title: Selective and ATP-driven transport of ions across supported membranes into nanoporous carriers using gramicidin A and ATP synthase.
abstract: We report a robust and versatile membrane protein based system for selective uptake and release of ions from nanoporous particles sealed with ion-tight lipid bilayers of various compositions that is driven by the addition of ATP or a chemical potential gradient. We have successfully incorporated both a passive ion channel-type peptide (gramicidin A) and a more complex primary sodium ion transporter (ATP synthase) into the supported lipid bilayers on solid nanoporous silica particles. Protein-mediated controlled release/uptake of sodium ions across the ion-tight lipid bilayer seal from or into the nanoporous silica carrier was imaged in real time using a confocal laser scanning microscope and the intensity changes were quantified. ATP-driven transport of sodium ions across the supported lipid bilayer against a chemical gradient was demonstrated. The possibility of designing durable carriers with tight lipid membranes, containing membrane proteins for selective ion uptake and release, offers new possibilities for functional studies of single or cascading membrane protein systems and could also be used as biomimetic microreactors for controlled synthesis of inorganic multicomponent materials.
authors: Department of Materials and Environmental Chemistry, Stockholm University, 10691 Stockholm, Sweden.
authors: Vitaliy
authors: V
authors: Oliynyk
authors: Christian
authors: C
authors: Mille
authors: Jovice B S
authors: JB
authors: Ng
authors: Christoph
authors: C
authors: von Ballmoos
authors: Robert W
authors: RW
authors: Corkery
authors: Lennart
authors: L
authors: Bergström
mesh_terms: D025181:ATP Synthetase Complexes / Q000737:chemistry / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D019793:Fluorescein / Q000737:chemistry; D006096:Gramicidin / Q000737:chemistry*; D007454:Iodides / Q000737:chemistry; D017136:Ion Transport; D007477:Ions / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism*; D058608:Nanopores; D012822:Silicon Dioxide / Q000737:chemistry; D012964:Sodium / Q000378:metabolism
chemical_list: D007454:Iodides; D007477:Ions; D008051:Lipid Bilayers; D006096:Gramicidin; D012822:Silicon Dioxide; D000255:Adenosine Triphosphate; D012964:Sodium; D025181:ATP Synthetase Complexes; D019793:Fluorescein