Synthesis of Heavily Glycosylated Peptide αThioester

Abstract

Erythropoietin (EPO) needs to be heavily glycosylated to exhibit its bioactivity in vivo. In order to synthesize heavily glycosylated EPO analogues, corresponding glycosylated peptide αthioesters are essential to prepare glycosylated whole EPO peptide backbones through native chemical ligation. After construction of the peptide αthioester corresponding to the 1–32 amino acid sequence in EPO, we aimed to incorporate three complex-type biantennary sialyloligosaccharides to this peptide αthioester by the haloacetamide method. The reaction afforded the desired heavily glycosylated peptide αthioester.