Figure 6
The identification of RCA-I-recognized membrane glycoprotein by SILAC and LC-MS/MS analysis. (a) A SILAC and LC-MS/MS combined strategy was used to detect both expression levels and galactosylations of the membrane glycoproteins captured by RCA-I. (b) LC-MS/MS spectrum of a peptide. The sequence of the peptide was identified as VAPEEHPVLLTEAPLNPK, which was from POTEF. (c) Representative base peak chromatogram of POTEF in the whole-membrane fraction (top) and RCA-I-enriched membrane fraction (down). The blue lines represent peptides of POTEF from 4175 cells whereas the red ones represent those from SCP2 cells (13C-labeled). LC-MS/MS, liquid chromatography-mass spectrometry/tandem spectrometry; POTEF, POTE ankyrin domain family member F; RCA-I, Ricinus communis agglutinin I; SILAC, stable isotope labeling by amino acids in cell culture.