1. Uppsala Centre for Computational Chemistry, Science for Life Laboratory, Department of Cell and Molecular Biology, Uppsala University, Husargatan 3, Box 596, SE-75124 Uppsala, Sweden
2. Center of Biotechnology, Universidade Federal do Rio Grande do Sul, Bento Gonçalves 9500, BR-91500-970 Porto Alegre, Brazil
3. Department of Chemistry, University of Konstanz, Universitätstraße 10, D-78457 Konstanz, Germany