title: Synthetic minimalistic tryptophan zippers as a chiroptical switch.
abstract: In this paper, we presented a new design strategy for a peptide-based chiral supramolecular assembly. A series of aryl linked peptides 1a-1f were designed and synthesized. The bis-urea peptides 1a-1c self-assembled into a helical supramolecular arrangement resembling Trp zipper (Trpzip) structures present in proteins. Interestingly, a dihydrogenphosphate anion, upon binding to the assembly, could invert the chirality of the supramolecular assembly which could be reverted to the original by the addition of water. This chiroptical behavior can be repeated several times. Microscopy analysis showed that the supramolecular helices were assembled to form spheres. In addition to that, we also found that the handedness of supramolecular chirality is dependent on the position of Trp residues on the aromatic scaffold. Both left and right handed helical supramolecular arrangements were obtained by placing l-Trp residues at different positions on the aromatic core. The unprecedented Trpzip in these designed small peptidomimetics will stimulate more work in the area of peptide-based assemblies.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India. haridasv@chemistry.iitd.ac.in.
authors.forename: V
authors.initials: V
authors.lastname: Haridas
authors.forename: Sandhya
authors.initials: S
authors.lastname: Sadanandan
authors.forename: Sameer
authors.initials: S
authors.lastname: Dhawan
authors.forename: Rituraj
authors.initials: R
authors.lastname: Mishra
authors.forename: Ishani
authors.initials: I
authors.lastname: Jain
authors.forename: Gaurav
authors.initials: G
authors.lastname: Goel
authors.forename: Yuan
authors.initials: Y
authors.lastname: Hu
authors.forename: Sandeep
authors.initials: S
authors.lastname: Patel
mesh_terms: D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D010316:Particle Size; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D013499:Surface Properties; D014364:Tryptophan / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D010455:Peptides; D014364:Tryptophan