Acetyl CoA synthetase

A very high activity of mitochondrial aldehyde dehydrogenases (together with its low ensures very efficient oxidation in the liver so that the concentration of acetaldehyde in blood remains very low. Nonetheless, it is possible that some of the pathological effects of ethanol are due to acetaldehyde (ethanal). In contrast, a large proportion of the acetate escapes from the liver and is converted to acetyl-CoA by acetyl-CoA synthetase in other tissues ... 

Schwer, B., Bunkenborg, J., Verdin, R.O., Andersen, J.S. and Verdin, F. (2006) Reversible lysine acetylation controls the activity of the mitochondrial enzyme acetyl-CoA synthetase 2. Proceedings... 

Acetyl-CoA p-Nitroaniline Disappearance Arylamine Acetyltransferase Acetyl-CoA Synthetase, ATP-Citrate Lyase" ... 

Potent metabolic inhibitors of the citric acid cycle. Fluo-roacetate (F-CH2COO ) must first be converted to flu-oroacetyl-S-CoA (by acetyl-CoA synthetase) and thence to fluorocitrate (by citrate synthase) before it can act as a potent metabohc inhibitor of the aconitase reaction as well as citrate transport. Submicromolar concentrations of ( )-erythro-Q iOTOcitTate can irreversibly inhibit citrate uptake by isolated brain mitochondria. 

AMP, and pyrophosphate (or, diphosphate). Propenoate can also act as the substrate. This enzyme is not identical with acetyl-CoA synthetase or with butyryl-CoA synthetase. 

Acetyl-CoA arylamine N-acetyltransferase, ARYLAMINE ACETYLTRANSFERASE ACETYL-CoA CARBOXYLASE ACETYL-CoA SYNTHETASE... 

ACETATE KINASE ACETYL-CoA CARBOXYLASE ACETYL-CoA SYNTHETASE N-ACETYLCLUCOSAMINE KINASE ACTIN ATPase ACTOMYOSIN ATPase N-ACYLMANNOSAMINE KINASE ADENINE NUCLEOTIDE TRANSLOCASE ADENOSINE KINASE ADENYLATE KINASE (MYOKINASE) ADENYLYLSULFATE KINASE d-ALANINE-d-ALANINE LIGASE... 

Fig. 7. Enzyme-coupled assay in which the hydrolase-catalyzed reaction releases acetic acid. The latter is converted by acetyl-CoA synthetase (ACS) into acetyl-CoA in the presence of (ATP) and coenzyme A (CoA). Citrate synthase (CS) catalyzes the reaction between acetyl-CoA and oxaloacetate to give citrate. The oxaloacetate required for this reaction is formed from L-malate and NAD in the presence of L-malate dehydrogenase (l-MDH). Initial rates of acetic acid formation can thus be determined by the increase in adsorption at 340 nm due to the increase in NADH concentration. Use of optically pure (Ry- or (5)-acetates allows the determination of the apparent enantioselectivity i app i81)-...

Field J, Rosenthal B, Samuelson J (2000) Early lateral transfer of genes encoding malic enzyme, acetyl-CoA synthetase and alcohol dehydrogenases from anaerobic prokaryotes to Entamoeba histolytica. Mol Microbiol 38 446-455... 

In the ruminant mammary tissue, it appears that acetate and /3-hydroxybutyrate contribute almost equally as primers for fatty acid synthesis (Palmquist et al. 1969 Smith and McCarthy 1969 Luick and Kameoka 1966). In nonruminant mammary tissue there is a preference for butyryl-CoA over acetyl-CoA as a primer. This preference increases with the length of the fatty acid being synthesized (Lin and Kumar 1972 Smith and Abraham 1971). The primary source of carbons for elongation is malonyl-CoA synthesized from acetate. The acetate is derived from blood acetate or from catabolism of glucose and is activated to acetyl-CoA by the action of acetyl-CoA synthetase and then converted to malonyl-CoA via the action of acetyl-CoA carboxylase (Moore and Christie, 1978). Acetyl-CoA carboxylase requires biotin to function. While this pathway is the primary source of carbons for synthesis of fatty acids, there also appears to be a nonbiotin pathway for synthesis of fatty acids C4, C6, and C8 in ruminant mammary-tissue (Kumar et al. 1965 McCarthy and Smith 1972). This nonmalonyl pathway for short chain fatty acid synthesis may be a reversal of the /3-oxidation pathway (Lin and Kumar 1972). 

An enzyme catalyzing a reaction similar to that of acetyl-CoA synthetase is succinyl-CoA synthetase... 

Acetic acid measurement involves conversion of acetate to acetyl-CoA by acetyl-CoA synthetase with the consumption of ATP (Boehringer Mannheim, 1986). Acetyl-CoA reacts with oxaloacetate and water in the presence of citrate synthetase to form citrate and CoA. Oxaloacetate for this reaction is obtained from malate by the action of malate dehydrogenase with concomitant conversion of NADH from NAD+. NADH is spectrophotometrically measured and correlated to acetic acid concentration. 

O Neill and Sakamoto reported an enzymatic fluorimetric method for the determination of acetylcholine in biological extracts [41]. Nanomolar amounts of acetylcholine were determined in perchloric acid extracts of biological materials (brain tissues) by use of a system containing acetylcholineesterase, acetyl CoA synthetase, maleate dehydrogenase, and citrate synthase. The production of NADH2 was stoichiometrically related to the amount of acetylcholine in the system, and was followed fluorimetrically. Interfering fluorescent substances in the brain extracts were removed with acid-washed Florisil. 

The pathway from acetate to palmitic acid (actually a palmitic acid-acyl carrier protein complex) involves at least nine enzymes acetyl CoA synthetase, acetyl CoA carboxylase, and the seven enzyme fatty acid synthetase complex. We chose first to test the effect of these compounds on acetyl CoA carboxylase (ACCase) activity. There were several reasons to select ACCase as the... 

Yeast acetyl-CoA synthetase is known to catalyze the conversion of ATP, acetate, and coenzyme A to acetyl-CoA, AMP and pyrophosphate by a mechanism involving the intermediate formation of acetyl-adenylate according to Equations 17 and 18 ... 

Acetyl-CoA synthetase catalyses the conversion of acetic acid to acetyl-CoA ATP + Acetate + CoA - AMP - - Pyrophosphate + Acetyl-CoA Acetyl-CoA can enter the TCA cycle or be used in fatty acid synthesis. 

Fig. 2. Pathway of ethanol utilization and ethyl acetate or acetaldehyde production by Candida utilis TCA cycle activity inhibited under ircn-limited conditions. Acetyl-CoA synthetase forward inhibited by acetaldehyde accumulated when elevated levels cf ethanol ( 3.5J w/v) present in the medium.

Acetyl-CoA is formed from CoA and acetate by the enzyme acetyl-CoA synthetase, an ADP-forming ligase. Phosphotrans-acetylase forms acetyl-CoA from CoA and acetyl-phosphate, which in turn is formed from acetate and ATP catalyzed by acetate kinase. Other enzymes that can form acetyl-CoA from CoA and other acetyl group donors include ATP citrate lyase and thiolase. Longer chain acyl-CoA thioesters are typically formed from CoA and a fatty acid catalyzed by ligases generally known as acyl-CoA synthetases. 

Methanothrix activates acetate differently than Methanosarcina, using only one enzyme, acetyl-CoA synthetase ... 

Fig. 10. Proposed pathway of methanogenesis from acetate (Methanosarcina, Methanothrix) and from pyruvate (Methanosarcina) Intermediates, enzymes and a site for Na dependence. CoA, coenzyme A PP, pyrophosphate CH3-H4MPT, methyl-tetrahydromethanopterin, CH3-S-C0M, methyl-coenzyme M [CO], CO bound to carbon monoxide dehydrogenase. Numbers in circles refer to enzymes involved (1) acetyl-CoA synthetase (2) pyrophosphatase (3) acetate kinase (4) phosphate acetyltransferase (5) pyruvate ferredoxin oxidoreductase (6) carbon monoxide dehydrogenase (7) CH3-H4MPT FI-S-CoM methyltransferase (8) methyl-coenzyme M reductase (9) heterodisulfide...

Cell extracts of Methanothrix soehngenii contain high activities of acetyl-CoA synthetase rather than acetate kinase and phosphate acetyltransferase [240,241] (Fig. 10). This indicates that in this organism acetate is activated to acetyl-CoA by acetyl-CoA synthase (AS). Since AMP is converted to ADP via adenylate kinase (AK), and pyrophosphate (PPj) is completely hydrolyzed via pyrophosphatase (PPj-ase), acetate activation by acetyl-CoA synthetase requires the input of 2 ATP equivalents ... 

From the postulated fermentation pathway (Fig. 14) it is probable that glucose degradation to pyruvate is not coupled with net ATP synthesis. Thus, ADP-forming acetyl-CoA synthetase appears to be the only energy-conserving site during maltose (and pyruvate) fermentation, which is in accordance with the growth yield data [294,295]. The enzyme... 

Fig. 14. Proposed pathway of maltose and of pyruvate fermentation to acetate, H2 and CO2 in Pyrococcus furiosus. Fdox, oxidized ferredoxin Fdred, reduced ferredoxin CoA, coenzymeA. Numbers in circles refer to enzymes involved (1) Q-glucosidase [296] (2) glucoserferredoxin oxidoreductase (3) gluconate dehydratase (this enzyme has not been detected so far in Pyrococcus furiosus) (4) 2-keto-3-deoxygluconate aldolase (5) glyceraldehyde ferredoxin oxidoreductase (6) glycerate kinase (2-phosphoglycerate forming) (7) enolase (8) pyruvate kinase (9) pyruvateiferredoxin oxidoreductase (10) ADP-forming acetyl-CoA synthetase (11)...

Further studies indicate that an ADP-forming acetyl-CoA synthetase is also operative in other extremely thermophilic archaea Pyrococcus woesei, Thermococcus celer, Hyperthermus butylicus, Desulfurococcus amylolyticus), which form acetate as end product of their fermentation [305]. In contrast, in acetate forming (eu)bacteria, acetate formation from acetyl-CoA and the synthesis of ATP from ADP and Pj are catalyzed by two enzymes phosphate acetyltransferase and acetate kinase. This holds true for the extremely thermophilic (eu)bacterium. Thermotoga maritima[3Q5], which ferments... 

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