Linked Life Data

10766771

Source:http://linkedlifedata.com/resource/pubmed/id/10766771

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
2000-5-10
pubmed:abstractText
Previous studies showed that natural human liver alcohol dehydrogenase gamma exhibits negative cooperativity (substrate activation) with ethanol. Studies with the recombinant gamma(2) isoenzyme now confirm that observation and show that the saturation kinetics with other alcohols are also nonhyperbolic, whereas the kinetics for reactions with NAD(+), NADH, and acetaldehyde are hyperbolic. The substrate activation with ethanol and 1-butanol are explained by an ordered mechanism with an abortive enzyme-NADH-alcohol complex that releases NADH more rapidly than does the enzyme-NADH complex. In contrast, high concentrations of cyclohexanol produce noncompetitive substrate inhibition against varied concentrations of NAD(+) and decrease the maximum velocity to 25% of the value that is observed at optimal concentrations of cyclohexanol. Transient kinetics experiments show that cyclohexanol inhibition is due to a slower rate of dissociation of NADH from the abortive enzyme-NADH-cyclohexanol complex than from the enzyme-NADH complex. Fluorescence quenching experiments confirm that the alcohols bind to the enzyme-NADH complex. The nonhyperbolic saturation kinetics for oxidation of ethanol, cyclohexanol, and 1-butanol are quantitatively explained with the abortive complex mechanism. Physiologically relevant concentrations of ethanol would be oxidized predominantly by the abortive complex pathway.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11569-75
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Kinetic cooperativity of human liver alcohol dehydrogenase gamma(2).
pubmed:affiliation
Department of Biochemistry, The University of Iowa, Iowa City, Iowa 52242, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.