A novel method for measuring membrane conductance changes by a voltage‐sensitive optical probe

Rosemberg, Yosef; Korenstein, Rafi

doi:10.1016/0014-5793(90)80727-z

Cited by 5 publications

(4 citation statements)

References 15 publications

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“…We attribute the attenuation in the second EPL signal to a transient change in membrane conductance due to a reversible electric breakdown which takes place during and after the first pulse. To translate the relative attenuation of the EPL signal into a conductance change we used the same strategy whose principles enabled us to measure ionomycin-mediated conductivity changes (Rosemberg and Korenstein, 1990). The EPL signal is an explicit function of the electric field induced in the membrane rather than of membrane conductance itself.…”

Section: Study By Electrophotoluminescencementioning

confidence: 99%

Electroporation of the photosynthetic membrane

Rosemberg

Korenstein

1990

Biophysical Journal

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The study examines the relationship between electric field-induced conductivity and permeability changes in a biological membrane (electroporation) and the amplitude-duration parameters of the externally applied electric field. These reversible changes were characterized in giant photosynthetic membrane vesicles by means of the calibrated response of an intrinsic voltage-sensitive optical probe (electrophotoluminescence) and by the uptake studies of dextran-FITC fluorescent probes of different molecular weights. We quantitatively monitored electric field-induced conductivity changes by translating the electrophotoluminescence changes into conductivity changes. This was carried out by measuring the attenuation of the electrophotoluminescent signal after the addition of known amounts of gramicidin. The results demonstrate that electroporation involves the reversible formation of discrete holes in the membrane having radii <5.8 nm. The total area of the electric field-induced holes was 0.075% of the total surface of the vesicle. The formation of the electropores was affected differently by the electric field strength than by its duration. Increase in electric field strength caused increase in the total area of the vesicle that undergoes electroporation. Increase in the duration of the electric field increases the area of single electropores. Each of the two electric parameters can be rate limiting for the dynamics of electropore formation. These results are in accordance with the model of electroporation based on electric field-induced expansion of transient aqueous holes.

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Section: Study By Electrophotoluminescencementioning

confidence: 99%

Electroporation of the photosynthetic membrane

Rosemberg

Korenstein

1990

Biophysical Journal

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“…The local membrane potential becomes 3 Vm = ~ E R cos0 and is built up with exponential kinetics with a time constant 3 7------~ pCm_/:~ where p is the specific resistance of the internal and external media and Cm the specific capacitance of the membrane (de Grooth et al 1980a). to investigate ionophore-mediated ion transfer across the membrane (Farkas et al 1982;Rosemberg and Korenstein 1990a), the equations are given by Farkas et al (1984a). For applications requiring separate treatment of the conductivities of internal and external media or a non-negligible conductivity of the membrane, e.g.…”

Section: Electric Field-induced Membrane Potentialmentioning

confidence: 99%

Electroluminescence

Gorkom

1996

Photosynth Res

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An overview is presented of research based on the observation by Arnold and Azzi (1971) (Photochem Photobiol 14: 233-240), that an electric field induces charge-recombination luminescence in a suspension of photosynthetic membrane vesicles. The 'electroluminescence' signals from Photosystems I and II are discussed in relation to the shape of the vesicles and the membrane potentials generated by the externally applied electric field. The use of the electroluminescence amplitude as a probe to study the kinetics and energetics of charge separation, and of its kinetics to monitor the electric-field induced charge recombination process are reviewed. Currently unresolved issues regarding the emission yield of electroluminescence are briefly discussed and the properties are summarized of the unexplained Photosystem II luminescence which is not sensitive to the membrane potential.

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“…The study of EPL revealed some thermodynamic features of electron transport in PS I and PS H (van Gorkom et al, 1986;Vos andVan Gorkom, 1988, 1990) and established the electrophoretic and diffusional mobilities of PS I in the photosynthetic membrane (Brumfeld et al, 1989). Moreover, by using the EPL as an intrinsic voltage-sensitive optical probe, the electrical properties of the photosynthetic membrane were examined (Farkas et al, 1984a), electroporation characteristics of the photosynthetic membrane were explored (Farkas et al, 1984b;Korenstein et al, 1984;Rosemberg and Korenstein, 1990b) and ionophore-mediated ion ransport was studied (Farkas et al, 1982;Rosemberg and Korenstein, 1990a The present study employs the unique features of the EPL, which depend both on photosynthetic activity and on the conductance of the photosynthetic membrane, to elucidate stctural changes both in protein and the lipid-protein domains imposed by high electric fields.…”

Section: Introductionmentioning

confidence: 99%

Electroporation of the photosynthetic membrane: structural changes in protein and lipid-protein domains

Rosemberg

Rotenberg

Korenstein

1994

Biophysical Journal

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A biological membrane undergoes a reversible permeability increase through structural changes in the lipid domain when exposed to high external electric fields. The present study shows the occurrence of electric field-induced changes in the conductance of the proton channel of the H(+)-ATPase as well as electric field-induced structural changes in the lipid-protein domain of photosystem (PS) II in the photosynthetic membrane. The study was carried out by analyzing the electric field-stimulated delayed luminescence (EPL), which originates from charge recombination in the protein complexes of PS I and II of photosynthetic vesicles. We established that a small fraction of the total electric field-induced conductance change was abolished by N,N'-dicyclohexylcarbodiimide (DCCD), an inhibitor of the H(+)-ATPase. This reversible electric field-induced conductance change has characteristics of a small channel and possesses a lifetime < or = 1 ms. To detect electric field-induced changes in the lipid-protein domains of PS II, we examined the effects of phospholipase A2 (PLA2) on EPL. Higher values of EPL were observed from vesicles that were exposed in the presence of PLA2 to an electroporating electric field than to a nonelectroporating electric field. The effect of the electroporating field was a long-lived one, lasting for a period > or = 2 min. This effect was attributed to long-lived electric field-induced structural changes in the lipid-protein domains of PS II.

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A novel method for measuring membrane conductance changes by a voltage‐sensitive optical probe

Cited by 5 publications

References 15 publications

Electroporation of the photosynthetic membrane

Electroporation of the photosynthetic membrane

Electroluminescence

Electroporation of the photosynthetic membrane: structural changes in protein and lipid-protein domains

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