1. Department of Chemistry Università degli Studi di Milano Via Golgi 19 20133 Milan Italy
2. Laboratory of Biomolecular Research Paul Scherrer Institute Forschungsstrasse 111 5232 Villigen PSI Switzerland
3. Centro de Investigaciones Biológicas Margarita Salas Consejo Superior de Investigaciones Científicas Ramiro de Maeztu 9 28040 Madrid Spain
4. Laboratory of Chemoinformatics, Faculty of Chemistry University of Strasbourg 67081 Strasbourg France