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Naturally occurring photosynthetic systems use elaborate pathways of self-repair to limit the impact of photo-damage. Here, we demonstrate a complex consisting of two recombinant proteins, phospholipids and a carbon nanotube that mimics this process. The components self-assemble into a configuration in which an array of lipid bilayers aggregate on the surface of the carbon nanotube, creating a platform for the attachment of light-converting proteins. The system can disassemble upon the addition of a surfactant and reassemble upon its removal over an indefinite number of cycles. The assembly is thermodynamically metastable and can only transition reversibly if the rate of surfactant removal exceeds a threshold value. Only in the assembled state do the complexes exhibit photoelectrochemical activity. We demonstrate a regeneration cycle that uses surfactant to switch between assembled and disassembled states, resulting in an increased photoconversion efficiency of more than 300% over 168 hours and an indefinite extension of the system lifetime. [ABSTRACT FROM AUTHOR]

One of the biggest challenges in pharmaceutical research is obtaining integral membrane proteins in a functional, solubilized, and monodisperse state that provides a native-like environment that maintains the spectrum of in vivo activities. Many of these integral membrane proteins are receptors, enzymes, or other macromolecular assemblies that are important drug targets. An example is the general class of proteins composed of seven-transmembrane segments (7-TM) as exemplified by the G-protein-coupled receptors. In this article, we describe a simple system for self-assembling bacteriorhodopsin, as a model protein containing 7-TM helices, with phospholipids to form a nanometer-scale soluble bilayer structure encircled by a 200 amino acid scaffold protein. The result is the single molecule incorporation of an integral membrane protein target into a soluble and monodisperse structure that allows the structural and functional tools of solution biochemistry to be applied. [ABSTRACT FROM AUTHOR]