L-Phenylalanine-derived pseudopeptidic bioinspired materials: Zn(II) induced fluorescence enhancement and precise tuning of self-assembled nanostructures

Design of C2-symmetric pseudopeptides for in vivo detection of Cu(II) through controlled supramolecular nano-assembly

Pseudopeptides are emerging next-generation soft bioinspired materials for biological applications. Therefore, a new class of C2-symmetric L-valine-derived pseudopeptides has been designed and developed. The newly developed pseudopeptides exhibit intracellular Cu(II) ion detection in live-cell fluorescence studies on RAW264.7 cells. We find that the changes in the amino acid side chain in desired pseudopeptidic moieties lead to a drastic change in their selectivity towards different metal ions. The L-valine-derived pseudopeptides exhibit selectivity towards Cu(II) ions through turn-off fluorescence, and the L-phenylalanine-derived pseudopeptides exhibit selectivity towards Zn(II) ions through turn-on fluorescence. In addition, the L-valine-derived pseudopeptides show an increase in spherical-shaped structures upon incubation with Cu(II) ions during supramolecular nano-assembly formation. In contrast, the L-phenylalanine-derived pseudopeptides show a decrease in spherical-shaped structures upon adding Zn(II) ions. The judiciously designed L-valine-derived and L-phenylalanine-derived bioinspired pseudopeptides are promising for exploring similar effects in various peptidomimetics in advanced biological applications.

Zinc-Induced Luminescent l-Valine-Based Pseudopeptidic Soft Bioinspired Materials for Precise Tuning of Nanoassembly

Pseudopeptide-based bioinspired materials are emerging for selective recognition of biologically significant analytes and are applicable in the modern nanoscience field. Therefore, we have developed novel multifunctional C2-symmetric soft pseudopeptides by amino acid l-valine and salicylaldehyde fragments using a series of aliphatic linkers. They are highly selective and sensitive to Zn (II) ions under physiological conditions and reveal significant fluorescence enhancement with the PET mechanism. The molecular self-assembly shows zinc-induced morphological transformation of the rod-shaped assembly into a chain-like morphology. Such a metal-induced hierarchical nano-assembly may have relevance for specific nanobiotechnology applications.

Intracellular Zn(II) induced turn-on fluorescence of an L-phenylalanine-derived pseudopeptide

A C2 symmetric L-phenylalanine-derived pseudopeptide has been synthesized for selective and sensitive recognition of Zn(II) ions in aqueous-organic media. The pseudopeptidic probes exhibit intracellular Zn(II) ion-sensing capabilities as demonstrated via live-cell fluorescence studies on RAW264.7 cells. Hence, we present a bioinspired pseudopeptide for potential biological applications involving intracellular Zn(II) ion detection.