Charge displacements during the photocycle of halorhodopsin

A. Dér, Sándor Száraz, Lajos Keszthelyi

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Halorhodopsin (hR)-containing, tween-washed membrane fragments were oriented by an electric field and immobilized in a polyacrylamide gel. Using this preparation, the photoelectric response of hR under various conditions was measured with a time resolution of 0.5 μs. At NACl or Na2SO4 concentrations below 25 mM a strong reduction of the signal was observed accompanied by bleaching of the sample. At 50 mM Cl-, four exponential components were distinguished with lifetimes of 0.5μs, 2 μs, 0.6 ms and 4 ms. The faster three components did not show a [Cl-] dependence. However, the slowest component only appeared in the presence of Cl-. We tentatively assign the fastest, non-resolved part of the signal (0.5 μs) to the primary charge separation in hR, and the two subsequent components (2 μs, 0.6 ms) to the relaxation of the dipole created in the first process. The additional component (4 ms), which only appears in the presence of Cl-, probably reflects the transport of Cl- ions. For comparison, an optical investigation was performed on the same membranes as used for the electric measurements. An approximate correlation between electric and optical signals was established.

Original languageEnglish
Pages (from-to)299-306
Number of pages8
JournalJournal of Photochemistry and Photobiology, B: Biology
Volume15
Issue number4
DOIs
Publication statusPublished - Sep 15 1992

Fingerprint

Halorhodopsins
ion transport
electric field
polyacrylamide
bleaching
Electric variables measurement
gels
Membranes
Bleaching
Polyacrylates
Gels
Polysorbates
Ion Transport
Electric fields
sampling
Ions
membranes
polarization (charge separation)
optical communication
fragments

Keywords

  • chloride transport.
  • Halorhodopsin
  • photocurrent
  • photocycle

ASJC Scopus subject areas

  • Plant Science
  • Bioengineering
  • Physical and Theoretical Chemistry

Cite this

Charge displacements during the photocycle of halorhodopsin. / Dér, A.; Száraz, Sándor; Keszthelyi, Lajos.

In: Journal of Photochemistry and Photobiology, B: Biology, Vol. 15, No. 4, 15.09.1992, p. 299-306.

Research output: Contribution to journalArticle

Dér, A. ; Száraz, Sándor ; Keszthelyi, Lajos. / Charge displacements during the photocycle of halorhodopsin. In: Journal of Photochemistry and Photobiology, B: Biology. 1992 ; Vol. 15, No. 4. pp. 299-306.
@article{b43b273804c9427cba59a24e3d90e953,
title = "Charge displacements during the photocycle of halorhodopsin",
abstract = "Halorhodopsin (hR)-containing, tween-washed membrane fragments were oriented by an electric field and immobilized in a polyacrylamide gel. Using this preparation, the photoelectric response of hR under various conditions was measured with a time resolution of 0.5 μs. At NACl or Na2SO4 concentrations below 25 mM a strong reduction of the signal was observed accompanied by bleaching of the sample. At 50 mM Cl-, four exponential components were distinguished with lifetimes of 0.5μs, 2 μs, 0.6 ms and 4 ms. The faster three components did not show a [Cl-] dependence. However, the slowest component only appeared in the presence of Cl-. We tentatively assign the fastest, non-resolved part of the signal (0.5 μs) to the primary charge separation in hR, and the two subsequent components (2 μs, 0.6 ms) to the relaxation of the dipole created in the first process. The additional component (4 ms), which only appears in the presence of Cl-, probably reflects the transport of Cl- ions. For comparison, an optical investigation was performed on the same membranes as used for the electric measurements. An approximate correlation between electric and optical signals was established.",
keywords = "chloride transport., Halorhodopsin, photocurrent, photocycle",
author = "A. D{\'e}r and S{\'a}ndor Sz{\'a}raz and Lajos Keszthelyi",
year = "1992",
month = "9",
day = "15",
doi = "10.1016/1011-1344(92)85136-I",
language = "English",
volume = "15",
pages = "299--306",
journal = "Journal of Photochemistry and Photobiology B: Biology",
issn = "1011-1344",
publisher = "Elsevier",
number = "4",

}

TY - JOUR

T1 - Charge displacements during the photocycle of halorhodopsin

AU - Dér, A.

AU - Száraz, Sándor

AU - Keszthelyi, Lajos

PY - 1992/9/15

Y1 - 1992/9/15

N2 - Halorhodopsin (hR)-containing, tween-washed membrane fragments were oriented by an electric field and immobilized in a polyacrylamide gel. Using this preparation, the photoelectric response of hR under various conditions was measured with a time resolution of 0.5 μs. At NACl or Na2SO4 concentrations below 25 mM a strong reduction of the signal was observed accompanied by bleaching of the sample. At 50 mM Cl-, four exponential components were distinguished with lifetimes of 0.5μs, 2 μs, 0.6 ms and 4 ms. The faster three components did not show a [Cl-] dependence. However, the slowest component only appeared in the presence of Cl-. We tentatively assign the fastest, non-resolved part of the signal (0.5 μs) to the primary charge separation in hR, and the two subsequent components (2 μs, 0.6 ms) to the relaxation of the dipole created in the first process. The additional component (4 ms), which only appears in the presence of Cl-, probably reflects the transport of Cl- ions. For comparison, an optical investigation was performed on the same membranes as used for the electric measurements. An approximate correlation between electric and optical signals was established.

AB - Halorhodopsin (hR)-containing, tween-washed membrane fragments were oriented by an electric field and immobilized in a polyacrylamide gel. Using this preparation, the photoelectric response of hR under various conditions was measured with a time resolution of 0.5 μs. At NACl or Na2SO4 concentrations below 25 mM a strong reduction of the signal was observed accompanied by bleaching of the sample. At 50 mM Cl-, four exponential components were distinguished with lifetimes of 0.5μs, 2 μs, 0.6 ms and 4 ms. The faster three components did not show a [Cl-] dependence. However, the slowest component only appeared in the presence of Cl-. We tentatively assign the fastest, non-resolved part of the signal (0.5 μs) to the primary charge separation in hR, and the two subsequent components (2 μs, 0.6 ms) to the relaxation of the dipole created in the first process. The additional component (4 ms), which only appears in the presence of Cl-, probably reflects the transport of Cl- ions. For comparison, an optical investigation was performed on the same membranes as used for the electric measurements. An approximate correlation between electric and optical signals was established.

KW - chloride transport.

KW - Halorhodopsin

KW - photocurrent

KW - photocycle

UR - http://www.scopus.com/inward/record.url?scp=0026709294&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026709294&partnerID=8YFLogxK

U2 - 10.1016/1011-1344(92)85136-I

DO - 10.1016/1011-1344(92)85136-I

M3 - Article

AN - SCOPUS:0026709294

VL - 15

SP - 299

EP - 306

JO - Journal of Photochemistry and Photobiology B: Biology

JF - Journal of Photochemistry and Photobiology B: Biology

SN - 1011-1344

IS - 4

ER -