Emulsion photobioelectrochemistry: Bacteriorhodopsin phototransfer of protons through the water/lipid interface

M. I. Gugeshashvili, V. I. Portnov, A. G. Volkov, L. N. Chekulaeva, V. S. Markin

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Lipid inserted at a water/oil interface has been used as a model of biological membranes. The phototransfer of protons from water into octane by bacteriorhodopsin immobilized in an oil-in-water emulsion, containing phospholipids in octane and inorganic salt in water, was investigated. During irradiation by visible light, a reversible alkalinization of the water phase was detected. The effect was not inhibited by uncouplers. The means of natural immobilization of bacteriorhodopsin at the water/lipid interface has been examined, and it was shown that the action spectrum of the reaction is the same as that of light absorption by bacteriorhodopsin. It has been shown that bacteriorhodopsin can perform the direct light-dependent transfer of protons from water into octane. This rules out the formation of trilaminary structures, with a cavity localized between a bacteriorhodopsin sheet and the lipid monolayer (so-called "third" water). The phototransfer of protons (H+) induces the transport of anions (X-) from water into octane as H+ X- ionic pairs. Valinomycin was shown to be an effective inhibitor of light-induced change of pH in the emulsion. A mathematical model of bacteriorhodopsin functioning at the interface is proposed. This model explains the experimentally observed dependence of the pH shift as a function of chemical composition of the medium and concentration of salt, and the different pH relaxation rates both in the dark, and under illumination. The model also describes the dependence of the photoeffect on light intensity. The emulsion enzymology allows the examination of naturally immobilized membrane enzymes in conditions close to those found in native systems.

Original languageEnglish (US)
Pages (from-to)139-158
Number of pages20
JournalBioelectrochemistry and Bioenergetics
Volume26
Issue number2
DOIs
StatePublished - 1991

Fingerprint

Bacteriorhodopsins
Emulsions
Lipids
emulsions
lipids
Protons
protons
Water
octanes
water
Light
enzymology
Oils
Salts
oils
membranes
salts
Biological membranes
Valinomycin
Biological Models

ASJC Scopus subject areas

  • Biochemistry

Cite this

Emulsion photobioelectrochemistry : Bacteriorhodopsin phototransfer of protons through the water/lipid interface. / Gugeshashvili, M. I.; Portnov, V. I.; Volkov, A. G.; Chekulaeva, L. N.; Markin, V. S.

In: Bioelectrochemistry and Bioenergetics, Vol. 26, No. 2, 1991, p. 139-158.

Research output: Contribution to journalArticle

Gugeshashvili, M. I. ; Portnov, V. I. ; Volkov, A. G. ; Chekulaeva, L. N. ; Markin, V. S. / Emulsion photobioelectrochemistry : Bacteriorhodopsin phototransfer of protons through the water/lipid interface. In: Bioelectrochemistry and Bioenergetics. 1991 ; Vol. 26, No. 2. pp. 139-158.
@article{3a424aa77e5c444e903919980e0e9874,
title = "Emulsion photobioelectrochemistry: Bacteriorhodopsin phototransfer of protons through the water/lipid interface",
abstract = "Lipid inserted at a water/oil interface has been used as a model of biological membranes. The phototransfer of protons from water into octane by bacteriorhodopsin immobilized in an oil-in-water emulsion, containing phospholipids in octane and inorganic salt in water, was investigated. During irradiation by visible light, a reversible alkalinization of the water phase was detected. The effect was not inhibited by uncouplers. The means of natural immobilization of bacteriorhodopsin at the water/lipid interface has been examined, and it was shown that the action spectrum of the reaction is the same as that of light absorption by bacteriorhodopsin. It has been shown that bacteriorhodopsin can perform the direct light-dependent transfer of protons from water into octane. This rules out the formation of trilaminary structures, with a cavity localized between a bacteriorhodopsin sheet and the lipid monolayer (so-called {"}third{"} water). The phototransfer of protons (H+) induces the transport of anions (X-) from water into octane as H+ X- ionic pairs. Valinomycin was shown to be an effective inhibitor of light-induced change of pH in the emulsion. A mathematical model of bacteriorhodopsin functioning at the interface is proposed. This model explains the experimentally observed dependence of the pH shift as a function of chemical composition of the medium and concentration of salt, and the different pH relaxation rates both in the dark, and under illumination. The model also describes the dependence of the photoeffect on light intensity. The emulsion enzymology allows the examination of naturally immobilized membrane enzymes in conditions close to those found in native systems.",
author = "Gugeshashvili, {M. I.} and Portnov, {V. I.} and Volkov, {A. G.} and Chekulaeva, {L. N.} and Markin, {V. S.}",
year = "1991",
doi = "10.1016/0302-4598(91)80019-Y",
language = "English (US)",
volume = "26",
pages = "139--158",
journal = "Bioelectrochemistry",
issn = "1567-5394",
publisher = "Elsevier",
number = "2",

}

TY - JOUR

T1 - Emulsion photobioelectrochemistry

T2 - Bacteriorhodopsin phototransfer of protons through the water/lipid interface

AU - Gugeshashvili, M. I.

AU - Portnov, V. I.

AU - Volkov, A. G.

AU - Chekulaeva, L. N.

AU - Markin, V. S.

PY - 1991

Y1 - 1991

N2 - Lipid inserted at a water/oil interface has been used as a model of biological membranes. The phototransfer of protons from water into octane by bacteriorhodopsin immobilized in an oil-in-water emulsion, containing phospholipids in octane and inorganic salt in water, was investigated. During irradiation by visible light, a reversible alkalinization of the water phase was detected. The effect was not inhibited by uncouplers. The means of natural immobilization of bacteriorhodopsin at the water/lipid interface has been examined, and it was shown that the action spectrum of the reaction is the same as that of light absorption by bacteriorhodopsin. It has been shown that bacteriorhodopsin can perform the direct light-dependent transfer of protons from water into octane. This rules out the formation of trilaminary structures, with a cavity localized between a bacteriorhodopsin sheet and the lipid monolayer (so-called "third" water). The phototransfer of protons (H+) induces the transport of anions (X-) from water into octane as H+ X- ionic pairs. Valinomycin was shown to be an effective inhibitor of light-induced change of pH in the emulsion. A mathematical model of bacteriorhodopsin functioning at the interface is proposed. This model explains the experimentally observed dependence of the pH shift as a function of chemical composition of the medium and concentration of salt, and the different pH relaxation rates both in the dark, and under illumination. The model also describes the dependence of the photoeffect on light intensity. The emulsion enzymology allows the examination of naturally immobilized membrane enzymes in conditions close to those found in native systems.

AB - Lipid inserted at a water/oil interface has been used as a model of biological membranes. The phototransfer of protons from water into octane by bacteriorhodopsin immobilized in an oil-in-water emulsion, containing phospholipids in octane and inorganic salt in water, was investigated. During irradiation by visible light, a reversible alkalinization of the water phase was detected. The effect was not inhibited by uncouplers. The means of natural immobilization of bacteriorhodopsin at the water/lipid interface has been examined, and it was shown that the action spectrum of the reaction is the same as that of light absorption by bacteriorhodopsin. It has been shown that bacteriorhodopsin can perform the direct light-dependent transfer of protons from water into octane. This rules out the formation of trilaminary structures, with a cavity localized between a bacteriorhodopsin sheet and the lipid monolayer (so-called "third" water). The phototransfer of protons (H+) induces the transport of anions (X-) from water into octane as H+ X- ionic pairs. Valinomycin was shown to be an effective inhibitor of light-induced change of pH in the emulsion. A mathematical model of bacteriorhodopsin functioning at the interface is proposed. This model explains the experimentally observed dependence of the pH shift as a function of chemical composition of the medium and concentration of salt, and the different pH relaxation rates both in the dark, and under illumination. The model also describes the dependence of the photoeffect on light intensity. The emulsion enzymology allows the examination of naturally immobilized membrane enzymes in conditions close to those found in native systems.

UR - http://www.scopus.com/inward/record.url?scp=0041711858&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0041711858&partnerID=8YFLogxK

U2 - 10.1016/0302-4598(91)80019-Y

DO - 10.1016/0302-4598(91)80019-Y

M3 - Article

AN - SCOPUS:0041711858

VL - 26

SP - 139

EP - 158

JO - Bioelectrochemistry

JF - Bioelectrochemistry

SN - 1567-5394

IS - 2

ER -