Structural and morphological diversity of self-assembled synthetic γ-amino acid containing peptides

Abstract

Regulating the nanostructural morphology of synthetic hybrid peptides through external stimuli is still a great challenge. Here, we report the synthesis of constrained amino acid building block gabapentin (Gpn) based hybrid peptides and their structural and morphological diversity in different conditions. The synthesized three hybrid peptides Boc-Gpn-Aib-Phe-Aib-OMe (P1), Boc-Gpn-Aib-Leu-Aib-OMe (P2) and Boc-Gpn-Aib-Tyr-Aib-OMe (P3) are folded into C12/C10 hydrogen-bonded double turn conformations. The double turn feature is probed and confirmed by conformational analysis of hybrid peptides using 2D-NMR studies and X-ray crystallography. DMSO-d6 solvent titration investigations also support the double turn conformation adopted by our reported peptides in CDCl3 solution. Solvent assisted self-assembled morphological features of peptides P1-P3 and the salt-prompted mineralization studies of peptide P1 under ambient conditions are studied. All three reported peptides P1-P3 form diverse supramolecular scaffolds in solid states through non-covalent interactions to attain higher order architectures. © 2016 The Royal Society of Chemistry.