Foldamers to Nanotubes: Influence of Amino Acid Side Chains in the Hierarchical Assembly of α,γ⁴-Hybrid Peptide Helices

Supramolecular assembly of various artificially folded 12-helical architectures composed of g4-Val, g4-Leu and g4-Phe residues is investigated. In contrast to the 12-helices composed of g4-Val and g4-Leu residues, the helices with g4-Phe residues displayed unique elongated nanotubular architectures. The elongated nanotube assembly was further explored as a template for biomineralization of silverions to silver nanowires. A comparative study using an analogous a-peptide helix reveals the importance of the spatial arrangement of aromatic side chains along the helical cylinder in a 12-helix. These results suggested that the proteolytically and structurally stable a,g4-hybrid peptide 12-helices may serve as a new generation of potential templates in the design of functional biomaterials.