[Kinetic evidence of the interaction of three nucleotide-binding centers of mitochondrial ATP-synthetase].
It is shown that methanol significantly decreases the rate of ATP-dependent activation of submitochondrial particle ATPase blocked by low (approximately 1 microM) ADP concentrations, having an insignificant effect on the initial rate of ATP hydrolysis. The dissociation rate constant for the F1.ADP complex (Kd = approximately 2.10(-8) M) decreases thereby from 0.28 to 0.12 min-1. Within a narrow range of ADP concentrations (2-40 microM) used to inhibit ATPase, the activation rate constant measured in the presence of methanol changes from the minimum (0.12 min-1) to the maximum (0.48 min-1) value. The rate of dissociation of the enzyme-inhibitor complexes formed in the presence of low (approximately 1 microM) or high (greater than or equal to 40 microM) ADP concentrations depends on the concentration of ATP in a similar way. In the presence of EDTA, the enzyme-inhibitor complex (ADP.F1.ADP) is activated within 1-3 minutes, whereas the dissociation of the F1.ADP complex proceeds on an hour scale. The results obtained are interpreted as the interaction of at least three nucleotide-binding sites in the membrane-bound F1.
Bulygin
V V
VV
Vinogradov
A D
AD
D000818:Animals; D001665:Binding Sites; D002417:Cattle; D004492:Edetic Acid / Q000494:pharmacology; D004789:Enzyme Activation; D007700:Kinetics; D000432:Methanol / Q000494:pharmacology; D008929:Mitochondria, Heart / Q000201:enzymology*; D009711:Nucleotides / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013367:Submitochondrial Particles / Q000201:enzymology*; D013447:Sulfites / Q000494:pharmacology
D009711:Nucleotides; D013447:Sulfites; D004492:Edetic Acid; D006180:Proton-Translocating ATPases; D000432:Methanol
Kineticheskie proiavleniia vzaimodeĭstviia trekh nukleotid- sviazyvaiushchikh tsentrov mitokhondrial'noĭ ATP-sintetazy.