Electrochemical evidence of the redox-controlled ligand exchange of the heme in the CO-sensing transcriptional activator CooA

摘要

The GO-sensing transcriptional activator CooA contains the six-coordinate, low-spin protoheme as a CO sensor. In this work, the reduction and oxidation midpoint potentials of CooA were determined by electrochemical redox titrations, which were -320 mV and -260 mV(vs. NHE), respectively. The different midpoint potentials provide evidence for exchange of the heme axial ligand during the change in the redox state of the heme. [References: 18]