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PDBsum entry 4d12
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Oxidoreductase
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PDB id
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4d12
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References listed in PDB file
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Key reference
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Title
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Direct evidence for a peroxide intermediate and a reactive enzyme-Substrate-Dioxygen configuration in a cofactor-Free oxidase.
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Authors
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S.Bui,
D.Von stetten,
P.G.Jambrina,
T.Prangé,
N.Colloc'H,
D.De sanctis,
A.Royant,
E.Rosta,
R.A.Steiner.
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Ref.
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Angew Chem Int Ed Engl, 2014,
53,
13710-13714.
[DOI no: ]
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PubMed id
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Abstract
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Cofactor-free oxidases and oxygenases promote and control the reactivity of O2
with limited chemical tools at their disposal. Their mechanism of action is not
completely understood and structural information is not available for any of the
reaction intermediates. Near-atomic resolution crystallography supported by
in crystallo Raman spectroscopy and QM/MM calculations showed unambiguously
that the archetypical cofactor-free uricase catalyzes uric acid degradation via
a C5(S)-(hydro)peroxide intermediate. Low X-ray doses break specifically the
intermediate C5OO(H) bond at 100 K, thus releasing O2 in situ, which is
trapped above the substrate radical. The dose-dependent rate of bond rupture
followed by combined crystallographic and Raman analysis indicates that ionizing
radiation kick-starts both peroxide decomposition and its regeneration.
Peroxidation can be explained by a mechanism in which the substrate radical
recombines with superoxide transiently produced in the active site.
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