Biomaterial Database

Evidence for two lipoic acid residues per lipoate acetyltransferase chain in the pyruvate dehydrogenase multienzyme complex of Escherichia coli. 1976

M J Danson, and R N Perham

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.

UI	MeSH Term	Description	Entries
D008063	Thioctic Acid	An octanoic acid bridged with two sulfurs so that it is sometimes also called a pentanoic acid in some naming schemes. It is biosynthesized by cleavage of LINOLEIC ACID and is a coenzyme of oxoglutarate dehydrogenase (KETOGLUTARATE DEHYDROGENASE COMPLEX). It is used in DIETARY SUPPLEMENTS.	Lipoic Acid,Alpha-Lipogamma,Alpha-Lipon Stada,Alpha-Liponsaure Sofotec,Alpha-Lippon AL,Alphaflam,Azulipont,Fenint,Juthiac,Liponsaure-ratiopharm,MTW-Alphaliponsaure,Neurium,Pleomix-Alpha,Pleomix-Alpha N,Thioctacid,Thioctacide T,Thiogamma Injekt,Thiogamma oral,Tromlipon,Verla-Lipon,alpha-Lipoic Acid,alpha-Liponaure Heumann,alpha-Liponsaure von ct,alpha-Vibolex,biomo-lipon,duralipon,espa-lipon,Acid, alpha-Lipoic,Alpha Lipogamma,Alpha Lipon Stada,Alpha Liponsaure Sofotec,Alpha Lippon AL,AlphaLipogamma,AlphaLipon Stada,AlphaLiponsaure Sofotec,AlphaLippon AL,Injekt, Thiogamma,Liponsaure ratiopharm,Liponsaureratiopharm,MTW Alphaliponsaure,MTWAlphaliponsaure,Pleomix Alpha,Pleomix Alpha N,PleomixAlpha,PleomixAlpha N,Verla Lipon,VerlaLipon,alpha Lipoic Acid,alpha Liponaure Heumann,alpha Liponsaure von ct,alpha Vibolex,alphaLiponaure Heumann,alphaLiponsaure von ct,alphaVibolex,biomo lipon,biomolipon,espa lipon,espalipon
D008301	Maleimides	Derivatives of maleimide (the structural formula H2C2(CO)2NH) containing a pyrroledione ring where the hydrogen atom of the NH group is replaced with aliphatic or aromatic groups.
D011768	Pyruvate Dehydrogenase Complex	A multienzyme complex responsible for the formation of ACETYL COENZYME A from pyruvate. The enzyme components are PYRUVATE DEHYDROGENASE (LIPOAMIDE); dihydrolipoamide acetyltransferase; and LIPOAMIDE DEHYDROGENASE. Pyruvate dehydrogenase complex is subject to three types of control: inhibited by acetyl-CoA and NADH; influenced by the energy state of the cell; and inhibited when a specific serine residue in the pyruvate decarboxylase is phosphorylated by ATP. PYRUVATE DEHYDROGENASE (LIPOAMIDE)-PHOSPHATASE catalyzes reactivation of the complex. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)	Complex, Pyruvate Dehydrogenase,Dehydrogenase Complex, Pyruvate
D011773	Pyruvates	Derivatives of PYRUVIC ACID, including its salts and esters.
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005033	Ethylmaleimide	A sulfhydryl reagent that is widely used in experimental biochemical studies.	N-Ethylmaleimide,N Ethylmaleimide
D000123	Acetyltransferases	Enzymes catalyzing the transfer of an acetyl group, usually from acetyl coenzyme A, to another compound. EC 2.3.1.	Acetyltransferase