Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: CAS:1763-10-6 (palmitoyl-CoA)
 1,624 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Palmitic acid solubilized with Triton WR-1339 was converted to palmitoyl-CoA by microsomal membranes but lignoceric acid solubilized with Triton WR-1339 was not an effective substrate even though the detergent dispersed the same amount of these fatty acids and was also not inhibitory to the enzyme [I. Singh, R. P. Singh, A. Bhushan, and A. K. Singh (1985) Arch. Biochem. Biophys. 236, 418-426]. This observation suggested that palmitoyl-CoA and lignoceroyl-CoA may be synthesized by two different enzymes. We have solubilized the acyl-CoA ligase activities for palmitic and lignoceric acid of rat brain microsomal membranes with Triton X-100 and resolved them into three separate peaks (fractions) by hydroxylapatite chromatography. Fraction A (palmitoyl-CoA ligase) had high specific activity for palmitic acid and Fraction C (lignoceroyl-CoA ligase) for lignoceric acid. Specific activity of palmitoyl-CoA ligase for palmitic acid was six times higher than in Fraction C and specific activity of lignoceroyl-CoA ligase for lignoceric acid was four times higher than in Fraction A. At higher concentrations of Triton X-100 (0.5%), lignoceroyl-CoA ligase loses activity whereas palmitoyl-CoA ligase does not. Lignoceroyl-CoA ligase lost 60% of activity at 0.6% Triton X-100. Palmitoyl-CoA ligase (T1/2 of 4.5 min) is more stable at 40 degrees C than lignoceroyl-CoA ligase (T1/2 of 1.5 min). The pH optimum of palmitoyl-CoA ligase was 7.7 and that of lignoceroyl-CoA ligase was 8.4. Similar to our results with intact membranes, palmitic acid solubilized with Triton WR-1339 was converted to palmitoyl-CoA by palmitoyl-CoA ligase whereas lignoceric acid when solubilized with Triton WR-1339 was not able to act as substrate for lignoceroyl-CoA ligase. Since solubilized enzyme activities for synthesis of palmitoyl-CoA and lignoceroyl-CoA from microsomal membranes can be resolved into different fractions by column chromatography and demonstrate different properties, we suggest that in microsomal membranes palmitoyl-CoA and lignoceroyl-CoA are synthesized by two different enzymes.
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PMID:Characterization of rat brain microsomal acyl-coenzyme A ligases: different enzymes for the synthesis of palmitoyl-coenzyme A and lignoceroyl-coenzyme A. 396 26

Fatty acyl-CoA synthetase purified from rat liver microsomes was immobilized on either CNBr-activated Sepharose 4B or activated CH-Sepharose 4B, and the enzymatic activities of the syntheses of CoA esters from lignoceric acid (C24:0) and palmitic acid (C16:0) were studied and compared. The ratio of activities of the synthesis of lignoceroyl-CoA to palmitoyl-CoA increased 4.5 fold with CH-Sepharose, but only slightly with CNBr-Sepharose. The effects of a detergent and chaotropic agent on both substrates were significantly altered by the immobilization. The results of this study thus indicate that the stability and fatty acid specificity of fatty acyl-CoA synthetase are significantly affected by the physical state of the enzyme.
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PMID:Immobilization of fatty acyl-CoA synthetase: effect on its stability and substrate specificity. 396 83

1. The synthesis of glycerides from l-3-glycerophosphate and palmitic acid by mitochondrial preparations from rat liver was shown to be stimulated markedly by a soluble factor from the supernatant fraction of the liver. 2. That the soluble factor was a protein was indicated by its inactivation after treatment with papain and after boiling for 3min. at 100 degrees , its precipitation by ammonium sulphate and its behaviour on Sephadex G-200. The soluble factor was purified by ammonium sulphate fractionation and gel filtration. 3. Bovine serum albumin and lipoprotein fractions from rat and human serum also stimulated glyceride biosynthesis but the stimulations were one-twentieth to one-third of that obtained with the soluble factor. 4. The function of the soluble factor could not be explained by assuming a leakage of acyl-CoA synthetase, phosphatidate phosphatase or diglyceride acyltransferase from the mitochondria into the supernatant during preparation of the mitochondrial fraction. 5. Palmitic acid, in the presence of the soluble factor and optimum amounts of ATP and CoA, was a more effective substrate than palmitoyl-CoA or palmitoylcarnitine for the biosynthesis of glycerides by mitochondria.
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PMID:The biosynthesis of glycerides by mitochondria from rat liver. The requirement for a soluble protein. 429 Jul 20

An enzyme-bound intermediate of the overall reaction catalysed by rat liver microsomal long-chain fatty acyl-CoA synthetase is described. It was found to contain equimolar amounts of adenylate and fatty acid moieties bound to protein, and was stabilized by ATP. The intermediate reacted with CoA to give palmitoyl-CoA.
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PMID:Palmitoyl-coenzyme A synthetase. Isolation of an enzyme-bound intermediate. 477 69

1. Medium-chain fatty acyl-CoA synthetase (EC 6.2.1.2) was isolated by the method of Mahler, Wakil & Bock (1953) and the enzyme activity determined by the disappearance of CoA in the presence either of butyrate and ATP or of butyryl-AMP, as well as by ATP formation from butyryl-AMP and PP(i). 2. Preincubation of the enzyme with CoA and ATP alone or together, followed by the removal of these substrates by gel filtration, caused a marked inhibition of ATP formation, contrary to results previously obtained with palmitoyl-CoA synthetase. 3. The effect of ATP on butyryl-AMP-dependent CoA disappearance was inconsistent. Low concentrations of ATP (0.1-0.5mm) always caused inhibition, whereas higher concentrations (5-10mm) activated in some enzyme preparations and inhibited in others. 4. This inconsistency was shown to be due to the presence of two enzyme fractions. Both fractions had similar activities when assayed by the butyryl-AMP- or butyrate-plus-ATP-dependent CoA disappearance. However, fraction I was activated by ATP as measured by butyryl-AMP-dependent CoA disappearance whereas fraction II was inhibited by it. Fraction I also catalysed ATP formation from butyryl-AMP and PP(i) whereas fraction II was lacking in such activity. 5. The relationship of these observations with respect to other known mechanisms of fatty acid-activating systems is discussed.
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PMID:Studies on medium-chain fatty acyl-coenzyme a synthetase. Purification and properties. 567 68

The presence of acyl-CoA synthetase (EC 6.2.1.3) in peroxisomes and the subcellular distribution of beta-oxidation enzymes in human liver were investigated by using a single-step fractionation method of whole liver homogenates in metrizamide continuous density gradients and a novel procedure of computer analysis of results. Peroxisomes were found to contain 16% of the liver palmitoyl-CoA synthetase activity, and 21% and 60% of the enzyme activity was localized in mitochondria and microsomal fractions respectively. Fatty acyl-CoA oxidase was localized exclusively in peroxisomes, confirming previous results. Human liver peroxisomes were found to contribute 13%, 17% and 11% of the liver activities of crotonase, beta-hydroxyacyl-CoA dehydrogenase and thiolase respectively. The absolute activities found in peroxisomes for the enzymes investigated suggest that in human liver fatty acyl-CoA oxidase is the rate-limiting enzyme of the peroxisomal beta-oxidation pathway, when palmitic acid is the substrate.
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PMID:Acyl-CoA synthetase and the peroxisomal enzymes of beta-oxidation in human liver. Quantitative analysis of their subcellular localization. 624 Sep 78

Administration of p-chlorophenoxyisobutyric acid (clofibric acid) to rats induced a marked change in acyl composition of hepatic glycerolipids; a considerable increase in the proportion of octadecenoic acid (18:1) was accompanied by a marked decrease in the proportion of octadecadienoic acid (18:2). Among the glycerolipids, the changes in the proportions of 18:1 and 18:2 were the most marked in phosphatidylcholine. The change in the acyl composition of phosphatidylcholine paralleled the change in free fatty acid composition in microsomes. The treatment of rats with clofibric acid resulted in a 2.3-fold increase in activity of microsomal palmitoyl-CoA chain elongation and a 4.8-fold increase in activity of stearoyl-CoA desaturation. The activities of acyl-CoA synthetase, 1-acylglycerophosphate acyltransferase and 1-acylglycerophosphorylcholine acyltransferase in hepatic microsomes were increased approx. 3-, 1.7- and 3.6-times, respectively, by the treatment of rats with clofibric acid. These findings are discussed with respect to the role of fatty acid modification systems in the regulation of acyl composition of phosphatidylcholine.
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PMID:Modification by clofibric acid of acyl composition of glycerolipids in rat liver. Possible involvement of fatty acid chain elongation and desaturation. 647 60

1. Subfractionation by isopycnic density-gradient centrifugation in self-generating Percoll gradients of peroxisome-rich fractions prepared by differential centrifugation confirmed the presence of acyl-CoA synthetase in peroxisomes. Peroxisomes did not contain nicotinamide or adenine nucleotides other than CoA. 2. The gradient fractions most enriched in peroxisomes were pooled and the peroxisomes sedimented by centrifugation, resulting in a 50-fold-purified peroxisomal preparation as revealed by marker enzyme analysis. 3. Palmitate oxidation by intact purified peroxisomes was CoA-dependent, whereas palmitoyl-CoA oxidation was not, demonstrating that the peroxisomal CoA was available for the thiolase reaction, located in the peroxisomal matrix, but not for acyl-CoA synthetase. This suggests that the latter enzyme is located at the cytoplasmic side of the peroxisomal membrane. 4. Additional evidence for this location of peroxisomal acyl-CoA synthetase was as follows. Mechanical disruption of purified peroxisomes resulted in the release of catalase from the broken organelles, but not of acyl-CoA synthetase, indicating that the enzyme was membrane-bound. Acyl-CoA synthetase was not latent, despite the fact that at least one of its substrates appears to have a limited membrane permeability, as evidenced by the presence of CoA in purified peroxisomes. Finally, Pronase, a proteinase that does not penetrate the peroxisomal membrane, almost completely inactivated the acyl-CoA synthetase of intact peroxisomes.
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PMID:Evidence that peroxisomal acyl-CoA synthetase is located at the cytoplasmic side of the peroxisomal membrane. 711 21

The effects of salicylic acid on palmitic acid oxidation were studied using rat skeletal muscle mitochondria. Salicylic acid, in concentrations that exerted no effect on mitochondrial coupling (0.1 mM), significantly stimulated mitochondrial palmitic acid oxidation, with maximal stimulation occurring at subsaturating concentrations of substrate. In the same preparation, salicylate had no effect on the oxidation of palmitoylcarnitine or palmitoyl-CoA. Salicylate appears to augment the initial step of palmitic acid oxidation by lowering the apparent Michaelis constant (Km) of long chain fatty acid: CoASH ligase (AMP) (EC 6.2.1.3) for palmitic acid.
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PMID:Salicylic acid stimulation of palmitic acid oxidation by rat skeletal muscle mitochondria. 729 59

The subcellular distribution of the acyl coenzyme A synthetases of rat liver was reinvestigated in order to determine whether part of this activity occurs in peroxisomes. Rat liver was fractionated by differential centrifugation and by equilibrium density centrifugation. Acyl-CoA synthetase was assayed using a new, simple extraction procedure on three substrates: palmitate, laurate, and octanoate. Comparison of the resulting synthetase distributions with the distributions of marker enzymes for peroxisomes, mitochondria, and endoplasmic reticulum demonstrated the presence of some synthetase activity in each of the three organelles. These trimodal synthetase distributions were evaluated quantitatively by means of a computer program that calculated optimal linear combinations of marker enzymes using a least squares criterion. Peroxisomes were found to contain 7% of the liver's palmitoyl-CoA synthetase activity and 6% of its lauroyl-CoA synthetase activity, but no demonstrable octanoyl-CoA synthetase activity. The remainder of these activities are divided between the mitochondria and endoplasmic reticulum, in a manner that agrees with previous studies. The chain length specificity of the synthetase(s) of each organelle appears to be unique. The absolute activity of the peroxisomal palmitoyl-CoA synthetase is sufficient to maintain maximal peroxisomal beta-oxidation. Clofibrate treatment of the rats caused a 2.6- to 3.1-fold increase in the liver's total acyl-CoA synthetase activities. The subcellular distribution was not greatly affected by this drug treatment.
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PMID:Acyl-CoA synthetase in rat liver peroxisomes. Computer-assisted analysis of cell fractionation experiments. 743 88


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