After incubating the purified pColdI-PRMT5, pColdI-PP2C1 and SAM in the above 50 μL reaction buffer, they were treated at 30 °C for 90 minutes and separated on a 12% (wt/vol) SDS‒PAGE gel. The GlPP2C1 protein was cleaved, digested with trypsin in the gel, and analyzed by LC‒MS/MS analysis of polypeptides. Peptide identification was performed using MS/MS spectra of the GlPP2C1 protein.