Kinetics and mechanism of redox-coupled, long-range proton transfer in an iron-sulfur protein. Investigation by fast-scan protein-film voltammetry

The kinetics and mechanism of redox-coupled, long-range proton transfer in an iron-sulfur protein, Azotobacter vinelandii Ferredoxin, was investigated using fast-scan protein-film voltammetry. Results conform to a model for stepwise electron and proton transfers. The system offers an intriguing functional model for redox-driven proton pumps, being both well-defined at the molecular level and amenable to detailed examination by film voltammetry.