1. Biomolecular Systems Department; Max-Planck-Institute of Colloids and Interfaces; Am Mühlenberg 1 14476 Potsdam Germany
2. Department of Biology, Chemistry and Pharmacy; Free University Berlin; Arnimallee 22 14195 Berlin Germany
3. Current address: Science for Life Laboratory; Tomtebodavägen 23A 17121 Stockholm Sweden
4. Current address: Institute of Organic Chemistry and Macromolecular Chemistry; Friedrich-Schiller-University Jena; Humboldtstr. 10, Office 310A 07743 Jena Germany