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PDBsum entry 4pqb
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Oxygen transport
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PDB id
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4pqb
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References listed in PDB file
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Key reference
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Title
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Regulating the coordination state of a heme protein by a designed distal hydrogen-Bonding network.
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Authors
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J.F.Du,
W.Li,
L.Li,
G.B.Wen,
Y.W.Lin,
X.Tan.
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Ref.
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Chemistryopen, 2015,
4,
97.
[DOI no: ]
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PubMed id
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Abstract
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Heme coordination state determines the functional diversity of heme proteins.
Using myoglobin as a model protein, we designed a distal hydrogen-bonding
network by introducing both distal glutamic acid (Glu29) and histidine (His43)
residues and regulated the heme into a bis-His coordination state with native
ligands His64 and His93. This resembles the heme site in natural bis-His
coordinated heme proteins such as cytoglobin and neuroglobin. A single mutation
of L29E or F43H was found to form a distinct hydrogen-bonding network involving
distal water molecules, instead of the bis-His heme coordination, which
highlights the importance of the combination of multiple hydrogen-bonding
interactions to regulate the heme coordination state. Kinetic studies further
revealed that direct coordination of distal His64 to the heme iron negatively
regulates fluoride binding and hydrogen peroxide activation by competing with
the exogenous ligands. The new approach developed in this study can be generally
applicable for fine-tuning the structure and function of heme proteins.
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