title: Active membranes studied by X-ray scattering.
abstract: In view of recent theories of "active" membranes, we have studied multilamellar phospholipid membrane stacks with reconstituted transmembrane protein bacteriorhodopsin (BR) under different illumination conditions by X-ray scattering. The light-active protein is considered as an active constituent which drives the system out of equilibrium and is predicted to change the collective fluctuation properties of the membranes. Using X-ray reflectivity, X-ray non-specular (diffuse) scattering, and grazing incidence scattering, we find no detectable change in the scattering curves when changing the illumination condition. In particular the intermembrane spacing d remains constant, after eliminating hydration-related artifacts by design of a suitable sample environment. The absence of any observable non-equilibrium effects in the experimental window is discussed in view of the relevant parameters and recent theories.
authors: Institut für Röntgenphysik, Friedrich-Hund-Platz 1, 37073, Göttingen, Germany. agiahi@gwdg.de
authors: A
authors: A
authors: Giahi
authors: M
authors: M
authors: El Alaoui Faris
authors: P
authors: P
authors: Bassereau
authors: T
authors: T
authors: Salditt
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry* / Q000378:metabolism; D001703:Biophysics / Q000379:methods*; D004583:Electrons; D004867:Equipment Design; D006217:Halobacterium / Q000378:metabolism; D006813:Humidity; D008051:Lipid Bilayers / Q000737:chemistry*; D008968:Molecular Conformation; D009502:Neutrons; D010713:Phosphatidylcholines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry*; D011485:Protein Binding; D018717:Purple Membrane / Q000378:metabolism; D012542:Scattering, Radiation; D014965:X-Rays
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D010743:Phospholipids; D001436:Bacteriorhodopsins
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