Lyophilization protects [FeFe]-hydrogenases against O2-induced H-cluster degradation

Lyophilization protects [FeFe]-hydrogenases against O2-induced H-cluster degradation

Nature has developed an impressive repertoire of metal-based enzymes that perform complex chemical reactions under moderate conditions. Catalysts that produce molecular hydrogen (H2) are particularly promising for renewable energy applications. Unfortunately, natural and chemical H2-catalysts are often irreversibly degraded by molecular oxygen (O2). Here we present a straightforward procedure b...

Aerobic Damage to [FeFe]-Hydrogenases: Activation Barriers for the Chemical Attachment of O2**

[FeFe]-hydrogenases are the best natural hydrogen-producing enzymes but their biotechnological exploitation is hampered by their extreme oxygen sensitivity. The free energy profile for the chemical attachment of O2 to the enzyme active site was investigated by using a range-separated density functional re-parametrized to reproduce high-level ab initio data. An activation free-energy barrier of ...

Computational studies of [NiFe] and [FeFe] hydrogenases.

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...

Electrochemical Measurements of the Kinetics of Inhibition of Two FeFe Hydrogenases by O2 Demonstrate That the Reaction Is Partly Reversible.

The mechanism of reaction of FeFe hydrogenases with oxygen has been debated. It is complex, apparently very dependent on the details of the protein structure, and difficult to study using conventional kinetic techniques. Here we build on our recent work on the anaerobic inactivation of the enzyme [Fourmond et al. Nat. Chem. 2014, 4, 336-342] to propose and apply a new method for studying this r...