Saturation kinetics of coenzyme Q in NADH and succinate oxidation in beef heart mitochondria.
The saturation kinetics of NADH and succinate oxidation for Coenzyme Q (CoQ) has been re-investigated in pentane-extracted lyophilized beef heart mitochondria reconstituted with exogenous CoQ10. The apparent 'Km' for CoQ10 was one order of magnitude lower in succinate cytochrome c reductase than in NADH cytochrome c reductase. The Km value in NADH oxidation approaches the natural CoQ content of beef heart mitochondria, whereas that in succinate oxidation is close to the content of respiratory chain enzymes.
Estornell
E
E
Dipartimento di Biochimica, University of Bologna, Italy.
Fato
R
R
Castelluccio
C
C
Cavazzoni
M
M
Parenti Castelli
G
G
Lenaz
G
G
D000818:Animals; D002417:Cattle; D007700:Kinetics; D008929:Mitochondria, Heart / Q000201:enzymology / Q000378:metabolism*; D009243:NAD / Q000378:metabolism*; D009245:NADH Dehydrogenase / Q000378:metabolism; D010084:Oxidation-Reduction; D013384:Succinate Cytochrome c Oxidoreductase / Q000378:metabolism; D013386:Succinates / Q000378:metabolism*; D019802:Succinic Acid; D014451:Ubiquinone / Q000378:metabolism*
D013386:Succinates; D009243:NAD; D014451:Ubiquinone; D019802:Succinic Acid; D013384:Succinate Cytochrome c Oxidoreductase; D009245:NADH Dehydrogenase