The MS analysis was performed in negative ion mode as previously described, using the PASEF acquisition mode . Briefly, the LC was coupled to a hybrid trapped ion mobility-quadrupole time-of-flight mass spectrometer (timsTOF Pro, Bruker Daltonics, Bremen, Germany) via an Apollo II ESI ion source (Bruker Daltonics, Bremen, Germany). The voltage capillary was set to 4200 V and the TIMS ion charge control to 7.5 mio counts. The accumulation and ramp time was set to 100 ms. Mass spectra were recorded in a range of m/z 100-1500 and the ion mobility was scanned from 0.55 to 1.90 V*s/cm 2 . Precursors for data-dependent acquisition were isolated within the entire m/z mass range and fragmented with a constant collision energy of 35 eV. If necessary, the precursors were automatically fragmented multiple times within the same run to increase the quality of their MS/MS spectra. The mass calibration was performed using a mixture of sodium formate clusters with Agilent ESI LC-MS Tune Mix (50:50). The TIMS dimension was calibrated linearly using that same mixture.