The [NiFe]-Hydrogenase of Pyrococcus furiosus Exhibits a New Type of Oxygen Tolerance

Patrick Kwan, Chelsea L. McIntosh, David P. Jennings, R. Chris Hopkins, Sanjeev K. Chandrayan, Chang Hao Wu, Michael W W Adams, Anne Jones

Research output: Contribution to journalArticle

17 Scopus citations

Abstract

We report the first direct electrochemical characterization of the impact of oxygen on the hydrogen oxidation activity of an oxygen-tolerant, group 3, soluble [NiFe]-hydrogenase: hydrogenase I from Pyrococcus furiosus (PfSHI), which grows optimally near 100 °C. Chronoamperometric experiments were used to probe the sensitivity of PfSHI hydrogen oxidation activity to both brief and prolonged exposure to oxygen. For experiments between 15 and 80 °C, following short (2 under oxidizing conditions, PfSHI always maintains some fraction of its initial hydrogen oxidation activity; i.e., it is oxygen-tolerant. Reactivation experiments show that two inactive states are formed by interaction with oxygen and both can be quickly (2/ 99% H2 exposure, the H2oxidation activity drops nearly to zero. However, at 80 °C, up to 32% of the enzymes oxidation activity is retained. Reactivation of PfSHI following sustained exposure to oxygen occurs on a much longer time scale (tens of minutes), suggesting that a third inactive species predominates under these conditions. These results stand in contrast to the properties of oxygen-tolerant, group 1 [NiFe]-hydrogenases, which form a single state upon reaction with oxygen, and we propose that this new type of hydrogenase should be referred to as oxygen-resilient. Furthermore, PfSHI, like other group 3 [NiFe]-hydrogenases, does not possess the proximal [4Fe3S] cluster associated with the oxygen tolerance of some group 1 enzymes. Thus, a new mechanism is necessary to explain the observed oxygen tolerance in soluble, group 3 [NiFe]-hydrogenases, and we present a model integrating both electrochemical and spectroscopic results to define the relationships of these inactive states.

Original languageEnglish (US)
Pages (from-to)13556-13565
Number of pages10
JournalJournal of the American Chemical Society
Volume137
Issue number42
DOIs
Publication statusPublished - Oct 28 2015

    Fingerprint

ASJC Scopus subject areas

  • Chemistry(all)
  • Catalysis
  • Biochemistry
  • Colloid and Surface Chemistry

Cite this

Kwan, P., McIntosh, C. L., Jennings, D. P., Hopkins, R. C., Chandrayan, S. K., Wu, C. H., ... Jones, A. (2015). The [NiFe]-Hydrogenase of Pyrococcus furiosus Exhibits a New Type of Oxygen Tolerance. Journal of the American Chemical Society, 137(42), 13556-13565. https://doi.org/10.1021/jacs.5b07680