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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
34
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pubmed:dateCreated |
1990-1-8
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pubmed:abstractText |
We have determined the relative affinities in solution for various metals which bind to the lone calcium-binding site of the D-galactose-binding protein which resembles the EF-hand loop. In order of affinity the metals are: Ca2+ approximately Tb3+ approximately Pb2+ greater than Cd2+ greater than Sr2+ greater than Mg2+ much greater than Ba2+. The binding affinity for calcium (Kd = 2 microM) and the slow off-rate determined for terbium (1 x 10(-3) s-1) and that the metal-binding site is unperturbed by sugar binding argue for a structural role. Furthermore, we have crystallographically refined the structure of the binding protein with the calcium substituted by cadmium, compared it with the calcium-bound structure, and found them to be identical. The results of these structural and solution studies support the hypothesis that for a given metal-binding loop, cation hydration energy, size, and charge are major factors contributing to binding affinity.
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pubmed:grant |
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0021-9258
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
5
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pubmed:volume |
264
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
20817-21
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2684986-Binding Sites,
pubmed-meshheading:2684986-Calcium,
pubmed-meshheading:2684986-Calcium-Binding Proteins,
pubmed-meshheading:2684986-Carrier Proteins,
pubmed-meshheading:2684986-Cations, Divalent,
pubmed-meshheading:2684986-Escherichia coli,
pubmed-meshheading:2684986-Galactose,
pubmed-meshheading:2684986-Kinetics,
pubmed-meshheading:2684986-Models, Molecular,
pubmed-meshheading:2684986-Monosaccharide Transport Proteins,
pubmed-meshheading:2684986-Periplasmic Binding Proteins,
pubmed-meshheading:2684986-Protein Binding,
pubmed-meshheading:2684986-Protein Conformation,
pubmed-meshheading:2684986-Terbium
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pubmed:year |
1989
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pubmed:articleTitle |
The calcium-binding site in the galactose chemoreceptor protein. Crystallographic and metal-binding studies.
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pubmed:affiliation |
Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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