2v1e
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| , resolution 1.30Å | |||||||
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| Sites: | , , , , , and | ||||||
| Ligands: | , , , | ||||||
| Domains: | globin | ||||||
| Related: | 1AZI, 1BJE, 1DWR, 1DWS, 1DWT, 1GJN, 1HRM, 1HSY, 1NPF, 1NPG, 1NZ2, 1NZ3, 1NZ4, 1NZ5, 1RSE, 1WLA, 1XCH, 1YMA, 1YMB, 1YMC, 2FRF, 2FRI, 2FRJ, 2FRK, 2IN4, 2V1F, 2V1G, 2V1H, 2V1I, 2V1J, 2V1K
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF RADIATION-INDUCED MYOGLOBIN COMPOUND II- INTERMEDIATE H AT PH 6.8
OverviewOverview
High resolution crystal structures of myoglobin in the pH range 5.2-8.7 have been used as models for the peroxide-derived compound II intermediates in heme peroxidases and oxygenases. The observed Fe-O bond length (1.86-1.90 A) is consistent with that of a single bond. The compound II state of myoglobin in crystals was controlled by single-crystal microspectrophotometry before and after synchrotron data collection. We observe some radiation-induced changes in both compound II (resulting in intermediate H) and in the resting ferric state of myoglobin. These radiation-induced states are quite unstable, and compound II and ferric myoglobin are immediately regenerated through a short heating above the glass transition temperature (<1 s) of the crystals. It is unclear how this influences our compound II structures compared with the unaffected compound II, but some crystallographic data suggest that the influence on the Fe-O bond distance is minimal. Based on our crystallographic and spectroscopic data we suggest that for myoglobin the compound II intermediate consists of an Fe(IV)-O species with a single bond. The presence of Fe(IV) is indicated by a small isomer shift of delta = 0.07 mm/s from Mossbauer spectroscopy. Earlier quantum refinements (crystallographic refinement where the molecular-mechanics potential is replaced by a quantum chemical calculation) and density functional theory calculations suggest that this intermediate H species is protonated.
About this StructureAbout this Structure
2V1E is a Single protein structure of sequence from Equus caballus. Full crystallographic information is available from OCA.
ReferenceReference
Crystallographic and spectroscopic studies of peroxide-derived myoglobin compound II and occurrence of protonated FeIV O., Hersleth HP, Uchida T, Rohr AK, Teschner T, Schunemann V, Kitagawa T, Trautwein AX, Gorbitz CH, Andersson KK, J Biol Chem. 2007 Aug 10;282(32):23372-86. Epub 2007 Jun 12. PMID:17565988
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