Oligomycin A is an inhibitor of ATP synthase. In oxidative phosphorylation research, it is used to prevent state 3 (phosphorylating) respiration. Oligomycin A inhibits ATP synthase by blocking its proton channel (Fo subunit), which is necessary for oxidative phosphorylation of ADP to ATP (energy production). The inhibition of ATP synthesis by oligomycin A will significantly reduce electron flow through the electron transport chain; however, electron flow is not stopped completely due to a process known as proton leak or mitochondrial uncoupling. This process is due to the facilitated diffusion of protons into the mitochondrial matrix through an uncoupling protein such as thermogenin, or UCP1. Oligomycin, inhibitor of F(0)F(1)-ATPase, prevented hypoxia-induced HIF-1alpha protein accumulation and had no effect on HIF-1alpha induction by hypoxia-mimicking agents desferrioxamine or dimethyloxalylglycine.
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