Details

Autor(en) / Beteiligte

• Meneghello, Marta
• Uzel, Alexandre
• Broc, Marianne
• Manuel, Rita R.
• Magalon, Axel
• Léger, Christophe
• Pereira, Inês A. C.
• Walburger, Anne
• Fourmond, Vincent

Titel

Electrochemical Kinetics Support a Second Coordination Sphere Mechanism in Metal‐Based Formate Dehydrogenase

Ist Teil von

• Angewandte Chemie International Edition, 2023-02, Vol.62 (6), p.e202212224-n/a

Auflage

International ed. in English

Ort / Verlag

Germany: Wiley Subscription Services, Inc

Erscheinungsjahr

2023

Quelle

MEDLINE

Beschreibungen/Notizen

• Metal‐based formate dehydrogenases are molybdenum or tungsten‐dependent enzymes that catalyze the interconversion between formate and CO2. According to the current consensus, the metal ion of the catalytic center in its active form is coordinated by 6 S (or 5 S and 1 Se) atoms, leaving no free coordination sites to which formate could bind to the metal. Some authors have proposed that one of the active site ligands decoordinates during turnover to allow formate binding. Another proposal is that the oxidation of formate takes place in the second coordination sphere of the metal. Here, we have used electrochemical steady‐state kinetics to elucidate the order of the steps in the catalytic cycle of two formate dehydrogenases. Our results strongly support the “second coordination sphere” hypothesis. The catalytic mechanism of Mo/W formate dehydrogenases (FDHs) is debated because the metal ion of the active site is 6‐coordinated, leaving no coordination site open for substrate binding. We have used direct electrochemistry to investigate the catalytic cycle of two homologous FDHs: our results strongly support a “second coordination sphere” mechanism.