Electric-field effects on the [FeFe]-hydrogenase active site

Synthetic [FeFe] Hydrogenase Active Site Model Complexes

Spectroelectrochemical characterization of the active site of the [FeFe] hydrogenase HydA1 from Chlamydomonas reinhardtii.

Hydrogenases catalyze the reversible oxidation of molecular hydrogen. The active site of the [FeFe] hydrogenases (H-cluster) contains a catalytically active binuclear subcluster ([2Fe](H)) connected to a "cubane" [4Fe4S](H) subcluster. Here we present an IR spectroelectrochemical study of the [FeFe] hydrogenase HydA1 isolated from the green alga Chlamydomonas reinhardtii. The enzyme shows IR ba...

O2 reduction and O2-induced damage at the active site of FeFe hydrogenase

FeFe hydrogenases are the most efficient H2 producing enzymes, but inactivation by O2 is an obstacle to using them in biotechnological devices. Here we combine electrochemistry, sitedirected mutagenesis, molecular dynamics and quantum chemical calculations to uncover the molecular mechanism of O2 diffusion within the enzyme and its reactions at the active site. We find that the partial reversib...

1H NMR Spectroscopy of [FeFe] Hydrogenase: Insight into the Electronic Structure of the Active Site

The [FeFe] hydrogenase HydA1 from Chlamydomonas reinhardtii has been studied using 1H NMR spectroscopy identifying the paramagnetically shifted 1H resonances associated with both the [4Fe-4S]H and the [2Fe]H subclusters of the active site "H-cluster". The signal pattern of the unmaturated HydA1 containing only [4Fe-4S]H is reminiscent of bacterial-type ferredoxins. The spectra of maturated HydA...

Coordination and conformational isomers in mononuclear iron complexes with pertinence to the [FeFe] hydrogenase active site.

A series of six mononuclear iron complexes of the type [Fe(X-bdt)(P(R)2N(Ph)2)(CO)] (P(R)2N(Ph)2 = 1,5-diaza-3,7-diphosphaoctane, bdt = benzenedithiolate with X = H, Cl2 or Me and R = Ph, Bn, Cyc or tert-Bu) was prepared. This new class of penta-coordinate iron complexes contains a free coordination site and a pendant base as essential structural features of the [FeFe]-hydrogenase active site. ...