March 07, 2022
Monday, March 07, 2022 – Auditoire Maisin – 1 pm
Chloé MARTENS - ULB, Unité de recherche en Structure et Fonction des Membranes biologiques
H/D exchange coupled to Mass Spectrometry: a multifaceted tool to study membrane proteins
Abstract:
Membrane proteins participate in a myriad of vital biological processes, including nutrient transport, cell-cell signaling and toxin export. This central role makes them an attractive class of drug targets and uncovering their molecular mechanism is an intense area of research. Membrane proteins are, however, notoriously difficult to work with, mainly due to their localization within the heterogeneous of environment of the biological membrane and instability once extracted from the lipid bilayer.
Hydrogen‐deuterium exchange coupled to mass spectrometry (HDX‐MS) has recently emerged as a powerful method to investigate aspects eluding traditional biophysical tools, such as the conformational dynamics of membrane proteins and their interactions with substrates, ions and lipids. This technique measures the rate of H/D exchange of labile protons from backbone amides1. This exchange rate is directly correlated to solvent accessibility and local structural dynamics. Specifically, we have demonstrated that HDX-MS is an ideal tool to decipher the mechanism of membrane transporters2. Changes in the conformational landscape caused by different lipid environments lead to changes in global and local dynamics measurable by HDX-MS. In combination with predictions from molecular dynamics simulations, specific lipid-modulated changes in the conformational dynamics can be identified at the molecular level3. Similarly, the coupling between a substrate and an ion in a secondary transporter leads to a structural fingerprint that can be observed with this approach. A summary of the insights that HDX-MS applied to membrane transporters can reveal, as well as the practical means to obtain those will be presented.
Related references:
- Masson, G. R. et al. Recommendations for performing, interpreting and reporting hydrogen deuterium exchange mass spectrometry (HDX-MS) experiments. Nat. Methods 16, 595–602 (2019).
- Martens, C. et al. Direct protein-lipid interactions shape the conformational landscape of secondary transporters. Nat. Commun. 9, 4151 (2018).
- Martens, C., Shekhar, M., Lau, A. M., Tajkhorshid, E. & Politis, A. Integrating hydrogen–deuterium exchange mass spectrometry with molecular dynamics simulations to probe lipid-modulated conformational changes in membrane proteins. Nat. Protoc. 14, 3183–3204 (2019).