Petkova Vera, Benattar Jean-Jacques, Zoonens Manuela, Zito Francesca, Popot Jean-Luc, Polidori Ange, Jasseron Sylvain, Pucci Bernard
Service de Physique de l'Etat Condensé, CEA-Saclay, DSM/DRECAM, F-91191 Gif sur Yvette, France.
Langmuir. 2007 Apr 10;23(8):4303-9. doi: 10.1021/la063249o. Epub 2007 Mar 17.
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.
研究了在由氟化表面活性剂形成的牛顿黑膜（NBFs）核心平面内组织去污剂增溶膜蛋白的可能性。氟化表面活性剂具有与去污剂互溶性差且表面活性高的有趣特性。因此，当用非离子去污剂C8E4（四甘醇单辛醚）增溶的膜蛋白——外膜蛋白A（OmpA）的跨膜结构域（tOmpA）——注入到氟化表面活性剂单层之下时，C8E4和tOmpA/C8E4复合物仍局限于亚相。绘制了垂直的宏观NBFs，并通过X射线反射率研究了它们的结构。根据实验条件，蛋白质被证明可以组织成由两层氟化表面活性剂稳定的一层或两层单分子层。研究了两种不同的蛋白质插入机制：（i）带有多组氨酸标签的tOmpA/C8E4复合物与氟化表面活性剂携带的含镍极性基团的附着，以及（ii）自发扩散到表面活性剂膜中。讨论了可能的应用。
