Figure 5.

The integrin α6 subunit carries NSCLC-type N-glycans.A, IP of the integrin α6 subunit from detergent-solubilized SCC-sEVs (H520, SK-MES-1, and LK-2), followed by SDS-PAGE/silver staining. Heavy chain (HC) of immunoglobulin G used for immunoprecipitation. Arrows indicate the immunoprecipitated integrin α6 subunit. Asterisks indicate bands that were not detected with the anti-integrin α6 antibody in Western blot analysis. B, LC-ESI-MS analysis of major N-glycans detected in the immunoprecipitated integrin α6 subunit prepared in (A). The relative amounts (%, upper panel) of each glycan structure were calculated by setting the total peak intensities of all detected alditol N-glycans in each extracted-ion chromatogram (EIC) to 100%. Peak intensities of each alditol N-glycan were calculated based on the EIC in Fig. S6. Bottom panels show the average mass spectrum (28–55 min) in the base peak chromatogram of N-glycan alditols. The deduced structures of the major N-glycans are shown with the theoretical mass and the charge state. The structure number, observed mass, theoretical mass, peak intensities, and retention time are summarized in Data S4. C, relative amounts of oligomannose-type (Oligo-Man) and nonfucosylated (Non-Fuc) or monofucosylated (Mon-Fuc) complex-type N-glycans in total N-glycans. D, relative amounts of biantennary (Bi-antenna) and triantennary (Tri-antenna) N-glycans in the total complex-type N-glycans. E, sialylation profiles (Non-Sia, Mono-Sia, Di-Sia, and Tri-Sia) of biantennary and triantennary N-glycans. See also Fig. S6 and Data S4. All experiments were performed once. ESI, electrospray ionization; LC, liquid chromatography; MS, mass spectrometry; NSCLC, non–small-cell lung carcinoma; SCC, squamous-cell lung carcinoma; sEV, small extracellular vesicle.