Taming gas-converting metalloenzymes: (spectro)electrochemical insights
Joint seminar with the Soft Matter group at LPS
Alexandre Ciaccafava (Marseille Molecular Science Institute, France)
Metalloenzymes are at the heart of a wide range of bioenergetic processes essential to all living organisms. They are responsible for the exchange and conversion of energy by making or breaking chemical bonds with the concomitant exchange of electrons (e–) and protons (H+). They are extremely efficient biocatalysts that convert with high efficiency and affinity a multitude of substrates, from the simplest molecule such as hydrogen (H2) to much larger polymeric entities (cellulose), opening the way to high-impact biotechnological applications. Because of the biodiversity of the microorganisms from which they are derived (notably extremophiles adapted to various unusual biotopes), redox metalloenzymes can operate under a wide range of experimental conditions. Most redox enzymes contain non-noble metals (Ni, Fe, Cu, Mo,… ), assembled in a more or less complex way in the active center where their catalytic activity is located or in electronic relays that transfer electrons to other physiological partners, constituting a larger set of multi-partner electron transfer chains. As a result, redox metalloenzymes can advantageously replace chemical catalysts based on noble metals, whose scarcity generates a consequent cost, limiting their large-scale development. This set of remarkable properties shared by redox metalloenzymes has fuelled both the desire to control their reactivity and the attention of chemists to create bio-inspired catalysts. However, a thorough understanding of the functioning of redox metalloenzymes is a prerequisite for taming their exceptional properties and ultimately for their integration into biotechnological processes.