Artificial microtubules based on switchable cyclic peptides

Descrizione del progetto

Nuovi materiali realistici

I microtubuli fanno parte del citoscheletro cellulare e dimostrano la capacità di assemblarsi e scomporsi a seconda delle esigenze della cellula. La scienza dei materiali ha cercato di simulare la capacità di autoassemblaggio dei microtubuli progettando polimeri supramolecolari artificiali, che tuttavia restano indietro in termini di proprietà meccaniche. Per ovviare a questo, il progetto CYCLOTUBES, finanziato dall’UE, sta impiegando peptidi ciclici in grado di passare dallo stato assemblato a quello disassemblato usando sostanze chimiche o enzimi. Le prestazioni di questi microtubuli artificiali saranno monitorate in un ambiente simile a una cellula mediante microscopia e potrebbero potenzialmente condurre a materiali innovativi con nuove proprietà meccaniche.

Obiettivo

Naturally occurring living materials, for e.g. the cell cytoskeleton, consist of intricate supramolecular polymers whose self-assembly is controlled by high energy molecules such as guanosine triphosphate GTP. MiNaturally occurring living materials, such as the cell cytoskeleton, consist of intricate supramolecular polymers whose self-assembly is controlled by high energy molecules such as guanosine triphosphate GTP. Microtubules for example, are incredibly strong, but because they are chemically fueled by GTP, they can be built up or broken down at specific times and locations inside the cell. The tubules are in so-called non-equilibrium steady states, and are kept away from the thermodynamic equilibrium for extended periods of time. In the recent years, artificial supramolecular polymers have been made that are transiently out-of-equilibrium by addition of a single shot of chemical fuel, or for long times by continuous addition of fuel and removal of waste. The mechanical properties of the latter artificial systems are quite poor in comparison with real microtubules. The aim of this CYCLOTUBES project is to make artificial microtubules from cyclic peptides that can chemically or enzymatically be switched between the assembled and disassembled state. To this end, we will use oxidation and reduction reactions in a cell-like environment, that is, in a membrane enclosed chamber. In the latter, chemical fuel can be added and waste be removed continuously. In addition, the assembly/disassembly of the artificial tubules can be monitored using microscopy. Our work will give fundamentally new insights into out-of-equilibrium self-assembly, and could lead to novel life-like materials that are capable of performing significant mechanical work due to the unique mechanical properties of the cyclic peptide tubules. The candidate will work at the forefront of the field of systems chemistry and supramolecular chemistry, which are very important for the competitiveness of Europe.