title: Probing ground and excited states of phospholamban in model and native lipid membranes by magic angle spinning NMR spectroscopy.
abstract: In this paper, we analyzed the ground and excited states of phospholamban (PLN), a membrane protein that regulates sarcoplasmic reticulum calcium ATPase (SERCA), in different membrane mimetic environments. Previously, we proposed that the conformational equilibria of PLN are central to SERCA regulation. Here, we show that these equilibria detected in micelles and bicelles are also present in native sarcoplasmic reticulum lipid membranes as probed by MAS solid-state NMR. Importantly, we found that the kinetics of conformational exchange and the extent of ground and excited states in detergent micelles and lipid bilayers are different, revealing a possible role of the membrane composition on the allosteric regulation of SERCA. Since the extent of excited states is directly correlated to SERCA inhibition, these findings open up the exciting possibility that calcium transport in the heart can be controlled by the lipid bilayer composition. This article is part of a Special Issue entitled: Membrane protein structure and function.
authors.affiliation: Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Gustavsson
authors.forename: Nathaniel J
authors.initials: NJ
authors.lastname: Traaseth
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Veglia
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008563:Membrane Lipids / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011817:Rabbits; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000737:chemistry / Q000378:metabolism; D000099211:Phospholamban
chemical_list: D002135:Calcium-Binding Proteins; D008563:Membrane Lipids; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000099211:Phospholamban