2.3. Mass spectrometric measurement

The volume of 5 μl re-suspended peptides were injected into nanoHPLC (UltiMate 3000 RSLCnano, Dionex, Thermo Fisher Scientific), trapped on a C18-reverse phase trapping column (C18 PepMap100, 300 μm × 5 mm, particle size 3 μm, Thermo Fischer Scientific) and followed by separation on a C18-reverse phase analytical column (Acclaim PepMap® 100, 75 μm × 25 cm, particle size 3 μm, nanoViper, Thermo Fischer Scientific). Both columns were tempered to 40 °C at all times. Mass spectrometry of eluated peptides were analyzed on a Q Exactive HF mass spectrometer (Thermo Fisher Scientific, Waltham, MA, USA) coupled to a TriVersa NanoMate source (Advion, Ltd., Harlow, UK) in LC chip coupling mode. The LC Gradient, ionization and MS settings were described in detail [7].