The Molecular Motion of Spin Labeled Amphiphilic Molecules in Model Membranes
The theoretical background of a method to evaluate EPR spectra of spin labeled amphiphilic molecules in lipid bilayers is outlined. A model of restricted motion is applied including restricted rotation around the molecular long axis and rapid tumbling of this axis within the confines of a cone. The validity of the model is critically tested by application to oriented lipid multibilayer samples measured at three microwave frequencies. It is shown that detailed information about the mode of ordering and motion of the spin label molecule may be obtained.
KeywordsLipid Bilayer Electron Spin Resonance Spectrum Correlation Time Molecular Motion Spin Label
Unable to display preview. Download preview PDF.
- Berliner, L. J., (ed.) “Spin labeling. Theory and applications”, Academic Press, New York, 1976.Google Scholar
- Gaffney, B. J. and H. M. McConnell, The paramagnetic resonance spectra of spin labels in phospholipid membranes, J. Magn. Resonance 16, 1, 1974.Google Scholar
- Israelachvili, J., J. Sjösten, L. E. G. Eriksson, M. Ehrstriin, A. Gräslund and A. Ehrenberg, ESR spectral analysis of the molecular motion of spin label in lipid bilayers and membranes based on a model in terms of two angular motional parameters and rotational correlation times, Biochim. Biophys. Acta 382, 125, 1975.CrossRefGoogle Scholar
- Wilson, R. and D. Kivelson, ESR linewidths in solution. I. Experiments on anisotropic and spin-rotational effects, J. Chen. Phys. 44, 154, 1966.Google Scholar