1. Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland, Biological Physics Group, Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw, Poland, Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, Warsaw University, 02-089 Warsaw, Poland, and Institute of Genetics and Biotechnology, Faculty of Biology, Warsaw University, 02-089 Warsaw, Poland