The Functional Significance of Lipid Diversity: Orientation of Cholesterol in Bilayers Is Determined by Lipid Species Export

@article{citeulike:6013707, abstract = {The chemical diversity of lipids and their complex arrangements in supramolecular assemblies are in stark contrast to our previous notions of them as passive structural components. For example, in plasma membranes, sphingolipids are primarily located in the outer monolayer, whereas unsaturated phospholipids are more abundant in the inner leaflet. Our recent results offer a direct contribution to the importance of lipid diversity in biological membranes. We have studied the location of cholesterol within polyunsaturated fatty acid (PUFA) bilayers doped with different amounts of monounsaturated (POPC) or disaturated (DMPC) lipids. Using deuterium labeling and neutron diffraction, we have found that in PUFA bilayers, cholesterol can be flipped from its known position in the bilayer center to its commonly assumed upright orientation simply by varying the amount of POPC. Although it takes ∼50 mol \% POPC to flip cholesterol in PUFA bilayers, the same effect is achieved with only 5 mol \% DMPC, elegantly emphasizing cholesterol's affinity for saturated chains. It also suggests that the presence of PUFA in the inner leaflet of a cellular bilayer may enhance the transfer of cholesterol to the outer layer, potentially modifying raft composition and the local function of a membrane.}, author = {Kučerka, Norbert and Marquardt, Drew and Harroun, Thad A. and Nieh, Mu-Ping and Wassall, Stephen R. and Katsaras, John}, citeulike-article-id = {6013707}, citeulike-linkout-0 = {http://dx.doi.org/10.1021/ja907659u}, citeulike-linkout-1 = {http://pubs.acs.org/doi/abs/10.1021/ja907659u}, doi = {10.1021/ja907659u}, journal = {Journal of the American Chemical Society}, keywords = {bilayers, cholesterol, diversity, kucerk09apdf, lipid, orientation}, number = {0}, posted-at = {2009-10-27 00:45:42}, priority = {2}, title = {The Functional Significance of Lipid Diversity: Orientation of Cholesterol in Bilayers Is Determined by Lipid Species}, url = {http://dx.doi.org/10.1021/ja907659u}, volume = {0}, year = {0000} }

TY - JOUR ID - citeulike:6013707 L3 - citeulike-article-id:6013707 N2 - The chemical diversity of lipids and their complex arrangements in supramolecular assemblies are in stark contrast to our previous notions of them as passive structural components. For example, in plasma membranes, sphingolipids are primarily located in the outer monolayer, whereas unsaturated phospholipids are more abundant in the inner leaflet. Our recent results offer a direct contribution to the importance of lipid diversity in biological membranes. We have studied the location of cholesterol within polyunsaturated fatty acid (PUFA) bilayers doped with different amounts of monounsaturated (POPC) or disaturated (DMPC) lipids. Using deuterium labeling and neutron diffraction, we have found that in PUFA bilayers, cholesterol can be flipped from its known position in the bilayer center to its commonly assumed upright orientation simply by varying the amount of POPC. Although it takes ∼50 mol % POPC to flip cholesterol in PUFA bilayers, the same effect is achieved with only 5 mol % DMPC, elegantly emphasizing cholesterol’s affinity for saturated chains. It also suggests that the presence of PUFA in the inner leaflet of a cellular bilayer may enhance the transfer of cholesterol to the outer layer, potentially modifying raft composition and the local function of a membrane. IS - 0 JF - Journal of the American Chemical Society TI - The Functional Significance of Lipid Diversity: Orientation of Cholesterol in Bilayers Is Determined by Lipid Species VL - 0 KW - bilayers KW - cholesterol KW - diversity KW - kucerk09apdf KW - lipid KW - orientation AU - Kučerka, Norbert AU - Marquardt, Drew AU - Harroun, Thad AU - Nieh, Mu-Ping AU - Wassall, Stephen AU - Katsaras, John PY - 2000/// UR - http://dx.doi.org/10.1021/ja907659u ER -