Molecular Self-Assembly of Short Aromatic Peptides: From Biology to Nanotechnology and Material Science

The formation of ordered amyloid fibrils is the hallmark of several diseases of unrelated origin. In spite of grave clinical consequence, the mechanism of amyloid formation is not fully understood. We have suggested, based on experimental and bioinformatic analysis, that aromatic interactions may provide energetic contribution as well as order and directionality in the molecular-recognition and self-association processes that lead to the formation of these assemblies. This is in line with the well-known central role of aromatic-stacking interactions in self-assembly processes. Our works on the mechanism of aromatic peptide self-assembly, lead to the discovery that the diphenylalanine recognition motif self-assembles into peptide nanotubes with a remarkable persistence length. Other aromatic homodipeptides could self-assemble in nano-spheres, nano-plates, nano-fibrils and hydrogels with nano-scale order. We demonstrated that the peptide nanostructures have unique chemical, physical and mechanical properties including ultra-rigidity as aramides, semi-conductive, piezoelectric and non-linear optic properties. We also demonstrated the ability to use these peptide nanostructures as casting mold for the fabrication of metallic nano-wires and coaxial nano-cables. The application of the nanostructures was demonstrated in various fields including electrochemical biosensors, tissue engineering, and molecular imaging. Finally, we had developed ways for depositing of the peptide nanostructures and their organization. We had use inkjet technology as well as vapour deposition methods to coat surface and from the peptide ``nano-forests''. We recently demonstrated that even a single phenylalanine amino-acid can form well-ordered fibrilar assemblies.\\[4pt] References: Reches, M. and Gazit, E. (2003) Casting Metal Nanowires within Discrete Self-Assembled Peptide Nanotubes. \textbf{Science} \textit{300}, 625-627. Reches, M. and Gazit, E. (2006) Controlled Patterning of Aligned Self-Assembled Peptide Nanotubes. \textbf{Nature Nanotechnol.} \textit{1}, 195-200. Adler-Abramovich L., Aronov D., Beker P., Yevnin M., Stempler S., Buzhansky L., Rosenman G. and Gazit E. (2009) Self-Assembled Arrays of Peptide Nanotubes by Vapour Deposition. \textbf{Nature Nanotechnol.} \textit{4}, 849-854. Carny, O., Shalev, D., and Gazit, E. (2006) Fabrication of Coaxial Metal Nanowires Using Self-Assembled Peptide Nanotube Scaffold. \textbf{Nano Lett.}\textit{ 6}, 1594-1597. (Featured in the \textit{Research Highlights} of \textbf{Nature Nanotechnol.}; doi:10.1038/nnano.2006.23). Amdursky, N., Molotskii, M., Gazit, E., and Rosenman, G. (2010) Elementary Building Blocks of Self-Assembled Peptide Nanotubes. \textbf{J. Am. Chem. Soc.} \textit{132}, 15632-1563. (Featured in the \textit{News and Views} of \textbf{Nature} \textit{468}, 516-517). Adler-Abramovich, L., Vaks, L., Carny, O., Trudler, D., Magno, A., Caflisch, A., Frenkel, D. and Gazit, E. (2012) Phenylalanine Assembly into Toxic Fibrils Suggests Amyloid Etiology in Phenylketonuria. \textbf{Nature Chem. Biol.} \textit{8}, 701--706.