Carolanne E Norris, James E Keener, Suchithranga M D C Perera, Nipuna Weerasinghe, Steven D E Fried, William C Resager, James G Rohrbough, Michael F Brown, Michael T Marty
Rhodopsin, a prototypical G-protein-coupled receptor, is responsible for scoptic vision at low-light levels. Although rhodopsin's photoactivation cascade is well understood, it remains unclear how lipid and zinc binding to the receptor are coupled. Using native mass spectrometry, we developed a novel data analysis strategy to deconvolve zinc and lipid bound to the proteoforms of rhodopsin and investigated the allosteric interaction between lipids and zinc binding. We discovered that phosphatidylcholine bound to rhodopsin with a greater affinity than phosphatidylserine or phosphatidylethanolamine, and that binding of all lipids was influenced by zinc but with different effects...
February 2021: International Journal of Mass Spectrometry