1. Department of Chemistry, Institute of Chemical Epigenetics, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 Munich, Germany
2. Mass Spectrometry Core Facility, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, 82152, Planegg, Germany
3. Department of Molecular Biology, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Str. 9, Martinsried, 82152 Planegg, Germany