Chemoenzymatic synthesis of linear- and head-to-tail cyclic peptides using omniligase-1

Abstract

Omniligase-1-catalyzed ligation represents a powerful tool for the efficient intermolecular and intramolecular (head-to-tail cyclization) ligation of peptides. Reactions are irreversible and proceed with unprotected peptides (μM–mM concentration) in aqueous solution at slightly basic pH. Due to its high catalytic efficiency, only very low molar equivalents of omniligase-1 are required. In this chapter, a chemoenzymatic peptide synthesis (CEPS) approach for the assembly of medium-to-long-sized linear peptides as well as for efficient peptide head-to-tail cyclization is described. In particular, we provide protocols for the chemoenzymatic synthesis of the peptide therapeutic exenatide, a GLP-1 (glucagon-like peptide) analogue, and the macrocyclization and oxidative folding of the cyclotide MCoTI-II in a one-pot procedure.