Lipid bilayer discs and banded tubules: photoinduced lipid sorting in ternary mixtures.
The self-assembly of biological amphiphiles has proved a fascinating topic in recent years, the hollow cylindrical lipid tubule morphology being of particular interest due to its potential applications in "soft" microtechnologies. Lateral coexistence of liquid-ordered (lo) and liquid-disordered (ld) phases, which may resemble raft formation in cell membranes, was investigated in lipid tubules, prepared from 1,2-dioleoyl-sn-glycero-3-phosphocholine, egg-sphingomyelin, and cholesterol. Fluorescence microscopy shows that the appearance of micrometer-scale lo domains in the lipid tubule is not an intrinsic phase behavior of the system but a consequence of photoinduced lipid peroxidation. Most interestingly, new photoinduced bilayer structures: lipid discs, essentially stable flattened liposomes, were observed for the first time in a model membrane system. This investigation not only aids in our understanding of lipid sorting phenomena in cell membranes but also demonstrates how control of this process may provide a route to the generation of new, functional structures.
Yuan
Jing
J
MARTECH (Center for Materials Science and Technology) and the Department of Physics, Florida State University, Tallahassee, Florida 32306-4350, USA.
Hira
Steven M
SM
Strouse
Geoffrey F
GF
Hirst
Linda S
LS
D002784:Cholesterol / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D015227:Lipid Peroxidation; D008055:Lipids / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry; D008567:Membranes, Artificial; D008856:Microscopy, Fluorescence / Q000379:methods; D010713:Phosphatidylcholines / Q000737:chemistry; D010777:Photochemistry; D013109:Sphingomyelins / Q000737:chemistry
D008051:Lipid Bilayers; D008055:Lipids; D008081:Liposomes; D008567:Membranes, Artificial; D010713:Phosphatidylcholines; D013109:Sphingomyelins; D002784:Cholesterol