Valinomycin binds stoichiometrically to cytochrome c oxidase and changes its structure and function.
Valinomycin binds to soluble and reconstituted cytochrome c oxidase (COX) in a stoichiometric manner, as shown by a spectral shift of the oxidized gamma-band. No spectral change is found with nigericin or 18-crown-6 and in the absence of potassium ions. Titration of the proton pumping activity of reconstituted COX with valinomycin reached a maximum of H+/e- - 0.73 after addition of 1 mole of valinomycin per mole of reconstituted COX. It is concluded that K+-translocation in proton-pumping COX vesicles occurs via enzyme-bound valinomycin.
Steverding
D
D
Biochemie, Fachbereich Chemie der Philipps-Universität, Marburg, F.R.G.
Kadenbach
B
B
D000818:Animals; D002417:Cattle; D043844:Crown Ethers; D003576:Electron Transport Complex IV / Q000378:metabolism*; D004988:Ethers, Cyclic / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism; D008081:Liposomes / Q000378:metabolism; D008564:Membrane Potentials; D009206:Myocardium / Q000201:enzymology; D009550:Nigericin / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D011522:Protons; D013053:Spectrophotometry; D014634:Valinomycin / Q000378:metabolism* / Q000494:pharmacology
D043844:Crown Ethers; D004988:Ethers, Cyclic; D007473:Ion Channels; D008081:Liposomes; D011522:Protons; D014634:Valinomycin; C015762:18-crown-6; D003576:Electron Transport Complex IV; D009550:Nigericin; D011188:Potassium