1. Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
2. Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Institute City of Hope, Duarte, California 91010, United States
3. Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
4. Department of Chemistry and Biochemistry, University of Montana, Missoula, Montana 59801, United States
5. Irell & Manella Graduate School of Biological Science, City of Hope, Duarte, California 91010, United States