Dynamic electrochemical experiments on hydrogenases

A powerful approach for studying hydrogenases, applying a suite of dynamic electrochemical techniques known as protein film electrochemistry, is trailblazing fresh discoveries and providing a wealth of quantitative data on these complex enzymes. The information now stemming from experiments on tiny quantities of hydrogenases ranges from their kinetics and catalytic bias (a preference to operate in H-2 oxidation vs. H-2 production) to wide differences in the ways they react with oxygen and other inhibitors. Tolerance of hydrogenase catalysis to oxygen is essential if organisms are to be exploited for photosynthetic hydrogen production, and is crucial in enabling aerobes to use trace H-2 as an energy source. Experiments described in this article may be adapted for other complex enzymes.