1. Life
Sciences Department, University of Modena and Reggio Emilia, Via
Campi 183, 41125 Modena, Italy
2. Department
of Life Science Informatics, B-IT, LIMES Program Unit Chemical Biology
and Medicinal Chemistry, Rheinische Friedrich-Wilhelms-Universität, Dahlmannstrasse 2, D-53113 Bonn, Germany