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 language | English |
|---|---|
| Pages (from-to) | 453-463 |
| Number of pages | 11 |
| Journal | BBA - Bioenergetics |
| Volume | 1365 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Jul 20 1998 |
| Externally published | Yes |
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Keywords
- Oxygen permeability
- Spin label
- Thylakoid membrane
ASJC Scopus subject areas
- Biophysics
Cite this
Oxygen permeability of thylakoid membranes : Electron paramagnetic resonance spin labeling study. / Ligeza, Agnieszka; Tikhonov, Alexander N.; Hyde, James S.; Subczynski, Witold K.
In: BBA - Bioenergetics, Vol. 1365, No. 3, 20.07.1998, p. 453-463.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Oxygen permeability of thylakoid membranes
T2 - Electron paramagnetic resonance spin labeling study
AU - Ligeza, Agnieszka
AU - Tikhonov, Alexander N.
AU - Hyde, James S.
AU - Subczynski, Witold K.
PY - 1998/7/20
Y1 - 1998/7/20
N2 - 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.
AB - 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.
KW - Oxygen permeability
KW - Spin label
KW - Thylakoid membrane
UR - http://www.scopus.com/inward/record.url?scp=0032551765&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032551765&partnerID=8YFLogxK
U2 - 10.1016/S0005-2728(98)00098-X
DO - 10.1016/S0005-2728(98)00098-X
M3 - Article
C2 - 9711298
AN - SCOPUS:0032551765
VL - 1365
SP - 453
EP - 463
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
SN - 0005-2728
IS - 3
ER -