1. Department of Biomolecular Systems Max Planck Institute of Colloids and Interfaces Am Mühlenberg 1 14476 Potsdam Germany
2. Department of Chemistry and Biochemistry Freie Universität Berlin Arnimallee 22 14195 Berlin Germany
3. Current address: Medicinal Chemistry Leibniz-Forschungsinstitut für Molekulare Pharmakologie Robert-Rössle Strasse 10 13125 Berlin Germany
4. Current address: Department of Pharmaceutical Chemistry University of Vienna Althanstrasse 14 1080 Vienna Austria
5. Current address: Department of Microbiology, Immunobiology and Genetics Max F. Perutz Labs Campus Vienna Biocenter 5 1030 Vienna Austria