Linked Life Data

7578233

Source:http://linkedlifedata.com/resource/pubmed/id/7578233

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-12-5
pubmed:abstractText
The enzyme kinetics of the FAD-containing membrane-associated D-lactate dehydrogenase (D-LDH) of Escherichia coli have been investigated by stopped-flow spectroscopy. The reduction of D-LDH by the substrate, D-lactate, exhibits a two-stage behavior as observed by the absorbance change for the enzyme-bound FAD. The fast stage with a maximum rate of 400 s-1 represents the rapid formation of the enzyme-substrate complex and the formation of the equilibrium between the oxidized and the reduced enzyme-substrate complexes. The slow stage, which occurs on the order of 0.36 s-1, represents the slow release of the product, pyruvate, from the reduced enzyme. The formation of a D-LDH semiquinone radical was not observed during the oxidation of D-lactate by D-LDH at 25 degrees C. However, during the subsequent electron transfer from the reduced enzyme to a nitroxide spin-label, a one-electron acceptor, an enzyme intermediate has been observed and identified by both optical and EPR spectroscopies as an anionic semiquinone. Results from 1H-NMR spectroscopic studies suggest the possible formation of a substrate carbanion when D-lactate is bound at the active site of D-LDH.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
1252
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
269-77
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Stopped-flow kinetic and biophysical studies of membrane-associated D-lactate dehydrogenase of Escherichia coli.
pubmed:affiliation
Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.