A Soret Marker Band for Four-Coordinate Ferric Heme Proteins from Absorption Spectra of Isolated Fe(III)-Heme+ and Fe(III)-Heme+(His) Ions in Vacuo
| Autor: | Morten Køcks Lykkegaard, Jean Ann Wyer, Anneli Ehlerding, Henning Zettergren, Subhasis Panja, Preben Hvelplund, Umesh Kadhane, Steen Brøndsted Nielsen, Maj-Britt Suhr Kirketerp |
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| Rok vydání: | 2008 |
| Předmět: |
Hemeprotein
Absorption spectroscopy Static Electricity Heme General Chemistry Photochemistry Ferric Compounds Biochemistry Catalysis chemistry.chemical_compound Colloid and Surface Chemistry chemistry Metmyoglobin Spectrophotometry medicine Hemin Ferric Histidine Absorption (chemistry) Spectroscopy medicine.drug |
| Zdroj: | Journal of the American Chemical Society. 130:11856-11857 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/ja803460c |
| Popis: | In this work, we report the absorption spectra in the Soret band region of isolated Fe(III)-heme+ and Fe(III)-heme+(His) ions in vacuo from action spectroscopy. Fe(III)-heme+ refers to iron(III) coordinated by the dianion of protoporphyrin IX. We find that the absorption of the five-coordinate complex is similar to that of pentacoordinate metmyoglobin variants with hydrophobic binding pockets except for an overall blueshift of about 16 nm. In the case of four-coordinate iron(III), the Soret band is similar to that of five-coordinate iron(III) but much narrower. These spectra serve as a benchmark for theoretical modeling and also serve to identify the coordination state of ferric heme proteins. To our knowledge this is the first unequivocal spectroscopic characterization of isolated 4c ferric heme in the gas phase. |
| Databáze: | OpenAIRE |
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