1. Departments of Cellular and Molecular Physiology and Pharmacology, The Pennsylvania State University College of Medicine, P.O. Box 850, Hershey, Pennsylvania 17033, Department of Chemistry and Biochemistry, Concordia University, 7141 Sherbrooke Street West, Montreal, QC, Canada H4B 1R6, The Skaggs Institute for Chemical Biology and Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, MB4, La Jolla, California 92037, and Department of Biochemistry and Center in...