Copper-mediated oxidative C-terminal N-dealkylation of peptide-derived ligands. A possible model for enzymatic generation of desglycine peptide amides

A number of Cu(II) complexes of peptide derivatives that coordinate via N-deprotonation at the C-terminal amino acid residue have been characterized by titrimetry and the Cu(III)-Cu(II) electrochemical potentials. Reaction of these complexes with persulfate induces oxidative decarboxylation and hydrolysis of the resulting N-acylimines to carboxamide and either HCHO, CH 3 CHO, or acetone depending on the identity of the C-terminal residue