Modification and enrichment

Dissolve the obtained peptide in the enrichment buffer solution (50% acetonitrile/6% trifluoroacetic acid), transfer the supernatant to the IMAC material washed in advance, and place it on a rotary shaker for incubation with mild shaking. After completion of the incubation, the resin was washed three times sequentially with the buffer solutions 50% acetonitrile/6% trifluoroacetic acid and 30% acetonitrile/0.1% trifluoroacetic acid. Finally, the modified peptide was eluted with 10% ammonia, and the eluate was collected and vacuum-frozen. Desalting was performed according to the instructions of C18 ZipTips after pumping, and the samples were subjected to liquid chromatography-mass spectrometry after vacuum freezing and pumping.