Effects of a water environment on the structure and H2 production of the [FeFe]H cluster of di-iron hydrogenase

Federico Zipoli, Roberto Car, Morrel H. Cohen, G. Charles Dismukes, Annabella Selloni

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

In previous work [1] we showed that the CO-bridging configuration had to be stable for the [FeFe]H cluster of hydrogenase to function as an efficient hydrogen-production catalyst. We found that in vacuo, however, the CO-terminal configuration was slightly more stable and would effectively stop catalytic action. In practice, the catalyst would be linked to the surface of an electrode of the surface of a photovoltaic device and immersed in water. Accordingly, we have investigated by first principles molecular dynamics simulations the effects of a water environment on the structure, stability, and activity of the cluster with a candidate linking moiety. We found a remarkable competition for protons among the five plausible protonation sites of the [FeFe]H cluster in its various charge states. The most significant effect found is the stabilization of the bridging configuration by water molecules weakly hydrogen bonded to the protonated distal CN ligand. This finding supports the interpretation of the stability of the bridging configuration in the enzyme as due to hydrogen bonding of the distal CN to a cysteine residue in the protein backbone. Consequences for the H2 production cycle and link stability will be discussed as well.

Original languageEnglish
Title of host publicationAmerican Chemical Society - 237th National Meeting and Exposition, ACS 2009, Abstracts of Scientific Papers
Publication statusPublished - Dec 1 2009
Event237th National Meeting and Exposition of the American Chemical Society, ACS 2009 - Salt Lake City, UT, United States
Duration: Mar 22 2009Mar 26 2009

Publication series

NameACS National Meeting Book of Abstracts
ISSN (Print)0065-7727

Other

Other237th National Meeting and Exposition of the American Chemical Society, ACS 2009
CountryUnited States
CitySalt Lake City, UT
Period3/22/093/26/09

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ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)

Cite this

Zipoli, F., Car, R., Cohen, M. H., Dismukes, G. C., & Selloni, A. (2009). Effects of a water environment on the structure and H2 production of the [FeFe]H cluster of di-iron hydrogenase. In American Chemical Society - 237th National Meeting and Exposition, ACS 2009, Abstracts of Scientific Papers (ACS National Meeting Book of Abstracts).