1. Laboratorium
für Organische Chemie, Eidgenössische Technische Hochschule Zürich, Vladimir-Prelog-Weg 3, 8093 Zürich, Switzerland
2. Department
of Chemistry and Center for Integrated Protein Science, Ludwig Maximilians University Munich, Butenandtstraße 5-13, 81377 Munich, Germany
3. Department
of Psychological and Brain Sciences and the Gill Center, Indiana University, Bloomington, Indiana 47405, United States
4. Department
of Biological Sciences and Department of Chemistry, Bridge Institute, University of Southern California, Los Angeles, California 90089, United States
5. Department
of Chemistry, New York University, 100 Washington Square East, New York, New York 10003-6699, United States