1. Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
2. Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg 199034, Russia
3. Bindley Bioscience Center, West Lafayette, Indiana 47906, United States
4. Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47906, United States
5. Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588, United States