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)

1. The enzymes involved in glycerolphosphate and monoacylglycerol acylation of rat small intestine were more active in villi than in crypts. Monoglyceride acyltransferase (EC 2.3.1.22) was found to be absent from crypts. 2. In the villi, the enzymes are mainly localized in microsomes, although low activities of palmitoyl-CoA synthetase (EC 6.2.1.3), glycerolphosphate acyltransferase (EC 2.3.1.15) and cholinephosphotransferase (EC 2.7.8.2) are found in mitochondria. Mitochondria lack monoglyceride acyltransferase and lysolecithin acyltransferase (EC 2.3.1.23), both of which are involved in the reacylation of alimentary partial glycerides. Therefore, this process is confined to microsomes. 3. The monoacylglycerol and lysolecithin acyltransferases, as well as choline-phosphotransferase, are probably localized within the endoplasmic reticulum, since these enzymes are relatively Nagerse resistant (subtilisin; EC 3.4.2.1, compared with palmitoyl-CoA synthetase and glycerolphosphate acyltransferase, which are highly Nagarse-sensitive and therefore probably localized on the outside of the microsomes (and mitochondria). 4. The physical separation of alimentary product reacylation from de novo synthetic processes provides the basis of metabolic compartmentation observed by other workers. 5. The use of sucrose instead of a salt medium for the isolation and homogenization of small intestinal epithelial cells allowed the separation of mitochondria and microsomes by differential centrifugation without mutual contamination. 6. Phospholipids were found to stimulate glycerolphosphate acylation in vitro. 7. The glycerolphosphate and monoacylglycerol acylation pathways are not competitive.
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PMID:Topographic distribution of enzymes involved in glycerolipid synthesis in rat small, intestinal epithelium. 18 50

Rat liver peroxisomes oxidized palmitate in the presence of ATP, CoA and NAD+, and the rate of palmitate oxidation exceeded that of palmitoyl-CoA oxidation. Acyl-CoA synthetase [acid: CoA ligase (AMP-forming); EC 6.2.1.3] was found in peroxisomes. The substrate specificity of the peroxisomal synthetase towards fatty acids with various carbon chain lengths was similar to that of the microsomal enzyme. The peroxisomal synthetase activity toward palmitate (40--100 nmol/min per mg protein) was higher than the rate of palmitate oxidation by the peroxisomal system (0.7--1.7 nmol/min per mg protein). The data show that peroxisomes activate long chain fatty acids and oxidize their acyl-CoA derivatives.
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PMID:Acyl-Coenzyme A synthetase and fatty acid oxidation in rat liver peroxisomes. 21 93

The incorporation of [1-C14] palmitate into palmitoyl CoA and triglycerides by homogenates of human adipose tissue have been studied. Adipose tissue samples were taken from three sites varying in adipocytes size (omentum, subcutaneous abdominal wall, buttock). The donors were normal weight women of constant weight. A significant positive correlation was found between initial velocity of palmitoyl CoA synthetase (EC 6.2.1.3) and total [1-C14] palmitate incorporation into triglycerides on one hand and adipocyte cell size on the other hand : these relations with cell size were apparent both within and between individuals. The mechanism of this "size effect" which is unrelated to the higher protein content of larger cells, is still unexplained. Lipogenesis, like most of the metabolic activities of adipose tissue increases with enlarging cell size. Acceleration of a lipogenesis-lipolysis cycle could constitute an energy wasting system able to limit the volume of the adipocytes.
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PMID:Lipogenesis in human adipose tissue in vitro: effect of fat cell size on some enzymatic activities. 47 82

Long chain fatty acyl coenzyme A ligase (EC 6.2.1.3) purified from rat liver mitochondria has been characterized with respect to several kinetic parameters. Many of the kinetic properties of the mitochondrial enzyme are similar to those of the purified microsomal enzyme with respect to palmitoyl-CoA formation, but there are distinct differences. The fatty acid and nucleotide specificities of the mitochondrial enzyme are similar to those of the microsomal enzyme, as are the apparent Km values for ATP and coenzyme A. On the other hand, the mitochondrial enzyme differs from the microsomal enzyme in that it has a lower pH optimum, is different in molecular weight, and does not show simple saturation kinetics with palmitate as substrate. Of particular interest is the evidence presented which indicates that the mitochondrial long chain fatty acyl-CoA ligase, unlike short and medium chain ligases, does not utilize an acyladenylate as an intermediate in the formation of fatty acyl-CoA.
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PMID:Kinetic characterization of long chain fatty acyl coenzyme A ligase from rat liver mitochondria. 50 Jun 34

1. The specific activity of lysolecithin acyltransferase (EC 2.3.1.23) in sonicated adult rat lung alveolar type II epithelial cells, measured either alone or in combination with acyl-CoA synthetase (EC 6.2.1.3), was found to be an order of magnitude greater than that of lysolecithin:lysolecithin acyltransferase. 2. Lysolecithin acyltransferase in type II cells was found to prefer palmitoyl-CoA over oleoyl-CoA as substrate. The combination of lysolecithin acyltransferase and acyl-CoA synthetase was found to prefer palmitate over oleate for incorporation into phosphatidylcholine. 3. Compared to whole lung homogenate, sonicated adult rat type II cells are highly enriched in lysolecithin acyltransferase but not in lysolecithin:lysolecithin acyltransferase. 4. These observations indicate that in normal adult rat type II cells the deacylation-reacylation cycle is more important for the formation of dipalmitoyl phosphatidylcholine than the deacylation-transacylation process.
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PMID:Lysolecithin acyltransferase and lysolecithin: lysolecithin acyltransferase in adult rat lung alveolar type II epithelial cells. 58 86

1. State-3 (i.e. ADP-stimulated) rates of O(2) uptake with palmitoylcarnitine, palmitoyl-CoA plus carnitine, pyruvate plus malonate plus carnitine and octanoate as respiratory substrate were all diminished in heart mitochondria isolated from senescent (24-month-old) rats compared with mitochondria from young adults (6 months old). By contrast, State-3 rates of O(2) uptake with pyruvate plus malate or glutamate plus malate were the same for mitochondria from each age group. 2. Measurements of enzyme activities in disrupted mitochondria showed a decline with senescence in the activity of acyl-CoA synthetase (EC 6.2.1.2 and 6.2.1.3), carnitine acetyltransferase (EC 2.3.1.7) and 3-hydroxy-acyl-CoA dehydrogenase (EC 1.1.1.35), but no change in the activity of carnitine palmitoyltransferase (EC 2.3.1.21) or acyl-CoA dehydrogenase (EC 1.3.99.3). 3. Measurement of dl-[(3)H]carnitine (in)/acetyl-l-carnitine (out) exchange in intact mitochondria showed decreased rates when the animals used were senescent. However, this followed from a decreased intramitochondrial pool of exchangeable carnitine, such that calculated first-order rate constants for exchange were identical in mitochondria from the two age groups. 4. The decline in acyl-CoA synthetase activity is thought to be the reason for the diminished rate of O(2) uptake with octanoate in senescence. The decline in carnitine acetyltransferase activity is considered to be the cause of the diminished rate of O(2) uptake with acetylcarnitine or with pyruvate plus malonate plus carnitine as substrate. The mechanism of the diminished rate of O(2) uptake with palmitoylcarnitine in senescence is discussed.
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PMID:Lipid oxidation by heart mitochondria from young adult and senescent rats. 63 43

1. The activities of long-chain acyl-CoA synthetase (acid: CoA ligase (AMP-forming), EC 6.2.1.3) and the "outer" carnitine long-chain acyltransferase (palmitoyl-CoA: L-carnitine O-palmitoyltransferase, EC 2.3.1.21) have been estimated in intact brown adipose tissue mitochondria. The assay of both enzymes is based on a coupled reaction in which the intramitochondrial (matrix) CoASH is the final acyl acceptor and the oxidation-reduction state of the flavoproteins in the acyl-CoA dehydrogens pathway is used to determine the intramitochondrial level of acyl-CoA. 2. Using endogenous fatty acids as the substrate, the progress curve of acyl-CoA synthetase activity was in most mitochondrial preparations linear within the first 30 s. When initial rates were measured, the Km value for CoASH (2.4 micron) was lower than previously determined for the acyl-CoA synthetase in brown adipose tissue mitochondria as well as in mitochondria of other tissues. The pH activity curve indicates that the unprotonated form of the fatty acids represents the substrate of acyl-CoA synthetase, i.e. similar to the effect of pH on the binding of fatty acids to bovine serum albumin. 3. Experimental evidence is presented that at temperatures higher than the transition temperature of the acyl-CoA synthetase (i.e. Tt = 19 degrees C), this enzymic reaction is rate-limiting in the sequence of coupled reactions leading to beta-oxidation in the mitochondrial matrix. 4. The initial rate of the long-chain acyl-COA synthetase reaction was estimated to v = 119 +/- 16 nmol . min-1 . mg-1 protein (mean +/- S.D., n = 5) at an optimal concentration of palmitate which exceeds that of rat heart mitochondria by a factor of 10.
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PMID:Long-chain acyl-CoA synthetase and "outer" carnitine long-chain acyltransferase activities of intact brown adipose tissue mitochondria. 69 44

The presence of palmitoyl-CoA synthetase (EC 6.2.1.3) in the brush border-free particulate fraction of chicken intestinal mucosa is demonstrated. The enzyme was dependent on the simultaneous presence of lysophosphatidylcholine and Triton X-100 as well as ATP, CoA and Mg2+ for maximal activity. Lysophosphatidylcholine could not be replaced by other lipids. Enzyme preparations solubilized by Triton X-100 or lysophosphatidylcholine were still dependent on the presence of detergents for maximal activity.
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PMID:Specific requirement of lysophosphatidylcholine for palmitoyl-CoA synthetase of chicken intestine. 83 63

1. Age-related changes in the activities of fatty acid synthetase and palmitoyl-CoA synthetase (EC 6.2.1.3) have been determined in rabbit brain from the foetal stage through to maturity. 2. Fatty acid synthetase was most active in the soluble fraction of brain homogenates at 5 days of age, prior to the active phase of myelination. Palmitic acid was the major fatty acid synthesised throughout development. 3. Palmitoyl-CoA synthetase had a constant specific activity in the full homogenate, but in the microsomal fraction reached a maximum specific activity at 15-20 days of age. The specific activity was higher than in the mitochondrial fraction which declined from birth. Most of the palmitoyl-CoA synthetase activity was present in the fraction containing cell membranes plus nuclei. 4. From a comparison of the total activities of the enzymes involved in the metabolism of fatty acids in the brain, de novo fatty acid synthesis may be rate limiting compared with esterification of synthesised fatty acids, but not in the further transformations of the synthesised fatty acids.
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PMID:Changes in the activities of de novo fatty acid synthesis and palmitoyl-CoA synthetase in relation to myelination in rabbit brain. 112 Jan 38

1. Incorporation of [14C]malonyl-CoA into fatty acid and lipid by the microsomal fraction from developing rabbit brain has been determined. 2. The specific activity for malonyl-CoA incorporation into preformed fatty acid reached a maximum at 15-20 days of age and the increase in enzyme activity paralleled that of palmitoyl-CoA synthesis in the microsomal fraction. 3. Most of the preformed fatty acid was derived from microsomal membrane lipid, and added acyl-CoA only slightly increased the incorporation. Inhibition occurred at concentrations in excess of 2 muM acyl-CoA. Endogenous acyl-CoA may be formed by acyl-group turnover through the action of phospholipase A and acyl-CoA synthetase. 4. Added 14C-labelled acyl-CoA was elongated to a longer chain-length product than endogenous fatty acid elongated with [14C]malonyl-CoA. 5. Both ATP and acyl-CoA influence the incorporation of elongated fatty acids into complex lipids, possibly through their effect on acyl-CoA synthetase.
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PMID:Fatty acid metabolism in the microsomal fraction of developing rabbit brain. 112 Jan 39


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