title: Binding of radioactively labeled carboxyatractyloside, atractyloside and bongkrekic acid to the ADP translocator of potato mitochondria.
abstract: 1. The inhibition of the ADP-stimulated respiration of potato mitochondria by carboxyatractyloside is relieved by high concentration of ADP or by the uncoupler carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP). Atractyloside is a much less potent inhibitor than carboxyatractyloside. The inhibition of the ADP-stimulated respiration required about 60-times more atractyloside than carboxyatractyloside. 2. [35S]carboxyatractyloside and [3H]bongkrekic acid bind to potato mitochondria with high affinity (Kd = 10 to 20 nM, n=0.6-0.7 nmol per mg protein). Added ADP competes with carboxyatractyloside for binding; on the contrary ADP increases the amount of bound bongkrekic acid. [3H]atractyloside binds to potato mitochondria with a much lower affinity (Kd=0.45 muM) than carboxyatractyloside or bongkrekic acid. 3. Bound [3H]atractyloside is displaced by ADP, carboxyatractyloside and bongkrekic acid. The displacement of bound [35S]carboxyatractyloside by bongkrekic acid and of bound [3H]bongkrekic acid by carboxyatractyloside is markedly increased by ADP. 4. Bongkrekic acid competes with [35S]carboxyatractyloside for binding. Addition of a small concentration of ADP considerably enhances the inhibitory effect of bongkrekic acid on [35S]carboxyatractyloside binding. 5. The adenine nucleotide content of potato mitochondria is of the order of 1 nmol per mg protein. ADP transport in potato mitochondria is inhibited by atractyloside 30- to 40-times less efficiently than by carboxyatractyloside.
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism* / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D001278:Atractyloside / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D001665:Binding Sites; D001865:Bongkrekic Acid / Q000378:metabolism* / Q000494:pharmacology; D006027:Glycosides / Q000378:metabolism*; D007700:Kinetics; D008566:Membranes / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D010101:Oxygen Consumption; D010940:Plant Proteins / Q000378:metabolism*; D010944:Plants / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D000900:Anti-Bacterial Agents; D006027:Glycosides; D010940:Plant Proteins; D001865:Bongkrekic Acid; D001278:Atractyloside; D000244:Adenosine Diphosphate