Kinetic limitations in the overall reaction of mitochondrial oxidative phosphorylation accounting for flux-dependent changes in the apparent ΔGexP/ΔμH+ ratio

AbstractChanges in J0, ΔμH+ and ΔGexP 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 ΔμH+ in load-controlled, well coupled systems, but JP was found to depend on ΔμH+ at excessive load and increasing proton leakage. All the results presented can be elucidated on the grounds of delocalized chemiosmotic coupling