Cytochrome c oxidase from eucaryotes but not from procaryotes is allosterically inhibited by ATP.
The activity of reconstituted cytochrome c oxidase from bovine heart but not from Rhodobacter sphaeroides is allosterically inhibited by intraliposomal ATP, which binds to subunit IV. The activity of cytochrome c oxidase of wild-type yeast and of a subunit VIa-deleted yeast mutant, measured with Tween 20-solubilized mitochondria in the presence of an ATP-regenerating system, was also allosterically inhibited by ATP, indicating the general validity of this mechanism of "respiratory control" in eucaryotic cytochrome c oxidases (Arnold and Kadenbach, Eur. J. Biochem. (1997) 249, 350-354). Deletion of subunit VIa changes the biphysic into monophysic kinetics of the yeast enzyme in the presence of ADP. A tenfold higher amount of horse heart cytochrome c, as compared to yeast cytochrome c, was required to relieve the ATP inhibition of the yeast enzyme.
Follmann
K
K
Fachbereich Chemie, Philipps-Universität, Marburg, Germany.
Arnold
S
S
Ferguson-Miller
S
S
Kadenbach
B
B
D000244:Adenosine Diphosphate / Q000378:metabolism / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology*; D000494:Allosteric Regulation; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D003576:Electron Transport Complex IV / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008928:Mitochondria / Q000201:enzymology; D008929:Mitochondria, Heart / Q000201:enzymology*; D009154:Mutation; D012242:Rhodobacter sphaeroides / Q000201:enzymology*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D003576:Electron Transport Complex IV