Hydrogen-Deuterium Exchange Mass Spectrometry (HDX-MS) is an innovative tool for the characterisation of therapeutic monoclonal antibodies. Besides the study of higher-order structures, HDX/MS can also be used for epitope mapping studies in order to determine to which region of the target a monoclonal antibody binds.
In this application note, we present a case study in which we performed epitope mapping for three monoclonal antibodies binding to an interleukin receptor.
Using HDX-MS, the epitope of three mAbs were straightforwardly inferred, in solution, for a same interleukin receptor target. Qualitative and quantitative analysis allowed pinpointing the peptidic regions of the antigen that are protected from deuteration upon antibody binding. The resulting epitope location is analogous for all three candidates, although one mAb seems to also bind a secondary site.