Use of an Octapeptide-Guanidiniocarbonylpyrrole Conjugate for the Formation of a Supramolecular β-Helix that Self-Assembles into pH-Responsive Fibers.

Peptides that adopt β-helix structures are predominantly found in transmembrane protein domains or in the lipid bilayer of vesicles. Constructing a β-helix structure in pure water has been considered difficult without the addition of membrane mimics. Herein, we report such an example; peptide 1 self-assembles into a supramolecular β-helix in pure water based on charge interactions between the individual peptides. Peptide 1 further showed intriguing transitions from small particles to helical fibers in a time-dependent process. The fibers can be switched to vesicles by changing the pH value.