1. Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany
2. Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 5, 91058 Erlangen, Germany
3. Department of Chemistry and Munich Center for Integrated Protein Science CIPSM, Ludwig-Maximilians-Universität München, D-81377 Munich, Germany