Bacteriorhodopsin/amphipol complexes: structural and functional properties.
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.
Gohon
Yann
Y
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.
Dahmane
Tassadite
T
Ruigrok
Rob W H
RW
Schuck
Peter
P
Charvolin
Delphine
D
Rappaport
Fabrice
F
Timmins
Peter
P
Engelman
Donald M
DM
Tribet
Christophe
C
Popot
Jean-Luc
JL
Ebel
Christine
C
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
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