|
|
|
|
|
|
|
||
The Journal of General Physiology, Vol 100, 69-87, Copyright © 1992 by The Rockefeller University Press
ARTICLES |
WK Subczynski, LE Hopwood and JS Hyde
Department of Radiology, Medical College of Wisconsin, Milwaukee 53226.
Oxygen transport in the Chinese hamster ovary (CHO) plasma membrane has been studied by observing the collision of molecular oxygen with nitroxide radical spin labels placed in the lipid bilayer portion of the membrane at various distances from the membrane surface using the long-pulse saturation-recovery electron spin resonance (ESR) technique. The collision rate was estimated for 5-, 12-, and 16-doxylstearic acids from spin-lattice relaxation times (T1) measured in the presence and absence of molecular oxygen. Profiles of the local oxygen transport parameters across the membrane were obtained showing that the oxygen diffusion-concentration product is lower than in water for all locations at 37 degrees C. From oxygen transport parameter profiles, the membrane oxygen permeability coefficients were estimated according to the procedure developed earlier by Subczynski et al. (Subczynski, W. K., J. S. Hyde, and A. Kusumi. 1989. Proceedings of the National Academy of Sciences, USA. 86:4474-4478). At 37 degrees C, the oxygen permeability coefficient for the plasma membrane was found to be 42 cm/s, about two times lower than for a water layer of the same thickness as the membrane. The oxygen concentration difference across the CHO plasma membrane at physiological conditions is in the nanomolar range. It is concluded that oxygen permeation across the cell plasma membrane cannot be a rate-limiting step for cellular respiration. Correlations of the form PM = cKs between membrane permeabilities PM of small nonelectrolyte solutes of mol wt less than 50, including oxygen, and their partition coefficients K into hexadecane and olive oil are reported. Hexadecane: c = 26 cm/s, s = 0.95; olive oil: c = 23 cm/s, s = 1.56. These values of c and s differ from those reported in the literature for solutes of 50 less than mol wt less than 300 (Walter, A., and J. Gutknecht. 1986. Journal of Membrane Biology. 90:207-217). It is concluded that oxygen permeability through membranes can be reliably predicted from measurement of partition coefficients.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Facebook 
Reddit 
Technorati 
Twitter What's this?
This article has been cited by other articles:
|
|
 |
|
  M. Echevarria, A. M. Munoz-Cabello, R. Sanchez-Silva, J. J. Toledo-Aral, and J. Lopez-Barneo Development of Cytosolic Hypoxia and Hypoxia-inducible Factor Stabilization Are Facilitated by Aquaporin-1 Expression J. Biol. Chem., October 12, 2007; 282(41): 30207 - 30215. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. S. TIMMINS, F. J. ROBB, C. M. WILMOT, S. K. JACKSON, and H. M. SWARTZ FIREFLY FLASHING IS CONTROLLED BY GATING OXYGEN TO LIGHT-EMITTING CELLS J. Exp. Biol., March 10, 2002; 204(16): 2795 - 2801. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Lammertyn, C. Franck, B.E. Verlinden, and B.M. Nicolai Comparative study of the O2, CO2 and temperature effect on respiration between Conference' pear cell protoplasts in suspension and intact pears J. Exp. Bot., September 1, 2001; 52(362): 1769 - 1777. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Timmins, C. Penatti, E. Bechara, and H. Swartz Measurement of oxygen partial pressure, its control during hypoxia and hyperoxia, and its effect upon light emission in a bioluminescent elaterid larva J. Exp. Biol., January 10, 1999; 202(19): 2631 - 2638. [Abstract] [PDF]
|
|
|
|
