Bacteriorhodopsin as an electrogenic proton pump: Reconstitution of bacteriorhodopsin proteoliposomes generating Δψ and ΔpH

Kayushin, L.P.; Skulachev, Vladimir P.

doi:10.1016/0014-5793(74)80011-6

Cited by 111 publications

(33 citation statements)

References 12 publications

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“…Confirmation that bacteriorhodopsin may operate as a proton pump was obtained by Racker (1973) and Racker and Stoeckenius (1974) wlro showed that purple membrane vesicles consisting only of bacteriorhodopsin and lipid, produced light-dependent changes in extravesicular pH which disappeared in the presence of uncouplers known to act as proton carriers. Similar observations have been made by others (Kayushin & Skulachev, 1974). Recently Lozier, Niederberger, Bogomolni, Hwang and Stoeckenius (1976) and have demonstrated that the change in pH produced by the bacteriorhodopsin model membrane vesicles result from vectorial proton transport across the membrane in the light, and not merely from binding and release of protons.…”

supporting

confidence: 61%

“…Recently Lozier, Niederberger, Bogomolni, Hwang and Stoeckenius (1976) and have demonstrated that the change in pH produced by the bacteriorhodopsin model membrane vesicles result from vectorial proton transport across the membrane in the light, and not merely from binding and release of protons. Several groups have shown that this proton transport generates a membrane potential both in model membrane vesicles (Kayushin & Skulachev, 1974;Racker & Hinkle, 1974) and in intact membrane vesicles or bacteria (Renthal & Lanyi, 1976;Bakker, Rottenberg & Caplan, 1976;Bogomolni, 1977).…”

mentioning

confidence: 96%

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Proton transport by bacteriorhodopsin through an interface film

1977

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Interface films of purple membrane and lipid containing spectroscopically intact and oriented bacteriorhodopsin have been used as a model system to study the function of this protein. Small positive charges in surface potential (less than 1 mV) are detected upon illumination of these films at the air-water interface. These photopotentials are not affected by overlaying the interface film with a thin layer (0.3 mm) of decane. However, they are dramatically increased when lipid soluble proton carriers FCCP or DNP are added to the decane. The polarity of the photopotential indicates that, in the light, positive charges are transported through the interface from the aqueous to the organic phase. The action spectrum of the photopotential is identical to the absorption spectrum of bacteriorhodopsin. Since bacteriorhodopsin molecules are oriented with their intracellular surface towards the aqueous subphase, the characteristics of the photopotential indicate that in the light bacteriorhodopsin translocates protons from its intracellular to its extracellular surface. The kinetics of the photopotential reveal that the rate and extent of proton transport are proportional both to the fraction of bacteriorhodopsin molecules excited and to the concentration of proton acceptor. The photopotentials result from changes in the ionic distribution across the decane-water interface and can be cancelled by lipid soluble anions.

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supporting

confidence: 61%

mentioning

confidence: 96%

Proton transport by bacteriorhodopsin through an interface film

1977

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“…The action of uncouplers alone or in the presence of other ionophores further emphasizes this point because they are without effect on the light-induced protonation changes in isolated purple membrane, at least in the concentrations used here . The action of these ionophores also strongly suggests that the light-driven proton translocation is an electrogenic process; a conclusion for which more direct evidence has already been published on similar model systems (Drachev, Jasaitis, Kaulen, Kondrashin, Liberman, Nemecek, Ostroumov, Semenov & Skulachev, 1974;Kayushin & Skulachev, 1974;Racker & Hinkle, 1974;Yaguzhinsky, Boguslavsky, Volkov & Rakhmaninova, 1976). The organization of bacteriorhodopsin in the vesicle wall is obviously a dominating factor determining the direction and extent of the light response.…”

Section: Discussionmentioning

confidence: 86%

Purple membrane vesicles: Morphology and proton translocation

Hwang

Stoeckenius

1977

J. Membrain Biol.

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Purple membrane vesicles prepared by different techniques differ widely in their morphology and ability to establish a proton gradient in the light. The procedures used to prepare active vesicles do not completely dissociate the purple membrane and thus preserve a preferential orientation of the protein, while most of the lipid is exchanged for added lipid. Responses to illumination are largely determined by the size of the vesicles and the degree to which bacteriorhodopsin is preferentially oriented. Any attempt to compare the interaction of different lipids with bacteriorhodopsin by measuring the pH response must take these factors into account. With an improved technique we have obtained vesicles of rather uniform size and bacteriorhodopsin orientation, which accumulate protons with an initial rate of 160 ng H+ sec-1 mg-1 protein at light intensities of 10(6) erg cm-2 sec-1. The kinetics of the process are complex and at present insufficiently understood.

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“…IA). This effect is due to H' pumping into liposomes by BR [21]. Relaxation of this response in the dark represents the passive dissipation of the H' gradient.…”

Section: Resultsmentioning

confidence: 99%

Ion permeability induced in artificial membranes by the ATP/ADP antiporter

et al. 1994

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The hypothesis on the additional function of the ATP/ADP antiporter (ANT) as uncoupling protein has been tested in proteoliposomes and planar bilayer phospholipid membranes (BLM). It is found that dissipation of the light-induced dpH in the dark is very much faster in ANT-bacteriorhodopsin proteoliposomes than in proteoliposomes containing bacteriorhodopsin as the only protein. Mersalyl treatment of ANT-bacteriorhodopsin proteoliposomes causes further increase in the dpH dissipation rate due to formation of a high conductance pore. The properties of this pore are studied on ANT incorporated to BLM. They proved to be similar to those of so-called multiple conductance channel or permeability transition pore of inner mitochondrial membrane. The conductance of the single channel is as high as 2.2 nS. The channel fails to discriminate between K', Na', H' and Cl-. Thus the obtained data are consistent with the assumption that native and modified ANT might function as an H'-specific conductor and as a permeability transition pore, respectively.

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Bacteriorhodopsin as an electrogenic proton pump: Reconstitution of bacteriorhodopsin proteoliposomes generating Δψ and ΔpH

Cited by 111 publications

References 12 publications

Proton transport by bacteriorhodopsin through an interface film

Proton transport by bacteriorhodopsin through an interface film

Purple membrane vesicles: Morphology and proton translocation

Ion permeability induced in artificial membranes by the ATP/ADP antiporter

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