Studies for Elucidation of Oligosaccharide Functions of Glycoproteins

The attachment of oligosaccharides is one of the most abundant post-translational modification of proteins. The resultant glycoproteins play central roles in many biological processes. However, the intrinsic heterogeneity of native glycoproteins regarding to the structures of oligosaccharides has hampered the detailed functional studies of the oligosaccharides attached to the proteins. To address this issue, we have been developing chemical methodologies for the synthesis of homogeneous glycoproteins. The chemical approach for the glycoprotein synthesis consists of the preparation of oligosaccharide and glycopeptide building blocks, the assembly of the full length glycopeptides of the target glycoproteins, and folding. This synthetic strategy allowed us to synthesize a variety of structurally defined forms of glycoproteins.