Sulfur K-Edge X-ray Absorption Spectroscopy and Density Functional Theory Calculations on Monooxo Mo and Bisoxo Mo Bisdithiolenes: Insights into the Mechanism of Oxo Transfer in Sulfite Oxidase and Its Relation to the...
Sulfur K-edge X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations have been used to determine the electronic structures of two complexes [MolvO(bdt)2]2- and [Movl0 2(bdt)2]2- (bdt = benzene-1,2-dithiolate(2—)) that relate to the reduced and oxidized forms of sulfite...
| Publicado en: | Journal of the American Chemical Society Vol. 136; no. 25; pp. 9094 - 9106 |
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| Autores principales: | , , , , , |
| Formato: | Artículo |
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American Chemical Society
6/25/2014
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| 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=96970372&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 96970372 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: 6/25/2014 vid: 136 iid: 25 pid: 997 pub: American Chemical Society artinfo: ui: 96970372 10.1021/ja503316p ppf: 9094 ppct: 12 formats: tig: atl: Sulfur K-Edge X-ray Absorption Spectroscopy and Density Functional Theory Calculations on Monooxo Mo and Bisoxo Mo Bisdithiolenes: Insights into the Mechanism of Oxo Transfer in Sulfite Oxidase and Its Relation to the... aug: au: Yang Ha Tenderholt, Adam L. Holm, Richard H. Hedman, Britt Hodgson, Keith O. Solomon, Edward I. affil: Department of Chemistry, Stanford University, Stanford, California 94305, United States Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States Stanford Synchrotron Radiation Lightsource, SLAC, Stanford University, Menlo Park, California 94025, United States su: Electronic structure X-ray absorption Density functional theory Molybdenum compounds Oxo compounds Dimethyl sulfoxide reductase Energy transfer sug: subj: Electronic structure X-ray absorption Density functional theory Molybdenum compounds Oxo compounds Dimethyl sulfoxide reductase Energy transfer ab: Sulfur K-edge X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations have been used to determine the electronic structures of two complexes [MolvO(bdt)2]2- and [Movl0 2(bdt)2]2- (bdt = benzene-1,2-dithiolate(2—)) that relate to the reduced and oxidized forms of sulfite oxidase (SO). These are compared with those of previously studied dimethyl sulfoxide reductase (DMSOr) models. DFT calculations supported by the data are extended to evaluate the reaction coordinate for oxo transfer to a phosphite ester substrate. Three possible transition states are found with the one at lowest energy, stabilized by a P—S interaction, in good agreement with experimental kinetics data. Comparison of both oxo transfer reactions shows that in DMSOr, where the oxo is transferred from the substrate to the metal ion, the oxo transfer induces electron transfer, while in SO, where the oxo transfer is from the metal site to the substrate, the electron transfer initiates oxo transfer. This difference in reactivity is related to the difference in frontier molecular orbitals (FMO) of the metal—oxo and substrate—oxo bonds. Finally, these experimentally related calculations are extended to oxo transfer by sulfite oxidase. The presence of only one dithiolene at the enzyme active site selectively activates the equatorial oxo for transfer, and allows facile structural reorganization during turnover. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2014 holdings: @attributes: islocal: N |
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