| dc.description.abstract | The structure and function of membrane proteins are often under the regulation of cofactors such as lipids and other small molecules in the biological membrane bilayer. The characterization of most membrane proteins with lipids, however, remains challenging due to the inherent complicacy of membrane protein complexes and the lack of methods. The emergence of native mass spectrometry (MS) has largely facilitated the study of the interaction between membrane proteins and lipids, as native MS offers direct measurements on individual ligand binding events, protein stabilization, allosteric coupling, and thermodynamics. This thesis will be focused on the study of the interaction between inwardly rectifying potassium channels (Kirs) and phospholipids by employing native MS. Specifically, the work will include the following topics: the correlation between Kir channels activity and their binding affinity towards key regulators phosphorylated phosphotidylinositdes (PIPs), the intervention of copurified contaminants on membrane proteins towards the interaction between lipids and membrane proteins, the specific roles of conserved amino acid residues in the binding pocket of Kir channel, the corroboration of the lipid-binding measurements made by native MS and a soluble binding assay using Förster resonance energy transfer (FRET), and the thermodynamic binding signatures of Kir3.2 with PIPs. | |
