1gjn
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The biological conversions of O(2) and peroxides to water as well as | + | 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. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Equus caballus]] | [[Category: Equus caballus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Andersson, K | + | [[Category: Andersson, K K.]] |
[[Category: Dalhus, B.]] | [[Category: Dalhus, B.]] | ||
| - | [[Category: Gorbitz, C | + | [[Category: Gorbitz, C H.]] |
| - | [[Category: Hersleth, H | + | [[Category: Hersleth, H P.]] |
[[Category: HEM]] | [[Category: HEM]] | ||
[[Category: HYD]] | [[Category: HYD]] | ||
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[[Category: reaction intermediate]] | [[Category: reaction intermediate]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:50:47 2008'' |
Revision as of 10:50, 21 February 2008
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HYDROGEN PEROXIDE DERIVED MYOGLOBIN COMPOUND II AT PH 5.2
Overview
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.
About this Structure
1GJN is a Single protein structure of sequence from Equus caballus with , and as ligands. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
An iron hydroxide moiety in the 1.35 A resolution structure of hydrogen peroxide derived myoglobin compound II at pH 5.2., Hersleth HP, Dalhus B, Gorbitz CH, Andersson KK, J Biol Inorg Chem. 2002 Mar;7(3):299-304. Epub 2001 Oct 11. PMID:11935353
Page seeded by OCA on Thu Feb 21 12:50:47 2008
Categories: Equus caballus | Single protein | Andersson, K K. | Dalhus, B. | Gorbitz, C H. | Hersleth, H P. | HEM | HYD | SO4 | Ferryl | Haem | Heme | Hydroxy radical | Monooxygenase | Oxygen activation | Peroxidase | Reaction intermediate
