title: Dynamics of the Glycophorin A Dimer in Membranes of Native-Like Composition Uncovered by Coarse-Grained Molecular Dynamics Simulations.
abstract: Membranes are central for cells as borders to the environment or intracellular organelle definition. They are composed of and harbor different molecules like various lipid species and sterols, and they are generally crowded with proteins. The membrane system is very dynamic and components show lateral, rotational and translational diffusion. The consequence of the latter is that phase separation can occur in membranes in vivo and in vitro. It was documented that molecular dynamics simulations of an idealized plasma membrane model result in formation of membrane areas where either saturated lipids and cholesterol (liquid-ordered character, Lo) or unsaturated lipids (liquid-disordered character, Ld) were enriched. Furthermore, current discussions favor the idea that proteins are sorted into the liquid-disordered phase of model membranes, but experimental support for the behavior of isolated proteins in native membranes is sparse. To gain insight into the protein behavior we built a model of the red blood cell membrane with integrated glycophorin A dimer. The sorting and the dynamics of the dimer were subsequently explored by coarse-grained molecular dynamics simulations. In addition, we inspected the impact of lipid head groups and the presence of cholesterol within the membrane on the dynamics of the dimer within the membrane. We observed that cholesterol is important for the formation of membrane areas with Lo and Ld character. Moreover, it is an important factor for the reproduction of the dynamic behavior of the protein found in its native environment. The protein dimer was exclusively sorted into the domain of Ld character in the model red blood cell plasma membrane. Therefore, we present structural information on the glycophorin A dimer distribution in the plasma membrane in the absence of other factors like e.g. lipid anchors in a coarse grain resolution.
authors.affiliation: Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Max von Laue Str. 9, 60438, Frankfurt/Main, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Flinner
authors.affiliation: Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Max von Laue Str. 9, 60438, Frankfurt/Main, Germany; Cluster of Excellence Frankfurt, Goethe University, Max von Laue Str. 9, 60438, Frankfurt/Main, Germany; Buchmann Institute of Molecular Life Sciences (BMLS), Goethe University, Max von Laue Str. 15, 60438, Frankfurt/Main, Germany; Center of Membrane Proteomics, Goethe University, Max von Laue Str. 9, 60438 Frankfurt/Main, Germany.
authors.forename: Enrico
authors.initials: E
authors.lastname: Schleiff
mesh_terms: D002784:Cholesterol / Q000737:chemistry / Q000378:metabolism; D004910:Erythrocyte Membrane / Q000378:metabolism; D005227:Fatty Acids / Q000737:chemistry; D006021:Glycophorins / Q000737:chemistry* / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary
chemical_list: D005227:Fatty Acids; D006021:Glycophorins; D002784:Cholesterol