Two-color fluorescent probes for imaging the dipole potential of cell plasma membranes

• Published in: Biochimica et biophysica acta 2005-06, Vol.1712 (2), p.128-136
• Main Authors: Shynkar, Vasyl V., Klymchenko, Andrey S., Duportail, Guy, Demchenko, Alexander P., Mély, Yves
• Format: Article
• Language: English
• Subjects: 3-Hydroxyflavone derivative; Animals; Cell Adhesion; Cell Line; Cell Line, Tumor; Cell Membrane - metabolism; Cell plasma membrane; Confocal fluorescence microscopy; Dipole potential; Dose-Response Relationship, Drug; Fibroblasts - metabolism; Flavonoids - chemistry; Flavonoids - metabolism; Fluorescence probe; Fluorescence spectroscopy; Fluorescent Dyes - pharmacology; Humans; Hydrogen-Ion Concentration; Ketocholesterols - chemistry; Lipid Bilayers - chemistry; Lipids - chemistry; Membrane Potentials; Mice; Microscopy, Confocal - methods; Microscopy, Fluorescence - methods; Models, Chemical; Phosphatidylcholines - chemistry; Phosphatidylglycerols - chemistry; Protons; Pyridinium Compounds - pharmacology; Static Electricity
• ISSN: 0005-2736; 0006-3002; 1879-2642
• DOI: 10.1016/j.bbamem.2005.03.015

The dipole potential ( Ψ d) constitutes a large and functionally important part of the electrostatic potential of cell plasma membranes. However, its direct measurement is not possible. Herein, new 3-hydroxyflavone fluorescent probes were developed that respond strongly to Ψ d changes by a variation of the intensity ratio of their two well-separated fluorescence bands. Using fluorescence spectroscopy with cell suspensions and confocal microscopy with adherent cells, we showed, for the first time, two-color fluorescence ratiometric measurement and visualization of Ψ d in cell plasma membranes. Using this new tool, a heterogeneous distribution of this potential within the membrane was evidenced.