New self-assembled archetypes in crown ether substituted ΔZPhe containing tripeptides

We examine the effect of crown ether ring sizes on structure and properties of three terminally protected tripeptides containing substituted dehydrophenylalanine residues; Bz- Δ Phe (12-crown-4)-Phe-Phe-OMe, Bz- Δ Phe (15-crown-5)-Phe-Phe-OMe, Bz- Δ Phe (18-crown-6)-Phe-Phe-OMe. The resultant self-assembly of the peptides generates nano-vesicles, which further alter into the necklace type of structures that were characterized via their SEM, LRTEM, and AFM images. We also report the disruption of these vesicles in the presence of different metal ions. Graphical abstract: Crown ether conjugated tripeptidesP-12C4 and P-15C5 showed a turn-on fluorescence in the presence of Hg 2 + ions. While the peptides P-12C4 and P-15C5 self-assembled into nanovesicles, P-18C6 self-assembled into a necklace type of structures. Furthermore, incubation of P-12C4 and P-15C5 with Hg 2 + and Na + ions resulted in the fusion of these well-defined nanovesicles.