Binding of aromatic anion amphiphile to phospholipid vesicles: a fluorescence study

The fluorescence properties of an aromatic anion amphiphile, N-(4-decyloxy-2-hydroxy-benzylidene)glycine (C10HG) have been investigated. The fluorescence spectra of C10HG in lipid vesicles showed stronger intensity than that in aqueous solution, which is due to the less polarity of microenvironment in the former case. A blue-shift maximum of C10HG fluorescence spectra caused by the carbonyl and phosphate groups in the membrane lipid was also observed. The fluorescence lifetimes and anisotropy data showed that the C10HG molecule is immobilized in the membrane, and its motion is blocked by phospholipid. Fluorescence quenching suggested that the molecule is embedded but does not penetrate deeply in the bilayer.