title: Orientation of xanthophylls in phosphatidylcholine multibilayers.
abstract: Oriented multibilayers of dimyristoyl phosphatidylcholine (DMPC) modified with violaxanthin or zeaxanthin were examined by X-ray diffractometry and linear dichroism. It appears that pigment molecules and the normal to the bilayer plane form an angle of 24-25 degrees. It was also observed that rather small concentrations of added xanthophylls (molar fraction up to 3%) increase the pigmented bilayer thickness by a value of about 2 A as compared with that of the pure DMPC bilayer. The observed nonzero linear dichroism at normal incidence of light suggests the possibility of nonhomogeneous orientation of transition dipoles in the plane of the bilayer.
authors.affiliation: Institute of Physics, Maria Curie-Skłodowska University, Lublin, Poland.
authors.forename: W I
authors.initials: WI
authors.lastname: Gruszecki
authors.forename: J
authors.initials: J
authors.lastname: Sielewiesiuk
mesh_terms: D002338:Carotenoids / Q000031:analogs & derivatives / Q000032:analysis; D004134:Dimyristoylphosphatidylcholine / Q000032:analysis*; D008027:Light; D008051:Lipid Bilayers / Q000032:analysis*; D014975:Lutein / Q000032:analysis*; D008433:Mathematics; D008563:Membrane Lipids / Q000032:analysis*; D014961:X-Ray Diffraction; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene / Q000031:analogs & derivatives*
chemical_list: D008051:Lipid Bilayers; D008563:Membrane Lipids; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D002338:Carotenoids; C005613:violaxanthin; D004134:Dimyristoylphosphatidylcholine; D014975:Lutein