Self-assembly of a Peptide [2]Catenane through Ω-Loop Folding

Abstract

In this work, a peptide [2]catenane was created by exploiting the strong tendency of the Pro-Gly-Pro (PGP) sequence to fold into an Ω-loop. Ditopic heptapeptide ligand 1, which includes the PGP sequence, formed peptide [2]catenane 2 on complexation with Ag+. Moreover, addition/removal of Na+ triggered a reversible structural change between 2 and twisted macrocycle 3.