Cell respiration is controlled by ATP, an allosteric inhibitor of cytochrome-c oxidase.
The activity of cytochrome-c oxidase, the terminal enzyme of the mitochondrial respiratory chain, is known to be regulated by the substrate pressure, i.e. the ferro-/ferricytochrome c ratio, by the oxygen concentration, and by the electrochemical proton gradient delta muH+ across the inner mitochondrial membrane. Here we describe a further mechanism of 'respiratory control' via allosteric inhibition of cytochrome-c oxidase by ATP, which binds to the matrix domain, of subunit IV. The cooperativity between cytochrome-c-binding sites in the dimeric enzyme complex is mediated by cardiolipin, which is essential for cooperativity of the enzyme within the lipid membrane.
Arnold
S
S
Fachbereich Chemie, Philipps-Universität, Marburg, Germany.
Kadenbach
B
B
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000494:Allosteric Regulation; D000818:Animals; D001665:Binding Sites; D002308:Cardiolipins / Q000378:metabolism; D019069:Cell Respiration / Q000502:physiology*; D019281:Dimerization; D003576:Electron Transport Complex IV / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008563:Membrane Lipids / Q000378:metabolism; D008929:Mitochondria, Heart / Q000378:metabolism; D011487:Protein Conformation; D014413:Tuna / Q000378:metabolism
D002308:Cardiolipins; D004791:Enzyme Inhibitors; D008563:Membrane Lipids; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D003576:Electron Transport Complex IV