1. Institute for Biological Instrumentation, Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia, Institute of Immunological Engineering, 142380 Lyubuchany, Moscow Region, Russia, Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, Departments of Physics and Chemistry, Stanford University, Stanford, California 94305, and Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117871 Moscow, Russia