Allosteric conformational changes of G proteins upon its interaction with membrane and GPCR

Current resolved structures of GPCRs and G protein complexes provided important insights into G protein activation. However, the binding or dissociation of GPCRs with G protein is instantaneous and highly dynamic in the intracellular environment. The conformational dynamic of G protein still needs to be addressed. In this study, we applied 19F solution NMR spectroscopy to monitor the conformational changes of G protein upon interact with detergent mimicking membrane and receptor. Our results show that there are two states equilibria in the Gα in apo states. The interaction of Gα with detergents will accelerate this conformational transformation and induce a state that tends to bind to GPCRs. Finally, the Gα proteins presented a fully activation state when they coupled to GPCRs.