Limited proteolysis combined with mass spectrometry of farrerol treated. Briefly, cell lysates containing approximately 500 μg of total protein sample were incubated with farrerol or vehicle (DMSO) for 10 min at 25 °C. Proteinase K (5 μg, Sigma–Aldrich) was added simultaneously to each sample for the following 10 min. Then, the reaction was stopped by heating at 98 °C for 3 min. The samples were subjected to limited proteolysis to generate structure-specific protein fragments. Complete digestion was performed with trypsin (Promega) at a 1:50 ratio (trypsin:protein, w:w) for 16 h at 37 °C, and then the reaction was stopped by adding formic acid to reach a pH less than 2. The polypeptide samples were dissolved in 0.1% formic acid and detected by Orbitrap mass spectrometry with label-free quantitation (LFQ) analysis to search for differential proteins on the MaxQuant platform via MS sensitivity.