1. Faculty of Physics and Research Center for Nanoscale Structure of Matter, Southern Federal University, 344090 Rostov-on-Don, Russia, Max-Planck Institute for Bioinorganic Chemistry, Stiftstr. 34-36, 45470 Mülheim, Germany, Stanford Synchrotron Radiation Lightsource, P.O. Box 20450 Stanford, California 94309, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, and European Synchrotron Radiation Facility, 6, rue Jules Horowitz, 38043 Grenoble, France