DYNAMIC CHEMISTRY OF COILED COIL PROTEIN ASSEMBLIES ON SOLID SURFACES

Smart surfaces can switch their properties by responding to specific stimuli leading to transition from active to inactive states. In particular, the molecules functionalizing the surface dictate its specific switchable properties. This stimulates scientists` interest in applications of dynamic systems on surfaces in various fields, such as: biomedical, environmental and memory devices. We decided to use coiled coil protein assemblies to tune the surface features.¹ Coiled coil peptides have been designed, synthesized and characterized in solution by circular dichroism and fluorescence spectroscopy. Several reversible binding and releasing, folding and unfolding, processes of heterodimeric coiled coil proteins have been performed on silicon nitride. The surface layer was characterized by ellipsometry and fluorescence after each step to probe the reaction efficiency. Finally, the programmable reactions have been performed demonstrating Boolean logic operation (Fig. 1). For that purpose, the coiled coil peptides were labelled with a FRET couple, allowing the simultaneous implementation of different logic gates, e.g., AND and INHIBIT, by two following different readout: monolayer thickness and fluorescence donor quenching, respectively. The experiments accomplished demonstrated the feasibility of this system for reversible protein self-assembly on solid surface. We suggest that this new approach of programmable manipulation of synthetic proteins on solid surfaces will pave the way to the development of more effective, robust and flexible biosensing smart devices.

¹ C. Shlizerman, A. Atanassov, I. Berkovich, G. Ashkenasy and N. Ashkenasy, J. Am. Chem. Soc., 2010, 132, 5070-5076