1. Department of Biochemistry, Arrhenius Laboratories for Natural Sciences, Stockholm University, S-106 91 Stockholm, Sweden, Biochemistry, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, S-221 00 Lund, Sweden, Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France, URBB, U263 INSERM, Universite Paris 7, 2 Place Jussieu, 75251 Paris Cedex 05, France, and Section de Biophysique des Protéines et des Membranes,...