2V1H

Crystal structure of radiation-induced metmyoglobin - aqua ferrous myoglobin at pH 5.2

Summary for 2V1H

• Entry DOI: 10.2210/pdb2v1h/pdb
• 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 2V1E 2V1F 2V1G 2V1I 2V1J 2V1K
• Descriptor: MYOGLOBIN, PROTOPORPHYRIN IX CONTAINING FE, SULFATE ION, ... (5 entities in total)
• Functional Keywords: oxygen transport, oxygen activation, radiation, monooxygenase, metal-binding, muscle protein, reaction intermediate, iron, heme, transport, haem
• Biological source: EQUUS CABALLUS (HORSE)
• Total number of polymer chains: 1
• Total formula weight: 18160.50

Authors

Hersleth, H.-P.,Gorbitz, C.H.,Andersson, K.K. (deposition date: 2007-05-24, release date: 2007-06-12, Last modification date: 2023-12-13)

Primary citation

Hersleth, H.-P.,Uchida, T.,Rohr, A.K.,Teschner, T.,Schunemann, V.,Kitagawa, T.,Trautwein, A.X.,Gorbitz, C.H.,Andersson, K.K.
Crystallographic and Spectroscopic Studies of Peroxide-Derived Myoglobin Compound II and Occurrence of Protonated Fe(Iv)-O
J.Biol.Chem., 282:23372-, 2007

PubMed Abstract: 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 Mössbauer 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.

PubMed: 17565988
DOI: 10.1074/JBC.M701948200

Experimental method

X-RAY DIFFRACTION (1.3 Å)