TY - JOUR

T1 - Effect of phospholipid composition and phase on nanodisc films at the solid-liquid interface as studied by neutron reflectivity

AU - Wadsäter, Maria Helena

AU - Barker, Robert

AU - Mortensen, Kell

AU - Feidenhans'l, Robert Krarup

AU - Cardenas Gomez, Marite

PY - 2013

Y1 - 2013

N2 - Nanodiscs are disc-like self-assembled structures formed by phospholipids and amphipatic proteins. The proteins wrap like a belt around the hydrophobic part of the lipids, basically producing nanometer-sized patches of lipid bilayers. The bilayer in the nanodisc constitutes a native-like model of the cell membrane and can act as a nanometer-sized container for functional single membrane proteins. In this study, we present a general nanodisc-based system, intended for structural and functional studies of membrane proteins. In this method, the nanodiscs are aligned at a solid surface, providing the ability to determine the average structure of the film along an axis perpendicular to the interface as measured by neutron reflectivity. The nanodisc film was optimized in terms of nanodisc coverage, reduced film roughness, and stability for time-consuming studies. This was achieved by a systematic variation of the lipid phase, charge, and length of lipid tails. Herein, we show that, although all studied nanodiscs align with their lipid bilayer parallel to the interface, gel-phase DMPC nanodiscs form the most suitable film for future membrane protein studies since they yield a dense irreversibly adsorbed film with low roughness and high stability over time. This may be explained by the appropriate matching between the thickness of the hydrophobic lipid core of gel phase DMPC and the height of the belt protein. Moreover, once formed the gel-phase DMPC nanodiscs film can be heated up to melt the lipid bilayer, thus providing a more biologically friendly environment for membrane proteins.

AB - Nanodiscs are disc-like self-assembled structures formed by phospholipids and amphipatic proteins. The proteins wrap like a belt around the hydrophobic part of the lipids, basically producing nanometer-sized patches of lipid bilayers. The bilayer in the nanodisc constitutes a native-like model of the cell membrane and can act as a nanometer-sized container for functional single membrane proteins. In this study, we present a general nanodisc-based system, intended for structural and functional studies of membrane proteins. In this method, the nanodiscs are aligned at a solid surface, providing the ability to determine the average structure of the film along an axis perpendicular to the interface as measured by neutron reflectivity. The nanodisc film was optimized in terms of nanodisc coverage, reduced film roughness, and stability for time-consuming studies. This was achieved by a systematic variation of the lipid phase, charge, and length of lipid tails. Herein, we show that, although all studied nanodiscs align with their lipid bilayer parallel to the interface, gel-phase DMPC nanodiscs form the most suitable film for future membrane protein studies since they yield a dense irreversibly adsorbed film with low roughness and high stability over time. This may be explained by the appropriate matching between the thickness of the hydrophobic lipid core of gel phase DMPC and the height of the belt protein. Moreover, once formed the gel-phase DMPC nanodiscs film can be heated up to melt the lipid bilayer, thus providing a more biologically friendly environment for membrane proteins.

U2 - 10.1021/la3024698

DO - 10.1021/la3024698

M3 - Journal article

C2 - 23373466

AN - SCOPUS:84874587577

VL - 29

SP - 2871

EP - 2880

JO - Langmuir

JF - Langmuir

SN - 0743-7463

IS - 9

ER -