2.2. LC-MS/MS for identifying acetyl lysine residues

Digestion of each sample and quantitative proteomic analysis were performed as previously described [²²]. Briefly, each sample was digested using the phase transfer surfactant (PTS) method, as previously reported [^23,24]. Specific peptide data were detected by Sequential Window Acquisition of All Theoretical Fragment-ion Mass Spectra (SWATH-MS) on a TripleTOF 5600 instrument (SCIEX) interfaced with a DIONEX Ultimate 3000 RSLC nano system (Thermo Fisher Scientific). Peptides were identified by Protein Pilot 4.5 (SCIEX) with MS/MS data from Information-Dependent Acquisition (IDA). The peak of peptide acetylated lysine was analyzed using PeakView Software version 2.1 (SCIEX). The average peptide peak area of the samples in each group was compared between the 4 groups. Statistical analyses were performed using one-way analysis of variance (ANOVA).