title: Bacteriorhodopsin/amphipol complexes: structural and functional properties.
abstract: The membrane protein bacteriorhodopsin (BR) can be kept soluble in its native state for months in the absence of detergent by amphipol (APol) A8-35, an amphiphilic polymer. After an actinic flash, A8-35-complexed BR undergoes a complete photocycle, with kinetics intermediate between that in detergent solution and that in its native membrane. BR/APol complexes form well defined, globular particles comprising a monomer of BR, a complete set of purple membrane lipids, and, in a peripheral distribution, approximately 2 g APol/g BR, arranged in a compact layer. In the absence of free APol, BR/APol particles can autoassociate into small or large ordered fibrils.
authors.affiliation: Laboratoire de Physico-Chimie Moléculaire des Membranes Biologiques, Centre National de la Recherche Scientifique, and Université Paris-7, Institut de Biologie Physico-Chimique, Paris, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Gohon
authors.forename: Tassadite
authors.initials: T
authors.lastname: Dahmane
authors.forename: Rob W H
authors.initials: RW
authors.lastname: Ruigrok
authors.forename: Peter
authors.initials: P
authors.lastname: Schuck
authors.forename: Delphine
authors.initials: D
authors.lastname: Charvolin
authors.forename: Fabrice
authors.initials: F
authors.lastname: Rappaport
authors.forename: Peter
authors.initials: P
authors.lastname: Timmins
authors.forename: Donald M
authors.initials: DM
authors.lastname: Engelman
authors.forename: Christophe
authors.initials: C
authors.lastname: Tribet
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Popot
authors.forename: Christine
authors.initials: C
authors.lastname: Ebel
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001436:Bacteriorhodopsins / Q000737:chemistry* / Q000378:metabolism*; D002850:Chromatography, Gel; D003102:Colloids / Q000737:chemistry; D003116:Color; D019617:Halobacterium salinarum / Q000378:metabolism; D008055:Lipids / Q000737:chemistry; D008854:Microscopy, Electron; D033363:Neutron Diffraction; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism*; D011437:Propylamines / Q000737:chemistry* / Q000378:metabolism*; D017433:Protein Structure, Secondary; D018717:Purple Membrane / Q000737:chemistry / Q000378:metabolism; D053838:Scattering, Small Angle; D013863:Thioglucosides / Q000737:chemistry; D014461:Ultracentrifugation
chemical_list: D001426:Bacterial Proteins; D003102:Colloids; D008055:Lipids; D011108:Polymers; D011437:Propylamines; D013863:Thioglucosides; C499017:amphipol A8-35; D001436:Bacteriorhodopsins; C042989:n-octyl-beta-D-thioglucopyranoside