title: Intermolecular detergent-membrane protein noes for the characterization of the dynamics of membrane protein-detergent complexes.
abstract: The interaction between membrane proteins and lipids or lipid mimetics such as detergents is key for the three-dimensional structure and dynamics of membrane proteins. In NMR-based structural studies of membrane proteins, qualitative analysis of intermolecular nuclear Overhauser enhancements (NOEs) or paramagnetic resonance enhancement are used in general to identify the transmembrane segments of a membrane protein. Here, we employed a quantitative characterization of intermolecular NOEs between (1)H of the detergent and (1)H(N) of (2)H-perdeuterated, (15)N-labeled α-helical membrane protein-detergent complexes following the exact NOE (eNOE) approach. Structural considerations suggest that these intermolecular NOEs should show a helical-wheel-type behavior along a transmembrane helix or a membrane-attached helix within a membrane protein as experimentally demonstrated for the complete influenza hemagglutinin fusion domain HAfp23. The partial absence of such a NOE pattern along the amino acid sequence as shown for a truncated variant of HAfp23 and for the Escherichia coli inner membrane protein YidH indicates the presence of large tertiary structure fluctuations such as an opening between helices or the presence of large rotational dynamics of the helices. Detergent-protein NOEs thus appear to be a straightforward probe for a qualitative characterization of structural and dynamical properties of membrane proteins embedded in detergent micelles.
authors.affiliation: Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, ETH-Hönggerberg , CH-8093 Zürich, Switzerland.
authors.forename: Cédric
authors.initials: C
authors.lastname: Eichmann
authors.forename: Julien
authors.initials: J
authors.lastname: Orts
authors.forename: Christos
authors.initials: C
authors.lastname: Tzitzilonis
authors.forename: Beat
authors.initials: B
authors.lastname: Vögeli
authors.forename: Sean
authors.initials: S
authors.lastname: Smrt
authors.forename: Justin
authors.initials: J
authors.lastname: Lorieau
authors.forename: Roland
authors.initials: R
authors.lastname: Riek
mesh_terms: D003902:Detergents / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry; D029968:Escherichia coli Proteins / Q000737:chemistry; D006388:Hemagglutinins / Q000737:chemistry; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry*; D008823:Micelles; D056004:Molecular Dynamics Simulation; D009975:Orthomyxoviridae / Q000737:chemistry; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D003902:Detergents; D029968:Escherichia coli Proteins; D006388:Hemagglutinins; D008565:Membrane Proteins; D008823:Micelles