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1
Mechanism of the Biological Conversion of Citric Acid. 6: Citrate-Synthase Is an Acetyl-Coa Enolase.
1984-01-01

The enolization of acetyl coenzyme A is demonstrated by means of isotope experiments. It requires citrate-synthase and an inductor, (S)-malate. The mechanism of the biosynthesis of citrate and the results of the experiments are in agreement with the sugge...

National Technical Information Service (NTIS)

2
Pulse-chase studies of the synthesis of acetyl-CoA by carbon monoxide dehydrogenase/acetyl-CoA synthase: evidence for a random mechanism of methyl and carbonyl addition.
2008-01-18

Carbon monoxide dehydrogenase/acetyl-CoA synthase catalyzes acetyl-CoA synthesis from CO, CoA, and a methylated corrinoid iron-sulfur protein, which acts as a methyl donor. This reaction is the last step in the Wood-Ljungdahl pathway of anaerobic carbon fixation. The binding sequence for the three substrates has ...

PubMed

3
Pulse-Chase Studies of the Synthesis of Acetyl-CoA by Carbon Monoxide Dehydrogenase/Acetyl-CoA Synthase
2008-03-28

Carbon monoxide dehydrogenase/acetyl-CoA synthase catalyzes acetyl-CoA synthesis from CO, CoA, and a methylated corrinoid iron-sulfur protein, which acts as a methyl donor. This reaction is the last step in the Wood-Ljungdahl pathway of anaerobic carbon fixation. The binding sequence ...

PubMed Central

4
Identification of a novel CoA synthase isoform, which is primarily expressed in Brain
2006-03-24

CoA and its derivatives Acetyl-CoA and Acyl-CoA are important players in cellular metabolism and signal transduction. CoA synthase is a bifunctional enzyme which mediates the final stages of CoA biosynthesis. In previous studies, we have reported molecular cloning, biochemical characterization, ...

Energy Citations Database

5
Targeting intermediary metabolism in the hypothalamus as a mechanism to regulate appetite.
2010-04-14

The central nervous system mediates energy balance (energy intake and energy expenditure) in the body; the hypothalamus has a key role in this process. Recent evidence has demonstrated an important role for hypothalamic malonyl CoA in mediating energy balance. Malonyl CoA is generated by the carboxylation of acetyl ...

PubMed

6
Intracellular acetyl unit transport in fungal carbon metabolism.
2010-10-01

Acetyl coenzyme A (acetyl-CoA) is a central metabolite in carbon and energy metabolism. Because of its amphiphilic nature and bulkiness, acetyl-CoA cannot readily traverse biological membranes. In fungi, two systems for acetyl unit transport have been identified: a shuttle dependent on the carrier carnitine and a ...

PubMed

7
Intracellular Acetyl Unit Transport in Fungal Carbon Metabolism ?
2010-12-01

Acetyl coenzyme A (acetyl-CoA) is a central metabolite in carbon and energy metabolism. Because of its amphiphilic nature and bulkiness, acetyl-CoA cannot readily traverse biological membranes. In fungi, two systems for acetyl unit transport have been identified: a shuttle dependent on the carrier carnitine and a ...

PubMed Central

8
3-Hydroxy-3-methylglutaryl-coenzyme A synthase from ox liver. Properties of its acetyl derivative.
1985-04-15

Ox liver mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (EC 4.1.3.5) reacts with acetyl-CoA to form a complex in which the acetyl group is covalently bound to the enzyme. This acetyl group can be removed by addition of acetoacetyl-CoA or CoA. The extent of ...

PubMed Central

9
Demonstration of carbon-carbon bond cleavage of acetyl coenzyme A by using isotopic exchange catalyzed by the CO dehydrogenase complex from acetate-grown Methanosarcina thermophila.
1991-01-01

The purified nickel-containing CO dehydrogenase complex isolated from methanogenic Methanosarcina thermophila grown on acetate is able to catalyze the exchange of [1-14C] acetyl-coenzyme A (CoA) (carbonyl group) with 12CO as well as the exchange of [3'-32P]CoA with acetyl-CoA. Kinetic parameters for the carbonyl exchange have been ...

PubMed

10
Demonstration of carbon-carbon bond cleavage of acetyl coenzyme A by using isotopic exchange catalyzed by the CO dehydrogenase complex from acetate-grown Methanosarcina thermophila.
1991-01-01

The purified nickel-containing CO dehydrogenase complex isolated from methanogenic Methanosarcina thermophila grown on acetate is able to catalyze the exchange of [1-14C] acetyl-coenzyme A (CoA) (carbonyl group) with 12CO as well as the exchange of [3'-32P]CoA with acetyl-CoA. Kinetic parameters for the carbonyl exchange have been ...

PubMed Central

11
Isolated poly(3-hydroxybutyrate) (PHB) granules are complex bacterial organelles catalyzing formation of PHB from acetyl coenzyme A (CoA) and degradation of PHB to acetyl-CoA.
2007-08-24

Poly(3-hydroxybutyrate) (PHB) granules isolated in native form (nPHB granules) from Ralstonia eutropha catalyzed formation of PHB from (14)C-labeled acetyl coenzyme A (CoA) in the presence of NADPH and concomitantly released CoA, revealing that PHB biosynthetic proteins (acetoacetyl-CoA thiolase, acetoacetyl-CoA reductase, and PHB ...

PubMed

12
Project: � CIW � 2007 � Annual Reports � Library of Resources ...

... a metal-sulfide-catalyzed reaction that mimics the action of acetyl CoA synthase; ... Studies of the formation of RNA oligomers on the clay mineral sodium ... number of oligomers could have formed by this mechanism on the early Earth, ... A combination of scanning transmission X-ray microscopy and micro- Raman ...

NASA Website

13
Life with CO or CO2 and H2 as a source of carbon and energy.
1991-02-01

An account is presented of the recent discovery of a pathway of growth by bacteria in which CO or CO2 and H2 are sources of carbon and energy. The Calvin cycle and subsequently other cycles were discovered in the 1950s, and in each the initial reaction of CO2 involved adding CO2 to an organic compound formed during the cyclic pathway (for example, CO2 and ribulose diphosphate). Studies were ...

PubMed

14
SIRT1 and SIRT3 Deacetylate Homologous Substrates: AceCS1,2 and HMGCS1,2
2011-06-19

SIRT1 and SIRT3 are NAD+-dependent protein deacetylases that are evolutionarily conserved across mammals. These proteins are located in the cytoplasm/nucleus and mitochondria, respectively. Previous reports demonstrated that human SIRT1 deacetylates Acetyl-CoA Synthase 1 (AceCS1) in the cytoplasm, whereas SIRT3 deacetylates the homologous ...

PubMed Central

15
Arylamine N-Acetyltransferases in Mycobacteria
2008-07-01

Polymorphic Human arylamine N-acetyltransferase (NAT2) inactivates the anti-tubercular drug isoniazid by acetyltransfer from acetylCoA. There are active NAT proteins encoded by homologous genes in mycobacteria including M. tuberculosis, M. bovis BCG, M. smegmatis and M. marinum. Crystallographic structures of NATs from M. smegmatis and M. marinum, as native enzymes and with ...

PubMed Central

16
Analysis of Streptomyces coelicolor phosphopantetheinyl transferase, AcpS, reveals the basis for relaxed substrate specificity.
2011-06-06

The transfer of the phosphopantetheine chain from coenzyme A (CoA) to the acyl carrier protein (ACP), a key protein in both fatty acid and polyketide synthesis, is catalyzed by ACP synthase (AcpS). Streptomyces coelicolor AcpS is a doubly promiscuous enzyme capable of activation of ACPs from both fatty acid and polyketide synthesis and catalyzes the ...

PubMed

17
An alkyl etherase in rat liver.
1975-11-01

1. Diethyl ether, which is known to be partly metabolized in vivo, has been found to show an O2 uptake with the rat liver microsomal membranes; a similar reaction is given with other short chain aliphatic ethers, isoproply and n-butyl ether. 2. The "etherase" reaction is optimal at pH 7.2-7.4 and is not accompanied by an increased formation of malondialdehyde. 3. When CoA is ...

PubMed Central

18
Mitochondrial storage form of acetyl CoA carboxylase in fasted and alloxan diabetic rats
1986-05-01

Sodium dodecyl sulfate-denatured biotinyl proteins will bind (/sup 14/C)methyl avidin which remains bound through polyacrylamide gel electrophoresis. The method has been used to demonstrate the presence of two high molecular weight subunit forms of acetyl CoA carboxylase in rat liver cytoplasm, both of which are precipitated by antibody to purifed rat ...

Energy Citations Database

19
FUNCTION OF CARNITINE IN THE FATTY ACID OXIDASE ...
1967-01-01

... of acetylcarnitine from acetyl coenzyme A (CoA ... ACIDS, OXIDATION), (*MUSCLES, ENZYMES), TRANSFERASES, COENZYMES, DIPTERA, FLIGHT ...

DTIC Science & Technology

20
Biotechnology Consultation Memorandum of Conference BNF ...

... in nature in microbes, plants, and animals, have a common enzymatic function (transfer of an acetyl group from acetyl CoA to a substrate) but differ ...

Center for Food Safety and Applied Nutrition (CFSAN)

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21
Structure of the Escherichia coli malate synthase G:pyruvate:acetyl-coenzyme A abortive ternary complex at 1.95 � resolution
2003-09-01

Malate synthase, an enzyme of the glyoxylate pathway, catalyzes the condensation and subsequent hydrolysis of acetyl-coenzyme A (acetyl-CoA) and glyoxylate to form malate and CoA. In the present study, we present the 1.95 Ŗresolution crystal structure of Escherichia coli malate synthase ...

PubMed Central

22
Novel domain arrangement in the crystal structure of a truncated acetyl-CoA synthase fromMoorella thermoacetica��
2009-08-25

Ni-dependent Acetyl-CoA synthase (ACS) and CO dehydrogenase (CODH) constitute the central enzyme complex of the Wood-Ljungdahl pathway of acetyl-CoA formation. The crystal structure of a recombinant bacterial ACS lacking the N-terminal domain that interacts with CODH shows a large reorganization of the remaining two globular domains, ...

PubMed Central

23
A functional Ni-Ni-[4Fe-4S] cluster in the monomeric acetyl-CoA synthase from Carboxydothermus hydrogenoformans.
2003-12-29

In anaerobic microorganisms employing the acetyl-CoA pathway, acetyl-CoA synthase (ACS) and CO dehydrogenase (CODH) form a complex (ACS/CODH) that catalyzes the synthesis of acetyl-CoA from CO, a methyl group, and CoA. Previously, a [4Fe-4S] cubane bridged to a copper-nickel binuclear site ...

PubMed

24
A functional Ni-Ni-[4Fe-4S] cluster in the monomeric acetyl-CoA synthase from Carboxydothermus hydrogenoformans
2004-01-13

In anaerobic microorganisms employing the acetyl-CoA pathway, acetyl-CoA synthase (ACS) and CO dehydrogenase (CODH) form a complex (ACS/CODH) that catalyzes the synthesis of acetyl-CoA from CO, a methyl group, and CoA. Previously, a [4Fe-4S] cubane bridged to a copper-nickel binuclear site ...

PubMed Central

25
Summary of Summer Activities Christian L. Omidiran, Jason Ou

+ ATP + CoA (7) AcetylCoA + 2NADH Ethanol + CoA + 2NAD+ (8) Isocitrate Glyoxalate + Succinate (9) AcetylCoA + Glyoxalate Malate + CoA (10) OAA + NADH Malate + NAD+ (11) Malate Fumarate (12) Fumarate

E-print Network

26
A dicarboxylate/4-hydroxybutyrate autotrophic carbon assimilation cycle in the hyperthermophilic Archaeum Ignicoccus hospitalis
2008-06-03

Ignicoccus hospitalis is an anaerobic, autotrophic, hyperthermophilic Archaeum that serves as a host for the symbiotic/parasitic Archaeum Nanoarchaeum equitans. It uses a yet unsolved autotrophic CO2 fixation pathway that starts from acetyl-CoA (CoA), which is reductively carboxylated to pyruvate. Pyruvate is converted to ...

PubMed Central

27
The Crystal Structure of N-Acetyl-L-glutamate Synthase from Neisseria gonorrhoeae Provides Insights into Mechanisms of Catalysis and Regulation
2010-01-07

The crystal structures of N-acetylglutamate synthase (NAGS) in the arginine biosynthetic pathway of Neisseria gonorrhoeae complexed with acetyl-CoA and with CoA plus N-acetylglutamate have been determined at 2.5- and 2.6-A resolution, respectively. The monomer consists of two separately folded domains, an amino acid kinase (AAK) domain ...

Energy Citations Database

28
Mechanistic investigations of the A-cluster of acetyl-CoA synthase
2004-12-01

The A-cluster of acetyl-CoA synthase (ACS) catalyzes the formation of acetyl- CoA from CO, coenzyme-A, and a methyl group donated by a corrinoid iron-sulfur protein. Recent crystal structures have exhibited three different metals, Zn, Cu, and Ni, in the proximal site, which bridges a square-planar nickel site and a ...

E-print Network

29
H55N polymorphism as a likely cause of variation in citrate synthase activity of mouse skeletal muscle.
2010-08-17

Citrate synthase (CS) is an enzyme of the Krebs cycle that plays a key role in mitochondrial metabolism. The aim of this study was to investigate the mechanisms underlying low activity of citrate synthase (CS) in A/J mice compared with other inbred strains of mice. Enzyme activity, protein content, and mRNA levels of CS were studied in the quadriceps ...

PubMed

30
Funding Opportunities ? NAI ? NASA ... - Astrobiology - NASA

Sep 5, 2011 ... Title: Minerals to Enzymes: The Path to CO Dehydrogenase/Acetyl CoA ... prokaryotes originated as the result of an endosymbiosis between ...

NASA Website

31
Surprising Arginine Biosynthesis: a Reappraisal of the Enzymology and Evolution of the Pathway in Microorganisms
2007-03-01

Summary: Major aspects of the pathway of de novo arginine biosynthesis via acetylated intermediates in microorganisms must be revised in light of recent enzymatic and genomic investigations. The enzyme N-acetylglutamate synthase (NAGS), which used to be considered responsible for the first committed step of the pathway, is present in a limited number of ...

PubMed Central

32
Identification of a Johnsongrass (Sorghum halepense) Biotype Resistant to ACCase-Inhibiting Herbicides in Northern ...

... cross-resistance to cycloxydim, propaquizafop, and fluazifop (acetyl coenzyme A [CoA] carboxylase [ACCase]-inhibiting herbicides), and multiple ... 318. BioOneDélye, C. 2005. Weed resistance to acetyl coe...

NBII National Biological Information Infrastructure

33
Differential sensitivity of Italian ryegrass (Lolium multiflorum) cultivars to fenoxaprop

... differed slightly in the specific activity of acetyl�coenzyme A carboxylase (ACCase) (EC 6.4.1.2) ... compounds are potent inhibitors of the enzyme acetyl�coenzyme A (CoA) carboxylase (ACCase) (Gronwald 1...

NBII National Biological Information Infrastructure

34
Acetyl coenzyme A synthetase catalyzed reactions of coenzyme A with. cap alpha. -. beta. -unsaturated carboxylic acids
1988-05-01

..cap alpha..,..beta..-Unsaturated coenzyme A(CoA) thioesters including acrylyl CoA, methacrylyl CoA, and propiolyl CoA were synthesized by catalysis with acetyl CoA synthetase. After isolation from the enzymatic reactions, the products were found to be the result of 1,4 addition of CoASH to ...

Energy Citations Database

35
Genetic Construction of Truncated and Chimeric Metalloproteins Derived from the Alpha Subunit of Acetyl-CoA Synthase from Clostridium thermoaceticum
2002-06-28

In this study, a genetics-based method is used to truncate acetyl-coenzyme A synthase from Clostridium thermoaceticum (ACS), an alpha2beta2 tetrameric 310 kda bifunctional enzyme. ACS catalyzes the reversible reduction of CO2 to CO and the synthesis of acetyl-CoA from CO (or CO2 in the presence of low-potential reductants), ...

DOE Information Bridge

36
Modification of bovine kidney pyruvate dehydrogenase kinase activity by CoA esters and their mechanism of action
1985-08-25

The activation of pyruvate dehydrogenasea kinase activity by CoA esters has been further characterized. Half-maximal activation of kinase activity was achieved with about 1.0 microM acetyl-CoA after a 20-s preincubation in the presence of NADH. More than 80% of the acetyl-CoA was consumed during this period in ...

Energy Citations Database

37
Carnitine and derivatives in rat tissues
1967-12-01

1. Free carnitine, acetylcarnitine, short-chain acylcarnitine and acid-insoluble carnitine (probably long-chain acylcarnitine) have been measured in rat tissues. 2. Starvation caused an increase in the proportion of carnitine that was acetylated in liver and kidney; at least in liver fat-feeding had the same effect, whereas a carbohydrate diet caused a very low acetylcarnitine ...

PubMed Central

38
The Apparent Malate Synthase Activity of Rhodobacter sphaeroides Is Due to Two Paralogous Enzymes, (3S)-Malyl-Coenzyme A (CoA)/?-Methylmalyl-CoA Lyase and (3S)- Malyl-CoA Thioesterase?
2010-03-04

Assimilation of acetyl coenzyme A (acetyl-CoA) is an essential process in many bacteria that proceeds via the glyoxylate cycle or the ethylmalonyl-CoA pathway. In both assimilation strategies, one of the final products is malate that is formed by the condensation of acetyl-CoA with glyoxylate. In the glyoxylate cycle this reaction is ...

PubMed Central

39
Regulation of lipid metabolism and gene expression by fenofibrate in hamsters.
2001-10-31

Fenofibrate is a potent hypolipidemic agent that lowers plasma lipid levels and may thus decrease the incidence of atherosclerosis. Here we investigated the molecular mechanism of fenofibrate's hypolipidemic action by characterizing its in vivo effects on the expression of mRNAs and the activities of pivotal enzymes in cholesterol and triglyceride metabolism in the hamster. Treatment of hamsters ...

PubMed

40
Cross Resistance of Acetyl-coa Carboxylase (ACCase) Inhibitor�Resistant Wild Oat (Avena fatua) Biotypes in the Pacific ...

... Acetyl-coa Carboxylase (ACCase) Inhibitor�Resistant Wild Oat (Avena fatua) Biotypes in the Pacific NorthwestAhmet Uludag, Kee Woong ... diclofop, fenoxaprop, pinoxaden, quizalofop, sethoxydim, tralkoxydim...

NBII National Biological Information Infrastructure

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41
Fatty acyl CoA elongation in the endoplasmic reticulum
2009-01-02

This shows the overall process of fatty acyl elongation in the endoplasmic reticulum. The process resembles that catalyzed by fatty acyl synthase, but the individual activities appear to be on separate enzymes.

NSDL National Science Digital Library

42
Enzymology of acetoclastic methanogenesis. Final technical report, August 1994--July 1997
1997-12-31

The overall aims of the proposal were to identify intermediates in the process of methane formation from acetate. The specific aims were: (1) to characterize the mechanism of acetyl-CoA conversion to CH{sub 3}-H{sub 4}MPT, CO, and CoA and elucidate the mechanism of CO oxidation by the methanosarcina thermophila CO ...

DOE Information Bridge

43
Directing vanillin production from ferulic acid by increased acetyl-CoA consumption in recombinant Escherichia coli.
2009-01-01

The amplification of gltA gene encoding citrate synthase of TCA cycle was required for the efficient conversion of acetyl-CoA, generated during vanillin production from ferulic acid, to CoA, which is essential for vanillin production. Vanillin of 1.98 g/L was produced from the E. coli DH5alpha (pTAHEF-gltA) with gltA amplification in ...

PubMed

44
Unprecedented acetoacetyl-coenzyme A synthesizing enzyme of the thiolase superfamily involved in the mevalonate pathway.
2010-06-07

Acetoacetyl-CoA is the precursor of 3-hydroxy-3-methylglutaryl (HMG)-CoA in the mevalonate pathway, which is essential for terpenoid backbone biosynthesis. Acetoacetyl-CoA is also the precursor of poly-beta-hydroxybutyrate, a polymer belonging to the polyester class produced by microorganisms. The de novo synthesis of acetoacetyl-CoA is usually catalyzed by acetoacetyl-CoA thiolase via a ...

PubMed

45
Unprecedented acetoacetyl-coenzyme A synthesizing enzyme of the thiolase superfamily involved in the mevalonate pathway
2010-06-22

Acetoacetyl-CoA is the precursor of 3-hydroxy-3-methylglutaryl (HMG)-CoA in the mevalonate pathway, which is essential for terpenoid backbone biosynthesis. Acetoacetyl-CoA is also the precursor of poly-?-hydroxybutyrate, a polymer belonging to the polyester class produced by microorganisms. The de novo synthesis of acetoacetyl-CoA is usually catalyzed by acetoacetyl-CoA thiolase via a ...

PubMed Central

46
Characterization of a bifunctional glyoxylate cycle enzyme, malate synthase/isocitrate lyase, of Euglena gracilis.
2011-02-18

The glyoxylate cycle is a modified form of the tricarboxylic acid cycle, which enables organisms to synthesize carbohydrates from C2 compounds. In the protozoan Euglena gracilis, the key enzyme activities of the glyoxylate cycle, isocitrate lyase (ICL) and malate synthase (MS), are conferred by a single bifunctional protein named glyoxylate cycle enzyme (Euglena gracilis ...

PubMed

47
Protein acyltransferase function of purified calreticulin: the exclusive role of P-domain in mediating protein acylation utilizing acyloxycoumarins and acetyl CoA as the acyl group donors.
2011-05-01

The distinct biochemical function of endoplasmic reticulum (ER) protein Calreticulin (CR) catalyzing the transfer of acyl group from acyloxycoumarin to a receptor protein was termed calreticulin transacylase (CRTAase). The present study, unlike the previous reports of others utilizing CR-deficient cells alone, dealt with the recombinant CR domains of Heamonchus contortus (rhCRTAase) in order to ...

PubMed

48
Substrate Binding and Catalytic Mechanism of Human Choline Acetyltransferase
2006-01-01

Choline acetyltransferase (ChAT) catalyzes the synthesis of the neurotransmitter acetylcholine from choline and acetyl-CoA, and its presence is a defining feature of cholinergic neurons. We report the structure of human ChAT to a resolution of 2.2 {angstrom} along with structures for binary complexes of ChAT with choline, CoA, and a nonhydrolyzable ...

Energy Citations Database

49
3-Hydroxypropionyl-Coenzyme A Dehydratase and Acryloyl-Coenzyme A Reductase, Enzymes of the Autotrophic 3-Hydroxypropionate/4-Hydroxybutyrate Cycle in the Sulfolobales?
2009-07-08

A 3-hydroxypropionate/4-hydroxybutyrate cycle operates in autotrophic CO2 fixation in various Crenarchaea, as studied in some detail in Metallosphaera sedula. This cycle and the autotrophic 3-hydroxypropionate cycle in Chloroflexus aurantiacus have in common the conversion of acetyl-coenzyme A (CoA) and two bicarbonates via ...

PubMed Central

50
Enhanced isoamyl acetate production upon manipulation of the acetyl-CoA node in Escherichia coli.

Coenzyme A (CoA) and its thioester derivative acetyl-Coenzyme A (acetyl-CoA) participate in over 100 different reactions in intermediary metabolism of microorganisms. Earlier results indicated that overexpression of upstream rate-limiting enzyme pantothenate kinase with simultaneous supplementation of precursor pantothenic acid to the ...

PubMed

51
The glcB locus of Rhizobium leguminosarum VF39 encodes an arabinose-inducible malate synthase.
2002-10-01

In the course of a study conducted to isolate genes upregulated by plant cell wall sugars, we identified an arabinose-inducible locus from a transcriptional fusion library of Rhizobium leguminosarum VF39, carrying random insertions of the lacZ transposon Tn5B22. Sequence analysis of the locus disrupted by the transposon revealed a high similarity to uncharacterized malate ...

PubMed

52
Dissecting the component reactions catalyzed by the actinorhodin minimal polyketide synthase.
2007-11-23

The actinorhodin (act) minimal polyketide synthase (PKS) from Streptomyces coelicolor consists of three proteins: an acyl carrier protein (ACP) and two beta-ketoacyl ACP synthase components known as KSalpha and KSbeta. The act minimal PKS catalyzes at least 18 separate reactions which can be divided into loading, initiation, extension, and cyclization and ...

PubMed

53
The antibiotic activity of N-pentylpantothenamide results from its conversion to ethyldethia-coenzyme a, a coenzyme a antimetabolite.
2002-10-07

Pantothenic acid (vitamin B(5)) is the natural precursor of coenzyme A (CoA), an essential cofactor in all organisms. The pantothenic acid antimetabolite N-pentylpantothenamide inhibits the growth of Escherichia coli with a minimum inhibitory concentration of 2 microm. In this study, we examine the mechanism of this inhibition. Using the last five enzymes of the ...

PubMed

54
Insights into the Autotrophic CO2 Fixation Pathway of the Archaeon Ignicoccus hospitalis: Comprehensive Analysis of the Central Carbon Metabolism?
2007-06-30

Ignicoccus hospitalis is an autotrophic hyperthermophilic archaeon that serves as a host for another parasitic/symbiotic archaeon, Nanoarchaeum equitans. In this study, the biosynthetic pathways of I. hospitalis were investigated by in vitro enzymatic analyses, in vivo 13C-labeling experiments, and genomic analyses. Our results suggest the operation of a so far unknown ...

PubMed Central

55
Stimulation of CoA biosynthesis by P-aminobenzoate and benzoate in cultured rat hepatocytes
1987-05-01

The effects of paraminobenzoate (PABA) and benzoate (BA) on CoA metabolism were studied in intact hepatocytes to elucidate the role of CoASH and acetyl-CoA in the regulation of CoA biosynthesis. CoASH and acetyl-CoA inhibit isolated pantothenate kinase, a cytosolic enzyme. PABA is N-acetylated ...

Energy Citations Database

56
Discovery of amide (peptide) bond synthetic activity in Acyl-CoA synthetase.
2008-02-27

Acyl-CoA synthetase, which is one of the acid-thiol ligases (EC 6.2.1), plays key roles in metabolic and regulatory processes. This enzyme forms a carbon-sulfur bond in the presence of ATP and Mg(2+), yielding acyl-CoA thioesters from the corresponding free acids and CoA. This enzyme belongs to the superfamily of adenylate-forming enzymes, whose three-dimensional structures ...

PubMed

57
Two Arabidopsis Genes (IPMS1 and IPMS2) Encode Isopropylmalate Synthase, the Branchpoint Step in the Biosynthesis of Leucine1[W][OA
2007-02-01

Heterologous expression of the Arabidopsis (Arabidopsis thaliana) IPMS1 (At1g18500) and IPMS2 (At1g74040) cDNAs in Escherichia coli yields isopropylmalate synthases (IPMSs; EC 2.3.3.13). These enzymes catalyze the first dedicated step in leucine (Leu) biosynthesis, an aldol-type condensation of acetyl-coenzyme A (CoA) and ...

PubMed Central

58
Kinetic and Chemical Mechanism of Malate Synthase from Mycobacterium tuberculosis.
2011-07-18

Malate synthase catalyzes the Claisen-like condensation of acetyl-coenzyme A (AcCoA) and glyoxylate in the glyoxylate shunt of the citric acid cycle. The Mycobacterium tuberculosis malate synthase G gene, glcB, was cloned, and the N-terminal His(6)-tagged 80 kDa protein was expressed in soluble form and purified by metal affinity ...

PubMed

59
Effect of alterations of the specific activity of the intracellular acetyl CoA pool on apparent rates of hepatic cholesterogenesis.
1974-09-01

We have previously shown significant dilution of the specific activity of the intracellular acetyl CoA pool when radiolabeled acetate is used as the precursor in liver slice experiments. In the present study, using liver from animals subjected to various manipulations known to alter the rate of cholesterogenesis, the specific activity of the ...

PubMed

60
Application of reverse-phase HPLC to quantify oligopeptide acetylation eliminates interference from unspecific acetyl CoA hydrolysis
2009-08-04

Protein acetylation is a common modification that plays a central role in several cellular processes. The most widely used methods to study these modifications are either based on the detection of radioactively acetylated oligopetide products or an enzyme-coupled reaction measuring conversion of the acetyl donor ...

PubMed Central

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61
Engineered reversal of the ?-oxidation cycle for the synthesis of fuels and chemicals.
2011-08-10

Advanced (long-chain) fuels and chemicals are generated from short-chain metabolic intermediates through pathways that require carbon-chain elongation. The condensation reactions mediating this carbon-carbon bond formation can be catalysed by enzymes from the thiolase superfamily, including ?-ketoacyl-acyl-carrier protein (ACP) synthases, polyketide ...

PubMed

62
Rhein, an inhibitor of adipocyte differentiation and adipogenesis.
2011-08-01

Rhein (RH), a compound purified from Radix et Rhizoma Rhei, has been used to alleviate liver and kidney damage. It is found that RH inhibited the differentiation of 3T3-L1 preadipocytes induced by differentiation medium in a time- and dose-dependent manner. It was revealed that RH downregulated the expression of adipogenesis-specific transcription factors PPAR? and C/EBP?, as well as their ...

PubMed

63
Fluxes of carbon, phosphorylation, and redox intermediates during growth of Saccharomyces cerevisiae on different carbon sources
1995-07-20

In the present work the authors developed a method for estimating anabolic fluxes when yeast are growing on various carbon substrates (glucose, glycerol, lactate, pyruvate, acetate, or ethanol) in minimal medium. Fluxes through the central amphibolic pathways were calculated from the product of the total required amount of a specified carbon intermediate times the growth rate. The required amount ...

Energy Citations Database

64
Disruption of the Operon Encoding Ehb Hydrogenase Limits AnabolicCO2 Assimilation in the Archaeon Methanococcus maripaludis
2006-02-01

Methanococcus maripaludis is a mesophilic archaeon thatreduces CO2 to methane with H2 or formate as an energy source. Itcontains two membrane-bound energy-conserving hydrogenases, Eha and Ehb.To determine therole of Ehb, a deletion in the ehb operon wasconstructed to yield the mutant, strain S40. Growth of S40 was severelyimpaired in minimal medium. Both acetate and yeast extract were necessaryto ...

Energy Citations Database

65
An experimental and computational study of sulfur-modified nucleophilicity in a dianionic NiN2S2 complex.
2007-08-08

The dianionic NiN2S2 complex, Ni(ema)2-, ema=N,N'-ethylenebis-2-mercaptoacetamide, known as a reasonable model of the tripeptide complex Ni(CGC)2- (C=cysteine; G=glycine) with respect to the two carboxyamido nitrogens and cis-dithiolates in a (N2S2)4- ligand scaffold as found in acetyl CoA synthase, has been explored for S-based ...

PubMed

66
Contrasting Patterns of Evolutionary Divergence Within the Acinetobacter Calcoaceticus pca Operon.
1994-01-01

The six enzymes required for catabolism of protocatechuate to succinate and acetyl CoA are encoded by pca genes in Gm- bacterium Acinetobacter calcoaceticus. The clustered A. calcoaceticus cat genes encode an analogous set of enzymes associated with the m...

National Technical Information Service (NTIS)

67
The Evolution of Acetyl-CoA Synthase
2001-08-01

Acetyl-coenzyme A synthases (ACS) are Ni-Fe-S containing enzymes found in archaea and bacteria. They are divisible into 4 classes. Class I ACS's catalyze the synthesis of acetyl-CoA from CO_2 + 2e^-, CoA, and a methyl group, and contain 5 types of subunits (?, ?, ?, ?, and ?). Class II enzymes catalyze essentially ...

NASA Astrophysics Data System (ADS)

68
Probing the allosteric activation of pyruvate carboxylase using 2',3'-O-(2,4,6-trinitrophenyl) adenosine 5'-triphosphate as a fluorescent mimic of the allosteric activator acetyl CoA.
2011-03-21

2',3'-O-(2,4,6-Trinitrophenyl) adenosine 5'-triphosphate (TNP-ATP) is a fluorescent analogue of ATP. MgTNP-ATP was found to be an allosteric activator of pyruvate carboxylase that exhibits competition with acetyl CoA in activating the enzyme. There is no evidence that MgTNP-ATP binds to the MgATP substrate binding site of the enzyme. At concentrations ...

PubMed

69
Operation of the CO Dehydrogenase/Acetyl Coenzyme A Pathway in both Acetate Oxidation and Acetate Formation by the Syntrophically Acetate-Oxidizing Bacterium Thermacetogenium phaeum
2005-05-01

Thermacetogenium phaeum is a homoacetogenic bacterium that can grow on various substrates, such as pyruvate, methanol, or H2/CO2. It can also grow on acetate if cocultured with the hydrogen-consuming methanogenic partner Methanothermobacter thermautotrophicus. Enzyme activities of the CO dehydrogenase/acetyl coenzyme A ...

PubMed Central

70
Fatty Acid Biosynthesis in Human Leukocytes*
1967-10-01

Extracts from human leukocytes have been examined for the enzymes of de novo fatty acid biosynthesis. These extracts do not catalyze the synthesis of long-chain fatty acids because they lack acetyl CoA carboxylase, the first enzyme unique to the fatty acid synthesis pathway.Since these cells cannot form malonyl CoA, they are unable to ...

PubMed Central

71
UV modulation of subcutaneous fat metabolism.
2011-05-12

Adipose tissue is not a homogeneous organ. Visceral fat accumulation is associated with atherosclerosis and metabolic syndrome, but peripheral subcutaneous (SC) fat accumulation may be protective. Human skin is continuously exposed to UV light. UV can penetrate the epidermis and into the mid-dermis, but not into the SC fat tissue of human skin. However, we here show that SC fat tissue in ...

PubMed

72
Sulfated Oxysterol, 25HC3S, is a Potent Regulator of Lipid Metabolism in Human Hepatocytes
2007-07-06

Recently, a novel oxysterol, 5-cholesten-3?, 25-diol 3-sulfate (25HC3S) was identified in primary rat hepatocytes following overexpression of the cholesterol transport protein, StarD1. This oxysterol was also detected in human liver nuclei. In the present study, 25HC3S was chemically synthesized. Addition of 25HC3S (6 ?M) to human hepatocytes markedly inhibited cholesterol biosynthesis. ...

PubMed Central

73
Effects of perilla extract on productive performance, serum values and hepatic expression of lipid-related genes in Shaoxing ducks.
2011-06-01

1. The aim of this study was to identify the effect of perilla extract, a source of polyunsaturated fatty acids, on lipid metabolism and expression of lipid-related genes in livers of Shaoxing ducks. 2. Two hundred and forty 28-week-old laying ducks received a commercial diet with perilla extract added at 0 (control) or 200?mg/kg of feed. 3. Ducks fed on a diet with perilla extract had increased ...

PubMed

74
Expanding the biosynthetic repertoire of plant type III polyketide synthases by altering starter molecule specificity
2002-04-16

Type III polyketide synthases (PKS) generate an array of natural products by condensing multiple acetyl units derived from malonyl-CoA to thioester-linked starter molecules covalently bound in the PKS active site. One strategy adopted by Nature for increasing the functional diversity of these biosynthetic enzymes involves modifying polyketide assembly by ...

PubMed Central

75
Crystal structure of Salmonella typhimurium 2-methylcitrate synthase: Insights on domain movement and substrate specificity.
2010-10-21

2-Methylcitric acid (2-MCA) cycle is one of the well studied pathways for the utilization of propionate as a source of carbon and energy in bacteria such as Salmonella typhimurium and Escherichia coli. 2-Methylcitrate synthase (2-MCS) catalyzes the conversion of oxaloacetate and propionyl-CoA to 2-methylcitrate and CoA in the second step of 2-MCA cycle. ...

PubMed

76
Alternative route for glyoxylate consumption during growth on two-carbon compounds by Methylobacterium extorquens AM1.
2010-01-29

Methylobacterium extorquens AM1 is a facultative methylotroph capable of growth on both single-carbon and multicarbon compounds. Mutants defective in a pathway involved in converting acetyl-coenzyme A (CoA) to glyoxylate (the ethylmalonyl-CoA pathway) are unable to grow on both C(1) and C(2) compounds, showing that both modes of growth have this pathway in ...

PubMed

77
Interaction of analogues of coenzyme A with choline acetyltransferase.
1977-05-01

The finding that methyl methanethiolsulfonate appears to inhibit choline acetyltransferase from squid ganglia not by reacting with a thiol group of the enzyme but by reacting with the thiol group of coenzyme A to form a competitive inhibitor of acetyl coenzyme A led to the synthesis of the ethyl, propyl, and 3-carboxy-4-nitrophenyl disulfides of CoA. The ...

PubMed

78
Synthesis of acetyl coenzyme A by carbon monoxide dehydrogenase complex from acetate-grown Methanosarcina thermophila.
1990-12-01

The carbon monoxide dehydrogenase (CODH) complex from Methanosarcina thermophila catalyzed the synthesis of acetyl coenzyme A (acetyl-CoA) from CH3I, CO, and coenzyme A (CoA) at a rate of 65 nmol/min/mg at 55 degrees C. The reaction ended after 5 min with the synthesis of 52 nmol of acetyl-CoA per nmol of CODH ...

PubMed Central

79
Synthesis of acetyl coenzyme A by carbon monoxide dehydrogenase complex from acetate-grown Methanosarcina thermophila.
1990-12-01

The carbon monoxide dehydrogenase (CODH) complex from Methanosarcina thermophila catalyzed the synthesis of acetyl coenzyme A (acetyl-CoA) from CH3I, CO, and coenzyme A (CoA) at a rate of 65 nmol/min/mg at 55 degrees C. The reaction ended after 5 min with the synthesis of 52 nmol of acetyl-CoA per nmol of CODH ...

PubMed

80
The effect of alterations in total coenzyme A on metabolic pathways in the liver and heart
1989-01-01

The first set of experiments involved in vitro experiments using primary cultures of rat hepatocytes. A range of conditions were developed which resulted in cell cultures with variations in total CoA over a range of 1.3 to 2.9 nmol/mg protein with identical hormonal activation which simulated metabolic stress. Elevations of total CoA levels above that of ...

Energy Citations Database

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81
Nickel-Dependent Oligomerization of the Alpha Subunit of Acetyl-Coenzyme A Synthase/Carbon Monoxide Dehydrogenase�
2007-09-22

After activation with NiCl2, the recombinant ? subunit of the Ni-containing ?2?2 acetyl-CoA synthase/carbon monoxide dehydrogenase (ACS/CODH) catalyzes the synthesis of acetyl-CoA from CO, CoA and a methyl group donated from the ...

PubMed Central

82
Infrared and EPR spectroscopic characterization of a Ni(I) species formed by photolysis of a catalytically competent Ni(I)-CO intermediate in the acetyl-CoA synthase reaction.
2010-09-01

Acetyl-CoA synthase (ACS) catalyzes the synthesis of acetyl-CoA from CO, coenzyme A (CoA), and a methyl group from the CH(3)-Co(3+) site in the corrinoid iron-sulfur protein (CFeSP). These are the key steps in the Wood-Ljungdahl pathway of anaerobic CO and CO(2) fixation. The active site of ACS is the A-cluster, ...

PubMed

83
A Mycothiol Synthase Mutant of Mycobacterium smegmatis Produces Novel Thiols and Has an Altered Thiol Redox Status
2005-11-01

Mycobacteria and other actinomycetes do not produce glutathione but make mycothiol (MSH; AcCys-GlcN-Ins) that has functions similar to those of glutathione and is essential for growth of Mycobacterium tuberculosis. Mycothiol synthase (MshD) catalyzes N acetylation of Cys-GlcN-Ins to produce MSH in Mycobacterium smegmatis mc2155, and ...

PubMed Central

84
[Effect of hyperbaric oxygenation on N-acetyl-L-asparaginic acid metabolism in different cerebral areas].

The content of N-acetyl-l-asparaginic acid, CoA, CoASAc and the N-acetylaspartate amunohydrolase activity was determined in cerebral areas of rats at the normal level and at different stages of oxygen poisoning. At the preconvulsive stage of the oxygen poisoning the content of N-acetyl-l-asparaginic acid decreases in cerebral ...

PubMed

85
Molecular cloning, characterization, and elicitation of acetyl-CoA carboxylase from alfalfa.
1994-05-10

Acetyl-CoA carboxylase [ACCase; acetyl-CoA:carbon-dioxide ligase (ADP-forming), EC 6.4.1.2] catalyzes the ATP-dependent carboxylation of acetyl CoA to produce malonyl CoA. In plants, malonyl CoA is needed for plastid localized fatty acid biosynthesis and for a variety of ...

PubMed Central

86
Effect of (L-Carnitine) on acetyl-L-carnitine production by heart mitochondria
1986-05-01

The authors recently reported a large efflux of acetyl-L-carnitine from rat heart mitochondria during state 3 respiration with pyruvate as substrate both in the presence and absence of malate. In this series of experiments, the effect of the concentration of L-carnitine on the efflux of acetyl-L-carnitine and on the production of /sup 14/CO/sub 2/ from ...

Energy Citations Database

87
Levels of acetyl coenzyme A, reduced and oxidized coenzyme A, and coenzyme A in disulfide linkage to protein in dormant and germinated spores and growing and sporulating cells of Bacillus megaterium.
1977-11-01

Dormant spores of Bacillus megaterium were found to contain approximately 850 pmol of coenzyme A (CoA) per milligram of dry weight. Of this total, less than 1.5% was acetyl-CoA, 25% was CoA-disulfide, 43% was in disulfide linkage to protein, and the remainder was the free thiol. Dormand spores of Bacillus cereus and Clostridium bifermentans contained 700 ...

PubMed Central

88
When the fold fits the function - The external thioesterase of the Surfactin-Synthetase
2008-08-14

Non-ribosomal peptide synthetases (NRPS) and polyketide synthases (PKS) found in bacteria, fungi and plants utilize two different types of thioesterases for the production of highly active biological compounds1, 2. Type I thioesterases (TEI) catalyze the release step from the assembly line3 of the final product where it is transported from one reaction center to the next as a ...

PubMed Central

89
Structural basis for the selectivity of the external thioesterase of the surfactin synthetase.
2008-08-14

Non-ribosomal peptide synthetases (NRPS) and polyketide synthases (PKS) found in bacteria, fungi and plants use two different types of thioesterases for the production of highly active biological compounds. Type I thioesterases (TEI) catalyse the release step from the assembly line of the final product where it is transported from one reaction centre to the next as a thioester ...

PubMed

90
Biotechnological potential of the ethylmalonyl-CoA pathway.
2010-09-30

The ethylmalonyl-CoA pathway is central to the carbon metabolism of many ?-proteobacteria, like Rhodobacter sphaeroides and Methylobacterium extorquens as well as actinomycetes, like Streptomyces spp. Its function is to convert acetyl-CoA, a central carbon intermediate, to other precursor metabolites for cell carbon biosynthesis. In contrast to the glyoxylate cycle--another ...

PubMed

91
Synthesis of radiolabeled acetyl-coenzyme A from sodium acetate
1989-01-01

The synthesis of high specific radioactivity (/sup 14/C)-acetyl-Coenzyme A from (/sup 14/C)sodium acetate, 2,6-dichlorobenzoic acid, 1,1'-carbonyldiimidazole, and CoA is reported. Starting with 1 mumol of (/sup 14/C)sodium acetate, this method yields pure (/sup 14/C)acetyl-CoA in yields approaching 40%. Chromatography on a ...

Energy Citations Database

92
Mechanism of Allosteric Inhibition of N-Acetyl-L-glutamate Synthase by L-Arginine*
2009-02-20

N-Acetylglutamate synthase (NAGS) catalyzes the first committed step in l-arginine biosynthesis in plants and micro-organisms and is subject to feedback inhibition by l-arginine. This study compares the crystal structures of NAGS from Neisseria gonorrhoeae (ngNAGS) in the inactive T-state with l-arginine bound and in the active R-state complexed with ...

PubMed Central

93
l-Malyl-Coenzyme A/?-Methylmalyl-Coenzyme A Lyase Is Involved in Acetate Assimilation of the Isocitrate Lyase-Negative Bacterium Rhodobacter capsulatus
2005-02-01

Cell extracts of Rhodobacter capsulatus grown on acetate contained an apparent malate synthase activity but lacked isocitrate lyase activity. Therefore, R. capsulatus cannot use the glyoxylate cycle for acetate assimilation, and a different pathway must exist. It is shown that the apparent malate synthase activity is due to the combination of a ...

PubMed Central

94
Metabonomics classifies pathways affected by bioactive compounds. Artificial neural network classification of NMR spectra of plant extracts.
2003-03-01

The biochemical mode-of-action (MOA) for herbicides and other bioactive compounds can be rapidly and simultaneously classified by automated pattern recognition of the metabonome that is embodied in the 1H NMR spectrum of a crude plant extract. The ca. 300 herbicides that are used in agriculture today affect less than 30 different biochemical pathways. In this report, 19 of the most interesting ...

PubMed

95
Mechanism of Allosteric Inhibition of N-Acetyl-L-glutamate Synthase by L-Arginine
2010-01-07

N-Acetylglutamate synthase (NAGS) catalyzes the first committed step in L-arginine biosynthesis in plants and micro-organisms and is subject to feedback inhibition by L-arginine. This study compares the crystal structures of NAGS from Neisseria gonorrhoeae (ngNAGS) in the inactive T-state with L-arginine bound and in the active R-state complexed with CoA ...

Energy Citations Database

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