Effect of redox potential on rat liver F1-ATPase.
Redox titration of F1-ATPase from rat liver mitochondria referred to the modification of the hydrolytic activity on Mg-ATP has resulted in a three-step pattern, with three distinct jumps of activity separated by clear plateaus. The measured potentials ranged from -400 mV to +400 mV and were obtained by the addition of dithionite and ferricyanide. Electron exchange was facilitated with a mixture of different redox mediators. At pH 7.4 the midpoint potentials were +210 mV, +40 mV and -230 mV. These three midpoint potentials were displaced towards more negative values by 2,4-dinitrophenol or by an increase of the pH of the medium. The titration curves were described by n = 2 Nernst equations.
López-Zabalza
M J
MJ
Department of Biochemistry, University of Navarra, Pamplona, Spain.
Flores
F
F
Santiago
E
E
López-Moratalla
N
N
D000818:Animals; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008930:Mitochondria, Liver / Q000201:enzymology*; D010084:Oxidation-Reduction; D006180:Proton-Translocating ATPases / Q000502:physiology*; D051381:Rats
D006180:Proton-Translocating ATPases