title: Micelles, Bicelles, and Nanodiscs: Comparing the Impact of Membrane Mimetics on Membrane Protein Backbone Dynamics.
abstract: Detergents are often used to investigate the structure and dynamics of membrane proteins. Whereas the structural integrity seems to be preserved in detergents for many membrane proteins, their functional activity is frequently compromised, but can be restored in a lipid environment. Herein we show with per-residue resolution that while OmpX forms a stable β-barrel in DPC detergent micelles, DHPC/DMPC bicelles, and DMPC nanodiscs, the pico- to nanosecond and micro- to millisecond motions differ substantially between the detergent and lipid environment. In particular for the β-strands, there is pronounced dynamic variability in the lipid environment, which appears to be suppressed in micelles. This unexpected complex and membrane-mimetic-dependent dynamic behavior indicates that the frequent loss of membrane protein activity in detergents might be related to reduced internal dynamics and that membrane protein activity correlates with lipid flexibility.
authors.affiliation: Laboratory for Physical Chemistry, ETH Zurich, 8093, Zurich, Switzerland.
authors.forename: Lukas
authors.initials: L
authors.lastname: Frey
authors.affiliation: Laboratory for Physical Chemistry, ETH Zurich, 8093, Zurich, Switzerland.
authors.forename: Nils-Alexander
authors.initials: NA
authors.lastname: Lakomek
authors.affiliation: Laboratory for Physical Chemistry, ETH Zurich, 8093, Zurich, Switzerland.
authors.forename: Roland
authors.initials: R
authors.lastname: Riek
authors.affiliation: Laboratory for Physical Chemistry, ETH Zurich, 8093, Zurich, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Bibow
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D029968:Escherichia coli Proteins / Q000737:chemistry*; D006867:Hydrolases / Q000737:chemistry*; D008823:Micelles; D056004:Molecular Dynamics Simulation; D049329:Nanostructures / Q000737:chemistry*; D010767:Phosphorylcholine / Q000031:analogs & derivatives / Q000737:chemistry*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D008823:Micelles; D010767:Phosphorylcholine; C482905:OmpX protein, E coli; D006867:Hydrolases
keywords: NMR spectroscopy; OmpX; membrane proteins; protein dynamics; relaxation