Previously using a native MS approach, we showed that the salt-transporter NhaA required a lipid called cardiolipin to help to glue the protein together (Nature. 2017 541:421; Nat Commun 8:13993). We wondered if we could also use a thermal-shift assay to detect this lipid-dependent oligomerization and indeed we could! We developed the GFP-TS assay, which is a really nice complementation to native MS. Using this assay, we measured the stability of a number of bacterial and eukaryotic membrane proteins, mostly transporters. Our data suggests that eukaryotic membrane proteins may not be that much more unstable than bacterial membrane proteins in native membranes, but become comparatively more unstable after purification. We interpret this data to suggest that eukaryotic membrane proteins have evolved to be more sensitive to their lipid environment and this “sensitivity" is important for fine-tuning their dynamics and functional activity. 


The study was published in Nature Communications



The GFP-Thermal Shift assay