Periodic Reporting for period 4 - BISON (Bio-Inspired Self-Assembled Supramolecular Organic Nanostructures)
Reporting period: 2020-12-01 to 2022-05-31
The BISON project aims to develop a novel class of bio-inspired peptide nanostructures. These bio-inspired assemblies will provide novel and innovative directions for nano-science and nanotechnology, thereby laying the basis for their utilization in diverse applications. Specifically, the research focused on 3 main objectives: (i) Study of the assembly process, (ii) Technological application of the organic nanostructures, and (iii) Engineering of the building blocks.
Within the scope of the project, we have been able to design multiple peptide-based building blocks, which, when self-assembled, give rise to structures of various morphologies and diverse applicable properties including piezoelectric, optical, and catalytic characteristics. We currently continue our efforts towards the implementation of these supramolecular structures in various applications.
b. Technological application of the organic nanostructures: During the BISON project, we have demonstrated several intriguing applications of peptide-based nanostructures. Thus, we utilized the properties of the self-assembled nanostructures to develop microspheres which serve as sunlight-sensitive antennas for artificial photosynthesis. We were also able to fabricate a self-assembled photonic array with Opal-like multicolor appearance. These arrays display vivid coloration, strongly resembling the appearance of opal gemstones. Moreover, by controlling the solvent evaporation rate, we were able to manipulate the resulting coloration. We further designed a cyclic peptide which, upon coordination with metal, formed structures showing extremely high photoluminescence efficiency which could be used for detectable drug delivery. We also designed and characterized a metal-peptide structure showing efficient, stable, and reusable catalytic activity, providing a potent complement for minimalistic biocatalysts.
c. Engineering of the building blocks: As part of the BISON project, we were able to engineer the most stable emulsions reported so far for peptide and protein emulsifiers. We have established the ability of short heptapeptides to perform the dual functions of emulsifiers and thickeners. We further used our design principles in order to prepare phsopho-peptides that served as phospholipid-like analogues. Moreover, we designed a new tri-peptide building block that could form a variety of architectures, including nanowires, nanofibers, nanospheres, and nanotoroids. We also showed the transformation of an amyloid peptide structure into an unstructured conformation induced by co-assembly with a simple molecule. Finally, we demonstrated the assembly of a newly-designed ultra-aromatic peptide into structures showing enhanced mechanical properties comparable to aluminum, significant piezoelectric performance superior to organic counterparts, optical properties and high thermal stability.
In addition, a very important direction is the definition of the minimal building blocks for the formation of super-helical structures. Our work allowed the identification of peptide elements comprising 3 amino acids for the formation of stable super-helical structures. The mechanism of formation and utilization of the assemblies have been extensively explored.
Another important advancement beyond the state of the art is developing the field of peptide semiconductivity. This has significantly advanced peptide electronic towards the establishment of bio-inspired molecular electronics platforms.
Finally, the establishment of the activity of metal-coordinated minimal models has been another central contribution. This work further allowed to explore the enzymatic activity of peptide amyloids which has technological applications as well as implications for the origin of life.