1. Department of Biochemistry and Biophysics (R.L.W., A.K.S., R.J.F.), California 94143
2. Graduate Group in Biophysics (B.R.H., A.K.), California 94143
3. Metabolic Research Unit, Department of Medicine (S.T.C.L., J.W.A., J.D.B., B.L.W.), California 94143
4. Departments of Pharmaceutical Chemistry and Molecular and Cellular Pharmacology (T.S.S.) University of California, San Francisco San Francisco, California 94143