Thermal Equilibrium of High- and Low-Spin Forms of Cytochrome P450 BM-3: Repositioning of the Substrate?
We demonstrate that cytochrome P450 BM-3 in complex with N-palmitoylglycine undergoes a spin state change between room temperature, where optimal activity is seen, and low temperatures, where X-ray diffraction characterization has been carried out. On the basis of NMR measurements of the full-length...
| Publicado en: | Journal of the American Chemical Society Vol. 127; no. 39; pp. 13548 - 13553 |
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| Autores principales: | , , , |
| Formato: | Artículo |
| Publicado: |
American Chemical Society
10/5/2005
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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=18530832&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 18530832 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: 10/5/2005 vid: 127 iid: 39 pid: 997 pub: American Chemical Society artinfo: ui: 18530832 10.1021/ja0524604 ppf: 13548 ppct: 5 formats: tig: atl: Thermal Equilibrium of High- and Low-Spin Forms of Cytochrome P450 BM-3: Repositioning of the Substrate? aug: au: Jovanovic, Tijana Farid, Ramy Friesner, Richard A. McDermott, Ann E. affil: Department of Chemistry, Columbia University, New York, New York 10027. su: Cytochrome P-450 Thermal equilibrium Low temperatures Enzymes Optical diffraction Methodology sug: subj: Cytochrome P-450 Thermal equilibrium Low temperatures Enzymes Optical diffraction Methodology ab: We demonstrate that cytochrome P450 BM-3 in complex with N-palmitoylglycine undergoes a spin state change between room temperature, where optimal activity is seen, and low temperatures, where X-ray diffraction characterization has been carried out. On the basis of NMR measurements of the full-length protein, this spin state change is likely to be accompanied by a general structural rearrangement in the enzyme pocket. The substrate remains bound at all temperatures. We propose that the substrate may "slide" from a position directly atop the heme (thus displacing the ligating water) to the more distant position (thus restoring the ligating water) as the temperature is lowered. This proposal is evaluated on the basis of computational modeling of the protein-ligand complex, using a novel induced fit methodology. We thereby generate a structure with the ligand in close contact with the heme, similar in energy to the experimental structure. With this combination of theory and experiment we provide a specific proposal of how ligands may be positioned for chemistry for this enzyme. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2005 holdings: @attributes: islocal: N |
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