Chemical Synthesis of Homogeneous Human Glycosyl-interferon-β That Exhibits Potent Antitumor Activity in Vivo

Abstract

Chemical synthesis of homogeneous human glycoproteins exhibiting bioactivity in vivo has been a challenging task. In an effort to overcome this long-standing problem, we selected interferon-β and examined its synthesis. The 166 residue polypeptide chain of interferon-β was prepared by covalent condensation of two synthetic peptide segments and a glycosylated synthetic peptide bearing a complex-type glycan of biological origin. The peptides were covalently condensed by native chemical ligation. Selective desulfurization followed by deprotection of the two Cys(Acm) residues gave the target full-length polypeptide chain of interferon-β bearing either a complex-type sialyl biantennary oligosaccharide or its asialo form. Subsequent folding with concomitant formation of the native disulfide bond afforded correctly folded homogeneous glycosyl-interferon-β. The chemically synthesized sialyl interferon-β exhibited potent antitumor activity in vivo.

From EPOthilone to EPO: A challenge for natural product synthesis

“…With these nonnative saccharide groups, they were also able to fold their EPO construct into the correct 3D structure and show that it had biological activity similar to recombinant EPO. As evidenced by this semisynthetic work, as well as several other recent glycoprotein syntheses (12,13), the field of glycoprotein synthesis is certainly gaining momentum.…”

Chemical ligation from O-acyl isopeptides via 8- and 11-membered cyclic transition states

“…[5][6][7] Chemoselective ligations are increasingly the 'key to the success' of protein synthesis. [10][11][12][13] Native chemical ligation (NCL), uniquely joins two unprotected peptide segments chemoselectively and regioselectively to afford a native peptide bond. 5,7 As reported in 1953 by Wieland et al 8 NCL can join two peptide fragments through a thioester transesterification step followed by an intramolecular rearrangement involving an S-to N-acyl transfer via a cyclic transition state resulting in the native peptide bond.…”

Misfolded Glycoproteins as Probes for Analysis of Folding Sensor Enzyme UDP-Glucose

“…To obtain homogeneous glycoproteins, chemical synthesis has become an alternative method because of its dramatic advance in recent years (34)(35)(36)(37). Therefore, we examined the first chemical Fig.…”