Stepwise O2 -Induced Rearrangement and Disassembly of the [NiFe4 (OH)(µ3 -S)4 ] Active Site Cluster of CO Dehydrogenase.
Angew Chem Int Ed Engl
; 62(32): e202305341, 2023 08 07.
Article
en En
| MEDLINE
| ID: mdl-37279092
ABSTRACT
Ni,Fe-containing carbon monoxide dehydrogenases (CODHs) catalyze the reversible reduction of carbon dioxide to carbon monoxide. CODHs are found in anaerobic microorganisms and can rapidly lose their activity when exposed to air. What causes the loss of activity is unclear. In this study, we analyzed the time-dependent structural changes induced by the presence of air on the metal centers of CODH-II. We show that inactivation is a multistep process. In a reversible step, the open coordination site on the Ni ion is blocked by a Ni,Fe-bridging µ-sulfido or chlorido ligand. Blocking this open coordination site with a cyanide ligand stabilizes the cluster against O2 -induced decomposition, indicating that O2 attacks at the Ni ion. In the subsequent irreversible phase, nickel is lost, the Fe ions rearrange and the sulfido ligands disappear. Our data are consistent with a reversible reductive reactivation mechanism to protect CODHs from transient over-oxidation.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Monóxido de Carbono
/
Aldehído Oxidorreductasas
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Año:
2023
Tipo del documento:
Article
País de afiliación:
Alemania