Biomaterial Database

Spin-label study of the mobility of enzyme-bound lipoic acid in the pyruvate dehydrogenase multienzyme complex of Escherichia coli. 1976

M C Ambrose, and R N Perham

The lipoic acid residues covalently bound to the transacetylase component of the pyruvate dehydrogenase multienzyme complex of Escherichia coli were selectively modified by reaction with 4-maleimido-2,2,6,6-tetramethylpiperidino-oxyl. The electron-spin-resonance spectrum of the spin-labelled enzyme indicates that the bound nitroxide groups have high mobilities relative to the protein molecule. This physicochemical evidence is consistent with the view that the dithiolane ring of a lipoyl residue is capable of rapid migration between the active sites of the component enzymes in the catalytic mechanism.

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
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
D013113	Spin Labels	Molecules which contain an atom or a group of atoms exhibiting an unpaired electron spin that can be detected by electron spin resonance spectroscopy and can be bonded to another molecule. (McGraw-Hill Dictionary of Chemical and Technical Terms, 4th ed)	Spin Label,Label, Spin,Labels, Spin