The Problem of Aspartimide Formation During Protein Chemical Synthesis Using SEA-Mediated Ligation

should be addressed to O.M. (oleg.melnyk@ibl.cnrs.fr). Summary Aspartimide formation often complicates the solid phase synthesis of peptides. Much less discussed is the potential occurrence of this side-reaction during the coupling of peptide segments using chemoselective peptide bond forming reactions such as the native chemical ligation and extended methods. Here we describe how to manage this problem using bis(2-sulfenylethyl)amido (SEA)-mediated ligation.