Oriented purple-membrane films as a probe for studies of the mechanism of bacteriorhodopsin functioning. II. Photoelectric processes

Kononenko, A.A.; Лукашев, Е. П.; Chamorovsky, Sergey K.; Maximychev, Alexander V.; Тимашев, С. Ф.; Chekulaeva, L. N.; Rubin, A. B.; Paschenko, V.Z.

doi:10.1016/0005-2728(87)90247-7

Cited by 36 publications

(17 citation statements)

References 29 publications

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“…The photoelectric signals generated from reconstituted bR films as observed by a variety of independent research groups have proved that photochemical properties of bR can be maintained in its solid phase because of the unusual stability of purple membrane (PM) sheets (Váró and Keszthelyi, 1983;Kononenko et al, 1987;He et al, 1998;Crittenden et al, 2003). However, the photocycle and proton transfer kinetics of dried bR film dramatically differ from those of the more commonly studied wet bR samples due to the influence of dehydration.…”

Section: Introductionmentioning

confidence: 97%

Photoelectric properties of a detector based on dried bacteriorhodopsin film

Wang

Knopf

Bassi

2006

Biosensors and Bioelectronics

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Section: Introductionmentioning

confidence: 97%

Photoelectric properties of a detector based on dried bacteriorhodopsin film

Wang

Knopf

Bassi

2006

Biosensors and Bioelectronics

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“…Moreover, instead of 2D reconstitution of proton pumps into bilayers of lipid vesicles with limited and isolated internal volumes, 3D unidirectional assembly offers the sequential addition of proton gradients from individual proteogradient membranes. Because bR in purple membranes is well oriented natively, numerous reports focused on 3D stacking of purple membrane patches using approaches such as electric sedimen-tation (22), Langmuir-Blodgett transfer (23), electric field directed loading (24), sequential deposition with polyelectrolytes (25), etc. Unfortunately, the interdigitation of different patches along the stacking direction and the presence of randomly oriented patches are intrinsic problems.…”

mentioning

confidence: 99%

The directed cooperative assembly of proteorhodopsin into 2D and 3D polarized arrays

Liang

Whited²,

Nguyen

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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Proteorhodopsin is the membrane protein used by marine bacterioplankton as a light-driven proton pump. Here, we describe a rapid cooperative assembly process directed by universal electrostatic interactions that spontaneously organizes proteorhodopsin molecules into ordered arrays with well defined orientation and packing density. We demonstrate the charge density-matching mechanism that selectively controls the assembly process. The interactions among different components in the system are tuned by varying their charge densities to yield different organized transmembrane protein arrays: (i) a bacteriorhodopsin purple membrane-like structure where proteorhodopsin molecules are cooperatively arranged with charged lipids into a 2D hexagonal lattice; (ii) selected liquid-crystalline states in which crystalline lamellae made up of the coassembled proteorhodopsin and charged lipid molecules are coupled three-dimensionally with polarized proteorhodopsin orientation persisting through the macroscopic scale. Understanding this rapid electrostatically driven assembly process sheds light on organizing membrane proteins in general, which is a prerequisite for membrane protein structural and mechanistic studies as well as in vitro applications.cationic lipid-proteorhodopsin complexes ͉ membrane protein arrays ͉ membrane protein crystallization ͉ light-driven proton pump ͉ photovoltaics M embrane proteins (MPs) play an essential role in determining the interactions of biological systems with their surroundings. As gatekeepers of cellular boundaries, they are involved with matter, energy, and information transport to maintain life activities, and also with drug delivery to cure diseases. MPs are estimated to represent 20-30% of the currently sequenced genomes (1), and are targets for Ϸ70% of all drugs in the market (2). Although the sequence and function of many MPs have become known, their structures have only been solved at a rate of Ϸ0.2% of that of soluble proteins (3). Little is known about how to harness their unique biological functions in practical devices.Long-range ordering is the prerequisite for structure determination, and unidirectional packing is needed for many in vitro applications depending on MP orientation because the activities of most MPs have vectorial aspects (4). The key problem that hinders MP assembly is their amphiphilic character. Except for a very limited number of MPs that form ordered crystals naturally, most MPs require detergents to free them from their native membranes. Although detergent-solubilized MPs with the surrounding detergent micelle in place could be crystallized (5), the orientation of MPs in those crystals is more or less isotropic, and the effect of lacking the biological membrane confinement on MP structure and mechanistic properties is always a concern. Detergent-assisted reconstitution is the most commonly used strategy to form 2D proteolipsome arrays (6). The MP order in those arrays depends critically on the detergent removal kinetics. Moreover, the lipid versus protein rat...

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“…The protein occurs naturally in an ordered two-dimensional crystal array, usually referred to as the purple membrane (PM) sheet. The protein functions as a light-driven proton pump in the outer membrane of the organism and provides a photosynthetic source of energy when the oxygen concentration drops below that capable of sustaining respiration (Stoeckenius et al, 1979;Khorana et al, 1979;Czégé et al, 1982;Kononenko et al, 1987;Birge, 1990;Henderson et al, 1990). The absorption of visible light generates a photovoltage across the membrane with a large quantum efficiency (0.65) (Birge, 1990).…”

Section: Introductionmentioning

confidence: 98%