Modulating Hydrogen Bonded Self-assembled Patterns and Morphological Features by a Change in Side Chain of Third Amino Acid of Synthetic γ- Amino Acid Based Tripeptides

Abstract

Self-assembled structure and functions of peptides could be achieved by the design and synthesis of hybrid peptides. Here, we report structural and morphological studies of designed hybrid tripeptides Boc-Gpn-Aib-Xaa-OMe (where Xaa=Leu(L) for 1 and Phe(F) for 2), which show different conformations both in solid and solution states. The conformational modulations are achieved by the design and synthesis of reported peptides 1 and 2 by suitable choice of conventional and non-conventional amino acid building blocks and slight change in side-chain of third amino acids of tripeptides. The conformational modulations exhibited by peptides 1 and 2 are well probed and confirmed using Single crystal XRD, FT-IR, CD and 2D NMR studies. The morphological studies of peptides 1 and 2 show different self-assembled morphological preferences in THF – water (1:1) under similar experimental conditions.