High-Energy-Resolution Fluorescence-Detected X‑ray Absorption of the Q Intermediate of Soluble Methane Monooxygenase.
Kα high-energy-resolution fluorescence detected X-ray absorption spectroscopy (HERFD XAS) provides a powerful tool for overcoming the limitations of conventional XAS to identify the electronic structure and coordination environment of metalloprotein active sites. Herein, Fe Kα HERFD XAS is applied t...
| Publicado en: | Journal of the American Chemical Society Vol. 139; no. 49; pp. 18024 - 18034 |
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| Autores principales: | , , , , , , , |
| Formato: | Artículo |
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American Chemical Society
12/13/2017
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| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=126761873&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 126761873 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 12/13/2017 vid: 139 iid: 49 pid: 997 pub: American Chemical Society artinfo: ui: 126761873 10.1021/jacs.7b09560 ppf: 18024 ppct: 10 formats: tig: atl: High-Energy-Resolution Fluorescence-Detected X‑ray Absorption of the Q Intermediate of Soluble Methane Monooxygenase. aug: au: Castillo, Rebeca G. Banerjee, Rahul Allpress, Caleb J. Rohde, Gregory T. Bill, Eckhard Que, Jr.,, Lawrence Lipscomb, John D. DeBeer, Serena affil: Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States su: Methane monooxygenase Iron compounds X-ray absorption Intermediates (Chemistry) Density functional theory Catalytic oxidation sug: subj: Methane monooxygenase Iron compounds X-ray absorption Intermediates (Chemistry) Density functional theory Catalytic oxidation ab: Kα high-energy-resolution fluorescence detected X-ray absorption spectroscopy (HERFD XAS) provides a powerful tool for overcoming the limitations of conventional XAS to identify the electronic structure and coordination environment of metalloprotein active sites. Herein, Fe Kα HERFD XAS is applied to the diiron active site of soluble methane monooxygenase (sMMO) and to a series of high-valent diiron model complexes, including diamond-core [Fe(μ-O)(L)](ClO)] (3) and open-core [(O= Fe-O-Fe(OH)(L)](ClO). (4) models (where, L = tris(3,5-dimethyl-4- methoxypyridyl-2-methyl)amine) (TPA*)). Pronounced differences in the HERFD XAS pre-edge energies and intensities are observed for the open versus closed Fe.O. cores in the model compounds. These differences are reproduced by time-dependent density functional theory (TDDFT) calculations and allow for the pre-edge energies and intensity to be directly correlated with the local active site geometric and electronic structure. A comparison of the model complex HERFD XAS data to that of MMOH (the key intermediate in methane oxidation) is supportive of an open-core structure. Specifically, the large pre-edge area observed for MMOH may be rationalized by invoking an open-core structure with a terminal Fe=O motif, though further modulations of the core structure due to the protein environment cannot be ruled out. The present study thus motivates the need for additional experimental and theoretical studies to unambiguously assess the active site conformation of MMOH. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2017 holdings: @attributes: islocal: N |
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