scholarly journals Efficient coupling of catalysis and dynamics in the E1 component of Escherichia coli pyruvate dehydrogenase multienzyme complex

2008 ◽  
Vol 105 (4) ◽  
pp. 1158-1163 ◽  
Author(s):  
S. Kale ◽  
G. Ulas ◽  
J. Song ◽  
G. W. Brudvig ◽  
W. Furey ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pyruvate Dehydrogenase ◽  
Multienzyme Complex ◽  
Efficient Coupling

scholarly journals Evidence for two lipoic acid residues per lipoate acetyltransferase chain in the pyruvate dehydrogenase multienzyme complex of Escherichia coli

1976 ◽  
Vol 159 (3) ◽  
pp. 677-682 ◽  
Author(s):  
M J Danson ◽  
R N Perham
Keyword(s):  
Escherichia Coli ◽  
Lipoic Acid ◽  
Pyruvate Dehydrogenase ◽  
Acid Content ◽  
Polypeptide Chain ◽  
Multienzyme Complex ◽  
Covalently Bound

The reaction of two maleimides, N-ethylmaleimide and bis-(N-maleimidomethyl) ether, with the pyruvate dehydrogenase multienzyme complex of Escherichia coli in the presence of the substrate, pyruvate, was examined. In both cases, the reaction was demonstrated to be almost exclusively with the lipoate acetyltransferase component, and evidence is presented to show that the most likely sites of reaction are the lipoic acid residues covalently bound to this component. With both reagents the stoicheiometry of the reaction was measured: 2 mol of reagent reacted with each polypeptide chain of lipoate acetyltransferase, implying that each chain bears two functionally active lipolic acid residues. This observation can be reconciled with previous determinations of the lipoic acid content of the complex by allowing for the variability of the subunit polypeptide-chain ratio that can be demonstrated for this multimeric enzyme.

scholarly journals Mechanism of action of the pyruvate dehydrogenase multienzyme complex from Escherichia coli

1978 ◽  
Vol 75 (10) ◽  
pp. 4877-4880 ◽  
Author(s):  
K. J. Angelides ◽  
G. G. Hammes
Keyword(s):  
Escherichia Coli ◽  
Mechanism Of Action ◽  
Pyruvate Dehydrogenase ◽  
Multienzyme Complex

scholarly journals The role of lipoic acid residues in the pyruvate dehydrogenase multienzyme complex of Escherichia coli

1981 ◽  
Vol 199 (3) ◽  
pp. 505-511 ◽  
Author(s):  
M J Danson ◽  
G Hale ◽  
R N Perham
Keyword(s):  
Escherichia Coli ◽  
Chemical Modification ◽  
Lipoic Acid ◽  
Pyruvate Dehydrogenase ◽  
Enzymic Activity ◽  
Multienzyme Complex ◽  
Dihydrolipoic Acid ◽  
Lipoamide Dehydrogenase

Two lipoic acid residues on each dihydrolipoamide acetyltransferase (E2) chain of the pyruvate dehydrogenase multienzyme complex of Escherichia coli were found to undergo oxidoreduction reactions with NAD+ catalysed by the lipoamide dehydrogenase component. It was observed that: (a) 2 mol of reagent/mol of E2 chain was incorporated when the complex was incubated with N-ethylmaleimide in the presence of acetyl-SCoA and NADH; (b) 4 mol of reagent/mol of E2 chain was incorporated when the complex was incubated with N-ethylmaleimide in the presence of NADH; (c) between 1 and 2 mol of acetyl groups/mol of E2 chain was incorporated when the complex was incubated with acetyl-SCoA plus NADH; (d) 2 mol of acetyl groups/mol of E2 chain was incorporated when the complex was incubated with pyruvate either before or after many catalytic turnovers through the overall reaction. There was no evidence to support the view that only half of the dihydrolipoic acid residues can be reoxidized by NAD+. However, chemical modification of lipoic acid residues with N-ethylmaleimide was shown to proceed faster than the accompanying loss of enzymic activity under all conditions tested, which indicates that not all the lipoyl groups are essential for activity. The most likely explanation for this result is an enzymic mechanism in which one lipoic acid residue can take over the function of another.

Slow-binding inhibition of the Escherichia coli pyruvate dehydrogenase multienzyme complex by acetylphosphinate

Biochemistry ◽  
1990 ◽  
Vol 29 (20) ◽  
pp. 4880-4885 ◽  
Author(s):  
Ernst Schoenbrunn-Hanebeck ◽  
Bernd Laber ◽  
Nikolaus Amrhein
Keyword(s):  
Escherichia Coli ◽  
Pyruvate Dehydrogenase ◽  
Multienzyme Complex ◽  
Binding Inhibition

Tellurite-induced carbonylation of the Escherichia coli pyruvate dehydrogenase multienzyme complex

2010 ◽  
Vol 192 (11) ◽  
pp. 969-973 ◽  
Author(s):  
Nataly del P. Contreras ◽  
Claudio C. Vásquez
Keyword(s):  
Escherichia Coli ◽  
Pyruvate Dehydrogenase ◽  
Multienzyme Complex

scholarly journals Interactions of lipoyl domains with the E1p subunits of the pyruvate dehydrogenase multienzyme complex from Escherichia coli

FEBS Letters ◽  
1990 ◽  
Vol 262 (2) ◽  
pp. 241-244 ◽  
Author(s):  
Lloyd D. Graham ◽  
Richard N. Perham
Keyword(s):  
Escherichia Coli ◽  
Pyruvate Dehydrogenase ◽  
Multienzyme Complex
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