Effect of fluorophore linkage position of n-(9-anthroyloxy) fatty acids on probe distribution between coexisting gel and fluid phospholipid phases.
The quenching of probe fluorescence by spin-labeled phospholipid has been used to determine the distribution of a series of n-(9-anthroyloxy) fatty acids between coexisting gel and fluid liquid-crystal phases in multilamellar phospholipid vesicles. The phase distribution ratio in every case is found to favor the fluid lipid phase, but is much greater between fluid and Ca2+-induced gel than between fluid and thermal gel. For a given gel type, n-(9-anthroyloxy)stearic acids with n = 3, 6, 9 or 12 as well as 11-(9-anthroyloxy)undecanoic acid all exhibit similar behavior, favoring the fluid phase by about a factor of 4 over thermally-induced lipid gel phase and by 18 over Ca2+-induced gel phase. 16-(9-Anthroyloxy)palmitic acid, with the bulky probe at the terminus of the 16-carbon chain, favors the fluid phase less strongly, by a factor of 1.5 or 11 over thermally-induced or Ca2+-induced gel phase, respectively, indicating better packing of this probe in phospholipid gel phases.
Huang
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Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY 14853.
Florine-Casteel
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Feigenson
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GW
Spink
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C
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005227:Fatty Acids; D005456:Fluorescent Dyes; D008081:Liposomes; D008563:Membrane Lipids; D008968:Molecular Conformation; D010743:Phospholipids
D005227:Fatty Acids; D005456:Fluorescent Dyes; D008081:Liposomes; D008563:Membrane Lipids; D010743:Phospholipids