Hydrogen/Deuterium eXchange Mass Spectrometry > Epitope Mapping

Mapping the antibody-antigen binding region is critical for resolving the mechanism of action of drug and understand protein-protein interactions.

The antigen (bound and unbound) is incubated in deuterated solvent in order to exchange the hydrogen from the protein backbone with deuterium in exposed amino acid. The location of these deuterium on the molecule can be accurately determined using high-resolution mass spectrometry.

The exchange is slower for less accessible hydrogens such as those involved in the binding site of antibody-antigen complex. By comparing the unbound antigen with the bound antibody-antigen complex, the residues of the epitope can be determined.

Linear and conformational epitope can be investigated.