Fluorescence quenching of a series of membrane probes measured in living cells by flow cytometry.
The transverse location normal to the bilayer surface of a series of n-(9-anthroyloxy) fatty acid probes, where n = 2, 3, 6, 7, 9, 12, and 16, was determined by fluorescence quenching measurements with a flow cytometer. We show that the anthroyloxy moieties of the probes locate at a graded series of depths in the outer leaflet of the plasma membrane of living HeLa cells, in a manner similar to that previously observed for model membrane systems, and mitochondria. For different n, the efficiency of quenching with an aqueous phase quencher, Cu+2, was 2 greater than or equal to 3 greater than 6 greater than or equal to 7 greater than 9 greater than 12 greater than 16. Therefore, flow cytometry permits use of these probes for measurements of dynamic parameters related to membrane fluidity at different depths in the plasma membranes of living cells.
Collins
J M
JM
Department of Biochemistry and Molecular Biophysics, Medical College of Virginia Campus of Virginia Commonwealth University, Richmond 23298-0614.
Grogan
W M
WM
D005434:Flow Cytometry / Q000379:methods*; D006367:HeLa Cells; D006801:Humans; D008433:Mathematics; D008560:Membrane Fluidity / Q000502:physiology*; D015336:Molecular Probe Techniques; D015335:Molecular Probes; D010169:Palmitic Acids; D013229:Stearic Acids
D015335:Molecular Probes; D010169:Palmitic Acids; D013229:Stearic Acids; C047265:16-(9-anthroyloxy)palmitic acid; C041458:2-(9-anthroyloxy)stearic acid