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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
20
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pubmed:dateCreated |
2010-5-20
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pubmed:abstractText |
The purple acid phosphatases (PAP) are binuclear metallohydrolases that catalyze the hydrolysis of a broad range of phosphomonoester substrates. The mode of substrate binding during catalysis and the identity of the nucleophile is subject to debate. Here, we used native Fe(3+)-Fe(2+) pig PAP (uteroferrin; Uf) and its Fe(3+)-Mn(2+) derivative to investigate the effect of metal ion substitution on the mechanism of catalysis. Replacement of the Fe(2+) by Mn(2+) lowers the reactivity of Uf. However, using stopped-flow measurements it could be shown that this replacement facilitates approximately a ten-fold faster reaction between both substrate and inorganic phosphate with the chromophoric Fe(3+) site. These data also indicate that in both metal forms of Uf, phenyl phosphate hydrolysis occurs faster than formation of a mu-1,3 phosphate complex. The slower rate of interaction between substrate and the Fe(3+) site relative to catalysis suggests that the substrate is hydrolyzed while coordinated only to the divalent metal ion. The likely nucleophile is a water molecule in the second coordination sphere, activated by a hydroxide terminally coordinated to Fe(3+). The faster rates of interaction with the Fe(3+) site in the Fe(3+)-Mn(2+) derivative than the native Fe(3+)-Fe(2+) form are likely mediated via a hydrogen bond network connecting the first and second coordination spheres, and illustrate how the selection of metal ions may be important in fine-tuning the function of this enzyme.
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pubmed:grant |
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-10425678,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-10433698,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-11062342,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-11890810,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-12401084,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-1372824,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-14521509,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-15047187,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-15625111,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-15950921,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-15955057,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-16895331,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-17636903,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-17701232,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-17938975,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-18234116,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-19507905,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-19653693,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-21524,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-666864,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-7770774,
http://linkedlifedata.com/resource/pubmed/commentcorrection/20433174-8683579
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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 |
May
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pubmed:issn |
1520-5126
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pubmed:author |
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pubmed:issnType |
Electronic
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pubmed:day |
26
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pubmed:volume |
132
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
7049-54
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pubmed:dateRevised |
2011-7-28
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pubmed:meshHeading |
pubmed-meshheading:20433174-Acid Phosphatase,
pubmed-meshheading:20433174-Animals,
pubmed-meshheading:20433174-Biocatalysis,
pubmed-meshheading:20433174-Catalytic Domain,
pubmed-meshheading:20433174-Electron Transport,
pubmed-meshheading:20433174-Hydrogen-Ion Concentration,
pubmed-meshheading:20433174-Hydrolysis,
pubmed-meshheading:20433174-Iron,
pubmed-meshheading:20433174-Isoenzymes,
pubmed-meshheading:20433174-Kinetics,
pubmed-meshheading:20433174-Manganese,
pubmed-meshheading:20433174-Protein Binding,
pubmed-meshheading:20433174-Swine
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pubmed:year |
2010
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pubmed:articleTitle |
The divalent metal ion in the active site of uteroferrin modulates substrate binding and catalysis.
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pubmed:affiliation |
School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, 4072, Australia.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't,
Research Support, N.I.H., Extramural
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