Determination of Orientational Order Parameters from 2H NMR Spectra of Magnetically Partially Oriented Lipid Bilayers

Hartmut Schäfer, Burkhard Mädler, Edward Sternin
1998 Biophysical Journal  
The partial orientation of multilamellar vesicles (MLVs) in high magnetic fields is known to affect the shape of 2 H NMR spectra. There are numerical methods for extracting either the orientational order parameters of lipid molecules for a random distribution of domain orientations in the sample, or the distribution of orientations for a known set of spectral anisotropies. A first attempt at determining the orientational order parameters in the presence of an unknown nonrandom distribution of
more » ... ientations is presented. The numerical method is based on the Tikhonov regularization algorithm. It is tested using simulated partially oriented spectra. An experimental spectrum of a phospholipid-ether mixture in water is analyzed as an example. The experimental spectrum is consistent with an ellipsoidal shape of MLVs with a ratio of semiaxes of ϳ3.4.
doi:10.1016/s0006-3495(98)74025-1 pmid:9533713 pmcid:PMC1302581 fatcat:33uwhwnm7jdc5kafqwsf3o43mi