Synthesis of homogeneous glycoproteins with diverse N-glycans

In the post-genomic era, post- and co-translational modifications (P/C-TM) of proteins are known as the more essential elements for the activation of protein function. Among these protein modifications, glycosylation is one of the most abundant modifications in eukaryotic cells. The synthesis of glycoproteins with uniform glycan structures is essential for functional analysis of glycoproteins and biochemical research. For that purpose, chemical methods to synthesize glycoproteins with chemically uniform glycan structures have been developed. In this review, we highlight our recent advances in the preparation of homogeneous glycoproteins. Especially, we introduce both semi-synthesis and chemical synthesis of glycoproteins along with semi-synthesis of various complex-type N-glycans for the solid-phase synthesis of glycopeptide-thioesters.