1GJN
Hydrogen Peroxide Derived Myoglobin Compound II at pH 5.2
Summary for 1GJN
| Entry DOI | 10.2210/pdb1gjn/pdb |
| Related | 1AZI 1BJE 1DWR 1DWS 1DWT 1HRM 1HSY 1RSE 1WLA 1XCH 1YMA 1YMB 1YMC |
| Descriptor | MYOGLOBIN, PROTOPORPHYRIN IX CONTAINING FE, HYDROXIDE ION, ... (5 entities in total) |
| Functional Keywords | oxygen transport, reaction intermediate, haem, heme, oxygen activation, peroxidase, monooxygenase, ferryl, hydroxy radical |
| Biological source | EQUUS CABALLUS (HORSE) |
| Total number of polymer chains | 1 |
| Total formula weight | 17809.13 |
| Authors | Hersleth, H.-P.,Dalhus, B.,Gorbitz, C.H.,Andersson, K.K. (deposition date: 2001-07-27, release date: 2002-03-01, Last modification date: 2023-12-13) |
| Primary citation | Hersleth, H.-P.,Dalhus, B.,Gorbitz, C.H.,Andersson, K.K. An Iron Hydroxide Moiety in the 1.35 A Resolution Structure of Hydrogen Peroxide Derived Myoglobin Compound II at Ph 5.2 J.Biol.Inorg.Chem., 7:299-, 2002 Cited by PubMed Abstract: The biological conversions of O(2) and peroxides to water as well as certain incorporations of oxygen atoms into small organic molecules can be catalyzed by metal ions in different clusters or cofactors. The catalytic cycle of these reactions passes through similar metal-based complexes in which one oxygen- or peroxide-derived oxygen atom is coordinated to an oxidized form of the catalytic metal center. In haem-based peroxidases or oxygenases the ferryl (Fe(IV)O) form is important in compound I and compound II, which are two and one oxidation equivalents higher than the ferric (Fe(III)) form, respectively. In this study we report the 1.35 A structure of a compound II model protein, obtained by reacting hydrogen peroxide with ferric myoglobin at pH 5.2. The molecular geometry is virtually unchanged compared to the ferric form, indicating that these reactive intermediates do not undergo large structural changes. It is further suggested that at low pH the dominating compound II resonance form is a hydroxyl radical ferric iron rather than an oxo-ferryl form, based on the short hydrogen bonding to the distal histidine (2.70 A) and the Fe...O distance. The 1.92 A Fe...O distance is in agreement with an EXAFS study of compound II in horseradish peroxidase. PubMed: 11935353DOI: 10.1007/S007750100296 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.35 Å) |
Structure validation
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