1. Department of Physiology and Biophysics, State University of New York at Stony Brook, Stony Brook, New York 11794-8661, Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794-3400, Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, Department of Molecular, Cellular and Developmental Biology, Haverford College, Haverford Pennsylvania 19041, and Graduate Programs in Biophysics and in Molecular and Cellular Biology,...