Hydrogenase maturation enzymes

Abstract

This work is part of a comprehensive investigation of hydrogenases, aimed at understanding their reaction mechanisms, the structure of the active sites and the impact of oxygen on their inactivation. Hydrogenases, enzymes that facilitate the reversible reaction of hydrogen production by proton reduction, play a crucial role in energetic transformations involving redox reactions. This study explores the sensitivity of hydrogenases to oxygen, elucidating the impact of oxygen concentration on their redox potential and subsequent inactivation due to oxidative stress. Understanding the influence of the environment on enzyme activity is critical to developing versatile systems. The research delves into the reaction of oxygen with the H-cluster, an essential component of hydrogenases, although the specific mechanism remains unknown and a matter of debate. This study aims to unravel the intricacies of this reaction and identify sites within the H-cluster susceptible to degradation. The overall objective is to exploit this knowledge for various biotechnological applications, in particular in the development of efficient bioelectrodes for hydrogen production.
Hydrogenases emerge as promising catalysts for hydrogen production due to their high and low overpotential. Immobilization experiments on different materials, such as pyrolytic graphite electrodes, aim to create devices for biological hydrogen production. The study also explores applications in hydrogen photoelectrochemistry by providing a sustainable alternative to platinum-based catalysts. The immobilization of hydrogenases on various electrodes and their coupling with sensitized nanoparticles has shown promise, with the ultimate ambition of mimicking natural processes to produce hydrogen and oxygen from water in a light-driven water splitting cell.