Mammalian Fatty Acid Synthetase. I. Purification and Properties of Human Liver Complex

1974 ◽  
Vol 52 (3) ◽  
pp. 221-230 ◽  
Author(s):  
Daniel A. K. Roncari
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Human Liver ◽  
Analytical Ultracentrifugation ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Major Product ◽  
Performic Acid ◽  
Sedimentation Equilibrium ◽  
Prosthetic Group

The human liver fatty acid synthetase complex was obtained in highly purified form as judged by agarose gel filtration chromatography, analytical ultracentrifugation, and polyacrylamide disc gel electrophoresis. On the basis of sedimentation equilibrium, its molecular weight was computed to be 410 000 ± 20 000. The major product was palmitic acid. One mole of the prosthetic group, 4′-phosphopantetheine, was present per mole of synthetase.Both acetyl-CoA and butyryl-CoA were effective primers of fatty acid synthesis. Under appropriate conditions, the intermediates, acetyl – and malonyl – fatty acid synthetase could be isolated. On the basis of pretreatment of the synthetase with N-ethylmaleimide and exposure of the intermediates to performic acid, it was determined that the complex had both thiol and non-thiol acyl-binding sites. The available evidence indicates that the mechanism of fatty acid synthesis is analogous to that previously described for the yeast and avian synthetases.

scholarly journals Modulation of lipid-synthesizing enzymes by insulin in differentiated ob17 adipose-like cells

1983 ◽  
Vol 214 (2) ◽  
pp. 443-449 ◽  
Author(s):  
P Grimaldi ◽  
C Forest ◽  
P Poli ◽  
R Negrel ◽  
G Ailhaud
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Specific Activity ◽  
Fatty Acid Synthetase ◽  
Lipid Synthesis ◽  
Acid Synthesis ◽  
Acetate Incorporation ◽  
Long Term Effects ◽  
Response Curves ◽  
Glycerol 3 Phosphate Dehydrogenase

ob17 cells convert into adipose-like cells when maintained in the presence of physiological concentrations of insulin and tri-iodothyronine. After this conversion, insulin removal from differentiated ob17 cells gives within 24-48 h a large decrease in fatty acid synthetase, glycerol 3-phosphate dehydrogenase and acid:CoA ligase activities, as well as in the rate of fatty acid synthesis determined by [14C]acetate incorporation into lipids. All parameters are restored by insulin addition to initial values within 24-48 h. Dose-response curves of insulin on the restoration of glycerol 3-phosphate dehydrogenase activity and of fatty acid synthesis give half-maximally effective concentrations close to 1 nM, in agreement with the affinity for insulin of the insulin receptors previously characterized in these cells. Immunotitration experiments indicate that the changes in the specific activity of fatty acid synthetase are due to parallel changes in the cellular enzyme content. Therefore the ob17 cell line should be a useful model to study the long-term effects of insulin on the modulation of lipid synthesis in adipose cells.

scholarly journals Hepatic lipogenesis in young rats given proteins of different quality

1984 ◽  
Vol 52 (1) ◽  
pp. 131-137 ◽  
Author(s):  
G. R. Herzberg ◽  
Minda Rogerson
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Protein Quality ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Hepatic Lipogenesis ◽  
Atp Citrate Lyase ◽  
Specific Activities ◽  
Glucose 6 Phosphate Dehydrogenase

1. The effect of feeding casein, lactalbumin, soya-bean protein, gluten or gelatin on hepatic lipogenesis and the levels of hepatic fatty acid synthetase (FAS), glucose-6-phosphate dehydrogenase (EC 1. 1. 1.49; G6PD), malic enzyme (EC 1. 1. 1.40; ME) ATP-citrate lyase (EC 4. 1. 3. 8; CL), acetyl CoA carboxylase (EC 6.4.1.2; ACCx) and glucokinase (EC 2. 7. 1. 2; GK) was examined in young growing rats.2. The total activities of ACCx, FAS, CL, GK, G6PD, GK, ME and fatty acid synthesis in vivo were positively correlated with protein quality.3. The specific activities of ACCx, FAS, CL, G6PD and fatty acid synthesis in vivo were positively correlated with protein quality.4. The specific activities of GK and ME were unrelated to protein quality.5. The results demonstrate a dissociation between ME and hepatic lipogenesis and suggest a role for the NADPH generated by ME which is not related to the needs of fatty acid synthesis.

scholarly journals The role of dietary protein in hepatic lipogenesis in the young rat

1981 ◽  
Vol 45 (3) ◽  
pp. 529-538 ◽  
Author(s):  
G. R. Herzberg ◽  
Minda Rogerson
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Dietary Protein ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Hepatic Lipogenesis ◽  
Hepatic Fatty Acid ◽  
Cleavage Enzyme ◽  
Glucose 6 Phosphate Dehydrogenase

1. The effect of varying dietary levels of casein (40–140 g/kg) on hepatic lipogenesis and the levels of hepatic fatty acid synthetase (FAS), glucose-6-phosphate dehydrogenase (EC 1.1.1.49; G6PD), malic enzyme (EC 1.1.1.40; ME), citrate cleavage enzyme (EC 4.1.3.8;CCE), acetyl CoA carboxylase (EC 6.4.1.2; AcCx), glucokinase (EC 2.7.1.2; GK), and pyruvate dehydrogenase (PDH) was examined in young, growing rats.2. The activities of AcCx, FAS, G6PD and in vivo fatty acid synthesis were generally found to increase with increased dietary protein.3. The levels of GK and PDH were not related to dietary protein.4. ME decreased with increasing dietary protein.5. The results demonstrate a dissociation between hepatic fatty acid synthesis and ME and suggest that when rats consume low-protein diets the NADPH needed for fatty acid synthesis is generated primarily by ME but that as the level of dietary protein is increased the contribution of ME is reduced while that of the phosphogluconate pathway becomes more important.

scholarly journals Effect of Diet Supplementation on the Expression of Bovine Genes Associated with Fatty Acid Synthesis and Metabolism

2010 ◽  
Vol 4 ◽  
pp. BBI.S4168 ◽  
Author(s):  
Sandeep J. Joseph ◽  
Kelly R. Robbins ◽  
Enrique Pavan ◽  
Scott L. Pratt ◽  
Susan K. Duckett ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Corn Oil ◽  
Fatty Acid Content ◽  
Fatty Acid Synthetase ◽  
Health Benefit ◽  
Acid Synthesis ◽  
Animal Origin ◽  
Expression Of Genes ◽  
Diet Supplementation

Conjugated linoleic acids (CLA) are of important nutritional and health benefit to human. Food products of animal origin are their major dietary source and their concentration increases with high concentrate diets fed to animals. To examine the effects of diet supplementation on the expression of genes related to lipid metabolism, 28 Angus steers were fed either pasture only, pasture with soybean hulls and corn oil, pasture with corn grain, or high concentrate diet. At slaughter, samples of subcutaneous adipose tissue were collected, from which RNA was extracted. Relative abundance of gene expression was measured using Affymetrix GeneChip Bovine Genome array. An ANOVA model nested within gene was used to analyze the background adjusted, normalized average difference of probe-level intensities. To control experiment wise error, a false discovery rate of 0.01 was imposed on all contrasts. Expression of several genes involved in the synthesis of enzymes related to fatty acid metabolism and lipogenesis such as stearoyl-CoA desaturase (SCD), fatty acid synthetase (FASN), lipoprotein lipase (LPL), fatty-acyl elongase (LCE) along with several trancription factors and co-activators involved in lipogenesis were found to be differentially expressed. Confirmatory RT-qPCR was done to validate the microarray results, which showed satisfactory correspondence between the two platforms. Results show that changes in diet by increasing dietary energy intake by supplementing high concentrate diet have effects on the transcription of genes encoding enzymes involved in fat metabolism which in turn has effects on fatty acid content in the carcass tissue as well as carcass quality. Corn supplementation either as oil or grain appeared to significantly alter the expression of genes directly associated with fatty acid synthesis.

scholarly journals Chronic ethanol administration depresses fatty acid synthesis in rat adipose tissue

1988 ◽  
Vol 251 (2) ◽  
pp. 547-551 ◽  
Author(s):  
J S Wilson ◽  
M A Korsten ◽  
L P Donnelly ◽  
P W Colley ◽  
J B Somer ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Chronic Ethanol ◽  
Ethanol Administration ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Chronic Ethanol Administration

Administration of ethanol as part of a nutritionally adequate liquid diet to female Wistar rats was found to depress markedly incorporation of labelled glucose into adipose-tissue acylglycerol fatty acids. Similar results with labelled pyruvate and acetate suggested inhibition of the fatty-acid-synthesis pathway at, or distal to, the acetyl-CoA carboxylase step. Activities of acetyl-CoA carboxylase and fatty acid synthetase were markedly lower in ethanol-fed animals. The activity of another lipogenic enzyme, phosphatidate phosphohydrolase, was not affected by chronic ethanol feeding. These findings suggest that chronic ethanol administration has marked effects on adipose-tissue lipogenesis.

scholarly journals Regulation of hepatic lipogenesis by dietary maize oil or tripalmitin in the meal-fed mouse

1980 ◽  
Vol 43 (3) ◽  
pp. 571-579 ◽  
Author(s):  
G. R. Herzberg ◽  
N. Janmohamed
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Malic Enzyme ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Hepatic Lipogenesis ◽  
Meal Feeding ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Maize Oil

The effect of varying dietary levels of maize oil and tripalmitin (0–250 g fat/kg) on hepatic lipogenesis and the levels of hepatic fatty acid synthetase (FAS), glucose-6-phosphate dehydrogenase (EC 1.1.1.49; G6PD), malic enzyme (EC 1.1.1.38, 1.1.1.39, 1.1.1.40; ME) and glucokinase (EC 2.7.1.2; GK) was examined in meal-fed mice.2. Meal-fed mice compared to mice fed ad lib. show enhanced hepatic lipogenesis as demonstrated by an increased rate of in vivo fatty acid synthesis and increased levels of FAS, ME and G6PD. The level of GK in meal-fed mice was unchanged by meal feeding.3. Maize oil more effectively reduced in vivo hepatic lipogenesis than tripalmitin in meal-fed mice.4. Maize oil more effectively reduced the hepatic levels of FAS, G6PD, ME and GK than tripalmitin in meal-fed mice.5. The increased inhibition by maize oil is observed at all levels of fat in the diet investigated and has been shown not to be due to decreased carbohydrate intake nor to differences between the absorption of maize oil and tripalmitin.

scholarly journals Localization of chloroplastic fatty acid synthesis de novo in the stroma

1985 ◽  
Vol 226 (2) ◽  
pp. 551-556 ◽  
Author(s):  
K A Walker ◽  
J L Harwood
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
High Speed ◽  
De Novo ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Synthetic Activity ◽  
Bisphosphate Carboxylase ◽  
Osmotic Lysis ◽  
Almost All

The synthesis of fatty acids de novo from [2-14C]malonyl-CoA was studied in fractions from lettuce (Lactuca sativa) and pea (Pisum sativum) chloroplasts. When lettuce chloroplasts were subjected to osmotic lysis, disintegration through a Yeda press and high-speed centrifugation, essentially all of the fatty-acid-synthetic activity was found to be soluble. The distribution of the activity in various chloroplast fractions was similar to that of soluble marker enzymes such as ribulose-1,5-bisphosphate carboxylase and NADP+-linked glyceraldehyde-3-phosphate dehydrogenase. Marked differences were apparent in the quality of products from fatty acid synthesis de novo in the various fractions of chloroplasts. Thus soluble fractions produced predominantly stearate, whereas those containing membranes produced a greater proportion of palmitate. In pea chloroplasts, osmotic lysis released almost all of the fatty acid synthetase into the stromal fraction. In this instance, no major alterations in the products of fatty acid synthesis were observed. The fatty-acid-synthetic activity of the stromal fraction was still soluble after prolonged ultracentrifugation. The results show clearly the soluble nature of fatty acid synthesis de novo in lettuce and pea chloroplasts. Thus fatty acid synthesis measured in microsomal fractions from such plant tissues is not due to the presence of chloroplastic membranes.

scholarly journals Purification and some properties of a medium-chain acyl-thioester hydrolase from lactating-rabbit mammary gland which terminates chain elongation in fatty acid synthesis

1976 ◽  
Vol 160 (3) ◽  
pp. 683-691 ◽  
Author(s):  
J Knudsen ◽  
S Clark ◽  
R Dils
Keyword(s):  
Mammary Gland ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Chain Elongation ◽  
Medium Chain ◽  
Chain Acyl

1. An acyl-thioester hydrolase was isolated from the cytosol of lactating-rabbit mammary gland. The purified enzyme terminates fatty acid synthesis at medium-chain (C8:0-C12:0) acids when it is incubated with fatty acid synthetase and rate-limiting concentrations of malonyl-CoA. These acids are characteristic products of the lactating gland. 2. The mol.wt. of the enzyme is 29000±500 (mean±S.D. of three independent preparations), as estimated by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. 3. The enzyme also hydrolyses acyl-CoA esters of chain lengths C10:0-C16:0 when these are used as model substrates. The greatest activity was towards dodecanoyl-CoA, and the three preparations had specific activities of 305, 1130 and 2010 nmol of dodecanoyl-CoA hydrolysed/min per mg of protein when 56muM substrate was used. 4. The way in which this enzyme controls the synthesis of medium-chain fatty acids by fatty acid synthetase is briefly discussed.

scholarly journals Fatty acid elongation by a particulate fraction from germinating pea

1980 ◽  
Vol 191 (3) ◽  
pp. 791-797 ◽  
Author(s):  
B R Jordan ◽  
J L Harwood
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
High Speed ◽  
Saturated Fatty Acids ◽  
Acyl Chain ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Particulate Fraction

The synthesis of fatty acids from [14C]malonyl-CoA was studied with a high-speed particulate fraction from germinating pea (Pisum sativum). The variety used (Feltham First) produced mainly saturated fatty acids with palmitate (30–40%) and stearate (40–60%) predominating. Several palmitate-containing lipids stimulated overall synthesis and, in addition, increased the percentage of label in stearate. The production of stearate was severely inhibited by preincubation of the microsomal fraction with snake venom phospholipase A2 or by incubation with Rhizopus arrhizus lipase. Addition of a series of di-saturated phosphatidylcholines, with different acyl constituents, resulted in stimulation of overall fatty acid synthesis as well as an increase in the radiolabelling of the fatty acid two carbon atoms longer than the acyl chain added. This chain lengthening of fatty acids donated from phosphatidylcholine was due to the action of both fatty acid synthetase and palmitate elongase. The latter would utilize dipalmitoyl phosphatidylcholine and was sensitive to arsenite whereas fatty acid synthetase would use dilauroyl phosphatidylcholine and was sensitive to cerulenin. The results are discussed in relation to previous data obtained in vivo on plant fatty acid synthesis and current suggestions for the role of phosphatidylcholine in this process.

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