1. Institute for Biochemistry and Molecular Physiology, University of Potsdam, c/o Max-Delbrück-Centrum for Molecular Medicine, Robert Rössle Strasse 10, 13125 Berlin-Buch, Germany, Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, and Department of Biosensors, Research Center for Molecular Diagnostics and Therapy, Simpheropolsky Boulevard 8, 113 149 Moscow, Russia