This Proof of Concept proposal is designed to develop and test a novel way of monitoring the effects of drug binding to membrane protein targets. The idea stems from the basic research proposed in my ERC grant IMPRESS to study and rationalise the release of membrane proteins from detergent micelles in the gas phase of the mass spectrometer. During this research we discovered a new family of detergents, which we could formulate, to retain folded protein structure in the gas phase. Having achieved this goal, we then actively unfolded these assemblies in the mass spectrometer and by monitoring their unfolding trajectories we realised that we could quantify the effects of small molecule binding on protein stability. Not only can we now rank ligands according to their ability to confer stability but we can also count the number of molecules bound to a particular membrane protein target. By distinguishing bound molecules, either lipids or drugs, we can then carry out competitive binding experiments by displacing small molecules with higher affinity ligands.