Energized transport of potassium ions in the absence of valinomycin by cytochrome c oxidase-reconstituted vesicles.
Valinomycin-independent energized uptake of K+ was observed in cytochrome c oxidase reconstituted proteoliposome. The rate of K+ influx was proportional to the magnitude of electron flux. The energized uptake of K+ was abolished by p-trifluoromethoxycarbonylcyanide phenylhydrazone or by nigericin. Using the safranine fluorescence technique, it was demonstrated that even in the absence of valinomycin, liposomes and proteoliposomes reconstituted with cytochrome c oxidase are able to discriminate between Na+ and K+ and show a preference for K+ in the presence of excess Na+.
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D002417:Cattle; D002463:Cell Membrane Permeability; D004396:Coloring Agents; D003576:Electron Transport Complex IV / Q000378:metabolism*; D007700:Kinetics; D008081:Liposomes / Q000378:metabolism*; D009550:Nigericin / Q000494:pharmacology; D010619:Phenazines; D011188:Potassium / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D014634:Valinomycin / Q000494:pharmacology*
D004396:Coloring Agents; D008081:Liposomes; D010619:Phenazines; D014634:Valinomycin; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D012964:Sodium; D003576:Electron Transport Complex IV; D009550:Nigericin; D011188:Potassium; C009195:safranine T