Kinetics of ATP hydrolysis catalyzed by isolated TF1 and reconstituted TF0F1 ATPase.
The rate of ATP hydrolysis catalyzed by isolated TF1 and reconstituted TF0F1 was measured as a function of the ATP concentration in the presence of inhibitors [ADP, Pi and 3'-O-(1-naphthoyl)ATP]. ATP hydrolysis can be described by Michaelis-Menten kinetics with Km(TF1) = 390 microM and Km (TF0F1) = 180 microM. The inhibition constants are for ADP Ki(TF1) = 20 microM and Ki(TF0F1) = 100 microM, for 3'-O-(1-naphthoyl)ATP Ki(TF1) = 150 microM and Ki(TF0F1) = 3 microM, and for Pi Ki(TF1) = 60 mM. From these results it is concluded that upon binding of TF0 to TF1 the mechanism of ATP hydrolysis catalyzed by TF1 is not changed qualitatively; however, the kinetic constants differ quantitatively.
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000817:Anilino Naphthalenesulfonates; D005453:Fluorescence; D006868:Hydrolysis; D007700:Kinetics; D006180:Proton-Translocating ATPases / Q000494:pharmacology*
D000817:Anilino Naphthalenesulfonates; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases