Effects of drugs on the
gramicidin monomer ↔ dimer equilibrium.
(a) Schematic description of the stopped-flow fluorescence quench
experiments: gramicidin permeable Tl+ quenches the LUV
encapsulated fluorophore ANTS. (b) Representative fluorescence quench
traces in DC22:1PC LUVs doped with gD. (c) Effects of drugs
on the fluorescence quench rates (gramicidin monomer ↔ dimer
equilibrium) in DC18:1PC LUVs doped with gD (light gray),
DC22:1PC LUVs doped with gD (dark gray), and DC22:1PC LUVs doped with gA (black). The aqueous drug concentrations were
100, 30, 1800, 10, 300, 30, and 30,000 μM for capsaicin, resveratrol,
octanol, C12E6, FC12, Triton X-100, and cyclohexane, respectively,
and the estimated molar ratios of the drugs in the bilayers were 0.32,
0.02, 0.48, 0.04, 0.21, 0.04, and 0.93, respectively; cholesterol
was added at a molar ratio of cholesterol:lipid of 1:10 when preparing
the LUVs. Mean ± S.D. n = 3–4.