Microorganisms make large metalloenzymes which catalyse the production and recycling of biological "solar fuels" such as O2, H2 and CO2. Using these enzymes in biotechnological applications requires that they be selected according to their particular properties or that these properties be tuned. It may be important for example that a particular enzyme resists inhibition by oxygen or work with high efficiency in one particular direction of the reaction (e.g. H2 oxidation versus H2 production). Here we shall summarise our efforts to understand the molecular determinants of catalytic bias and oxygen sensitivity in hydrogenases and CO-dehydrogenases (enzymes that catalyse the H+/H2 and CO2/CO conversion), and explain why and how these properties are affected when the enzymes are incorporated in a redox hydrogel that allows mediated electron transfer to the electrode.

References:

http://bip.cnrs-mrs.fr/bip06/~leger/

http://orcid.org/0000-0002-8871-6059