1. Department of Chemistry, University of Wisconsin─Madison, Madison, Wisconsin 53706, United States
2. School of Life Sciences, University of Siegen, Siegen 57076, Germany
3. Department of Cell and Regenerative Biology, University of Wisconsin─Madison, Madison, Wisconsin 53705, United States
4. Human Proteomics Program, School of Medicine and Public Health, University of Wisconsin─Madison, Madison, Wisconsin 53705, United States