenation of LC with mass spectrometry also generates mass composition data for the LC peaks. The role of databases and bioinformatics tools is becoming increasingly important in assisting the interpretation of these large amounts of complex data.