One of the most common post-translational modifications of proteins involves the covalent attachment of N- or O-linked carbohydrates to the protein. Glycan moieties are involved in a wide variety of intracellular, cell-cell and cell-matrix recognition events. The study of glycoprotein-linked carbohydrates remains one of the most challenging tasks given to biochemists and bioanalysts as these molecules can exhibit complex branched structures that can differ in linkage and the level of branching. This is why understanding how glycosylation affects the activities and functions of proteins in health and disease represents a major challenge. Mass spectrometry, is one of the most powerful and versatile techniques for the structural analysis of glycoconjugates. This review summarizes the state of knowledge for the mass spectrometric analysis of glycoproteins and their glycan structures.
