1. Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen (Germany)
2. German Center for Neurodegenerative Diseases (DZNE), Göttingen (Germany)
3. Center for the Molecular Physiology of the Brain, University Medical Center, Göttingen (Germany)
4. Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden (The Netherlands)