Linked Life Data

8541313

Source:http://linkedlifedata.com/resource/pubmed/id/8541313

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1996-2-13
pubmed:abstractText
Acetolactate nonenzymatically reduced flavins, quinones and nicotinamide coenzymes in a time-dependent manner at physiological pH and moderate temperature. In the presence of excess acetolactate, the reduction of FAD and NAD+ followed pseudo-first-order kinetics. The rate of reduction was proportional to the concentration of acetolactate, and the rate constants at 37 degrees C and pH 7.5 were 4.8 x 10(-2) M-1 s-1 and 7.4 x 10(-3) M-1 s-1 for FAD and NAD+, respectively. In contrast, ubiquinone reduction followed pseudo-zero-order kinetics in the presence of excess acetolactate. At 37 degrees C and pH 7.5, the rate of reduction was proportional to the acetolactate concentration, and the apparent rate constant was 8.3 x 10(-6) s-1. In contrast to FAD, the rate of reduction of ubiquinone was higher at low pH. The kinetics of ubiquinone reduction suggested that the rate-limiting step was acetolactate decarboxylation and formation of the enolate anion, whereas the rate of FAD reduction was governed by the second-order reaction of the enolate anion. Following the oxidation, acetolactate was converted to diacetyl. Reduced FAD formed by the reaction with acetolactate generated a low rate of O2 consumption during assays of the oxygenase activity of acetohydroxy acid synthase. The reaction of acetolactate with quinones may provide a mechanism for the nonenzymatic formation diacetyl in whole milk.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
1245
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
366-70
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Nonenzymatic acetolactate oxidation to diacetyl by flavin, nicotinamide and quinone coenzymes.
pubmed:affiliation
Department of Microbiology, University of Georgia, Athens 30602-2605, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.