Proton transport by cytochrome c oxidase from the thermophilic bacterium PS3 reconstituted in liposomes.
Cytochrome oxidase from the thermophilic bacterium PS3 which contains three types of polypeptide subunits are reconstituted into liposomes by a freeze-thaw technique. The reconstituted enzyme caused acidification of the medium during cytochrome c oxidation with a stoichiometry of up to 0.8 H+/e. Uptake of K+ ions in the presence of valinomycin occurred with a stoichiometry between 1.5 and 2 K+/e. Dicyclohexylcarbodiimide inhibited the acidification and decreased the stoichiometry of K+ ion uptake to about 1 K+/e. This bacterial oxidase thus appears to be a proton pump with properties similar to the mitochondrial enzyme.
D001419:Bacteria / Q000201:enzymology*; D001692:Biological Transport; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D003576:Electron Transport Complex IV / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008081:Liposomes; D011188:Potassium / Q000378:metabolism; D013696:Temperature
D008081:Liposomes; D004024:Dicyclohexylcarbodiimide; D003576:Electron Transport Complex IV; D011188:Potassium