Secondary structure and protein fold of black mamba dendrotoxin I as determined by 1H-NMR: toward a molecular basis for the selective blockage of voltage-sensitive potassium channels: M.-F. Foray,1J.-M. Lancelin,1M. Hollecker2 and D. Marion1 (1Institut de Biologie Structurale, 41, Avenue des Martyrs, 38027 Grenoble, France; and 2Centre de Biophysique Moléculaire, 1A, Avenue de la Recherche Scientifique, 45071 Orléans, France)