Kinetic limitations in the overall reaction of mitochondrial oxidative phosphorylation accounting for flux-dependent changes in the apparent delta GexP/delta mu H+ ratio.

Changes in J0, delta muH+ and delta GexP were investigated as a function of load. The flux control coefficients, particularly those of the adenine nucleotide translocator and H+-ATPase at the maximum rate of oxidative phosphorylation were seen to strongly depend on the phosphate concentration accounting in common for the highest share in flux control. There was no unique relationship observed between JP and delta muH+ in load-controlled, well coupled systems, but JP was found to depend on delta muH+ at excessive load and increasing proton leakage. All the results presented can be elucidated on the grounds of delocalized chemiosmotic coupling.