title: Surfactant bilayers maintain transmembrane protein activity.
abstract: In vitro studies of membrane proteins are of interest only if their structure and function are significantly preserved. One approach is to insert them into the lipid bilayers of highly viscous cubic phases rendering the insertion and manipulation of proteins difficult. Less viscous lipid sponge phases are sometimes used, but their relatively narrow domain of existence can be easily disrupted by protein insertion. We present here a sponge phase consisting of nonionic surfactant bilayers. Its extended domain of existence and its low viscosity allow easy insertion and manipulation of membrane proteins. We show for the first time, to our knowledge, that transmembrane proteins, such as bacteriorhodopsin, sarcoplasmic reticulum Ca(2+)ATPase (SERCA1a), and its associated enzymes, are fully active in a surfactant phase.
authors.affiliation: Laboratoire de Physique Statistique de l'École Normale Supérieure, UPMC, Université Paris Diderot, CNRS, UMR 8550, Paris, France.
authors.forename: Gamal
authors.initials: G
authors.lastname: Rayan
authors.affiliation: Laboratoire de Physique Statistique de l'École Normale Supérieure, UPMC, Université Paris Diderot, CNRS, UMR 8550, Paris, France; Laboratoire de Cristallographie et RMN Biologiques, Université Paris Descartes, CNRS, UMR 8015, Paris, France.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Adrien
authors.affiliation: Laboratoire de Physique Statistique de l'École Normale Supérieure, UPMC, Université Paris Diderot, CNRS, UMR 8550, Paris, France.
authors.forename: Myriam
authors.initials: M
authors.lastname: Reffay
authors.affiliation: Laboratoire de Cristallographie et RMN Biologiques, Université Paris Descartes, CNRS, UMR 8015, Paris, France.
authors.forename: Martin
authors.initials: M
authors.lastname: Picard
authors.affiliation: Laboratoire de Cristallographie et RMN Biologiques, Université Paris Descartes, CNRS, UMR 8015, Paris, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Ducruix
authors.affiliation: Institut Charles Sadron - UPR 022 - CNRS - Unistra, Strasbourg, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Schmutz
authors.affiliation: Laboratoire de Physique Statistique de l'École Normale Supérieure, UPMC, Université Paris Diderot, CNRS, UMR 8550, Paris, France; Sorbonnes Université Univ Paris 6, UMR 7371, UMR_S 1146, Laboratoire d'Imagerie Biomédicale, Paris, France; CNRS, UMR 7371, Laboratoire d'Imagerie Biomédicale, Paris, France; INSERM, UMR_S 1146, Laboratoire d'Imagerie Biomédicale, Paris, France.
authors.forename: Wladimir
authors.initials: W
authors.lastname: Urbach
authors.affiliation: Sorbonnes Université Univ Paris 6, UMR 7371, UMR_S 1146, Laboratoire d'Imagerie Biomédicale, Paris, France; CNRS, UMR 7371, Laboratoire d'Imagerie Biomédicale, Paris, France; INSERM, UMR_S 1146, Laboratoire d'Imagerie Biomédicale, Paris, France. Electronic address: nicolas.taulier@upmc.fr.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Taulier
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry; D040761:Biomimetic Materials / Q000737:chemistry; D004987:Ethers / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008565:Membrane Proteins / Q000737:chemistry*; D008823:Micelles; D008854:Microscopy, Electron; D044367:Phase Transition; D011092:Polyethylene Glycols / Q000737:chemistry*; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D004987:Ethers; D005960:Glucosides; D008051:Lipid Bilayers; D008565:Membrane Proteins; D008823:Micelles; D013501:Surface-Active Agents; D014867:Water; C018619:octyl-beta-D-glucoside; C077053:pentaethylene glycol monododecyl ether; D011092:Polyethylene Glycols; D001436:Bacteriorhodopsins; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases