1. Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
2. Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
3. Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
4. Institute of Clinical Chemistry, Bioanalytics Group, University Medical Center Göttingen, 37075 Göttingen, Germany.