The Electron-Transfer Kinetics of Spinach Ferredoxin with Strong Reductants
Format of Original
8 p.; 25 cm
Biochimica et Biophysica Acta: Bioenergetics
Original Item ID
The reduction of spinach ferredoxin by V(II)-EDTA, Eu(II)-DPTA and propylene viologen was monitored electrochemically. The rates of these reactions were found to be 3.0 · 104, 3.2 · 105 and 1.2 · 105 M−1 · s−1, respectively, by the use of chronoamperometry, pulse polarography, differential pulse polarography and rotating-disk voltammetry. These reaction rates were analyzed by tunneling theory for electron transfers, and the comparisons between the theoretical and experimental values were quite good. The tunneling theory also worked quite well with other ferredoxin electron-transfer rates that are available in the literature. In addition to that, the activation enthalpy and entropy compared well with the tunneling theory.