Self-Assembly of Nanorosettes and Artificial Signal Transduction Systems

Thomas Schrader

Department of Chemistry, University Duisburg-Essen, Universitätstr. 5, 45117 Essen, Germany




Our group focusses on the fabrication of bioinspired receptor materials.[1] Larger structures are generated by self-assembly.[2] Thus, instructed building blocks tailored for self-recognition or self-assembly within membranes generate new functional aggregates, which are used as sensors, protein switches or for signal transduction across a membrane. As an instructive example, aminopyrazole-peptide hybrid molecules with pendant oligoethylenglycol tails, are shown to form, in solution and in the solid state, well-defined hydrogen-bonded nanorosettes which stack on top of each other. This unusual structure bearing some similarity to nucleic acids was characterized by X-ray crystallography, NMR spectroscopy and quantum chemical calculations. The strictly hierachical self-assembly process holds promise for the construction of new nanorods with DNA-like properties. In the second part of the lecture, transmembrane building blocks are presented, which self-assemble with standard membrane units such as DPPC to unilamellar liposomes, able of performing an entirely artifial signal transduction. Imitating the principle of receptor tyrosine kinases, the ditopic recognition of primary messenger molecules at the extracellular liposome face leads to an induced signal on the intracellular side, e.g. by initiating a chemical reaction concomitant with second messenger release or by a photochemical FRET process.