Self-assembly of a Sequence-shuffled Short Peptide Amphiphile Triggered by Metal Ions into Terraced Nanodome-like Structures.

We highlight the structural diversity of strategically designed two short peptide amphiphiles (sPAs) and describe their structure-function relationship studies. The shuffling of two key amino acids, that is, tyrosine and phenylalanine, in a designed sPA lead to a pair of constitutional isomers. Such small and strategic alteration can bring a substantial change in the self-assembling pattern. Inspired from the naturally occurring metallopeptides, bioactive transition-metal ions were used for constructing the unusual nanostructures. Use of appropriate metal ions created bigger differences between the properties of these isomers and hence the self-assembly. Coordination of appropriate transition metal ions modifies the internal nanoscale structures of sPA, thus leading to the formation of vertically stacked terraced layers with decreasing size, which possess a high degree of dimensional regularity. We propose that such metal-induced terraced nanodome-like hierarchical self-assembly may have relevance for specific biotechnology applications.