1. Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid,
Spain
2. Institute of Experimental Physics, SAS, Watsonova 47, 041 01 Kosice, Slovak Republic
3. Department of Biochemistry, P.J. Safarik University of Kosice, Moyzesova 11, 040
11 Kosice, Slovak Republic
4. Department of Biophysics, P.J. Safarik University of Kosice, Jesenna 5, 041 54
Kosice, Slovak Republic