A Membrane-Reconstituted Multisubunit Functional Proton Pump on Mesoporous Silica Particles

作者：Nordlund Gustav; Ng Jovice Boon Sing; Bergstrom Lennart; Brzezinski Peter^*

来源：ACS Nano, 2009, 3(9): 2639-2646.

DOI：10.1021/nn9005413

• supported lipid bilayer
• mesoporous spheres
• nanoparticles
• membrane protein
• drug delivery
• cytochrome c oxidase

We have investigated formation of a proteolipid membrane surrounding mesoporous silica particles with a diameter of 550 nm and pore sizes of 3.0 nm. A multisubunit redox-driven proton pump, cytochrome c oxidase, was incorporated into the membrane, and we show that the enzyme is functional, both with respect to catalysis Of 02 reduction to water, and charge separation across the membrane. The orientation of cytochrome c oxidase in the membrane was found to be the same (similar to 70%) in the lipid vesicles and in the silica-particle-supported lipid membrane, which provides information on the mechanism by which the vesicles adsorb to the surface. Furthermore, cytochrome c oxidase could maintain a proton electrochemical gradient across the supported proteomembrane, that is, the membrane system was proton tight, defining an interior particle compartment that is separated from the surrounding aqueous media. Such a biofunctional cellular interface, supported onto a colloid that has a connected interior cytoskeleton-like pore structure, provides a basis for functional studies of membrane-bound transport proteins, and also for applications within pharmaceutical drug delivery.

• 出版日期2009-9