All digest mixtures were analysed on Q Exactive MS (Thermo Fisher Scientific) with one MS survey scan and up to 10 data-dependent MS/MS scans. The instrument was operated at a mass resolution of 35,000, 1e6 automatic gain control target, and 60 ms maximal ion time for MS, and a mass resolution of 17500, 105 automatic gain control, 250 ms maximal ion time, 2 m/z isolation window and 30 s dynamic exclusion time for MS/MS. The normalized collision energy was set to 28%.
