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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
5
|
| pubmed:dateCreated |
1988-6-14
|
| pubmed:abstractText |
The reaction mechanism for the phosphotriesterase from Pseudomonas diminuta has been examined. When paraoxon (diethyl 4-nitrophenyl phosphate) is hydrolyzed by this enzyme in oxygen-18-labeled water, the oxygen-18 label is found exclusively in the diethyl phosphate product. The absolute configurations for the (+) and (-) enantiomers of O-ethyl phenylphosphonothioic acid have been determined by X-ray diffraction structural determination of the individual crystalline 1-phenylethylamine salts. The (+) enantiomer of the free acid corresponds to the RP configuration. The RP enantiomer of O-ethyl phenylphosphonothioic acid has been converted to the SP enantiomer of EPN [O-ethyl O-(4-nitrophenyl) phenylphosphonothioate]. (SP)-EPN is hydrolyzed by the phosphotriesterase to the SP enantiomer of O-ethyl phenylphosphonothioic acid. The enzymatic reaction therefore proceeds with inversion of configuration. These results have been interpreted as an indication of a single in-line displacement by an activated water molecule directly at the phosphorus center of the phosphotriester substrate. (RP)-EPN is not hydrolyzed by the enzyme at an appreciable rate.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Mar
|
| pubmed:issn |
0006-2960
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
8
|
| pubmed:volume |
27
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
1591-7
|
| pubmed:dateRevised |
2008-11-21
|
| pubmed:meshHeading | |
| pubmed:year |
1988
|
| pubmed:articleTitle |
Mechanism and stereochemical course at phosphorus of the reaction catalyzed by a bacterial phosphotriesterase.
|
| pubmed:affiliation |
Department of Chemistry, Texas A&M University, College Station 77843.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
|