title: Effect of beta-carotene on structural and dynamic properties of model phosphatidylcholine membranes. I. An EPR spin label study.
abstract: The influence of beta-carotene on structural and dynamic properties of model membranes (multilamellar liposomes) prepared of dipalmitoylphosphatidylcholine was investigated. It was found that beta-carotene: (1) decreases order within crystalline state of the membrane; the effect of beta-carotene was more pronounced than in the case of the polar carotenoid, lutein, as revealed by means of spin label EPR; (2) increases penetration, stronger than lutein, of apolar molecules into the membrane as indicated by greater partition coefficient of 5-doxyldecane; (3) increases correlation times tau B tau C stronger than lutein. In all cases the effect of beta-carotene on a membrane was more pronounced at crystalline state than at fluid state. On this basis a hypothesis is proposed that beta-carotene plays a physiological function in the fluidization of chloroplast membranes in a chilling stress to the photosynthetic apparatus.
authors.affiliation: Department of Plant Physiology and Biochemistry, Jan Zurzycki Institute of Molecular Biology, Jagiellonian University, Kraków, Poland.
authors.forename: K
authors.initials: K
authors.lastname: Strzałka
authors.forename: W I
authors.initials: WI
authors.lastname: Gruszecki
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D002338:Carotenoids / Q000494:pharmacology*; D004578:Electron Spin Resonance Spectroscopy; D008051:Lipid Bilayers / Q000737:chemistry*; D014975:Lutein / Q000494:pharmacology; D008560:Membrane Fluidity / Q000187:drug effects; D008563:Membrane Lipids / Q000737:chemistry*; D008954:Models, Biological; D010713:Phosphatidylcholines / Q000737:chemistry*; D010788:Photosynthesis; D013113:Spin Labels; D013696:Temperature; D019207:beta Carotene
chemical_list: D008051:Lipid Bilayers; D008563:Membrane Lipids; D010713:Phosphatidylcholines; D013113:Spin Labels; D019207:beta Carotene; D015060:1,2-Dipalmitoylphosphatidylcholine; D002338:Carotenoids; D014975:Lutein