O2 Inhibition of Ni‐Containing CO Dehydrogenase Is Partly Reversible. Issue 52 (16th November 2015)

• Record Type: Journal Article
• Authors: Merrouch, Meriem; Hadj‐Saïd, Jessica; Domnik, Lilith; Dobbek, Holger; Léger, Christophe; Dementin, Sébastien; Fourmond, Vincent
• Is Part Of: Chemistry. Volume 21:Issue 52(2015)
• Page Start: 18934
• Page End: 18938
• Publication Date: 2015-11-16
• Subjects: bioinorganic chemistry -- CO dehydrogenase -- metalloenzymes -- protein film voltammetry; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201502835
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Ni‐containing CO dehydrogenases (CODHs) are very efficient metalloenzymes that catalyze the conversion between CO2 and CO. They are a source of inspiration for designing CO2 ‐reduction catalysts and can also find direct use in biotechnology. They are deemed extremely sensitive to O2, but very little is known about this aspect of their reactivity. We investigated the reaction with O2 of Carboxydothermus hydrogenoformans ( Ch ) CODH II and the homologous, recently characterized CODH from Desulfovibrio vulgaris ( Dv ) through protein film voltammetry and solution assays (in the oxidative direction). We found that O2 reacts very quickly with the active site of CODHs, generating species that reactivate upon reduction—this was unexpected. We observed that distinct CODHs exhibit different behaviors: Dv CODH reacts half as fast with O2 than Ch CODH, and only the former fully recovers the activity upon reduction. The results raise hope that fast CO/CO2 biological conversion may be feasible under aerobic conditions. Abstract : More resistant than expected: NiFe CO dehydrogenases (CODHs), which catalyze the interconversion between CO2 and CO, have always been considered as extremely sensitive to O2 . In contrast, the results presented here show that they are reductively reactivated after aerobic inhibition. Oxygen sensitivity varies greatly between the two CODHs that were characterized; suggesting that oxygen‐tolerant CODHs may exist.