Hydrogen-Deuterium Exchange Mass Spectrometry (HDX-MS) is an innovative tool for the characterisation of therapeutic monoclonal antibodies. One of the main applications of HDX-MS in the field of biotherapeutics is the study of higher-order structures. In this application note, we present how this technology can be used to monitor structural changes at the amino acid level during stress testing studies of a monoclonal antibody. This appreach can be applied similarly to stability studies.
Although adalimumab withstood fairly well the heat stress it was subjected to in this study, HDX-MS allowed to pinpoint structural alterations in two CDRs and – to a lower extent – at the N glycosylation site, which may in turn alter the function of the drug. This work demonstrates the utility of HDX-MS for the comparative study of biotherapeutics, bridging classical physico-chemical to biological methods. It may be used similarly to assess biosimilarity or stability of therapeutic proteins, as well as for binding studies (see our epitope mapping application note).