1. Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT, United Kingdom
2. Institute of Organic Chemistry, University of Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
3. Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
4. Research Unit, “Puerta del Mar” University Hospital, School of Medicine, and Institute of Biomedical Research Cadiz (INiBICA), University of Cadiz, Cadiz, Spain