Linked Life Data

16681373

Source:http://linkedlifedata.com/resource/pubmed/id/16681373

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2006-5-9
pubmed:abstractText
dl-2-Haloacid dehalogenase from Pseudomonas sp. 113 is a unique enzyme because it acts on the chiral carbons of both enantiomers, although its amino acid sequence is similar only to that of d-2-haloacid dehalogenase from Pseudomonas putida AJ1 that specifically acts on (R)-(+)-2-haloalkanoic acids. Furthermore, the catalyzed dehalogenation proceeds without formation of an ester intermediate; instead, a water molecule directly attacks the alpha-carbon of the 2-haloalkanoic acid. We have studied solvent deuterium and chlorine kinetic isotope effects for both stereoisomeric reactants. We have found that chlorine kinetic isotope effects are different: 1.0105 +/- 0.0001 for (S)-(-)-2-chloropropionate and 1.0082 +/- 0.0005 for the (R)-(+)-isomer. Together with solvent deuterium isotope effects on V(max)/K(M), 0.78 +/- 0.09 for (S)-(-)-2-chloropropionate and 0.90 +/- 0.13 for the (R)-(+)-isomer, these values indicate that in the case of the (R)-(+)-reactant another step preceding the dehalogenation is partly rate-limiting. Under the V(max) conditions, the corresponding solvent deuterium isotope effects are 1.48 +/- 0.10 and 0.87 +/- 0.27, respectively. These results indicate that the overall reaction rates are controlled by different steps in the catalysis of (S)-(-)- and (R)-(+)-reactants.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6012-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Mechanism of the reaction catalyzed by DL-2-haloacid dehalogenase as determined from kinetic isotope effects.
pubmed:affiliation
Institute of Radiation Chemistry, Department of Chemistry, Technical University of Lodz, Zeromskiego 116, 90-924 Lodz, Poland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't