Glycosylation Improves the Proteolytic Stability of Exenatide.

Exenatide was the first marketed GLP-1 receptor agonist for the treatment of type 2 diabetes. Modification to the chemical structure or the formulation has the potential to increase the stability of exenatide. We introduced human complex-type sialyloligosaccharide to exenatide at the native Asn28 position. The synthesis was achieved using both solid phase peptide synthesis (SPPS) and Omniligase-1-mediated chemoenzymatic ligation. The results demonstrate that glycosylation increases the proteolytic stability of exenatide while retaining its full biological activity.