[FeFe]-hydrogenases are highly efficient H-2-evolving metalloenzymes that include cyanides and carbonyls in the active site. The latter is an Fe6S6 cluster (the so-called H-cluster) that can be subdivided into a binuclear portion carrying the CO and CN- groups and a tetranuclear subcluster. The fundamental role of cyanide ligands in increasing the basicity of the H-cluster has been highlighted previously. Here a more subtle but crucial role played by the two CN- ligands in the active site of [FeFe]-hydrogenases is disclosed. In fact, QM/MM calculations on all-atom models of the enzyme from Desulfovibrio desulfuricans show that the cyanide groups fine-tune the electronic and redox properties of the active site, affecting both the protonation regiochemistry and electron transfer between the two subclusters of the H-cluster. Despite the crucial role of cyanides in the protein active site, the currently available bioinspired electrocatalysts generally lack CN- groups in order to avoid competition between the latter and the catalytic metal centers for proton binding. In this respect, we show that a targeted inclusion of phosphine ligands in hexanuclear biomimetic clusters may restore the electronic and redox features of the wild-type H-cluster.

Bruschi, M., Greco, C., Bertini, L., Fantucci, P., Ryde, U., DE GIOIA, L. (2010). Functionally relevant interplay between the Fe4S4 cluster and CN- ligands in the active site of [FeFe]-Hydrogenases. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 132(14), 4992-4993 [10.1021/ja1008773].

Functionally relevant interplay between the Fe4S4 cluster and CN- ligands in the active site of [FeFe]-Hydrogenases

BRUSCHI, MAURIZIO;GRECO, CLAUDIO;BERTINI, LUCA;FANTUCCI, PIERCARLO;DE GIOIA, LUCA
2010

Abstract

[FeFe]-hydrogenases are highly efficient H-2-evolving metalloenzymes that include cyanides and carbonyls in the active site. The latter is an Fe6S6 cluster (the so-called H-cluster) that can be subdivided into a binuclear portion carrying the CO and CN- groups and a tetranuclear subcluster. The fundamental role of cyanide ligands in increasing the basicity of the H-cluster has been highlighted previously. Here a more subtle but crucial role played by the two CN- ligands in the active site of [FeFe]-hydrogenases is disclosed. In fact, QM/MM calculations on all-atom models of the enzyme from Desulfovibrio desulfuricans show that the cyanide groups fine-tune the electronic and redox properties of the active site, affecting both the protonation regiochemistry and electron transfer between the two subclusters of the H-cluster. Despite the crucial role of cyanides in the protein active site, the currently available bioinspired electrocatalysts generally lack CN- groups in order to avoid competition between the latter and the catalytic metal centers for proton binding. In this respect, we show that a targeted inclusion of phosphine ligands in hexanuclear biomimetic clusters may restore the electronic and redox features of the wild-type H-cluster.
Articolo in rivista - Articolo scientifico
FE-ONLY HYDROGENASE; H-CLUSTER; REDUCTION; COMPLEXES; EVOLUTION; ELECTRON TRANSFER
English
2010
132
14
4992
4993
none
Bruschi, M., Greco, C., Bertini, L., Fantucci, P., Ryde, U., DE GIOIA, L. (2010). Functionally relevant interplay between the Fe4S4 cluster and CN- ligands in the active site of [FeFe]-Hydrogenases. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 132(14), 4992-4993 [10.1021/ja1008773].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/10695
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