Shedding light on biological hydrogen catalysis

Bio- and photocatalysis have both seen impressive development during the last decade.

Also their combination has seen great advance, and driving redox enzymes using artificial photosensitizers provides a pathway towards improved sustainability in catalysis.

It also serves as a useful tool for mechanistic investigations, as triggering a reaction with light provides a convenient entry point to time-resolved mechanistic studies.

Hydrogenases, enzymes that catalyze H+/H2 interconversion, provide an elegant example, and have been extensively studied under photocatalytic conditions.

The project outlined here will take advantage of my group’s extensive know-how and experience in hydrogenases and photocatalysis to investigate two new aspects of this photochemistry, “semi-artificial photosynthesis”, which aims at integrating living microorganisms with artificial photosensitizers; and mechanistic studies utilizing light-triggered transient spectroscopy.

In parallel, we will also improve our understanding of factors controlling the reactivity of these hydrogenases, by isolating and characterizing all four [FeFe] hydrogenases found in the model organism Clostridium perfringens.

A partner laboratory will complement our biochemical characterization of the enzymes with studies of the native organisms.

This will allow us to correlate biochemical properties of the different [FeFe] hydrogenases to their physiological function(s), and improve our understanding of anaerobic hydrogen metabolism.