title: Potential-dependent phase partitioning of fluorescent hydrophobic ions in phospholipid vesicles.
abstract: Fluorescent, dansyl derivatives of triphenylalkylphosphonium ions have been synthesized and exhibit fluorescence intensities in small sonicated phospholipid vesicles that are dependent upon transmembrane potentials. The voltage-dependent fluorescence changes are a result of changes in quantum yield that accompany a voltage-dependent phase partitioning of the probe. This phase partitioning is easily quantitated by calibrating the intensities of totally membrane-associated and aqueous probe. The voltage-dependence is well accounted for by a simple thermodynamic model and allows an estimation of potentials from fluorescence intensities in small vesicle systems.
mesh_terms: D003619:Dansyl Compounds / Q000138:chemical synthesis; D008081:Liposomes; D008564:Membrane Potentials; D010743:Phospholipids; D012995:Solubility; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
chemical_list: D003619:Dansyl Compounds; D008081:Liposomes; D010743:Phospholipids