![]() In case of the bacterial aquaglyceroporin, GlpF, negatively charged lipids are required for targeting to the cytoplasmic membrane and efficient membrane insertion. coli, the non-lamellar zwitterionic phosphatidylethanolamine (PE) determines the topological organization and functionality of lactose permease LacY and is required for cell motility and chemotaxis. ![]() Concentrating on lipid constituents of E. Thereby, different lipid types play diverse roles. The variation of lipid composition among different membranes, between the two membrane leaflets, in different membrane areas and over time has been recognized as one of very important factors for modulation of membrane properties and thus also the function of membrane-embedded proteins. The biomembrane components are thereby known to influence each other. Biomembranes are known to be heterogeneous in space and time, to be densely packed with proteins and to comprise hundreds of different lipid species. ![]() The picture of a biological membrane as a simple homogeneous slab of lipid molecules that is hydrophobic in the middle and hydrophilic at the surface is obsolete nowadays. In addition, they build a solid basis for manifold future simulation studies on more realistic lipid membranes bridging the gap between simulations and experiments. coli polar lipids extract revealed that lipid tail complexity, in terms of double bond and cyclopropane location and varying lipid tail length, is key to stabilize membrane properties over a broad temperature range. The here prepared and validated membrane models of E. Moreover, aquaporin-1 attracts and temporarily binds negatively charged lipids, mainly cardiolipins, with a distinct cardiolipin binding site in the crevice at the contact site between two monomers, most probably stabilizing the tetrameric protein assembly. Aquaporin-1 embedded in our native(-like) membranes causes partial lipid ordering and membrane thinning in its vicinity. The Martini3 models reflect extremely well both experimental and atomistic behavior of the E. ![]() The only Simple model that was able to satisfactory reproduce most of the structural properties of the complex Avanti model showed worse agreement of the activation energy of basal water permeation with the here performed measurements. The comparison of the Simple three lipid component models to the complex 14-lipid component model Avanti over a broad range of physiologically relevant temperatures revealed that the balance of lipid tail unsaturation and propanylation in different positions and inclusion of lipid tails of various length maintain realistic values for lipid mobility, membrane area compressibility, lipid ordering, lipid volume and area, and the bilayer thickness. coli grown at 37 ∘C until 3/4 of the log growth phase. The lipid tail (un)saturation and propanylation stereochemistry represent the bacterial lipid tail composition of E. coli inner membrane, i.e., phosphatidylethanolamines, phosphatidylglycerols, and cardiolipins, symmetrically distributed between the membrane leaflets. These models contain all main lipid headgroup types of the E. coli polar lipid extract, a typical model organism, each at all-atom (CHARMM36) and coarse-grained (Martini3) representations. To enable more accurate MD simulations, we have prepared four membrane models of E. However, to accurately complement in vitro experiments with molecular details at very high spatio-temporal resolution, molecular dynamics simulations have to be performed in natural(-like) lipid environments. Whereas in vitro experiments already account for the functional importance of lipids by using natural lipid extracts, in silico methods lack behind by embedding proteins in single component lipid bilayers. Lipid-protein interactions stabilize protein oligomers, shape their structure, and modulate their function.
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