Cryoradiolytic reduction of crystalline heme proteins : analysis by UV-Vis spectroscopy and X-ray crystallography
The X-ray crystallographic analysis of redox-active systems may be complicated by photoreduction. Although radiolytic reduction by the probing X-ray beam may be exploited to generate otherwise short-lived reaction intermediates of metalloproteins, it is generally an undesired feature. Here, the X-ra...
| Publié dans: | Journal of synchrotron radiation. - 1994. - 14(2007), Pt 1 vom: 01. Jan., Seite 11-23 |
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| Auteur principal: | |
| Autres auteurs: | , , , |
| Format: | Article |
| Langue: | English |
| Publié: |
2007
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| Accès à la collection: | Journal of synchrotron radiation |
| Sujets: | Journal Article Research Support, Non-U.S. Gov't Hemeproteins |
| Résumé: | The X-ray crystallographic analysis of redox-active systems may be complicated by photoreduction. Although radiolytic reduction by the probing X-ray beam may be exploited to generate otherwise short-lived reaction intermediates of metalloproteins, it is generally an undesired feature. Here, the X-ray-induced reduction of the three heme proteins myoglobin, cytochrome P450cam and chloroperoxidase has been followed by on-line UV-Vis absorption spectroscopy. All three systems showed a very rapid reduction of the heme iron. In chloroperoxidase the change of the ionization state from ferric to ferrous heme is associated with a movement of the heme-coordinating water molecule. The influence of the energy of the incident X-ray photons and of the presence of scavengers on the apparent reduction rate of ferric myoglobin crystals was analyzed |
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| Description: | Date Completed 06.03.2007 Date Revised 09.01.2007 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1600-5775 |