Synthesis of Lipid-Linked Oligosaccharides (LLOs) and Their Phosphonate Analogues as Probes To Study Protein Glycosylation Enzymes

Abstract

Here we review chemical and chemoenzymatic methods for the synthesis of lipid-linked oligosaccharides (LLOs) and their phosphonate analogues, which serve as substrates and inhibitors to investigate the structure and mechanism of protein N-glycosylation enzymes. We emphasize how to overcome the challenges pertaining to the instability and difficult physicochemical properties of this class of compounds.1 Introduction2 LLO Syntheses2.1 Glycosyl Phosphate Syntheses2.2 Glycosyl Phosphonates2.3 Lipid Elongation2.4 Lipid Phosphates2.5 Coupling Reaction Strategies3 Chemoenzymatic Synthesis of Elongated LLOs4 Biological Properties of Synthetic LLOs5 Conclusion