title: Proton pump coupled to cytochrome c oxidase in Paracoccus denitrificans.
abstract: The proton translocating properties of cytochrome c oxidase in whole cells of Paracoccus denitrificans have been studied with the oxidant pulse method. leads to H+/2e- quotients have been measured with endogenous substrates, added methanol and added ascorbate (+TMPD) as reductants, and oxygen and ferricyanide as oxidants. It was found that both the observed leads to H+/O with ascorbate (+TMPD) as reductant, and the differences in proton ejection between oxygen-and ferricyanide pulses, with endogenous substrates or added methanol as a substrate, indicate that the P. denitrificans cytochrome c oxidase translocates protons with a stoichiometry of 2H+/2e-. The results presented in this and previous papers are in good agreement with recent findings concerning the mitochondrial cytochrome c oxidase, and suggest unequal charge separation by different coupling segments of the respiratory chain of P. denitrificans.
mesh_terms: D000693:Anaerobiosis; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000378:metabolism*; D005292:Ferricyanides; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D010231:Paracoccus denitrificans / Q000201:enzymology*
chemical_list: D005292:Ferricyanides; D003576:Electron Transport Complex IV