Linked Life Data

3711105

Source:http://linkedlifedata.com/resource/pubmed/id/3711105

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
1986-7-9
pubmed:abstractText
We have determined reduction potentials for porcine mitochondrial general fatty acyl-CoA dehydrogenase (GAD) and electron transfer flavoprotein (ETF) using an anaerobic spectroelectrochemical titration method. Computer simulation techniques were used to analyze the absorbance data. Nernst plots of the simulated data gave E'0, 7.1, quinone/semiquinone = -0.014 V and E'0, 7.1, semiquinone/hydroquinone = -0.036 V for ETF and E'0, 7.1, quinone/semiquinone = -0.155 V and E'0, 7.1, semiquinone/hydroquinone = -0.122 V for GAD. Using these techniques we have also determined a conditional reduction potential of -0.156 V for the chromophore producing fatty acyl-CoA substrate beta-2-furylpropionyl-CoA. From this value and our previous determination of the equilibrium constant for the transhydrogenation reaction between beta-2-furylpropionyl-CoA and the oxidized substrate crotonyl-CoA (Keq = 10.4), we have determined a reduction potential of -0.126 V for the butyryl-CoA/crotonyl-CoA couple. In light of the structural similarity between butyryl-CoA and octanoyl-CoA, the optimal substrate for GAD, the reduction potential for octanoyl-CoA should be similar to that for butyryl-CoA; i.e. fatty acyl-CoA substrates and GAD are essentially isopotential. The ability of octanoyl-CoA to reduce GAD quantitatively (Keq = 9.0) poses a dilemma in light of the nearly equal reduction potentials. We postulate that the stable charge-transfer complex formed between enzyme and optimal product is significantly lower in energy than enzyme and product and thus is responsible for pulling the reaction toward completion.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
261
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7733-41
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Energetics of beta-oxidation. Reduction potentials of general fatty acyl-CoA dehydrogenase, electron transfer flavoprotein, and fatty acyl-CoA substrates.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't