Formate Dehydrogenases Reduce CO Rather than HCO : An Electrochemical Demonstration.

Mo/W formate dehydrogenases catalyze the reversible reduction of CO species to formate. It is thought that the substrate is CO and not a hydrated species like HCO , but there is still no indisputable evidence for this, in spite of the extreme importance of the nature of the substrate for mechanistic studies. We devised a simple electrochemical method to definitively demonstrate that the substrate of formate dehydrogenases is indeed CO .