1. LEDSS, UMR CNRS 5616, Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France, INSERM UR-350, Institut Curie Recherche, Laboratoire Raymond Latarjet, Centre Universitaire, 91405 Orsay Cedex, France, INSERM UR-524 and Laboratoire de Pharmacologie Antitumorale du Centre Oscar Lambret, IRCL, Place de Verdun, 59045 Lille, France, and Biospectroscopy Laboratory, Department of Chemistry, University of Liege, Belgium