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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3
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pubmed:dateCreated |
1994-2-28
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pubmed:abstractText |
The mechanism of irreversible inactivation of mandelate racemase (MR) from Pseudomonas putida by alpha-phenylglycidate (alpha PGA) has been investigated stereochemically and crystallographically. The (R) and (S) enantiomers of alpha PGA were synthesized in high enantiomeric excess (81% ee and 83% ee, respectively) using Sharpless epoxidation chemistry. (R)-alpha PGA was determined to be a stereospecific and stoichiometric irreversible inactivator of MR. (S)-alpha PGA does not inactivate MR and appears to bind noncovalently to the active site of MR with less affinity than that of (R)-alpha PGA. The X-ray crystal structure (2.0-A resolution) of MR inactivated by (R)-alpha PGA revealed the presence of a covalent adduct formed by nucleophilic attack of the epsilon-amino group of Lys 166 on the distal carbon on the epoxide ring of (R)-alpha PGA. The proximity of the alpha-proton of (S)-mandelate to Lys 166 [configurationally equivalent to (R)-alpha PGA] was corroborated by the crystal structure (2.1-A resolution) of MR complexed with the substrate analog/competitive inhibitor, (S)-atrolactate [(S)-alpha-methylmandelate]. These results support the proposal that Lys 166 is the polyvalent acid/base responsible for proton transfers on the (S) face of mandelate. In addition, the high-resolution structures also provide insight into the probable interactions of mandelate with the essential Mg2+ and functional groups in the active site.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Epoxy Compounds,
http://linkedlifedata.com/resource/pubmed/chemical/Ligands,
http://linkedlifedata.com/resource/pubmed/chemical/Lysine,
http://linkedlifedata.com/resource/pubmed/chemical/Phenylpropionates,
http://linkedlifedata.com/resource/pubmed/chemical/Racemases and Epimerases,
http://linkedlifedata.com/resource/pubmed/chemical/alpha-phenylglycidate,
http://linkedlifedata.com/resource/pubmed/chemical/mandelate racemase
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pubmed:status |
MEDLINE
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pubmed:month |
Jan
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
25
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pubmed:volume |
33
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
635-43
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:8292591-Alkylation,
pubmed-meshheading:8292591-Crystallography, X-Ray,
pubmed-meshheading:8292591-Epoxy Compounds,
pubmed-meshheading:8292591-Hydrogen-Ion Concentration,
pubmed-meshheading:8292591-Ligands,
pubmed-meshheading:8292591-Lysine,
pubmed-meshheading:8292591-Models, Molecular,
pubmed-meshheading:8292591-Phenylpropionates,
pubmed-meshheading:8292591-Protein Conformation,
pubmed-meshheading:8292591-Pseudomonas putida,
pubmed-meshheading:8292591-Racemases and Epimerases,
pubmed-meshheading:8292591-Stereoisomerism
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pubmed:year |
1994
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pubmed:articleTitle |
The role of lysine 166 in the mechanism of mandelate racemase from Pseudomonas putida: mechanistic and crystallographic evidence for stereospecific alkylation by (R)-alpha-phenylglycidate.
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pubmed:affiliation |
Department of Chemistry and Biochemistry, University of Maryland, College Park 20742.
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pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, U.S. Gov't, P.H.S.
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