1. Department of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, D-06120 Halle (Saale), Germany
2. Department of NMR-Based Structural Biology, Max Planck Institute of Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
3. Deutsche Forschungsgemeinschaft Research Center for Molecular Physiology of the Brain, Humboldtallee 23, D-37073 Göttingen, Germany