ADP increases the affinity for cytochrome c by interaction with the matrix side of bovine heart cytochrome c oxidase.
The effect of intraliposomal ADP and ATP on the kinetics of cytochrome c oxidation in reconstituted bovine heart cytochrome c oxidase was measured by the photometric and polarographic method: 1. Intraliposomal ADP decreases and intraliposomal ATP increases the Km for cytochrome c when measured by the photometric assay under uncoupled conditions. 2. The above described effects are not obtained when the kinetics are measured with the polarographic assay. 3. Extraliposomal ATP increases the Km for cytochrome c similar to intraliposomal ATP, but this effect is measured with both methods of assay. 4. Under coupled conditions only a small decrease of the Km for cytochrome c by intraliposomal ADP is found.
Hüther
F J
FJ
Fachbereich Chemie, Biochemie, Philipps-Universität, Marburg, F.R.G.
Kadenbach
B
B
D000244:Adenosine Diphosphate / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000494:Allosteric Regulation; D000818:Animals; D002417:Cattle; D002451:Cell Compartmentation; D003574:Cytochrome c Group / Q000378:metabolism*; D003576:Electron Transport Complex IV / Q000378:metabolism*; D008081:Liposomes; D008929:Mitochondria, Heart / Q000378:metabolism* / Q000648:ultrastructure; D014475:Uncoupling Agents / Q000494:pharmacology
D003574:Cytochrome c Group; D008081:Liposomes; D014475:Uncoupling Agents; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D003576:Electron Transport Complex IV