Reflex 3 maldi tof ms

MALDI-TOF MS was performed on a Bruker Reflex III MALDI-TOF-MS (Bruker Daltonics, Germany) operating in the reflectron mode with 20 kV accelerating voltage and 23 kV Reflecting voltage [25 (link)]. A saturated solution of cyano-4-hydroxy-cinnamic acid in 50% acetonitrile and 0.1% trifluoroactic acid was used as the matrix. Sample preparation for the mass spectrometry followed the protocol reported by Geng and colleagues [25 (link)]. One μL the matrix solution and one μL sample solution were added in the Score 384 target well. The mass spectrometry analysis was performed by a specialist in the Instrument Application Center of the Academy of Military Medical Sciences following the previously published protocol [25 (link)]. In brief, mass accuracy for peptide mass finger-prints (PMF) analysis was calibrated with a 0.1–0.2 Da external standard, and internal calibration was carried out with enzyme autolysis peaks, at a resolution of 12,000. The nanoLC- FT ICR MS was performed on an APEX-Q FT-ICR tandem mass spectrometer (Bruker Daltonics, Germany) equipped with a 9.4 T superconducting magnet (Magnex Scientific, UK) and an infinity cell. The trypsin digested peptides were sequenced by auto MS mode with MS/MS boost function. The FT-ICR mass spectra were processed using Data Analysis 3.4 software (Bruker Daltonics GmbH, Germany) as a gateway to set up database searches.