Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.4.1.2 (acetyl-CoA carboxylase)
 2,876 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Plasma insulin concentrations in fed rats were altered acutely by administration of glucose or anti-insulin serum. Rates of fatty acid synthesis in adipose tissue and liver were estimated from the incorporation of 3H from 3H2O. In the adipose tissue dehydrogenase and acetyl-CoA carboxylase were evident. In liver, although changes in rates of fatty acid synthesis were found, the initial activity of pyruvate dehydrogenase did not alter, but small parallel changes in acetyl-CoA carboxylase activity were observed.
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PMID:Acute effects in vivo of anti-insulin serum on rates of fatty acid synthesis and activities of acetyl-coenzyme A carboxylase and pyruvate dehydrogenase in liver and epididymal adipose tissue of fed rats. 1 55

Using stabilizing conditions the acetyl-CoA carboxylase (EC 6.4.1.2) of Pseudomonas citronellolis has been isolated as a complex containing four different polypeptide chains with molecular weights of 53 000, 36 000, 33 000 and 25 000. Evidence is presented to suggest that these polypeptide chains correspond to distinct biotin carboxylase, transcarboxylase and biotin carboxyl carrier protein subunits in analogy with similar subunits of Escherichia coli acetyl-CoA carboxylase, an unstable complex in vitro.
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PMID:Stabilization of an acetyl-coenzyme A carboxylase complex from Pseudomonas citronellolis. 1 1

Evidence is presented that rat liver microsomal fatty acid chain elongation synthesis and desaturation, as well as acetyl-CoA carboxylase and fatty acid synthetase, are strongly influenced by thyroid hormone level. Conversely, the fatty acid chain elongation system in mitochondria, unlike the oxidative capacity of palmitate, NADH, succinate and malate, does not seem significantly affected by the thyrotoxic state. In triiodothyronine-induced or thyroxine-induced hyperthyroidism, rat liver acetyl-CoA carboxylase, fatty acid synthetase and microsomal chain elongation and desaturation reactions are not greatly affected after the first 10 days of treatment, while after longer intervals a respective increase in these activities is shown of up to 87, 116 and 65% after 22 days. In propylthiouracil-induced hypothyroidism, all the above synthetic activities are strongly reduced immediately after three days of drug administration and diminished no further following longer periods. Although the pattern of synthesized fatty acids in the thyrotoxic state is similar to that obtained from normal subcellular rat fractions, the esterification process of fatty acids in microsomal lipids appears to be slightly inhibited in hypothyroid rats and increased following triiodothyronine or thyroxine administration. Finally, a reduction in the hepatic cyclic AMP level of about 41% is reported after 19 days of triiodothyronine-administration to rats. On the basis of the observed insensitivity of the mitochondrial fatty acid chain elongation system to the thyrotoxic state, a tentative interpretation of its role in the hepatic cell is postulated.
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PMID:Effect of thyroid hormones on microsomal fatty acid chain elongation synthesis in rat liver. 1 55

The level of acetyl-coenzyme-A carboxylase activity in Candida lipolytica undergoes large variations depending upon the carbon source on which the yeast is grown. Cells grown on n-alkanes or fatty acids exhibit a lower activity level than do cells grown on glucose. Among the n-alkanes and fatty acids tested, n-heptadecane, n-octadecane, oleic acid and linoleic acid reduce the enzyme activity to the lowest levels, which are 16-18% of the activity level in glucose-grown cells. Immunochemical titrations and Ouchterlony double-diffusion analysis with specific antibody as well as kinetic studies have indicated that the observed decrease in the level of acetyl-CoA carboxylase activity is due to a reduction in the cellular content of the enzyme. Furthermore, isotopic leucine incorporation studies with the use of the immunoprecipitation technique have demonstrated that the relative rate of synthesis of the enzyme in oleic-acid-grown cells is diminished to 12% of that in glucose-grown cells. Evidence has also been obtained to support the view that the enzyme in this yeast is not degraded at a rate high enough to contribute to the marked decrease in the cellular content of the enzyme. Thus, it is concluded that the reduction in acetyl-CoA carboxylase content in fatty-acid-grown cells is due to diminished synthesis of the enzyme.
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PMID:Acetyl-coenzyme-A carboxylase of Candida lipolytica. 2. Regulation of cellular content and synthesis of the enzyme. 1 59

Fatty acid synthesis was studied in testes of rats fed a fat-free or fat-supplemented diet. Testes of fat-deficient rats incorporated nearly twice as much intratesticularly injected [1-14C]acetate into total fatty acids (primarily into palmitic acid) as did supplemented rats. To determine the mechanism for the increased synthesis, the activities of the following enzymes were determined in the cytoplasmic fraction of testicular homogenates: fatty acid synthetase, acetyl CoA carboxylase [EC 6.4.1.2], citrate-cleavage [EC 4.1.3.8], malic [EC 1.1.1.38], and the glucose-l-phosphate dehydrogenase [EC 1.1.1.49]: 6-phosphogluconate dehydrogenase pair [EC 1.1.1.44]. Although the activity of fatty acid synthetase did increase in livers from fat-deficient rats, no change was observed in corresponding testes. No difference between the two groups could be demonstrated in testicular activity of citrate-cleavage enzyme, malic enzyme, or the glucose-6-phosphate dehydrogenase: 6-phosphogluconate dehydrogenase pair. However, the activity of cytoplasmic acetyl CoA carboxylase in testes of rats fed the fat-deficient diet was 1.4 times higher than the activity in testes of rats fed the supplemented diet. Fat deficiency did not affect the specific activity of the testicular microsomal elongation system, assayed by incubation with 14C-malonyl CoA. The concentration of unesterified fatty acids was lower in testes of the fat-deficient compared to supplemented rats, indicating that decreased inhibition of acetyl CoA carboxylase in the fat-deficient rats testes might have been responsible for the observed increased de novo synthesis of palmitic acid.
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PMID:Fatty acid synthesis in testes of fat-deficient and fat-supplemented rats. 1 68

Metabolism of perfused livers from control and ventromedial hypothalamus (VMH)-lesioned rats has been studied. To eliminate the possibility that observed metabolic abnormalities could be realted to hyperphagia, VMH-lesioned rats were placed on restricted diet matching that of controls. Ten days postoperatively, VMH-lesioned rats had hyperinsulinemia, hypertriglyceridemia, increased blood urea nitrogen levels, together with decreased plasma free fatty acid (FFA) and glucose levels. Insulin release produced in vivo by a glucose load was much higher in VMH-lesioned than in control rats. Perfused livers from VMH-lesioned rats secreted more triglycerides and produced more urea than controls, whereas production of glucose and ketone bodies was reduced. Lipogenesis, newly synthesized triglyceride secretion, and the activity of acetyl-CoA carboxylase and fatty acid synthetase were greatest in livers from VMH-lesioned rats. Fasting abolished hyperinsulinemia and most of these observed metabolic alterations. After treatment with anti-insulin serum, the high rate of lipogenesis observed in livers from VMH-lesioned rats was restored toward normal. It is suggested that hyperinsulinemia may be partly responsible for the metabolic disorders observed in livers from nonhyperphagic VMH-lesioned rats.
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PMID:Consequences of ventromedial hypothalamic lesions on metabolism of perfused rat liver. 1 11

Acetyl-CoA carboxylase (E.C. 6.4.1.2) was isolated from rat liver. The purified enzyme contains phospholipids with a rather large amount of phosphatidylinositol (26%). Incubation of the purified acetyl-CoA carboxylase with phospholipase A2 (E.C. 3.1.1.4) or with phospholipase D (E.C. 3.1.1.4) diminishes the phospholipid content by 70%, this treatment leading to a complete inactivation of the enzyme. After removal of the phospholipases, the lipid-depleted enzyme can be reactivated to a certain degree by incubation with a phospholipid extract from rat liver, with phosphatidylinositol alone, or with serum albumin.
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PMID:Effects of phospholipids in the action of acetyl-CoA carboxylase from rat liver. 1 56

The role of biotin-dependent enzymes in the fatty liver and kidney syndrome of young chicks was studied. Under conditions of a marginal deficiency of dietary biotin, the level of biotin in the liver has differing effects on the activities of two biotin-dependent enzymes, pyruvate carboxylase and acetyl-CoA carboxylase. The activity of acetyl-CoA carboxylase is increased, but when the dietary deficiency of biotin produces biotin levels which are below 0-8 mug/g of liver, the activity of pyruvate carboxylase may be insufficient to completely metabolize pyruvate via gluconeogenesis. There is an increase in liver size and in the activities of enzymes involved in alternate pathways for the removal of pyruvate. Blood lactate accumulates and there is increased synthesis of fatty acids, and an accumulation of palmitoleic acid; these steps are accomplished by increased activities of at least the following enzymes: acetyl-CoA carboxylase, malate dehydrogenase (decarboxylating) (NADP+) and the desaturase enzyme. When the biotin level is below 0-35 mug/g of liver and the chick is subjected to a stress, physiological defence mechanisms of the chick may be inadequate to maintain homeostasis and they finally collapse, resulting in accumulation of triacylglycerol in the liver and blood; the chick is unable to maintain blood glucose levels and death occurs, often only a few hours after the imposition of the stress.
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PMID:Fatty liver and kidney syndrome in chicks. II. Biochemical role of biotin. 1 36

It has been suggested that the carbohydrate-rich diet of chicks after hatching is responsible for the emergence of hepatic enzymes involved in lipogenesis; the injection of glucose to newly hatched chicks gives rise to an appreciable elvation on the activities of acetyl coenzyme A carboxylase and fatty acid synthetase. The present study shows that during the first hours after hatching, there is a natural elevation of glycemia which parallels the increase in acetyl coenzyme A carboxylase activity. However, the administration of hormones which alter the blood glucose levels considerably (insulin, tolbutamide, glucagon and hydrocortisone) did not influence the enzyme activity. The administration of thyroxine, estradiol and cyclic AMP, was also without effect. These results do not support the theory that the increased amount of blood glucose is the natural effector of the induction acetyl coenzyme A carboxylase. They also show that different lipogenic enzymes are not regulated via the same 'operon' since thyroxine or glucagon which alter the level of some enzymes on this pathway did not modify that of the acetyl coenzyme A carboxylase.
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PMID:Development of hepatic acetyl coenzyme A carboxylase in hormone-treated chicks. 1 45

The process leading to the rise of acetyl-CoA carboxylase activity in rat mammary tissue after the onset of lactation was investigated. The kinetics of change in enzyme activity and enzyme immunotitratable with antibody against avian liver acetyl-CoA carboxylase were determined during the course of lactogenic differentiation. The antibody inactivates and specifically precipitates acetyl-CoA carboxylase from rat mammary tissue as well as that from chicken liver cytosol. Characterization of the immunoprecipitate of the mammary tissue carboxylase by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis reveals a single biotin-containing polypeptide of about 230000mol.wt. This molecular weight is approximately twice that reported for the avian liver enzyme. However, chicken liver cytosol prepared in the presence of trypsin inhibitor and subjected to immunoprecipitation gives rise to a biotin-containing subunit of 230000mol.wt. as determined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis; omission of proteinase inhibitor leads to a subunit(s) approximately one-half this size. Throughout gestation both carboxylase activity and amounts of immunotitratable enzyme remained low; however, after parturition both parameters rose concomitantly to values 30-40 times the initial values. Therefore the elevated concentration of acetyl-CoA carboxylase appears to result from an increased rate of synthesis of enzyme relative to degradation rather than to activation of a pre-existing form of the enzyme.
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PMID:Changes in mammary-gland acetyl-coenzyme A carboxylase associated with lactogenic differentiation. 1 88


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