Mitochondrial Protein Involved in Oxidative Phosphorylation (OXPHOS Proteins)

Mitochondrial proteins involved in oxidative phosphorylation are essential components of the cellular machinery that generates ATP, the primary energy currency of the cell. These proteins are primarily located within the inner mitochondrial membrane and function as part of large multi-subunit complexes that make up the electron transport chain (ETC) and ATP synthase. The main role is to facilitate oxidative phosphorylation, a metabolic pathway where electrons from NADH and FADH₂ are transferred through a series of protein complexes to molecular oxygen. This electron transfer is coupled with proton pumping across the inner mitochondrial membrane, creating an electrochemical gradient (proton motive force). The return flow of protons through ATP synthase drives synthesis of ATP from ADP and inorganic phosphate. Oxidative phosphorylation provides most cellular ATP—upwards of 32–34 molecules per glucose molecule metabolized. Defects can lead to energy failure or excessive ROS production implicated in aging and various diseases.

Other names

Electron Transport Chain ProteinsRespiratory Chain ProteinsATP SynthaseComplex I (NADH:ubiquinone oxidoreductase)Complex II (Succinate dehydrogenase)Complex III (Cytochrome bc₁ complex)Complex IV (Cytochrome c oxidase)Complex V (ATP synthase)

Inhibition of electron transfer, uncoupling of proton gradient, direct inhibition of ATP synthase.