Extended Data Fig. 6: Analysis of site-specific conjugation of the tri-GalNAc ligand to three different locations on cetuximab.
From: LYTACs that engage the asialoglycoprotein receptor for targeted protein degradation
a, Reducing SDS-PAGE gel of Ctx and Ctx with aldehyde tag at C-terminus, Hinge, and CH1 Heavy chain. b, The proportion of signal seen between tri-GalNAc-modified (blue) peptides and peptides from the sequence that should have harbored the tri-GalNAc ligand but were seen unmodified (gray). Due to the dimer nature of the antibody, 50% of signal as modified indicates one site of modification per antibody molecule while 100% of signal as modified shows two ligands per antibody molecule. c, EThcD spectra of peptides showing site-specific localization of the tri-GalNAc ligand in the SMARTag sequence. Note, ‘M’ represents the intact mass of the modified peptide, ‘GalNAc’ shows the oxonium ion of a GalNAc residue, and the ‘M-GalNAc(x)’ annotations show the intact mass minus x number of GalNAc moieties. a is a representative data from two independent experiments.
