Free-standing films of fluorinated surfactants as 2D matrices for organizing detergent-solubilized membrane proteins.
The possibility of organizing detergent-solubilized membrane proteins in a plane within the core of Newton black films (NBFs) formed from fluorinated surfactants has been investigated. Fluorinated surfactants have the interesting characteristics of being poorly miscible with detergents and highly surface-active. As a result, when a membrane protein-the transmembrane domain of OmpA (tOmpA)-solubilized by the nonionic detergent C8E4 (tetraethylene glycol monooctyl ether) was injected under a monolayer of fluorinated surfactant, C8E4 and tOmpA/C8E4 complexes remained confined to the subphase. Vertical, macroscopic NBFs were drawn, and their structure was investigated by means of X-ray reflectivity. Depending on experimental conditions, the protein was shown to organize into either one or two monolayers stabilized by two monolayers of fluorinated surfactant. Two different mechanisms of protein insertion were investigated: (i) attachment of polyhistidine-tagged tOmpA/C8E4 complexes to nickel-bearing polar groups born by a fluorinated surfactant and (ii) spontaneous diffusion into the surfactant films. Possible applications are discussed.
Petkova
Vera
V
Service de Physique de l'Etat Condensé, CEA-Saclay, DSM/DRECAM, F-91191 Gif sur Yvette, France.
Benattar
Jean-Jacques
JJ
Zoonens
Manuela
M
Zito
Francesca
F
Popot
Jean-Luc
JL
Polidori
Ange
A
Jasseron
Sylvain
S
Pucci
Bernard
B
D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D002627:Chemistry, Physical / Q000379:methods*; D003902:Detergents / Q000737:chemistry* / Q000494:pharmacology; D005461:Fluorine / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry; D008074:Lipoproteins / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry; D008823:Micelles; D008956:Models, Chemical; D009532:Nickel; D017510:Protein Folding; D011506:Proteins / Q000737:chemistry; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*; D014965:X-Rays
D001425:Bacterial Outer Membrane Proteins; D003902:Detergents; D008074:Lipoproteins; D008565:Membrane Proteins; D008823:Micelles; D011506:Proteins; D013501:Surface-Active Agents; C078167:OMPA outer membrane proteins; C033223:polyhistidine; D005461:Fluorine; D006639:Histidine; D009532:Nickel