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

详细信息    查看全文

• 作者：Gustav Nordlund ; Jovice Boon Sing Ng ; Lennart Bergström ; Peter Brzezinski
• 刊名：ACS Nano
• 出版年：2009
• 出版时间：September 22, 2009
• 年：2009
• 卷：3
• 期：9
• 页码：2639-2646
• 全文大小：387K
• 年卷期：0
• ISSN：1936-086X

文摘

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 O₂ reduction to water, and charge separation across the membrane. The orientation of cytochrome c oxidase in the membrane was found to be the same (∼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.