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Diffusion of oxygen in water and hydrocarbons using an electron spin resonance spin-label technique. Biophys J 1984 Apr;45(4):743-8

Date

04/01/1984

Pubmed ID

6326877

Pubmed Central ID

PMC1434914

DOI

10.1016/S0006-3495(84)84217-4

Abstract

The Smoluchowski equation for the bimolecular collision rate of dissolved oxygen molecules with spin labels yielded values for the diffusion constant of oxygen in water that are in agreement with the Stokes-Einstein equation (D infinity T/eta, where eta is the macroscopic viscosity) and with published values obtained by conventional methods. Heisenberg exchange at an interaction distance of 4.5 A occurs with a probability close to one for each encounter. In mixed hydrocarbons (olive oil, paraffin oils) and sec-butyl benzene, D infinity (T/eta)rho, where rho lies between 0.5 and 1. Oxygen diffuses in the hydrocarbons between 10 and 100 times more rapidly than predicted from the macroscopic viscosity. Similar results would be expected for diffusion of oxygen in model and biological membranes. Parallel measurements of rotational diffusion of the spin labels show little correlation with measurements of translational diffusion of oxygen. Dipolar interactions between spin labels and oxygen appear negligible except in the limit of highest viscosities.

Author List

Subczynski WK, Hyde JS

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

Diffusion
Electron Spin Resonance Spectroscopy
Hydrocarbons
Kinetics
Oxygen
Spin Labels
Viscosity
Water