2VLY

Crystal structure of myoglobin compound III (radiation-induced)

Summary for 2VLY

• Entry DOI: 10.2210/pdb2vly/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 2V1H 2V1I 2V1J 2V1K 2VLX 2VLZ 2VM0
• Descriptor: MYOGLOBIN, PROTOPORPHYRIN IX CONTAINING FE, OXYGEN MOLECULE, ... (7 entities in total)
• Functional Keywords: oxygen storage-transport complex, haem, iron, heme, ferryl, transport, peroxidase, oxygen transport, oxygen activation, radiolytic- reduction, reaction intermediate, monooxygenase, metal-binding, muscle protein, x-ray-induced-photoreduction
• Biological source: EQUUS CABALLUS (HORSE)
• Total number of polymer chains: 1
• Total formula weight: 18076.34

Authors

Hersleth, H.-P.,Gorbitz, C.H.,Andersson, K.K. (deposition date: 2008-01-20, release date: 2008-01-29, Last modification date: 2023-12-13)

Primary citation

Hersleth, H.-P.,Hsiao, Y.,Ryde, U.,Gorbitz, C.H.,Andersson, K.K.
The Crystal Structure of Peroxymyoglobin Generated Through Cryoradiolytic Reduction of Myoglobin Compound III During Data Collection.
Biochem.J., 412:257-, 2008

PubMed Abstract: Myoglobin has the ability to react with hydrogen peroxide, generating high-valent complexes similar to peroxidases (compounds I and II), and in the presence of excess hydrogen peroxide a third intermediate, compound III, with an oxymyoglobin-type structure is generated from compound II. The compound III is, however, easily one-electron reduced to peroxymyoglobin by synchrotron radiation during crystallographic data collection. We have generated and solved the 1.30 A (1 A=0.1 nm) resolution crystal structure of the peroxymyoglobin intermediate, which is isoelectric to compound 0 and has a Fe-O distance of 1.8 A and O-O bond of 1.3 A in accordance with a Fe(II)-O-O- (or Fe(III)-O-O2-) structure. The generation of the peroxy intermediate through reduction of compound III by X-rays shows the importance of using single-crystal microspectrophotometry when doing crystallography on metalloproteins. After having collected crystallographic data on a peroxy-generated myoglobin crystal, we were able (by a short annealing) to break the O-O bond leading to formation of compound II. These results indicate that the cryoradiolytic-generated peroxymyoglobin is biologically relevant through its conversion into compound II upon heating. Additionally, we have observed that the Xe1 site is occupied by a water molecule, which might be the leaving group in the compound II to compound III reaction.

PubMed: 18215120
DOI: 10.1042/BJ20070921

Experimental method

X-RAY DIFFRACTION (1.6 Å)