Spectroelectrochemical investigation of Azotobacter vinelandii bacterial ferritin

Bacterial ferritin of Azotobacter vinelandii (AvBF) contains a function in accepting electrons from platinum electrode directly for complete iron release in the absence of a mediator. The reduction potentials of electron tunnels of -125, -310, and -370 mV for iron release are determined by direct spectroelectrochemical technique, which suggests which should be defined as midpoint potentials of electron-tunnel-heme on the surface of protein shell. A kinetic study for complete iron release by the electrode reduction at -600 mV fits the zero-order reaction law. (C) 1998 Elsevier Science S.A.