1. Institute of Organic Chemistry; University of Duisburg-Essen (Germany); Universitätsstrasse 7 45141 Essen Germany
2. Department of Bioinformatics and Computational Biophysics; ZMB/Faculty of Biology; University of Duisburg-Essen; 45117 Essen Germany
3. Computational Biochemistry; University of Duisburg-Essen; Universitätsstrasse 3 45141 Essen Germany
4. Department of Chemistry; University of Duisburg-Essen; Universitätsstrasse 7 45141 Essen Germany
5. Department of Biomedical Engineering and; Institute for Complex Molecular Systems; Technische Universiteit Eindhoven; P. O. Box 513 5600 MB Eindhoven Netherlands