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The structure of polyunsaturated lipid bilayers important for rhodopsin function: a neutron diffraction study.

Mihaela Mihailescu·Klaus Gawrisch
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Abstract

The structure of oriented 1-stearoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine bilayers with perdeuterated stearoyl- or docosahexaenoyl hydrocarbon chains was investigated by neutron diffraction. Experiments were conducted at two different relative humidities, 66 and 86%. At both humidities we observed that the polyunsaturated docosahexaenoyl chain has a preference to reside near the lipid water interface. That leaves voids in the bilayer center that are occupied by saturated stearoyl chain segments. This uneven distribution of saturated- and polyunsaturated chain densities is likely to result in membrane elastic stress that modulates function of integral receptor proteins like rhodopsin.

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BiophysicsDocosahexaenoic AcidsHydrocarbonsLipid BilayersLipidsModels, MolecularNeutron DiffractionNeutronsNormal DistributionPhosphatidylcholinesProtonsRhodopsinScattering, RadiationWaterLetterResearch Support, N.I.H., ExtramuralResearch Support, N.I.H., IntramuralResearch Support, U.S. Gov't, Non-P.H.S.

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Mihaela Mihailescu, Klaus Gawrisch. 2005-10-28. The structure of polyunsaturated lipid bilayers important for rhodopsin function: a neutron diffraction study.. https://doi.org/10.1529/biophysj.105.071712

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