Oxygen permeability of thylakoid membranes: Electron paramagnetic resonance spin labeling study

Agnieszka Ligeza, Alexander N. Tikhonov, James S. Hyde, Witold K. Subczynski

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

Oxygen transport in thylakoid membranes of spinach chloroplasts (Spinacia oleracea) has been studied by observing the collisions of molecular oxygen with spin labels, using line broadening electron paramagnetic resonance (EPR) spectroscopy. Stearic acid spin labels were used to probe the local oxygen diffusion-concentration product. The free radical moiety was located at various distances from the membrane surface, and collision rates were estimated from linewidths of the EPR spectra measured in the presence and absence of molecular oxygen. The profile of the local oxygen diffusion-concentration product across the membrane determined at 20°C demonstrates that this product, at all membrane locations, is higher than the value measured in water. From the profile of the oxygen diffusion-concentration product, the membrane oxygen permeability coefficient has been estimated using the procedure developed earlier (W.K. Subczynski, J.S. Hyde, A. Kusumi, Proc. Natl. Acad. Sci. USA 86 (1989) 4474-4478). At 20°C, the oxygen permeability coefficient for the lipid portion of the thylakoid membrane was found to be 39.5 cm s-1. This value is 20% higher than the oxygen permeability coefficient of a water layer of the same thickness as the thylakoid membrane. The high permeability coefficient implies that the oxygen concentration difference across the thylakoid membrane generated under the illumination of the leaf by saturating actinic light is negligible, smaller than 1 μM. Copyright (C) 1998 Elsevier Science B.V.

Original languageEnglish
Pages (from-to)453-463
Number of pages11
JournalBiochimica et Biophysica Acta - Bioenergetics
Volume1365
Issue number3
DOIs
Publication statusPublished - Jul 20 1998
Externally publishedYes

Keywords

  • Oxygen permeability
  • Spin label
  • Thylakoid membrane

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Cell Biology

Fingerprint Dive into the research topics of 'Oxygen permeability of thylakoid membranes: Electron paramagnetic resonance spin labeling study'. Together they form a unique fingerprint.

  • Cite this