title: Effects of seaweed sterols fucosterol and desmosterol on lipid membranes.
abstract: Higher sterols are universally present in large amounts (20-30%) in the plasma membranes of all eukaryotes whereas they are universally absent in prokaryotes. It is remarkable that each kingdom of the eukaryotes has chosen, during the course of evolution, its preferred sterol: cholesterol in animals, ergosterol in fungi and yeast, phytosterols in higher plants, and e.g., fucosterol and desmosterol in algae. The question arises as to which specific properties do sterols impart to membranes and to which extent do these properties differ among the different sterols. Using a range of biophysical techniques, including calorimetry, fluorescence microscopy, vesicle-fluctuation analysis, and atomic force microscopy, we have found that fucosterol and desmosterol, found in red and brown macroalgae (seaweeds), similar to cholesterol support liquid-ordered membrane phases and induce coexistence between liquid-ordered and liquid-disordered domains in lipid bilayers. Fucosterol and desmosterol induce acyl-chain order in liquid membranes, but less effectively than cholesterol and ergosterol in the order: cholesterol>ergosterol>desmosterol>fucosterol, possibly reflecting the different molecular structure of the sterols at the hydrocarbon tail.
authors.affiliation: MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark. Electronic address: ogm@memphys.sdu.dk.
authors.forename: Ole G
authors.initials: OG
authors.lastname: Mouritsen
authors.affiliation: MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark; Yachay EP and Yachay Tech, Yachay City of Knowledge, Ecuador(1).
authors.forename: Luis A
authors.initials: LA
authors.lastname: Bagatolli
authors.affiliation: MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Duelund
authors.affiliation: MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
authors.forename: Olav
authors.initials: O
authors.lastname: Garvik
authors.affiliation: MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
authors.forename: John H
authors.initials: JH
authors.lastname: Ipsen
authors.affiliation: MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
authors.forename: Adam Cohen
authors.initials: AC
authors.lastname: Simonsen
mesh_terms: D002152:Calorimetry, Differential Scanning; D002462:Cell Membrane; D003897:Desmosterol / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D055595:Mechanical Phenomena; D018625:Microscopy, Atomic Force; D008856:Microscopy, Fluorescence; D015394:Molecular Structure; D012624:Seaweed / Q000737:chemistry*; D013265:Stigmasterol / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D008051:Lipid Bilayers; D003897:Desmosterol; C015896:fucosterol; D013265:Stigmasterol
keywords: Cholesterol; Desmosterol; Ergosterol; Fucosterol; Higher sterols; Lipid bilayers; Lipid domains; Membrane mechanics; Phase behavior; Seaweed