0000000000756058
AUTHOR
Beate West
Interactions of membranes with coarse-grain proteins: a comparison
We study the interactions between lipid bilayers and rigid transmembrane proteins by Monte Carlo simulations of generic coarse-grain models. Different popular protein models are considered and compared with each other, and key parameters such as the hydrophobicity and the hydrophobic mismatch are varied systematically. Furthermore, the properties of the membrane are manipulated by applying different tensions. The response of the membrane to the insertion of single proteins is found to be mostly generic and independent of the choice of the protein model. Likewise, the orientational distributions of single proteins depend mainly on the hydrophobic mismatch and the hydrophobicity of the protei…
Membrane-mediated Protein-protein Interaction: A Monte Carlo Study
We investigate membrane-mediated interactions between transmembrane proteins using coarse-grained models. We compare the effective potential of mean force (PMF) between two proteins, which are always aligned parallel to the z-axis of the simulation box, with those PMFs obtained for proteins with fluctuating orientations. The PMFs are dominated by an oscillatory packing-driven contribution and a smooth attractive hydrophobic mismatch contribution, which vanishes if the hydrophobic length of the protein matches the thickness of the membrane. If protein orientations are allowed to fluctuate, the oscillations are greatly reduced compared to proteins with fixed orientation. Furthermore, the hydr…
Fluctuations and elastic properties of lipid membranes in the gel Lβ′ state: a coarse-grained Monte Carlo study
We study the stress distribution profiles and the height and thickness fluctuations of lipid membranes in the gel L-beta ' state by Monte Carlo simulations of a generic coarse-grained model for lipid membranes, which reproduces many known properties of dipalmitoylphosphatidyncholine (DPPC) bilayers. The results are related to the corresponding properties of fluid membranes, and to theoretical predictions for crystalline and hexatic membranes. One striking observation is that the spontaneous curvature of the monolayers changes sign from the fluid to the gel phase. In the gel-phase, the long-wavelength height fluctuations are suppressed, and the fluctuation spectrum is highly anisotropic. In …