Staneva, Galya Seigneuret, Michel Conjeaud, Hélène Puff, Nicolas Angelova, Miglena I. Making a Tool of an Artifact: The Application of Photoinduced Lo Domains in Giant Unilamellar Vesicles to the Study of Lo/Ld Phase Spinodal Decomposition and Its Modulation by the Ganglioside GM1 Electroformed giant unilamellar vesicles containing liquid-ordered Lo domains are important tools for the modeling of the physicochemical properties and biological functions of lipid rafts. Lo domains are usually imaged using fluorescence microscopy of differentially phase-partionioning membrane-embedded probes. Recently, it has been shown that these probes also have a photosensitizing effect that leads to lipid chemical modification during the fluorescence microscopy experiments. Moreover, the lipid reaction products are able as such to promote Lo microdomain formation, leading to potential artifacts. We show here that this photoinduced effect can also purposely be used as a new approach to study Lo microdomain formation in giant unilamellar vesicles. Photosensitized lipid modification can promote Lo microdomain appearance and growth uniformly and on a faster time scale, thereby yielding new information on such processes. For instance, in egg phosphatidylcholine/egg sphingomyelin/cholesterol 50:30:20 (mol/mol) giant unilamellar vesicles, photoinduced Lo microdomain formation appears to occur by the rarely observed spinodal decomposition process rather than by the common nucleation process usually observed for Lo domain formation in bilayers. Moreover, temperature and the presence of the ganglioside GM1 have a profound effect on the morphological outcome of the photoinduced phase separation, eventually leading to features such as bicontinuous phases, phase percolation inversions, and patterns evoking double phase separations. GM1 also has the effect of destabilizing Lo microdomains. These properties may have consequences for Lo nanodomains stability and therefore for raft dynamics in biomembranes. Our data show that photoinduced Lo microdomains can be used to obtain new data on fast raft-mimicking processes in giant unilamellar vesicles. phase percolation inversions;phase separations;Lo nanodomains stability;bicontinuous phases;time scale;Giant Unilamellar Vesicles;Lo microdomain formation;lipid rafts;photoinduced Lo microdomains;Lo domains;photosensitizing effect;Photoinduced Lo Domains;photoinduced phase separation;gm 1;spinodal decomposition process;ganglioside GM 1;Ganglioside GM 1Electroformed giant unilamellar vesicles;lipid reaction products;lipid chemical modification;fluorescence microscopy experiments;fluorescence microscopy;photoinduced effect;Lo microdomains;physicochemical properties;raft dynamics;Lo microdomain appearance;nucleation process;Lo domain formation;data show;giant unilamellar vesicles;Photosensitized lipid modification;study Lo microdomain formation;photoinduced Lo microdomain formation 2011-12-20
    https://acs.figshare.com/articles/media/Making_a_Tool_of_an_Artifact_The_Application_of_Photoinduced_Lo_Domains_in_Giant_Unilamellar_Vesicles_to_the_Study_of_Lo_Ld_Phase_Spinodal_Decomposition_and_Its_Modulation_by_the_Ganglioside_GM1/2569924
10.1021/la203101y.s005