Respiratory pathway (ETC)

The respiratory pathway, primarily encompassing the mitochondrial electron transport chain (ETC) and oxidative phosphorylation, is the fundamental biological system responsible for generating adenosine triphosphate (ATP), the primary energy currency of the cell (StatPearls: NBK553175). It consists of a series of protein complexes (Complex I through IV) and mobile electron carriers that facilitate the transfer of electrons to oxygen, creating a proton gradient used by ATP synthase (UniProt: P00338). While the pathway as a whole is a physiological system rather than a single molecular target, its constituent enzymes are frequently utilized as therapeutic targets. For instance, bedaquiline is a diarylquinoline antibiotic that specifically inhibits the mycobacterial ATP synthase to treat multi-drug-resistant tuberculosis (PubMed: 24511110). In metabolic health, metformin, a first-line treatment for type 2 diabetes, exerts its effects partly through the mild inhibition of mitochondrial Complex I (PubMed: 10839993). Dysregulation of this pathway is a hallmark of mitochondrial diseases and is increasingly recognized as a factor in neurodegeneration and cancer progression. Because of its essential role in all aerobic life, pharmacological intervention requires precise targeting to ensure efficacy against pathogens or diseased cells while minimizing host toxicity.

Other names

Cellular respirationElectron transport chainOxidative phosphorylationMitochondrial respiratory chain

Inhibition of specific complexes (I-IV) within the electron transport chain or inhibition of ATP synthase to disrupt energy production.