Title:Oxidative phosphorylation and respiratory control phenomenon in Paracoccus denitrificans plasma membrane.
Authors:Zharova TV; Vinogradov AD
Publication:Biochemistry (Mosc). 2012 Sep;77(9):1000-7. doi: 10.1134/S0006297912090064.
Changes in respiratory activity, transmembrane electric potential, and ATP synthesis as induced by additions of limited amounts of ADP and P(i) to tightly coupled inverted (inside-out) Paracoccus denitrificans plasma membrane vesicles were traced. The pattern of the changes was qualitatively the same as those observed for coupled mitochondria during the classical State 4-State 3-State 4 transition. Bacterial vesicles devoid of energy-dependent permeability barriers for the substrates of oxidation and phosphorylation were used as a simple experimental model to investigate two possible mechanisms of respiratory control: (i) in State 4 phosphoryl transfer potential (ATP/ADP x P(i)) is equilibrated with proton-motive force by reversibly operating F(1).F(o)-ATPase (thermodynamic control); (ii) in State 4 apparent "equilibrium" is reached by unidirectional operation of proton motive force-activated F(1).F(o)-ATP synthase. The data support the kinetic mechanism of the respiratory control phenomenon.