1. Contribution from the Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolski 135, 612 65 Brno, Czech Republic, Institute for Molecular Biology and Biophysics, ETH−Hönggerberg, CH-8093 Zürich, Switzerland, Drug Discovery Program and Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Medical School, Chicago, Illinois 60611-3008, and J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, 182 23...