| myo-Inositol oxygenase: a radical new pathway for O(2) and C-H activation at a nonheme diiron cluster. | |
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MedLine Citation:
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PMID: 19173070 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The enzyme myo-inositol oxygenase (MIOX) catalyzes conversion of myo-inositol (cyclohexan-1,2,3,5/4,6-hexa-ol or MI) to d-glucuronate (DG), initiating the only known pathway in humans for catabolism of the carbon skeleton of cell-signaling inositol (poly)phosphates and phosphoinositides. Recent kinetic, spectroscopic and crystallographic studies have shown that the enzyme activates its substrates, MI and O(2), at a carboxylate-bridged nonheme diiron(ii/iii) cluster, making it the first of many known nonheme diiron oxygenases to employ the mixed-valent form of its cofactor. Evidence suggests that: (1) the Fe(iii) site coordinates MI via its C1 and C6 hydroxyl groups; (2) the Fe(ii) site reversibly coordinates O(2) to produce a superoxo-diiron(iii/iii) intermediate; and (3) the pendant oxygen atom of the superoxide ligand abstracts hydrogen from C1 to initiate the unique C-C-bond-cleaving, four-electron oxidation reaction. This review recounts the studies leading to the recognition of the novel cofactor requirement and catalytic mechanism of MIOX and forecasts how remaining gaps in our understanding might be filled by additional experiments. |
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Authors:
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J Martin Bollinger; Yinghui Diao; Megan L Matthews; Gang Xing; Carsten Krebs |
Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Review Date: 2008-11-26 |
Journal Detail:
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Title: Dalton transactions (Cambridge, England : 2003) Volume: - ISSN: 1477-9226 ISO Abbreviation: Dalton Trans Publication Date: 2009 Feb |
Date Detail:
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Created Date: 2009-01-28 Completed Date: 2009-03-27 Revised Date: 2011-04-18 |
Medline Journal Info:
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Nlm Unique ID: 101176026 Medline TA: Dalton Trans Country: England |
Other Details:
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Languages: eng Pagination: 905-14 Citation Subset: IM |
Affiliation:
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Department of Chemistry, The Pennsylvania State University, Pennsylvania, PA 16802, USA. jmb21@psu.edu |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Carbon
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chemistry Catalysis Free Radicals / chemistry Glucuronates / biosynthesis, chemistry Humans Hydrogen / chemistry Inositol / chemistry Inositol Oxygenase / chemistry*, metabolism Iron / chemistry* Oxidation-Reduction Oxygen / chemistry*, metabolism |
| Grant Support | |
ID/Acronym/Agency:
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DK074641/DK/NIDDK NIH HHS; R01 DK074641-01A1/DK/NIDDK NIH HHS; R01 DK074641-02/DK/NIDDK NIH HHS; R01 DK074641-03/DK/NIDDK NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Free Radicals; 0/Glucuronates; 1333-74-0/Hydrogen; 6917-35-7/Inositol; 7439-89-6/Iron; 7440-44-0/Carbon; 7782-44-7/Oxygen; EC 1.13.99.1/Inositol Oxygenase |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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