51
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Nagel G, Kelety B, Möckel B, Büldt G, Bamberg E. Voltage dependence of proton pumping by bacteriorhodopsin is regulated by the voltage-sensitive ratio of M1 to M2. Biophys J 1998; 74:403-12. [PMID: 9449340 PMCID: PMC1299392 DOI: 10.1016/s0006-3495(98)77797-5] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The voltage dependence of light-induced proton pumping was studied with bacteriorhodopsin (bR) from Halobacterium salinarum, expressed in the plasma membrane of oocytes from Xenopus laevis in the range -160 mV to +60 mV at different light intensities. Depending on the applied field, the quenching effect by blue light, which bypasses the normal photo and transport cycle, is drastically increased at inhibiting (negative) potentials, and is diminished at pump current increasing (positive) potentials. At any potential, two processes with different time constants for the M --> bR decay of approximately 5 ms (tau1) and approximately 20 ms (tau2) are obtained. At pump-inhibiting potentials, a third, long-lasting process with tau3 approximately 300 ms at neutral pH is observed. The fast processes (tau1, tau2) can be assigned to the decay of M2 in the normal pump cycle, i.e., to the reprotonation of the Schiff base via the cytoplasmic side, whereas tau3 is due to the decay of M1 without net pumping, i.e., the reprotonation of the Schiff base via the extracellular side. The results are supported by determination of photocurrents induced by bR on planar lipid films. The pH dependence of the slow decay of M1 is fully in agreement with the interpretation that the reprotonation of the Schiff base occurs from the extracellular side. The results give strong evidence that an externally applied electrical field changes the ratio of the M1 and the M2 intermediate. As a consequence, the transport cycle branches into a nontransporting cycle at negative potentials. This interpretation explains the current-voltage behavior of bR on a new basis, but agrees with the isomerisation, switch, transfer model for vectorial transport.
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Affiliation(s)
- G Nagel
- Max-Planck-Institut für Biophysik, Frankfurt, Germany
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52
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Steinem C, Janshoff A, Höhn F, Sieber M, Galla HJ. Proton translocation across bacteriorhodopsin containing solid supported lipid bilayers. Chem Phys Lipids 1997. [DOI: 10.1016/s0009-3084(97)00071-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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53
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Tittor J, Haupts U, Haupts C, Oesterhelt D, Becker A, Bamberg E. Chloride and proton transport in bacteriorhodopsin mutant D85T: different modes of ion translocation in a retinal protein. J Mol Biol 1997; 271:405-16. [PMID: 9268668 DOI: 10.1006/jmbi.1997.1204] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Replacement of aspartate 85 (D85) in bacteriorhodopsin (BR) by threonine but not be asparagine creates at pH<7 an anion-binding site in the molecular similar to that in chloride pump halorhodopsin. Binding of various anions to BR-D85T causes a blue shift of the absorption maximum by maximally 57 nm. Connected to this color change is a change in the absorption difference spectrum of the initial state and the longest living photo intermediate from a positive difference maximum at 460 nm in the absence of transported anions to one at 630 nm in their presence. Increasing anion concentration cause decreasing decay times of this intermediate. At physiological pH, BR-D85T but not BR-D85N transports chloride ions inward in green light, protons outward in blue or green light and protons inward in white light (directions refer to the intact cell). The proton movements are observable also in BR-D85N. Thus, creation of an anion-binding site in BR is responsible for chloride transport and introduction of anion-dependent spectroscopic properties at physiological pH. The different transport modes are explained with the help of the recently proposed IST model, which states that after light-induced isomerization of the retinal an ion transfer step and an accessibility change of the active site follow. The latter two steps occur independently. In order to complete the cyclic event, the accessibility change, ion transfer and isomerization state have to be reversed. The relative rates of accessibility changes and ion transfer steps define ultimately the vectoriality of ion transfers. All transport modes described here for the same molecule can satisfactorily be described in the framework of this general concept.
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Affiliation(s)
- J Tittor
- Max-Planck-Institut für Biochemie, Martinsried, D82152, Germany
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54
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Molecular sensors based on the photoelectric effect of bacteriorhodopsin: Origin of differential responsivity. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 1997. [DOI: 10.1016/s0928-4931(97)00011-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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55
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Lipid bilayer formation in a microporous membrane filter monitored by ac impedance analysis and purple membrane photoresponses. J Electroanal Chem (Lausanne) 1996. [DOI: 10.1016/0022-0728(95)04307-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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56
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Ikematsu M, Sugiyama Y, Iseki M, Mizukami A. Time-dependent variation in a.c. impedance of lipid-impregnated membrane filters. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0302-4598(95)01803-m] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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57
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Analysis of the d.c. photoelectric signal from model bacteriorhodopsin membranes: d.c. photoconductivity determination by the null current method and the effect of proton ionophores. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0302-4598(95)05020-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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58
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Muneyuki E, Ikematsu M, Iseki M, Sugiyama Y, Mizukami A, Ohno K, Yoshida M, Hirata H. Direct transmembraneous reconstitution of bacteriorhodopsin into planar phospholipid bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1993. [DOI: 10.1016/0005-2728(93)90015-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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59
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Bamberg E, Butt HJ, Eisenrauch A, Fendler K. Charge transport of ion pumps on lipid bilayer membranes. Q Rev Biophys 1993; 26:1-25. [PMID: 7692462 DOI: 10.1017/s0033583500003942] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Ion pumps create ion gradients across cell membranes while consuming light energy or chemical energy. The ion gradients are used by the corresponding cell types for passive-ion transport via ion channels or carriers or for accumulation of nutrients like sugar or amino acids via cotransport systems or antiporters.
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Affiliation(s)
- E Bamberg
- Max-Planck-Institut für Biophysik, Frankfurt am Main, FRG
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60
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Oesterhelt D, Bräuchle C, Hampp N. Bacteriorhodopsin: a biological material for information processing. Q Rev Biophys 1991; 24:425-78. [PMID: 1784713 DOI: 10.1017/s0033583500003863] [Citation(s) in RCA: 135] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Technology which makes use of biological materials has advanced dramatically in the last few decades. Production of specific biochemicals by selected microbial strains, the use of enzymes for stereospecific biosynthesis of materials and gene technological production of biologically important macromolecules are a few examples of these developments.
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Affiliation(s)
- D Oesterhelt
- Max-Planck-Institute for Biochemistry, Martinsried, Germany
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61
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Jonas R, Koutalos Y, Ebrey TG. Purple membrane: surface charge density and the multiple effect of pH and cations. Photochem Photobiol 1990; 52:1163-77. [PMID: 2087503 DOI: 10.1111/j.1751-1097.1990.tb08455.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- R Jonas
- Department of Physiology and Biophysics, University of Illinois at Urbana-Champaign 61801
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62
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van der Hijden HT, Grell E, de Pont JJ, Bamberg E. Demonstration of the electrogenicity of proton translocation during the phosphorylation step in gastric H+K(+)-ATPase. J Membr Biol 1990; 114:245-56. [PMID: 2157846 DOI: 10.1007/bf01869218] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Membrane fragments containing the H+K(+)-ATPase from parietal cells have been adsorbed to a planar lipid membrane. The transport activity of the enzyme was determined by measuring electrical currents via the capacitive coupling between the membrane sheets and the planar lipid film. To initiate the pump currents by the ATPase a light-driven concentration jump of ATP from caged ATP was applied as demonstrated previously for Na+K(+)-ATPase (Fendler, K., Grell, E., Haubs, M., Bamberg, E. 1985. EMBO J. 4:3079-3085). Since H+K(+)-ATPase is an electroneutrally working enzyme no stationary pump currents were observed in the presence of K+. By separation of the H+ and K+ transport steps of the reaction cycle, however, the electrogenic step of the phosphorylation could be measured. This was achieved in the absence of K+ or at low concentrations of K+. The observed transient current is ATP dependent which can be assigned to the proton movement during the phosphorylation. From this it was concluded that the K+ transport during dephosphorylation is electrogenic, too, in contrast to the Na+K(+)-ATPase where the K+ step is electroneutral. The transient current was measured at different ionic conditions and could be blocked by vanadate and by the H+K(+)-ATPase specific inhibitor omeprazole. An alternative mechanism for activation of this inhibitor is discussed.
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63
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Butt HJ, Bamberg E, Oesterhelt D. Absorption- and photocurrent-measurements of two aspartat mutants of bacteriorhodopsin. JOURNAL OF PROTEIN CHEMISTRY 1989; 8:347-9. [PMID: 2789680 DOI: 10.1007/bf01674273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- H J Butt
- Max-Planck-Institut f. Biophysik, Frankfurt/M, FRG
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64
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Zundel G. Proton transfer in and proton polarizability of hydrogen bonds: IR and theoretical studies regarding mechanisms in biological systems. J Mol Struct 1988. [DOI: 10.1016/0022-2860(88)80078-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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65
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Gutman M, Nachliel E, Bamberg E, Christensen B. Time-resolved protonation dynamics of a black lipid membrane monitored by capacitative currents. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 905:390-8. [PMID: 2825785 DOI: 10.1016/0005-2736(87)90468-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The laser-induced proton pulse (Gutman, M. (1986) Methods Enzymol. 127, 522-538) was used for transient protonation of one side of a black lipid membrane. The charging of the membrane drives an electric (voltage or current) signal selectively representing the fast proton exchange at the membrane/electrolyte interface. The sensitivity of the electric signal to the presence of buffer indicates that proton transfer is measured, not some dyes or membrane photoelectric artifact. The same event can be visualized in an analogous system consisting of a pH indicator adsorbed to neutral detergent-phospholipid mixed micelles. The time-resolved light absorption transient is equivalent to the electrically determined transient charging of the membrane surface. The sensitivity of the current measurement exceeds the spectrophotometric method by 6-8 orders of magnitudes. As little as 10(-18) mol of H+ reacting with 0.75 mm2 of the membrane surface can be monitored in a time-resolved observation. Both types of observed transients were accurately reconstructed by the numerical solution of coupled, non-linear, differential equations describing the system. The rate constants of the various proton transfer reactions were calculated and found to be of diffusion controlled reactions. There is no evidence for any barrier at the interface which either prevents protons from reaching the membrane, or keeps proton on the interface. The electric measurements can be applied for monitoring proton transfer kinetics of complex biomembrane preparations.
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Affiliation(s)
- M Gutman
- Department of Biochemistry, Tel-Aviv University, Israel
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66
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Abstract
Purified Na+,K+-ATPase from pig kidney was attached to black lipid membranes. Pump currents of the enzyme could be measured with a time resolution of approx. 1 ms by releasing ATP from caged ATP with a UV laser flash. Analysis of the transient currents shows that a slow non-electrogenic step is followed by an electrogenic transition with a rate constant of 100 s-1 (22 degrees C). The exponential components found in the transient currents are compared to transitions in the Albers-Post scheme.
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Affiliation(s)
- K Fendler
- Max-Planck-Institut für Biophysik, Frankfurt am Main, FRG
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67
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Oesterhelt D, Marwan W. Change of membrane potential is not a component of the photophobic transduction chain in Halobacterium halobium. J Bacteriol 1987; 169:3515-20. [PMID: 3611021 PMCID: PMC212426 DOI: 10.1128/jb.169.8.3515-3520.1987] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Long (20 to 50 microns) and bipolarly flagellated cells of Halobacterium halobium were stimulated locally by a focused beam of light, and the photophobic response was analyzed. The results demonstrate that two flagellar bundles did not react in a coordinated fashion. The light-induced stop response of a flagellar bundle only occurred if the stimulus was applied within 5 microns of the polar region. This excluded membrane potential changes from being causally involved in photophobic signalling and indicated that there is a diffusible messenger in the signal transduction chain which is subjected to decay. In addition, the photoreceptor may be localized at the polar end of the cell.
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68
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Fendler K, Gärtner W, Oesterhelt D, Bamberg E. Electrogenic transport properties of bacteriorhodopsin containing chemically modified retinal analogues. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1987. [DOI: 10.1016/0005-2728(87)90148-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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69
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Nagel G, Fendler K, Grell E, Bamberg E. Na+ currents generated by the purified (Na+ + K+)-ATPase on planar lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 901:239-49. [PMID: 3038187 DOI: 10.1016/0005-2736(87)90120-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Purified (Na+ + K+)-ATPase from pig kidney was attached to black lipid membranes and ATP-induced electric currents were measured as described previously by Fendler et al. ((1985) EMBO J. 4, 3079-3085). An ATP concentration jump was produced by an ultraviolet-light flash converting non-hydrolysable caged ATP to ATP. In the presence of Na+ and Mg2+ this resulted in a transient current signal. The pump current was not only ATP dependent, but also was influenced by the ATP/caged ATP ratio. It was concluded that caged ATP binds to the enzyme (and hence inhibits the signal) with a Ki of approx. 30 microM, which was confirmed by enzymatic activity studies. An ATP affinity of approx. 2 microM was determined. The addition of the protonophore 1799 and the Me+/H+ exchanger monensin made the bilayer conductive leading to a stationary pump current. The stationary current was strongly increased by the addition of K+ with a K0.5 of 700 microM. Even in the absence of K+ a stationary current could be measured, which showed two Na+-affinities: a high-affinity (K0.5 less than or equal to 1 mM) and a low-affinity (K0.5 greater than or equal to 0.2 M). In order to explain the sustained electrogenic Na+ transport during the Na+-ATPase activity, it is proposed, that Na+ can replace K+ in dephosphorylating the enzyme, but binds about 1000-times weaker than K+. The ATP requirement of the Na+-ATPase was the same (K0.5 = 2 microM) with regard to the peak currents and the stationary currents. However, for the (Na+ + K+)-ATPase the stationary currents required more ATP. The results are discussed on the basis of the Albers-Post scheme.
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70
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Hartung K, Grell E, Hasselbach W, Bamberg E. Electrical pump currents generated by the Ca2+-ATPase of sarcoplasmic reticulum vesicles adsorbed on black lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 900:209-20. [PMID: 2954585 DOI: 10.1016/0005-2736(87)90335-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Sarcoplasmic reticulum vesicles adsorbed on a black lipid membrane generate an electrical current after a fast increment of the concentration of ATP. This demonstrates directly that the sarcoplasmic Ca2+-ATPase from skeletal muscle acts as an electrogenic ion pump. The increment of the concentration of ATP is achieved by the photolysis of caged ATP (P3-1-(2-nitro)phenylethyl adenosine 5'-triphosphate) a protected analogue of ATP (Kaplan, J.H. et al. (1978) Biochemistry 17, 1929-1935), which is split into ATP and 2-nitroso acetophenone. The release of ATP leads to a transient current flow across the lipid membrane indicating that the vesicles are capacitatively coupled to the underlying lipid membrane. In addition to this transient signal, a stationary current flow is obtained in the presence of ionophores which increase the conductance of the bilayer system and prevent the accumulation of Ca2+ in the lumen of the vesicles. The direction of the transient and the stationary current is in accordance with the concept that Ca2+ is pumped into the lumen of the vesicles. The transient current depends on the concentration of ATP, Ca2+ and Mg2+ as would be the case for a current generated by the sarcoplasmic Ca2+-ATPase. Its amplitude is half-maximal at 10 microM ATP and 1 microM Ca2+. At Ca2+ concentrations above 0.1 mM the amplitude of the current signal declines again. The Mg2+ concentration dependence of the current amplitude at a constant ATP concentration indicates that the MgATP complex is the substrate for the activation of the current. The pump current is inhibited by vanadate and ADP. No current signal is observed if caged ATP is replaced by caged ADP. However, the release of ADP from caged ADP generates a pump current in the presence of an ATP generating system such as creatine phosphate and creatine kinase.
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71
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The effect of trypsin treatment on the incorporation and energy-transducing properties of bacteriorhodopsin in liposomes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1987. [DOI: 10.1016/0005-2728(87)90009-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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72
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Vodyanoy I, Vodyanoy V, Lanyi JK. Current-voltage characteristics of planar lipid membranes with attached Halobacterium cell-envelope vesicles. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 858:92-8. [PMID: 3707964 DOI: 10.1016/0005-2736(86)90294-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We have studied the photoactivity of a system consisting of large, planar, essentially solvent free bilayers bearing adsorbed cell-envelope vesicles prepared from Halobacterium halobium (strain L 33). The system was made conductive by addition of a proton carrier (SF-6847). We observed photocurrents which were linearly dependent upon transmembrane voltage. Current-voltage curves were found to be well described by an equivalent circuit with the following significant parameters: planar bilayer conductance, planar bilayer-vesicle contact area conductance, cell-envelope vesicle conductance, and chloride pump equivalent voltage-generator potential. These parameters are uniquely obtained as a result of a few independent current measurements. The stationary photovoltage was dependent upon chloride concentration, and from this dependence an active transport (pump) affinity of the system for chloride was calculated to be about 50 mM.
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73
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Darszon A. Planar bilayers: a powerful tool to study membrane proteins involved in ion transport. Methods Enzymol 1986; 127:486-502. [PMID: 2426561 DOI: 10.1016/0076-6879(86)27039-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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74
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Läuger P. Mechanismen des biologischen Ionentransports – Carrier, Kanäle und Pumpen in künstlichen Lipidmembranen. Angew Chem Int Ed Engl 1985. [DOI: 10.1002/ange.19850971107] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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75
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The transport activity of the light-driven chloride pump halorhodopsin is regulated by green and blue light. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 1985. [DOI: 10.1016/0005-2736(85)90174-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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76
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Dér A, Hargittai P, Simon J. Time-resolved photoelectric and absorption signals from oriented purple membranes immobilized in gel. JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS 1985; 10:295-300. [PMID: 3998383 DOI: 10.1016/0165-022x(85)90063-6] [Citation(s) in RCA: 99] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Kinetics of photoelectric and absorption response signals were measured on samples containing oriented purple membranes immobilized in polyacrylamide gel. The orientation and aggregation states of purple membranes remain constant independently of pH and ionic strength in such samples and the gel does not influence the proton pump. The 'gel method' described in this study enables direct investigation of proton pump of bacteriorhodopsin and a simultaneous measurement of absorption signals within a wide range of parameters of the solution surrounding purple membranes and offers possibilities for study of other types of membranes as well.
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77
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Läuger P. Thermodynamic and kinetic properties of electrogenic ion pumps. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 779:307-41. [PMID: 6089889 DOI: 10.1016/0304-4157(84)90015-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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78
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Reconstitution of the light-driven electrogenic ion pump halorhodopsin in black lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 1984. [DOI: 10.1016/0005-2736(84)90549-2] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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79
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A study of bacteriorhodopsin-containing proteoliposome incorporation into bimolecular lipid membranes. ACTA ACUST UNITED AC 1983. [DOI: 10.1016/0302-4598(83)90029-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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80
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Darszon A. Strategies in the reassembly of membrane proteins into lipid bilayer systems and their functional assay. J Bioenerg Biomembr 1983; 15:321-34. [DOI: 10.1007/bf00751053] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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81
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Kinetic analysis of bacterial reaction centers reconstituted in lipid bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1983. [DOI: 10.1016/0005-2728(83)90145-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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82
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Abdulaev NG, Dencher NA, Dergachev AE, Fahr A, Kiselev AV. The chromophore retinal in bacteriorhodopsin does not change its attachment site, lysine 216, during proton translocation and light-dark adaptation. ACTA ACUST UNITED AC 1983. [DOI: 10.1007/bf00535550] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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83
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84
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Mirsky V, Sokolov V, Dyukova T, Melnik E. A study of bacteriorhodopsin-containing proteoliposome incorporation into bimolecular lipid membranes. J Electroanal Chem (Lausanne) 1983. [DOI: 10.1016/s0022-0728(83)80684-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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85
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Tien H. 521—Light-induced redox reactions in pigmented BLM. J Electroanal Chem (Lausanne) 1982. [DOI: 10.1016/0022-0728(82)85229-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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86
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Bienvenue E, Seta P, Gavach C. Reversal of the proton photopumping through bacteriorhodopsin under an applied voltage. J Electroanal Chem (Lausanne) 1982. [DOI: 10.1016/0368-1874(82)85317-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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87
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88
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Nystatin-induced increase in photocurrent in the system ‘bacteriorhodopsin proteoliposome/bilayer planar membrane’. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1982. [DOI: 10.1016/0005-2728(82)90037-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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89
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Läuger P, Benz R, Stark G, Bamberg E, Jordan PC, Fahr A, Brock W. Relaxation studies of ion transport systems in lipid bilayer membranes. Q Rev Biophys 1981; 14:513-98. [PMID: 6275448 DOI: 10.1017/s003358350000247x] [Citation(s) in RCA: 151] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Relaxation techniques have been widely used in kinetic studies of chemical reactions in homogeneous solution (Eigen & DeMayer, 1963). The principle of this method is well known: an external variable such as temperature or pressure is suddenly changed and the time course of a state parameter of the system such as concentration is recorded as it approaches a new steady value. Relaxation techniques can also be used for studying the rate of elementary processes in membranes. This method has proved particularly useful for the investigation of ion transport systems (ion carriers, channels, pumps) in artificial planar bilayer membranes. In this review we describe different relaxation techniques which have been developed for this purpose during the last years, as well as applications to a number of ion transport systems.
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Montal M, Darszon A, Schindler H. Functional reassembly of membrane proteins in planar lipid bilayers. Q Rev Biophys 1981; 14:1-79. [PMID: 6269143 DOI: 10.1017/s0033583500002079] [Citation(s) in RCA: 102] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Recent progress in membrane biology has brought us to a stage where it is possible to associate complex biological processes to identifiable membrane proteins. Technical advances in the biochemical characterization and purification of membrane proteins have contributed a wealth of structural information. The reconstitution approach has proved to be valuable in our efforts to understand the molecular mechanisms of membrane transport and energy transduction.
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92
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Bamberg E, Fahr A. Photocurrents induced on black lipid membranes by purple membranes: a method of reconstitution and a kinetic study of the photocurrents. Ann N Y Acad Sci 1980; 358:324-7. [PMID: 6938152 DOI: 10.1111/j.1749-6632.1980.tb15405.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Seta P, Ormos P, d'Epenoux B, Gavach C. Photocurrent response of bacteriorhodopsin adsorbed on bimolecular lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 591:37-52. [PMID: 7388016 DOI: 10.1016/0005-2728(80)90218-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The photo response of bacteriorhodopsin adsorbed on a bimolecular lipid membrane has been investigated using short-circuit current measurements. The results revealed a biphasic current vs. time curve for the photocurrent at pH values of approx. 7. This phenomenon could be modified by altering either the value of the external applied electrical field or the proton concentration differences. The observed effects of the external applied voltage, pH gradient and lipophilic proton carriers enabled us to conclude that the bacteriorhodopsin can be adsorbed in two different states, which give rise to a pumping effect and a flux of protons in opposite directions. A theoretical analysis of the photocycle in relation to the electrical field which acts on the proton uptake and release is proposed. The main effect of this field is to diminish the pumping rate due to the proton motive force resulting from the creation of space-charge in the vicinity of purple membrane fragments.
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Abstract
Purple membrane framents from Halobacterium halobium were oriented by a static electric field in a water suspension. It was found that an electric field of approx. 20 V/cm is sufficient to achieve practically complete orientation; the purple membranes have a permanent electric dipole moment of (6 +/- 1) . 10(-23) C . m, the orientation of the retinal transition moment relative to the direction of the electric dipole moment, theta, is (59 +/- 1)0, and the purple membrane rotational diffusion constant Drot = 0.65 s-1. It was found that because of the electrophoretic movement of the particles a hydrodynamic velocity gradient builds up which also orients the purple membranes.
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