1. Department of Molecular Biology and Immunology, University of North Texas, Fort Worth, Texas 76107, Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia, ArQule, Inc., 303 Bear Hill Road, Waltham, Massachusetts 02154, Department of Physiology, University of Texas Southwestern Medical School, Dallas, Texas 75235, and Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405