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)

Lipid synthesis as measured by the incorporation of acetate or 3H2O into slices of foetal liver, is much higher than in slices of adult liver and shows a peak at about two-thirds of gestation. At this time the synthesis from glucose was low and reached a peak 10 days later. The changes in the activity of ATP citrate lyase, which mirrored acetate incorporation, and the effect of glucose and pyruvate on acetate corporation into lipid suggests that some of the lipid synthesis occurs via intramitochondrial acetyl-CoA production from acetate. Despite this, lipid synthesis was not inhibited by (-)-hydroxycitrate. The low rate of synthesis from glucose at two-thirds of gestation is ascribed to the low activity of pyruvate carboxylase at this time and a role for a phosphoenolpyruvate carboxykinase in providing oxaloacetate for lipogenesis is proposed. The activity of fatty acid synthetase broadly agreed with the changes in lipid synthesis, whereas the activity of acetyl-CoA carboxylase was barely sufficient to account for the rates of lipid synthesis in vivo. Acetate and short-chain fatty acids are likely to be the major precursors for lipid synthesis in vivo.
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PMID:Lipid biosynthesis in liver slices of the foetal guinea pig. 0 15

A soluble acetyl-CoA carboxylase in homogenates of leaves from wild-type barley seedlings was studied. Centrifuging the homogenate at 150,000 X g did not reduce the total activity, but raised the specific activity. During chloroplast development in light-grown seedlings or during light-dependent greening of leaves grown in the dark, both the total activity of the carboxylase per plant and the specific activity per mg of protein in homogenates of the seedlings increased rapidly. The soluble leaf acetyl-CoA carboxylase was studied in a number of barley mutants with lesions in chloroplast development. In a group of three mutants light elicited an increase in acetyl-CoA carboxylase activity as in the wild-type. In two mutants light caused a decrease in activity. Dark-grown leaves of mutant albina-f17 contained levels of soluble acetyl-CoA carboxylase reached only in the light by the wild-type, whereas light-grown albina-f17 seedlings lacked carboxylase activities. The possibility is discussed that leaf cells contain two forms of acetyl-CoA carboxylase, one soluble with unknown location and a dissociable form located in the chloroplast.
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PMID:Acetyl-CoA carboxylase during development of plastids in wild-type and mutant barley seedlings. 0 78

The long-term regulation of fatty acid synthetase and acetyl-CoA carboxylase and of fatty acid and sterol synthesis was studied in C-6 glial cells in culture. When theophylline (10(-3) M) was added to the culture medium of these cells, rates of lipid synthesis from acetate and activities of synthetase and carboxylase became distinctly lower than in cells that were untreated. This effect appeared after approximately 12 h, and after 48 h enzymatic activities were reduced approx. 2-fold and rates of lipid synthesis from acetate 3- to 4-fold. The likelihood that the decrease in fatty acid synthesis from acetate was caused by the decrease in activities of fatty acid synthetase and acetyl-CoA carboxylase was established by several observations. These indicated that the locus of the effect probably did not reside at the level of acetate uptake into the cell, alterations in acetate pool sizes or conversion of acetate to acetyl-CoA. Moreover, de novo fatty acid synthesis was found to be the predominant pathway in these glial cells, whether treated with theophylline or not. The mechanism of the effect of theophylline on fatty acid synthetase was shown by immunochemical techniques to involve an alteration in content of enzyme rather than in catalytic efficiency. The change in content of fatty acid synthetase was shown by isotopic-immunochemical experiments to involve a decrease in synthesis of the enzyme. The mechanism whereby theophylline leads to a decrease in lipogenesis and in the synthesis of fatty acid synthetase may not be mediated entirely by inhibition of phosphodiesterase and an increase in cyclic AMP levels, because dibutyryl cyclic AMP (10(-3) M) only partially reproduced the effect.
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PMID:Long-term regulation by theophylline of fatty acid synthetase, acetyl-CoA carboxylase and lipid synthesis in cultured glial cells. 0 98

A temperature-sensitive mutation in Escherichia coli K-12 was shown to affect acetyl coenzyme A carboxylase and to map at min 63. This site is designated fabE.
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PMID:Partial characterization of a temperature-sensitive mutation affecting acetyl coenzyme A carboxylase in Escherichia coli K-12. 0 49

Specific polysomes involved the the synthesis of acetyl-CoA carboxylase [acetyl-CoA: carbon-dioxide ligase (ADP-forming), EC 6.4.1.2] have been identified by the binding of 125I-labeled antiacetyl-CoA carboxylase to rat liver polysomes. The binding is highly specific and occurs through the recognition of the nascent peptide chains on polysomes. With the use of the 125I-labeled antibody binding technique, it has been demonstrated that the relative content of acetyl-CoA carboxylase-synthesizing polysomes in the liver correlates well with the rate of hepatic synthesis of the enzyme in rats subjected to different dietary conditions as well as in alloxan-diabetic rats with or without insulin treatment.
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PMID:Dietary and hormonal regulation of the content of acetyl coenzyme A carboxylase-synthesizing polysomes in rat liver. 0 84

Pseudomonas citronellolis was shown to contain four different acyl-coenzyme A carboxylases, including acetyl-, propionyl-, 3-methylcrotonyl-, and geranyl-CoA carboxylases, when grown on the appropriate carbon sources. Acetyl-CoA carboxylase activity in crude extracts was stimulated approximately 40-fold by inclusion of 0.4-0.5 M ammonium sulfate in the assay. Unexpectedly high levels of propionyl-CoA carboxylase activity, also stimulated by ammonium sulfate, were found in acetate-grown cells. That these acetyl- and propionyl-CoA carboxylase activities were due to different enzymes was shown by their resolution during purification by a procedure that stabilized acetyl-CoA carboxylase as a complex and separated propionyl-CoA carboxylase into two required protein fractions. Propionate- or valine-grown cells contained a propionyl-CoA carboxylase activity that was strongly inhibited by ammonium sulfate in the assay, and which may represent an inducible form of the enzyme. Geranyl- and 3-methylcrotonyl-CoA carboxylases that catalyze the carboxylation of the 3-methyl groups of homologous acyl-CoA acceptors, were induced by growth on the monoterpenes, citronellic or geranoic acid; only 3-methylcrotonyl-CoA carboxylase was induced by growth on leucine or isovaleric acid. Induction of either carboxylase was associated with the appearance of similar high-molecular-weight, biotin-containing proteins as measured by gel filtration. These two carboxylases are probably distinct enzymes since 3-methyl-crotonyl-CoA carboxylase from isovalerate-grown cells does not carboxylate geranyl-CoA, while geranyl-CoA carboxylase will carboxylate both acyl-CoA homologues. P. citronellolis appears to be a useful system for studying the structural aspects of pairs of homologous acyl-CoA carboxylases.
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PMID:Multiple acyl-coenzyme A carboxylases in Pseudomonas citronellolis. 0 91

The abnormal accumulation of lipids due to myo-inositol deficiency in Saccharomyces carlsbergensis, and the mechanism involved was investigated. The deficient cells contained much more neutral lipids with a greater ratio of unsaturated fatty acids compared to the supplemented cells, whereas there was no significant change in their phospholipid contents. The biosynthesis of fatty acids and sterols from acetate, and of triacylglycerols and sterol esters from palmitate was markedly augmented in the deficient cells. Acetyl-CoA carboxylase activity of the deficient supernatant was 2- to 5-fold higher than that of the supplemented. However, the activity from both sources was not significantly different after Sephadex G-25 gel filtration of the supernatant, suggesting the presence of low molecular effector(s) in the deficient supernatant. There was a great increase in acid-soluble glycogen, trehalose, and fructose-1,6-P2, as well as a drastic decrease in citrate in the deficient cells. Their intracellular levels were calculated so that their effects on acetyl-CoA carboxylase was examined over the range of physiological concentration. Citrate strongly inhibited the enzyme activity of the supernatant, but it had no effect on the preparation after gel filtration. On the other hand, fructose-1,6-P2 stimulated the enzyme activity both before and after gel filtration. The acetyl-CoA carboxylase activity in the gel filtrate was measured as a function of citrate concentration at several fixed concentrations of fructose-1,6-P2. Citrate counteracted the activation by fructose-1,6-P2 in a dose-dependent manner. Citrate lacked the inhibitory effect in the absence of fructose-1,6-P2. It was concluded from these results that neutral lipid accumulation in the deficient cells reflected an increase in the synthesis of fatty acids, at least partly based on an enhancement of acetyl-CoA carboxylase activity, and that the operation of a reciprocal regulation of the enzyme by fructose-1,6-P2 and citrate caused a marked elevation of the enzyme activity in the deficient cells with a high fructose-1,6-P2 level and a low citrate level.
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PMID:Accumulation of neutral lipids in Saccharomyces carlsbergensis by myo-inositol deficiency and its mechanism. Reciprocal regulation of yeast acetyl-CoA carboxylase by fructose bisphosphate and citrate. 0

It has been previously reported that fasting may result in decreased lung surfactant production. In order to investigate this relationship and the role of nutrition in lung phospholipid synthesis, 21-day-old rats were exposed for 60 h to one of five dietary regimens: standard rat chow (controls), fasting, pure glucose, pure fat, or pure protein. After the period of fasting there was a 33% decrease in lung protein content, but there was no change in DNA content. Exposure to any of the experimental diets resulted in a decrease in tissue total phospholipid and phosphatidylcholine content per lung, but not per unit lung protein. Similarly lung lavage phospholipid and phosphatidylcholine content was decreased by 25% after fasting when expressed per lung or per unit DNA, but not per unit protein. Pulmonary cholinephosphotransferase (EC 2.7.8.2) activity was decreased in the fasted animals and those fed the protein diet, but not in the glucose or fat-fed animals. The activities of acetyl-CoA carboxylase (EC 6.4.1.2) and microsomal fatty acid elongation were decreased in all the experimental groups except for the glucose-fed group. It is concluded that fasting results in a decrease in lung cell size but not in lung cell number. Total phospholipid and phosphatidylcholine content in lung tissue and lung lavage is decreased per cell but not per unit cell mass.
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PMID:The influence of postnatal nutritional deprivation on the phospholipid content of developing rat lung. 0 87

3T3-L1 fibroblasts differentiate in culture into cells having adipocyte character. This transition is accompanied by a 40- to 50-fold rise in the incorporation of [14C]acetate into triglyceride. The increase in lipogenic rate is exactly parallel to a coordinate rise in the activities of the key enzymes of the fatty acid biosynthetic pathway (ATP-citrate lyase, acetyl-CoA carboxylase, and fatty acid synthetase). Immunological studies indicate that the elevated acetyl-CoA carboxylase activity is the product of an increased cellular enzyme level.
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PMID:Induction of lipogenesis during differentiation in a "preadipocyte" cell line. 1 Feb 98

Antisera were raised to acetyl-CoA carboxylase and 6-phosphogluconate dehydrogenase from mammary glands of lactating rabbits, and cytochrome oxidase from rat liver. The enzymes were all highly purified but gave rise to multispecific antisera when tested against tissue extracts. Absorption procedures were devised to free the antisera of contaminating antibodies. Antisera to acetyl-CoA carboxylase and cytochrome oxidase were absorbed with fractions discarded during enzyme purification. The antiserum to 6-phospho-gluconate dehydrogenase was absorbed with a tissue extract from an early stage in mammary-gland differentiation. Monospecific antisera are essential for enzyme turnover studies and therefore antisera should be extensively tested and absorbed before use. A general procedure for the absorption of antisera to purified enzymes has been devised on the basis of accepted principles of antisera absorption.
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PMID:Absorption of antisera for studies on specific enzyme turnover. 1 81


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