Electrostatic Interactions at Charged Lipid Membranes. Measurement of Surface pH with Fluorescent Lipoid pH Indicators
- 1 February 1978
- journal article
- Published by Wiley in European Journal of Biochemistry
- Vol. 83 (1), 299-305
- https://doi.org/10.1111/j.1432-1033.1978.tb12094.x
Abstract
The 5-dimethylaminonapthalene-1-sulfonyl (dansyl) chromophore attached to the polar head groups of lipids has been used as a fluorescent lipoid pH indicator to evaluate the interfacial pH in lipid-water lamellar systems prepared from negatively charged lipids. The pH in the vicinity of the charged lipid bilayers is different from the pH of the bulk aqueous phase and the difference is a function of the electrolyte concentration in the aqueous phase and of the lipid packing in the bilayer. At a fixed electrolyte concentration in the aqueous phase, the observed interfacial pH is 0.6 to 0.7 pH units lower above the thermal phase transition of the lipid than it is below this temperature. A quantitative interpretation of the results is given on the basis of the Gouy-Chapman theory. The results indicate that the dansyl chromophore is located in front of the charged surface and its distance from this surface increases with a decrease in lipid packing.Keywords
This publication has 18 references indexed in Scilit:
- Lipoid pH indicators as probes of electrical potential and polarity in micellesThe Journal of Physical Chemistry, 1977
- Importance of glycerol and fatty acid residues on the ionic properties of phosphatidylglycerols at the air—water interfaceChemistry and Physics of Lipids, 1977
- Electrostatic interactions at charged lipid membranes: I. Effects of ph and univalent cations on membrane structureBiophysical Chemistry, 1976
- Electrostatic free energy and shift of the phase transition for charged lipid membranesBiophysical Chemistry, 1976
- Ionic influences on the phase transition of dipalmitoylphosphatidylserineBiochemistry, 1976
- Isolation of N-acetylethylenediamine from urine of patients on amesecBiochemical Medicine, 1975
- Surface potential and the interaction of weakly acidic uncouplers of oxidative phosphorylation with liposomes and mitochondriaBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1975
- Interfacial pH at electrically charged lipid monolayers investigated by the lipid pH-indicator methodBiochimica et Biophysica Acta (BBA) - Biomembranes, 1974
- The influence of pH, Ca2+ and protein on the thermotropic behaviour of the negatively charged phospholipid, phosphatidylglycerolBiochimica et Biophysica Acta (BBA) - Biomembranes, 1974
- Studies on Coördination Compounds. I. A Method for Determining Thermodynamic Equilibrium Constants in Mixed Solvents1, 2Journal of the American Chemical Society, 1953