Bongkrekic acid. An inhibitor of the adenine nucleotide translocase of mitochondria.

The antibiotic bongkrekic acid is shown to inhibit the phosphorylation of added ADP coupled with either the reactions of the respiratory chain or the dismutation of oc-ketoglutarate in mammalian mitochondria. It also prevents the utilization of ATP for energy-linked cation transport and in energy dissipation by uncoupling agents. However, bongkrekic acid does not inhibit the Mg++-requiring ATPase of submitochondrial particles, the phosphorylation of endogenous ADP, or the stimulation of oxidation caused by arsenate. The ADP enhancement of the arsenate effect is prevented. These results distinguish its site of action from that of oligomycin (rutamytin), and indicate that bongkrekic acid inactivates translocation of adenine nucleotides into mitochondria. This is confirmed by measurement of the uptake of W-labeled adenine nucleotides. The extent of inhibition of oxidative phosphorylation by bongkrekic acid shows a sigmoidal relationship to the concentration of antibiotic, which is in contrast to the linear relationship reported for atractyloside, a known inhibitor of the translocase enzyme.