1. Department of Chemistry, University of Kansas, Multidisciplinary Research Building, 2030 Becker Drive, Lawrence, Kansas 66047, United States
2. Department of Chemistry, Louisiana State University, 229A Choppin Hall, Baton Rouge, Louisiana 70803, United States
3. Protein Structure Laboratory, Del Shankel Structural Biology Center, University of Kansas, 2034 Becker Drive, Lawrence, Kansas 66047, United States
4. IMCA-CAT, Hauptman Woodward Medical Research Institute, 9700 South Cass Avenue, Building 435A, Argonne, Illinois 60439, United States