title: Search for the most 'primitive' membranes and their reinforcers: a review of the polyprenyl phosphates theory.
abstract: Terpenoids have an essential function in present-day cellular membranes, either as membrane reinforcers in Eucarya and Bacteria or as principal membrane constituents in Archaea. We have shown that some terpenoids, such as cholesterol and α, ω-dipolar carotenoids reinforce lipid membranes by measuring the water permeability of unilamellar vesicles. It was possible to arrange the known membrane terpenoids in a 'phylogenetic' sequence, and a retrograde analysis led us to conceive that single-chain polyprenyl phosphates might have been 'primitive' membrane constituents. By using an optical microscopy, we have observed that polyprenyl phosphates containing 15 to 30 C-atoms form giant vesicles in water in a wide pH range. The addition of 10 % molar of some polyprenols to polyprenyl phosphate vesicles have been shown to reduce the water permeability of membranes even more efficiently than the equimolecular addition of cholesterol. A 'prebiotic' synthesis of C10 and C15 prenols from C5 monoprenols was achieved in the presence of a montmorillonite clay. Hypothetical pathway from C1 or C2 units to 'primitive' membranes and that from 'primitive' membranes to archaeal lipids are presented.
authors.affiliation: Institute of Chemistry, University of Strasbourg - CNRS, 67000, Strasbourg, France, nakatani@unistra.fr.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nakatani
authors.forename: Nigel
authors.initials: N
authors.lastname: Ribeiro
authors.forename: Stéphane
authors.initials: S
authors.lastname: Streiff
authors.forename: Mari
authors.initials: M
authors.lastname: Gotoh
authors.forename: Gianluca
authors.initials: G
authors.lastname: Pozzi
authors.forename: Laurent
authors.initials: L
authors.lastname: Désaubry
authors.forename: Alain
authors.initials: A
authors.lastname: Milon
mesh_terms: D000538:Aluminum Silicates; D001105:Archaea / Q000737:chemistry*; D001419:Bacteria / Q000737:chemistry; D001546:Bentonite; D002338:Carotenoids / Q000737:chemistry; D002462:Cell Membrane / Q000737:chemistry*; D002463:Cell Membrane Permeability; D002784:Cholesterol / Q000737:chemistry; D000077215:Clay; D056890:Eukaryota / Q000737:chemistry; D019143:Evolution, Molecular; D006863:Hydrogen-Ion Concentration; D000069497:Origin of Life; D011106:Polyisoprenyl Phosphates / Q000737:chemistry*; D013729:Terpenes / Q000737:chemistry; D053835:Unilamellar Liposomes / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D000538:Aluminum Silicates; D011106:Polyisoprenyl Phosphates; D013729:Terpenes; D053835:Unilamellar Liposomes; D014867:Water; D001546:Bentonite; D002338:Carotenoids; D002784:Cholesterol; D000077215:Clay