1. Division of Physical Chemistry, Department of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
2. Department of Applied Physics, Biophysics Group, SciLifeLab, Royal Institute of Technology-KTH, 171 65 Solna, Sweden
3. Division of Biochemistry and Structural Biology, Department of Chemistry, Lund University, SE-22100 Lund, Sweden