PYCR2 interacts with AKR1C1 and promotes the metastasis of hepatocellular carcinoma by activating the PPAR/EMT signaling pathway

Protein interaction mass spectrometry analysis of PYCR2 in HepG2 cells.Using PYCR2 as the IP antibody, the bound proteins were pulled down, and the gel strips were treated with Coomassie Brilliant Blue staining. Gel samples were reduced, alkylated and digested with trypsin. After which, the enzymatic digestion products were desalted and freeze-dried, and then re-solubilized in 0.1% formic acid solution. Subsequently, the samples were separated using the HPLC liquid phase system nanoElute. The resulting peptides were separated using a nano-flow liquid-chromatography system and analyzed using a timsTOF Pro mass spectrometer. Raw data were processed using MaxQuant software (version 2.6.3.0, Max Planck Institute of Biochemistry) against a human protein sequence database. Proteins enriched in the PYCR2 immunoprecipitates relative to the IgG controls were considered candidate PYCR2-associated proteins.