Is It Possible to Predict Any Properties of Oxidative Phosphorylation in a Theoretical Way?

Two theoretical approaches applied to oxidative phosphorylation, namely Metabolic Control Analysis (MCA) [ 1-7] and Non-Equilibrium Thermodynamics (NET) [8-11], turned out to be very useful tools for quantitative description and understanding of control and regulation of this process. However, they were not able to predict any new properties of the considered system. On the other hand, the previously developed dynamic model of oxidative phosphorylation [12-17], representing a kinetic approach, allowed to formulate several interesting predictions which can be tested experimentally. The most important of these predictions are: (1) Different steps of ATP-production must be directly activated to a similar extent as ATP-consumption during stimulation of ATP turnover by calcium-acting hormones as well as by neural signals during muscle contraction; (2) A universal activator/regulatory mechanism responsible for such a precise balance of activation should be identified; (3) The flux-force relationship for cytochrome oxidase can be inverse during the transition towards hypoxia and anoxia, when oxygen concentration falls below 30 microM; (4) The flux-force relationship can depend on the way in which the thermodynamic force is changed; (5) The pattern of metabolic control is completely different in normoxic and hypoxic conditions; in the latter case cytochrome oxidase has the flux control coefficient close to unity. Thus, the kinetic model of oxidative phosphorylation seems to be a useful scientific tool, offering some novel theoretical predictions, which then can be tested in the experimental way.