1. Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
2. Department of Pharmacology and Toxicology, University of Arizona, Tucson, Arizona 85721, United States
3. Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, United States
4. Molecular Evolution Protein Engineering and Production, Purdue University, West Lafayette, Indiana 47907, United States