Spectroscopic and Density Functional Theory Studies of the Blue—Copper Site in M121SeM and C112SeC Azurin: Cu—Se Versus Cu—S Bonding.
S K-edge X-ray absorption, UV-vis absorption, magnetic circular dichroism (MCD), and resonance Raman spectroscopies are used to investigate the electronic structure differences among WT, M121SeM, and C112SeC Pseudomonas aeruginosa (P.a) azurin. A comparison of S K-edge XAS of WT and M121SeM azurin a...
| Publicado en: | Journal of the American Chemical Society Vol. 130; no. 12; pp. 3866 - 3878 |
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| Autores principales: | , , , , , , , , , |
| Formato: | Artículo |
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American Chemical Society
3/26/2008
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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=31566098&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 31566098 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: 3/26/2008 vid: 130 iid: 12 pid: 997 pub: American Chemical Society artinfo: ui: 31566098 10.1021/ja076495a ppf: 3866 ppct: 12 formats: tig: atl: Spectroscopic and Density Functional Theory Studies of the Blue—Copper Site in M121SeM and C112SeC Azurin: Cu—Se Versus Cu—S Bonding. aug: au: Sarangi, Ritimukta Gorelsky, Serge I. Basumallick, Lipika Hee Jung Hwang Pratt, Russell C. Stack, T. Daniel P. Yi Lu Hodgson, Keith O. Hedman, Britt Solomon, Edward I. affil: Department of Chemistry, Stanford University, Stanford, California 94305 Center for Catalysis Research and Innovation, Department of Chemistry, University of Ottawa, Ottawa, Ontario KIN 6N5, Canada Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana—Champaign, Urbana, Illinois 61801 Stanford Synchrotron Radiation Laboratory Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309 su: Copper proteins Electronic structure Chemical bonds Raman spectroscopy Density functionals Binding sites sug: subj: Copper proteins Electronic structure Chemical bonds Raman spectroscopy Density functionals Binding sites ab: S K-edge X-ray absorption, UV-vis absorption, magnetic circular dichroism (MCD), and resonance Raman spectroscopies are used to investigate the electronic structure differences among WT, M121SeM, and C112SeC Pseudomonas aeruginosa (P.a) azurin. A comparison of S K-edge XAS of WT and M121SeM azurin and a Cu-thioether model complex shows that the 38% S character in the ground state wave function of the blue-copper (BC) sites solely reflects the Cu-S bond. Resonance Raman (rR) data on WI and C112SeC azurin give direct evidence for the kinematic coupling between the Cu-S stretch and the cysteine deformation modes in WT azurin, which leads to multiple features in the rR spectrum of the BC site. The UV-vis absorption and MCD data on WT, M121SeM, and C112SeC give very similar Go/Do ratios, indicating that the G-term MCD intensity mechanism involves Cu-centered spin-orbit coupling (SOC). The spectroscopic data combined with density functional theory (DFT) calculations indicate that S and Se have similar covalent interactions with Cu at their respective bond lengths of 2.1 and 2.3 Å. This reflects the similar electronegativites of S and Se in the thiolate/selenolate ligand fragment and explains the strong spectroscopic similarities between WT and C112SeC azurin. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2008 holdings: @attributes: islocal: N |
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