PEGS 2025 - Orthogonal techniques for LCMS characterization of a lysine-conjugated ADC
Streamlined peptide mapping and intact mass analysis for accurate DAR quantification and site-specific lysine conjugation profiling
About This Poster
Lysine-conjugated Antibody Drug Conjugates (ADCs) present significant analytical challenges due to their inherent heterogeneity. Traditional characterization methods struggle with:
- Accurate drug-to-antibody ratio (DAR) calculation.
- Site-specific conjugation localization.
- Quantification of site occupancy.
While bottom-up MS approaches using lysine-specific proteases (trypsin or LysC) are common, lysine conjugation introduces variability that complicates peptide mixtures and site occupancy measurements.
This poster presents an orthogonal analytical strategy combining arginine-specific digestion with RgpB (GingisREX®, Genovis AB) and intact mass analysis. By reconstructing intact mass spectra from peptide mapping data, we demonstrate improved correlation between peptide-level and intact-level analyses, enabling more precise DAR determination and site-specific conjugation profiling.
