1. Centre
for Molecular Simulation and Department of Biological Sciences, University of Calgary, 2500 University Drive, N.W., Calgary, Alberta T2N 1N4, Canada
2. Groningen
Biomolecular Sciences and Biotechnology (GBB) Institute and Zernike
Institute for Advanced Materials, University of Groningen, Nijenborgh
7, 9747 AG Groningen, The Netherlands