Photochemical control of membrane raft organization

Controllable membrane phase separation through the action of a synthetic photoresponsive amphiphile is reported. We studied multi-component giant vesicles formed from a ternary lipid mixture of saturated and unsaturated phospholipid and cholesterol together with the photoresponsive amphiphile. A change in the conformation of the photoresponsive amphiphile can switch membrane lateral segregation in a reversible manner. Cis-isomerization induces lateral phase separation in one-phase membranes or produces additional lateral domains in two-phase membranes. Membranes that are close to miscibility boundary show high photo-responsiveness. This is the first report on the reversible control of membrane lateral segregation triggered by a conformational change in a membrane-constituting molecule. These findings may lead to new methods for controlling membrane self-organization such as raft engineering.