Fig. 5.

A, select site-specific glycoforms of the T3 peptide at m/z 938.4 and at m/z 978.9 after neuraminidase and β1,4-galactosidase treatment consistent with the observed results in pooled HCC (left) and pooled cirrhosis (right) samples. The presented glycoforms with A3G1F2 and A3G2F2 composition are the only structures showing the correct fucose distribution based on the data obtained after consecutive exoglycosidase treatment with neuraminidase and β1,4-galactosidase. B, Western blot confirms the presence of Le(y)-type structures with higher intensity in the HCC sample. C, MALDI-MS/MS spectrum of detached permethylated glycan A3G1F2 showing the fragment ion at m/z 834.3 corresponding to the Le(y) structure. Inset shows the precursor ion at m/z 2459.2. Additional structure confirming digests with α1,2- and α1–3,4-fucosidase and β1,3-galactosidase are presented in supplemental Fig. 3.