1. Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117871 Moscow, Russia, and Laboratoire de Spectroscopie Biomoléculaire, UFR de Pharmacie, Université de Reims Champagne-Ardenne, 51, rue Cognacq Jay, 51096 Reims, France