Silvia Marchesan*
Dept. of Chemical & Pharmaceutical Sciences, University of Trieste,
Via L. Giorgieri 1, 34127 Trieste, Italy
*smarchesan@units.it - www.marchesanlab.com -  @MarchesanLab

Nature’s choice for homochirality has stimulated our research, as we question it with heterochirality. The scientific journey in this direction starts from the design of short peptides to define self-assembly rules within chemical systems of biological relevance. We use one or two D-amino acids in D,L-tripeptides and study small libraries with variations in stereochemistry or amino acid sequence. We established how chirality affects spatial conformation for assembly from the molecular, nano-, micro- and through to the macro-scale, to link the macroscopic properties back to structural details of the building blocks. As an example, substitution of intermolecular with intramolecular interactions can be used to direct self-organization and impede the uncontrolled formation of hierarchical structures.
As Alice steps beyond the mirror and enters Wonderland, we can get inspired by D-amino acids and use them in D,L-peptides to achieve functional superstructures. We monitored molecular conformation and its evolution as a continuum to macroscopic hydrogels. We have now identified a more diverse library of self-assembling tripeptides with different functional groups. Applications range from (antimicrobial) biomaterials to supramolecular catalysis, and molecular separation in combination with orthogonal supramolecular systems, with a function that can be switched on/off with assembly/disassembly.

Figure: Alice steps through the mirror into Wonderland, where everyday objects are to be found with a twist
(e.g., the clock and flower vase are animated). Adapted from the original illustration by Sir John Tenniel.