title: Self-reproduction of fatty acid vesicles: a combined experimental and simulation study.
abstract: Dilution of a fatty acid micellar solution at basic pH toward neutrality results in spontaneous formation of vesicles with a broad size distribution. However, when vesicles of a defined size are present before dilution, the size distribution of the newly formed vesicles is strongly biased toward that of the seed vesicles. This so-called matrix effect is believed to be a key feature of early life. Here we reproduced this effect for oleate micelles and seed vesicles of either oleate or dioleoylphosphatidylcholine. Fluorescence measurements showed that the vesicle contents do not leak out during the replication process. We hypothesized that the matrix effect results from vesicle fission induced by an imbalance of material across both leaflets of the vesicle upon initial insertion of fatty acids into the outer leaflet of the seed vesicle. This was supported by experiments that showed a significant increase in vesicle size when the equilibration of oleate over both leaflets was enhanced by either slowing down the rate of fatty acid addition or increasing the rate of fatty acid transbilayer movement. Coarse-grained molecular-dynamics simulations showed excellent agreement with the experimental results and provided further mechanistic details of the replication process.
authors.affiliation: Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, The Netherlands. a.j.markvoort@tue.nl
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Markvoort
authors.forename: Nicole
authors.initials: N
authors.lastname: Pfleger
authors.forename: Rutger
authors.initials: R
authors.lastname: Staffhorst
authors.forename: Peter A J
authors.initials: PA
authors.lastname: Hilbers
authors.forename: Rutger A
authors.initials: RA
authors.lastname: van Santen
authors.forename: J Antoinette
authors.initials: JA
authors.lastname: Killian
authors.forename: Ben
authors.initials: B
authors.lastname: de Kruijff
mesh_terms: D001692:Biological Transport; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D005227:Fatty Acids / Q000737:chemistry* / Q000378:metabolism; D008823:Micelles; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D010539:Permeability; D053835:Unilamellar Liposomes / Q000737:chemistry* / Q000378:metabolism
chemical_list: D005227:Fatty Acids; D008823:Micelles; D053835:Unilamellar Liposomes
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