Nickel L-edge X-ray absorption spectroscopy of Pyrococcus furiosus hydrogenase

Journal Article · Wed May 10 04:00:00 EDT 1995 · Inorganic Chemistry

DOI:https://doi.org/10.1021/ic00114a006· OSTI ID:458744

Elp, J van ^[1]; Baidya, N; Mascharak, P K ^[2]

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1. Lawrence Berkeley Laboratory, CA (United States)
2. Univ. of California, Santa Cruz, CA (United States); and others

The authors have investigated the reduced, thionine-treated at 20 {degrees}C, and thionine-treated at 80 {degrees}C forms of Pyrococcus furiosus [NiFe] hydrogenase using L-edge X-ray absorption spectroscopy. At 20 {degrees}C, the Ni site is apparently not redox active, since the reduced and 20 {degrees}C thionine-treated forms exhibit the same spectra. Results of theoretical simulations as well as comparison with the spectra of mode compounds indicate the presence of high-spin Ni(II) in these forms. On the basis of a comparison with the spectral features of model nickel complexes, the nickel site in the hydorgenase appears to be 5- or 6-coordinate. The 80 {degrees}C thionine-treated form has a broader Ni L-edge centered at a higher energy, consistent with a charge distribution of at least two holes on the nickel and at least one hole significantly delocalized onto the ligand framework.

• Sponsoring Organization: USDOE
• OSTI ID: 458744
• Journal Information: Inorganic Chemistry, Journal Name: Inorganic Chemistry Journal Issue: 10 Vol. 34; ISSN 0020-1669; ISSN INOCAJ
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
55 BIOLOGY AND MEDICINE
BASIC STUDIES
ABSORPTION SPECTROSCOPY
HYDROGENASES
IRON COMPLEXES
NICKEL COMPLEXES
X-RAY SPECTROSCOPY