Engineering the Sialome

The surface of every eukaryotic cell is coated in a dense layer of structurally diverse glycans that together comprise the glycocalyx, a key interface between intracellular biochemistry and the external environment. Many of the glycans within the glycocalyx terminate in anionic monosaccharides belonging to the sialic acid family. Advances in our understanding of the biological processes mediated by sialic acids at the interfaces between cells have catalyzed interest in metabolic, enzymatic, and chemical strategies to edit the total complement of cellular sialic acids-the sialome. Here, we review strategies for altering the composition of the sialome with particular focus on glycan structures and state-of-the-art tools.