Exploration of the dynamic interplay between lipids and membrane proteins by hydrostatic pressure

Abstract

Cell membranes represent a complex and variable medium in time and space of lipids and proteins. Their physico-chemical properties are determined by lipid components which can in turn influence the biological function of membranes. Here, we used hydrostatic pressure to study the close dynamic relationships between lipids and membrane proteins. Experiments on the β–barrel OmpX and the α–helical BLT2 G Protein-Coupled Receptor in nanodiscs of different lipid compositions reveal conformational landscapes intimately linked to pressure and lipids. Pressure can modify the conformational landscape of the membrane protein per se, but also increases the gelation of lipids, both being monitored simultaneously at high atomic resolution by NMR. Our study also clearly shows that a membrane protein can modulate, at least locally, the fluidity of the bilayer. The strategy proposed herein opens new perspectives to scrutinize the dynamic interplay between membrane proteins and their surrounding lipids.

The complex structure of Fomes fomentarius represents an architectural design for high-performance ultralightweight materials

“…We observed mostly correlations that would be compatible with the mobile lipid acyl chain signals in all layers (assignments are given in fig. S4) ( 33 ).…”

Perspective on the Effect of Membrane Mimetics on Dynamic Properties of Integral Membrane Proteins

“…Pozza et al utilized twodimensional (2D) 1 H, 13 C SOFAST-HMQC NMR spectroscopy through three transmembrane 13 CH 3 reporters, in residues M105 3.35 , M19 75.54 , and I229 6.40 to study the conformational ensemble of BLT2 GPCR in POPC/POPG and 1,2-dipalmitoylsn-glycero-3-phosphocholine (DPPC) lipid discs. 47 The results suggested that these three methyl NMR reporters are sensitive to the conformational plasticity of the receptor. The NMR data analysis of BLT2 in nanodiscs of various compositions and in the presence of agonists showed that BLT2 represents a complex conformational dynamic landscape in eukaryotic membranes enriched in POPC/POPG or in more rigid DPPC membrane.…”

“…Solution NMR approaches in combination with nanodiscs can provide a high-precision dynamic information about every atom of an amino acid in a wide range of time scales from picoseconds to seconds. 37,46,47 However, this method is challenging to obtain high-quality experimental data due to the larger size of the membrane-protein complex (>∼50 kDa). 35,48−51 NMR studies of membrane proteins are also limited by the larger spectral broadening and overlapping of NMR line widths.…”

“…42 A recent example of using NMR spectroscopy is the study of Leukotriene B4 receptor 2 (BLT2) in lipid nanodiscs. 47 BLT2 receptors are G proteincoupled receptors (GPCRs). GPCRs represent a large family of eukaryotic integral membrane proteins.…”

“…NMR spectroscopy is used to obtain structural and dynamic properties of membrane proteins under physiological conditions. Solution NMR approaches in combination with nanodiscs can provide a high-precision dynamic information about every atom of an amino acid in a wide range of time scales from picoseconds to seconds. ,, However, this method is challenging to obtain high-quality experimental data due to the larger size of the membrane-protein complex (>∼50 kDa). ,− NMR studies of membrane proteins are also limited by the larger spectral broadening and overlapping of NMR line widths. NMR experiments also require a large amount of highly pure and folded membrane protein samples to achieve better data quality. ,− A probe-based Förster resonance energy transfer (FRET) technique is another approach to obtaining conformational dynamics of membrane proteins .…”