1. Proteomics Center of Excellence, Northwestern University, Evanston, Illinois 60208, United States
2. Intact Genomics, Inc., St. Louis, Missouri 63132, United States
3. Department of Medical Microbiology and Immunology and Department of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
4. Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60201, United States
5. Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States