1. Department
of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
2. Dipartimento
di Biotecnologie, Chimica e Farmacia, via A. Moro 2, Universitá di Siena, I-53100 Siena, Italy
3. Chemistry Department, Overman
Hall, Bowling Green State University, Bowling
Green, Ohio 67200, United States
4. Institut
de Physique et de Chimie des Materiaux de Strasbourg, Université de Strasbourg, Batiment 69, 23 Rue du Loess, 67200 Strasbourg, France