TY - JOUR
T1 - Electrophotoluminescence and the electrical properties of the photosynthetic membrane. II. Electric field-induced electrical breakdown of the photosynthetic membrane and its recovery
AU - Farkas, Daniel L.
AU - Malkin, Shmuel
AU - Korenstein, Rafi
N1 - Funding Information:
This project was supported in part by the U.S.-Israel Binational Science Foundation.
PY - 1984/12/18
Y1 - 1984/12/18
N2 - Preilluminated suspensions of swollen thylakoid vesicles ('blebs') were exposed to uni- and bipolar pairs of identical electric field pulses of variable duration, intensity and spacing. The resulting field-stimulated luminescence (electrophotoluminescence) was used as an intrinsic, voltage-sensitive optical probe to monitor electrical phenomena at the membrane level. The application of a pair of voltage pulses of opposite polarity made it possible to produce electric changes in the membrane by the first pulse and to analyse these effects by a second pulse of opposite polarity. It was found that the relative amplitudes of the two electrophoto-luminescence signals depended on the intensity of the applied electric field and on the time interval (t*) between the two pulses. When t* varied from 0.4 to 12 ms, the second stimulated luminescence signal was at first much smaller than the first one and then increased exponentially until the two signals were equal for t* ≥ 3 ms. We analysed these differences between the two field-stimulated luminescence signals as a measure of the electrical breakdown of the membrane, induced during the first pulse. In this way a distinction between irreversible and reversible breakdown could be made with an estimation of the recovery kinetics of the reversible breakdown, which was found to be complete within 3 ms. Irreversible breakdown of the membrane was found to increase with lengthening the exposure time from 0.1 to 1.3 ms especially when applying high electric field of at least 2000 V/cm.
AB - Preilluminated suspensions of swollen thylakoid vesicles ('blebs') were exposed to uni- and bipolar pairs of identical electric field pulses of variable duration, intensity and spacing. The resulting field-stimulated luminescence (electrophotoluminescence) was used as an intrinsic, voltage-sensitive optical probe to monitor electrical phenomena at the membrane level. The application of a pair of voltage pulses of opposite polarity made it possible to produce electric changes in the membrane by the first pulse and to analyse these effects by a second pulse of opposite polarity. It was found that the relative amplitudes of the two electrophoto-luminescence signals depended on the intensity of the applied electric field and on the time interval (t*) between the two pulses. When t* varied from 0.4 to 12 ms, the second stimulated luminescence signal was at first much smaller than the first one and then increased exponentially until the two signals were equal for t* ≥ 3 ms. We analysed these differences between the two field-stimulated luminescence signals as a measure of the electrical breakdown of the membrane, induced during the first pulse. In this way a distinction between irreversible and reversible breakdown could be made with an estimation of the recovery kinetics of the reversible breakdown, which was found to be complete within 3 ms. Irreversible breakdown of the membrane was found to increase with lengthening the exposure time from 0.1 to 1.3 ms especially when applying high electric field of at least 2000 V/cm.
KW - (Pea, spinach, lettuce chloroplast)
KW - Electric field effect
KW - Electrophotoluminescence
KW - Luminescence
KW - Thylakoid vesicle
UR - http://www.scopus.com/inward/record.url?scp=12444345750&partnerID=8YFLogxK
U2 - 10.1016/0005-2728(84)90049-5
DO - 10.1016/0005-2728(84)90049-5
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AN - SCOPUS:12444345750
VL - 767
SP - 507
EP - 514
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
SN - 0005-2728
IS - 3
ER -