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Effect of polar carotenoids on the oxygen diffusion-concentration product in lipid bilayers. An EPR spin label study. Biochim Biophys Acta 1991 Sep 10;1068(1):68-72

Date

09/10/1991

Pubmed ID

1654104

DOI

10.1016/0005-2736(91)90061-c

Abstract

The oxygen diffusion-concentration product was determined in phosphatidylcholine (PC) bilayers from oxygen broadening of the spin label EPR spectra. The use of fatty acid spin labels makes it possible to do structural and oximetric measurements with the same sample. We find that polar carotenoids, zeaxanthin and violaxanthin, increase ordering of hydrocarbon chains in saturated (dimyristoyl-PC) and unsaturated (egg yolk PC) membranes and also significantly decrease the oxygen diffusion-concentration product in the hydrocarbon region of these membranes. At 25 degrees C in the presence of 10 mol% of carotenoids, the product is about 30% smaller than in pure PC membranes. Intercalation of carotenoids decreases the oxygen diffusion-concentration product in the central part of the bilayer and has little effect on the product in the polar head group region. In contrast, cholesterol molecules significantly reduce the product on and near the membrane surface, and do not change it (saturated PC) or increase it (unsaturated PC) in the middle of the bilayer (Subczynski, W.K., Hyde, J.S. and Kusumi, A. (1989) Proc. Natl. Acad. Sci. USA 86, 4474-4478). The decrease of oxygen diffusion-concentration product may be a mechanism of carotenoid protective activity, which should be effective in plant and animal cells in the light as well as in the dark.

Author List

Subczynski WK, Markowska E, Sielewiesiuk J

Author

Witold K. Subczynski PhD Professor in the Biophysics department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Carotenoids
Diffusion
Dimyristoylphosphatidylcholine
Electron Spin Resonance Spectroscopy
Fatty Acids
Glycolipids
Lipid Bilayers
Mathematics
Membranes, Artificial
Models, Molecular
Oximetry
Oxygen
Phosphatidylcholines
Xanthophylls
Zeaxanthins
beta Carotene