1. Discovery Biology, Discovery Sciences, IMED Biotech Unit, AstraZeneca, Boston, Massachusetts 02451, United States
2. Department of Chemistry and Ralph Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
3. Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, United States
4. Structure and Biophysics, Discovery Sciences, IMED Biotech Unit, AstraZeneca, Boston, Massachusetts 02451, United States