1. Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095–1751, USA.
2. UCLA–Department of Energy Institute of Genomics and Proteomics, University of California, Los Angeles, CA 90095, USA.
3. Laboratoire de Chimie Bioorganique, Université Louis Pasteur, CNRS UMR 7175 LC01, Faculté de Pharmacie, 74 Route du Rhin, 67401 Illkirch, France.