1. Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
2. VPPL, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, 9W. Watkins Mill Road, Suite 250, Gaithersburg, Maryland 20878, United States
3. Department of Biological Sciences, University at Buffalo, State University of New York, Buffalo, New York 14260, United States
4. Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, Ohio 43210, United States