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

(1) Subcutaneous or intra-abdominal injections of 8 mg of HgCl2/100 g body weight markedly depressed hepatic fatty acid synthetase activity of chicks at 1 h post-injection. The depression occurred despite the fact that the chicks continued to eat up until the time they were killed. Under these same conditions, the hepatic activity of acetyl-CoA carboxylase (EC 6.4.1.2) was not affected by HgCl2, while the activity of the mitochondrial system of fatty acid elongation was stimulated. (2) When 2-mercaptoethanol was included in the incubation medium for a highly purified preparation of fatty acid synthetase, 500 muM HgCl2 was required to show definite inhibition of the enzyme. When 2-mercaptoethanol was omitted, 50 muM HgCl2 was inhibitory and 100 muM HgCl2 abolished enzyme activity. (3) 2 mM dithiothreitol completely protected the purified fatty acid synthetase preparation from inhibition by 100 muM HgCl2. When dithiothreitol was added after the addition of enzyme to the mercury-containing medium, protection of the enzyme was not complete. (4) Dialysis of cytosol fractions from chicks injected with HgCl2 against 500 vol. of 0.2 M potassium phosphate buffer (pH 7.0) containing 1 mM EDTA and 10 mM dithiothreitol for 4 h at 4 degrees stimulated the fatty acid synthetase activity of the fractions. Dialysis of cytosol fractions from noninjected chicks under the same conditions was without effect on fatty acid synthetase activity. (5) These data support the hypothesis that the inhibitory effect of HgCl2 administered in vivo on hepatic fatty acid synthetase activity in chicks is mediated through the interaction of mercury with the sulfhydryl groups of the enzyme.
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PMID:Mercury inhibition of avian fatty acid synthetase complex. 0 Jan 50

1. Tryptophan was administered to rats under various nutritional conditions: fasted for 24 hr, fasted and refed with glucose or corn-oil, fasted and administered glycerol intramuscularly, and nonfasted. 2. The changes in the contents of glycolytic intermediates in the livers indicated that the phosphoenolpyruvate carboxykinase [EC 4.1.1.32] reaction is inhibited by tryptophan administration in all groups of rats. The inversely related changes in the contents of malate and phosphoenolpyruvate were associated with the accumulation of quinolinate in the livers. The content of quinolinate which exhibited the half-maximal effect on the contents of both metabolites was 0.1-0.2 mumole per g liver. 3. The rate of incorporation of 3H from 3H2O into the total hepatic fatty acids was increased about 2-fold by the administration of this amino acid to the fasted rats. The enhancement of the rate was closely related to the increase in the citrate content. The hyperlipogenesis was also related to the decrease of acetyl-CoA and the increase of malonyl-CoA. The content of long-chain acyl-CoA was not affected. These effects of tryptophan administration on the hepatic fatty acid metabolism were found in all groups of rats. The liver content of glycerol 3-phosphate was decreased by tryptophan administration was markedly increased by glycerol injection. The injection of glycerol into the control and the tryptophan-treated rats produced a marked increase of glycerol 3-phosphate but did not affect the rate of fatty acid synthesis in the livers of either group. 4. It may be concluded that, in the livers of rats under various nutritional conditions, the short-term control of fatty acid synthesis by tryptophan administration is most likely due to the activation of acetyl-coenzyme A carboxylase [EC 6.4.1.2] by citrate.
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PMID:The effect of tryptophan administration on fatty acid synthesis in the livers of rats under various nutritional conditions. 0 Mar 75

Administration of cortisol to fetal rabbits resulted in a 42% inhibition of pulmonary de novo fatty acid synthesis from acetyl coenzyme A (CoA) (P = less than 0.025). This was associated with inhibition of acetyl-CoA carboxylase (EC. 6.4.1.2.) activity (P = less than 0.01) and a tendency towards decreased activity of fatty acid synthetase. There was no effect on pulmonary microsomal fatty acid elongation activity. Light and electron microscopic examination of the apex of the right lung of control and cortisol-treated animals revealed changes consistent with accelerated lung maturation in the treated animals. The in vitro activities of acetyl-CoA carboxylase and fatty acid synthetase were similar in rabbit lung and thus acetyl-CoA carboxylase activity does not appear to be rate limiting for de novo fatty acid synthesis in lung. No significant change in the activity of enzymes associated with de novo fatty acid synthesis of microsomal fatty acid elongation was found in fetal brain after cortisol exposure. However, in a parallel study on fatty acid synthesis in fetal liver, cortisol administration resulted in a 30% increase in fatty acid synthetase activity (P less than 0.025). The finding of cortisol-induced inhibition of de novo fatty acid synthesis in fetal rabbit lung may be related to the known inhibitory effect of cortisol on lung growth in the fetus.
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PMID:The influence of cortisol on the enzymes of fatty acid synthesis in developing mammalian lung and brain. 0 Jun 48

Studies were made of the mechanisms regulating the quantity and catalytic efficiency of hepatic acetyl coenzyme A carboxylase, which plays a critical role in the control of fatty acid biosynthesis. The microsomal enzyme system responsible for the formation of phosphatidic acid, the initial step in glycerolipid biosynthesis, was resolved into two component enzymes. The acyl-donor specificities of these and other acyltransferases account for the asymmetric fatty acid distribution in naturally occurring glycerolipids.
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PMID:[Regulation of lipid synthesis in animal organs]. 0 82

The cellular content of acetyl-CoA carboxylase [acetyl-CoA:carbon-dioxide ligase (ADP-forming), EC 6.4.1.2] in Saccharomyces cerevisiae is reduced by the addition of long-chain fatty acids to the culture medium. Mutant strains of S. cerevisiae defective in acyl-CoA synthetase [acid:CoA ligase (AMP-forming), EC 6.2.1.3] were isolated and used to determine whether fatty acid itself or a metabolite of fatty acid is more directly responsible for the repression of acetyl-CoA carboxylase. Cells of the mutant strains were capable of incorporating fatty acid to an extent comparable to that observed with the wild-type strain, but they accumulated markedly more of the incorporated fatty acid in the nonesterified form than did the wild-type cells. The level of acetyl-CoA carboxylase activity in the mutants, in contrast to that in the wild-type strain, was hardly affected by the addition of fatty acids to the medium. These results indicate that the activation of exogenous fatty acid is required for the repression of acetyl-CoA carboxylase, supporting the view that the repressive effect is mediated by some compound metabolically derived from fatty acid.
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PMID:Evidence that acyl coenzyme A synthetase activity is required for repression of yeast acetyl coenzyme A carboxylase by exogenous fatty acids. 0 54

Several mammary and adipose enzymes were measured in normal, adrenal-ectomized, adrenalectomized cortisol-treated, and intake-restricted lactating rats. Acetyl-CoA carboxylase, lipoprotein lipase, and triglyceride synthetase complex activities in mammary tissue were unchanged by intake restriction, decreased by adrenalectomy, and increased by glucocorticoid-replacement therapy. Malic dehydrogenase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and lipoprotein lipase activities in adipose were unchanged after adrenalectomy.
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PMID:Effects of adrenalectomy and glucocorticoid therapy on enzyme activities in mammary and adipose tissues from lactating rats. 0 27

1. Acetyl-CoA carboxylase (EC 6.4.1.2) and methylmalonyl-CoA carboxyltransferase (EC 2.1.3.1) have been isolated from mycelia of Streptomyces noursei var. polifungini, and purified about 50-fold. 2. Both enzymes carboxylate acetyl-CoA and propionyl-CoA; the respective Km values are 1.1 and 1.6 mM with acetyl-CoA carboxylase and 2.5 and 1.25 mM with carboxyltransferase. 3. The activities of both enzymes are inhibited by free fatty acids. Almost total inhibition of methylmalonyl-CoA carboxyltransferase was observed by 0.1 mM-butyrate or 0.1 mM-C14-C18 acids. Acetyl-CoA carobxylase was affected to the same extent by these compounds at concentration of about 1 mM. 4. The role of both carboxylating enzymes is biosynthesis of the antibiotic is discussed.
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PMID:Non-specific acetyl-CoA carboxylase and methylmalonyl-CoA carboxyltransferase in Streptomyces noursei var. polifungini. 0 79

The microsomal fraction of M1 cells (an established cell line of myeloid leukemia) was capable of catalyzing acylation of sn-glycerol 3-phosphate by long-chain fatty acyl-CoA thioesters. The principal lipid product formed was identified as phosphatidic acid. Palmityl-CoA, stearyl-CoA, and oleyl-CoA were more effective acyl donors than linoleyl-CoA and arachidonyl-CoA. M1 cells and macrophages differentiated from them exhibited similar levels of sn-glycerol 3-phosphate-acylating activity, which were approximately one-half that in mouse liver and approximately four times that in peritoneal macrophages. The levels of acetyl-CoA carboxylase activity in M1 cells and macrophages differentiated from them were not significantly different from each other and were comparable to those in mouse liver, whereas no activity was detected in peritoneal macrophages. These results indicated that differentiation of the myeloid leukemic cells, which results in loss of leukemogenicity and mitotic activity, is not associated with changes in the activities of these lipogenic enzymes, although the cultured cells exhibited remarkably higher activities than freshly harvested peritoneal macrophages. Furthermore, the present study supports the view that the glycerophosphate pathway makes an essential contribution to the de novo synthesis of phospholipids in M1 cells, as well as in both types of macrophages.
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PMID:Studies on some lipogenic enzymes of cultured myeloid leukemic cells. 0 40

After a 1-h preincubation to remove endogenous insulin, adipose tissue of obese mice (C57BL/L4 ob/ob) had a lower rate of glucose metabolism than tissue which was not preincubated. In contrast, preincubation did not change the metabolism of adipose tissue from lean mice (C57B1/6J +/+). The preincubation effect was abolished in obese mice which had had their serum insulin levels lowered toward normal by streptozotocin treatment. Injection of anti-insulin serum to obese mice caused adipose tissue removed 15 min after the injection to display a rate of glucose metabolsim lower than that of tissue removed before the injection. No such effect was seen in lean mice. These data are consistent with the hypothesis that hyperinsulinemia in the obese mice causes a chronic state of insulin stimulation of their adipose tissue, possibly contributing to their high rates of lipogenesis and their obesity. Several lipogenic enzymes were measured in adipose tissue of both lean and obese mice, and no single enzymatic abnormality was detected which might explain the hyperlipogenesis. Pyruvate dehydrogenase and acetyl-CoA carboxylase were both insulin-sensitive enzymes in lean and obese mice.
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PMID:Does hyperinsulinemia in ob/ob mice cause an insulin-stimulated adipose tissue? 0 75

The biotin carboxyl carrier protein (BCCP) component of Escherichia coli acetyl coenzyme A carboxylase and three peptides derived from BCCP by proteolytic digestion have been examined by circular dichroism spectroscopy. BCCP, which has a peptide molecular weight of 22,500, has a spectrum typical of globular proteins with negative extrema at 222 nm and 208 nm. The two smallest peptides, BCCP(SC) and BCCP(9,100), with molecular weights of 8,900 and 9,100, respectively, exhibit unusual positive CD bands centered at 237 nm and 220 nm. BCCP(10,400), with a molecular weight of 10,400, has a CD spectrum intermediate between BCCP and that of the smallest peptides. Since d-biotin exhibits a positive CD band at 233 nm, it was suspected that the biotin prosthetic group might be the chromophore responsible for the 237 nm CD band seen in BCCP(SC) and BCCP(9,100). Enzymatic carboxylation of BCCP(SC) to form CO2-BCCP(SC) caused the CD spectrum to change with a shift of the 237 nm band to 232 nm. The positive CD band at 220 nm was unaffected by carboxylation of the biotin prosthetic group. These date suggest that the 237 nm signal may be due either to the biotin which acts as a chromophore directly or to a chromophore that is perturbed by the carboxylation of biotin. A spectropolarimetric titration was carried out to investigate the possible contribution of the single tyrosine residue of BCCP(SC) to the CD spectrum of this peptide. At pH values over 9 the CD spetrum changed with the disappearance of the 237 nm band, suggesting that tyrosine might contribute to this CD band. Denaturation of BCCP(SC) or BCCP(9,100) with 8 M urea of 6 M guanidine HCl abolished the positive CD bands and resulted in spectra typical of a random coil, whereas treatment of BCCP(SC) with 1% sodium dodecyl sulfate abolished the positive bands and left a spectrum exhibiting a shoulder at 222 nm and a negative band at 205 nm, suggestive of a high degree of ordered structure. It is concluded that the CD band at 237 nm in BCCP(SC) and BCCP(9,100) is prabably due to a noncovalent interaction of biotin with an amino acid residue(s) of the protein. It is suggested that the biotin prosthetic group is partially buried in the surface of the protein, rather than swinging free at the end of the lysine side chain through which it is covalently linked to the protein, to permit this interaction to occur.
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PMID:Acetyl coenzyme A carbosylase. Circular dichroism studies of Escherichia coli biotin carboxyl carrier protein. 0 38


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