Source:http://linkedlifedata.com/resource/pubmed/id/15323571
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
34
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| pubmed:dateCreated |
2004-8-24
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| pubmed:abstractText |
Iron-liganding-residue mutants of ovotransferrin, Y191F and Y524F, were investigated for their Fe(3+)-binding properties. The absorption spectrum and urea gel electrophoresis verified the single iron binding on the C- and N-lobes for Y191F and Y524F, respectively. A newly developed competitive Fe(3+)-binding analysis, in which equimolar Y191F and Y524F are mixed with less Fe(3+) than saturation, enabled us to quantitatively determine the lobe preference for initial iron entry as the ratio (alpha value) of N-lobe over C-lobe. The alpha value estimated on the basis of a kinetic model was highly dependent on pH; within a pH range from 6.5 to 9.0, alpha was increased from 2 to 5 on lowering pH with an apparent sigmoid curve. On differential scanning calorimetry, single thermal transition was observed around 61 degrees C for the apo forms of Y191F, Y524F, and wild-type ovotransferrin. The Fe(3+)-loaded mutants, however, showed dual transitions at 62.4 and 82.1 degrees C in Y191F and 66.4 and 76.0 degrees C in Y524F. According to the DeltaG(AB) value that is defined as the free energy change in a target lobe induced by the iron binding on the counter lobe, marked stabilization effects by interlobe interactions were found to be induced during the major iron-binding process: upon the primary N-lobe iron binding in the iron-free C-lobe (DeltaG(AB), -2.25 kcal/mol) and upon the secondary C-lobe iron binding in the monoferric N-lobe (DeltaG(AB), -6.45 kcal/mol).
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Conalbumin,
http://linkedlifedata.com/resource/pubmed/chemical/Ferric Compounds,
http://linkedlifedata.com/resource/pubmed/chemical/Iron-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Ligands,
http://linkedlifedata.com/resource/pubmed/chemical/Peptide Fragments,
http://linkedlifedata.com/resource/pubmed/chemical/Phenylalanine,
http://linkedlifedata.com/resource/pubmed/chemical/Tyrosine
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| pubmed:status |
MEDLINE
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| pubmed:month |
Aug
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| pubmed:issn |
0006-2960
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
31
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| pubmed:volume |
43
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
11118-25
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| pubmed:meshHeading |
pubmed-meshheading:15323571-Amino Acid Sequence,
pubmed-meshheading:15323571-Animals,
pubmed-meshheading:15323571-Binding, Competitive,
pubmed-meshheading:15323571-Calorimetry, Differential Scanning,
pubmed-meshheading:15323571-Chickens,
pubmed-meshheading:15323571-Conalbumin,
pubmed-meshheading:15323571-Ferric Compounds,
pubmed-meshheading:15323571-Iron-Binding Proteins,
pubmed-meshheading:15323571-Ligands,
pubmed-meshheading:15323571-Models, Chemical,
pubmed-meshheading:15323571-Mutagenesis, Site-Directed,
pubmed-meshheading:15323571-Peptide Fragments,
pubmed-meshheading:15323571-Phenylalanine,
pubmed-meshheading:15323571-Pichia,
pubmed-meshheading:15323571-Protein Binding,
pubmed-meshheading:15323571-Protein Denaturation,
pubmed-meshheading:15323571-Thermodynamics,
pubmed-meshheading:15323571-Tyrosine
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| pubmed:year |
2004
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| pubmed:articleTitle |
Iron-binding process in the amino- and carboxyl-terminal lobes of ovotransferrin: quantitative studies utilizing single Fe3+-binding mutants.
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| pubmed:affiliation |
Division of Applied Life Sciences, The Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
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| pubmed:publicationType |
Journal Article
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