ACS Catalysis
ACS Catalysis
5 years ago

Photoinhibition of FeFe Hydrogenase

Photoinhibition of FeFe Hydrogenase
Luca de Gioia, Matteo Sensi, Isabelle Meynial-Salles, Carole Baffert, Philippe Soucaille, Laura Fradale, Luca Bertini, Christophe Léger, Vincent Fourmond, Charles Gauquelin, Maurizio Bruschi, Hervé Bottin
In the enzyme FeFe hydrogenase, hydrogen oxidation and production occur at the H-cluster, a Fe6S6 active site that bears intrinsic carbonyl and cyanide ligands. This enzyme has been coupled to photosensitizers to design H2 photoproduction systems, and yet, according to earlier reports, the enzyme from Desulfovibrio desulfuricans is “easily destroyed” in “normal laboratory light”. Here we report direct electrochemistry measurements of the effect of light on the activity of the enzymes from Chlamydomonas reinhardtii and Clostridium acetobutylicum, together with TDDFT and DFT calculations of the reactivity of the excited states of the H-cluster. We conclude that visible light does not inhibit these enzymes, but absorption of UVB (280–315 nm) irreversibly damages the H-cluster by triggering the release of an intrinsic CO ligand; the resulting unsaturated species rearranges and protonates to form a stable, inactive dead-end. Answering the question of which particular hydrogenase can resist which particular wavelengths is important regarding solar H2 production, and our results show that some but not all FeFe hydrogenases can actually be combined with photosensitizers that utilize the solar spectrum, provided a UV screen is used. We suggest that further investigations of the compatibility of hydrogenases or hydrogenase mimics with light-harvesting systems should also consider the possibility of irreversible photoinhibition.

Publisher URL: http://dx.doi.org/10.1021/acscatal.7b02252

DOI: 10.1021/acscatal.7b02252

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.