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 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.

Fatty Acid Synthesis De Novo in Human Adipose Tissue

1974 ◽  
Vol 46 (4) ◽  
pp. 469-479
Author(s):  
R. B. Goldrick ◽  
D. J. Galton
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Subcutaneous Adipose Tissue ◽  
De Novo ◽  
Fatty Acid Synthetase ◽  
Human Adipose Tissue ◽  
Acid Synthesis ◽  
Cleavage Enzyme ◽  
Subcutaneous Adipose

1. Homogenates of subcutaneous adipose tissue from obese subjects contained sufficient citrate cleavage enzyme (EC 4.1.3.8: ATP—citrate oxaloacetate lyase), acetyl-CoA carboxylase (EC 6.4.1.2: acetyl-CoA—carbon dioxide ligase) and fatty acid synthetase to account for the rates of fatty acid synthesis reported in the literature for intact tissues in vitro. 2. The distribution of label in fatty acids after incubations of adipose tissue with [1-14C]acetate was consistent with fatty acid synthesis de novo, not chain elongation. 3. The activities of citrate cleavage enzyme and fatty acid synthetase in subcutaneous adipose tissue were reduced by short periods of starvation. 4. These findings indicate that human adipose tissue is capable of fatty acid synthesis de novo and that two of the enzymes concerned adapt to starvation.

scholarly journals Ethanol administration and the relationship of malonyl-coenzyme A concentrations to the rate of fatty acid synthesis in rat liver

1973 ◽  
Vol 136 (3) ◽  
pp. 639-647 ◽  
Author(s):  
Robert W. Guynn ◽  
Dulce Veloso ◽  
Raymond L. Harris ◽  
J. W. Randolph Lawson ◽  
Richard L. Veech
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
De Novo ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Ethanol Administration ◽  
Liver Fatty Acid ◽  
Malonyl Coa ◽  
Significant Difference

1. The effect of ethanol on liver fatty acid synthesis was studied in vivo in 24h-starved and ‘meal-fed’ rats (i.e. fed for 3h per day and not ad libitum). 2. In the fed animal3H2O was incorporated into fat at a rate of 0.46μmol of C2 units/min per g wet wt. of liver. Administration of either ethanol (3.2g/kg) or equicaloric amounts of glucose had no effect on the rate of3H2O incorporation into lipid. 3. In the 24h-starved animal, administration of the same dose of ethanol produced an increase in the rate of3H2O incorporation from 0.06 to 0.12μmol of C2 units/min per g fresh wt. after 3h whereas [malonyl-CoA] increased from 0.006 to 0.009μmol/g. Glucose given in amounts equicaloric to ethanol was significantly more lipogenic, increasing both the3H2O incorporation from 0.06 to 0.20μmol of C2 units/min per g and the malonyl-CoA content from 0.006 to 0.013 μmol/g wet wt. at 3h. 4. The decrease in the redox state of free cytoplasm NAD or NADP couples or the changes in content of citrate, glucose 6-phosphate and pyruvate of liver after ethanol administration had no measurable effect on the rate of fatty acid synthesis in vivo. 5. Under the conditions of the experiments there was no significant difference, among any of the groups, in the activity of liver fatty acid synthetase measured in vitro. A double-reciprocal plot of the rate of3H2O incorporation and the total tissue malonyl-CoA concentrations showed a striking relationship. It has been concluded that the rate of fatty acid synthesis in vivo is determined principally by the Vmax. of fatty acid synthetase and the concentration of free malonyl-CoA. 6. It has also been concluded that under the conditions of the present study, the synthesis of fatty acids de novo is unlikely to be an important factor in the increased liver lipid content associated with ethanol administration.

Insulin-like effects of fatty acid synthesis in liver of hamsters infected with plerocercoids of the tapeworm,Spirometra mansonoides

1984 ◽  
Vol 58 (1) ◽  
pp. 25-30 ◽  
Author(s):  
C. Kirk Phares ◽  
R. M. Carroll
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
De Novo ◽  
Elevated Serum ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Serum Lipoprotein ◽  
Very Low Density Lipoproteins ◽  
Laboratory Rodents ◽  
Insulin Like Activity

AbstractElevated serum lipids are associated with infections of laboratory rodents with plerocercoids ofSpirometra mansonoides. The effect of infection with these larval tapeworms on triglyceride degradation and hepaticde novofatty acid synthesis was investigated in Syrian hamsters. Serum lipoprotein electrophoresis revealed a consistent elevation in very low density lipoproteins in the infected animals. Lipoprotein lipase activity was enhanced in the infected animals. After seven days of plerocercoid infection the activity of acetyl-CoA carboxylase (E.C. 6.4.1.2) was significantly elevated after 6,12 and 18 hours of fasting. Fatty acid synthetase was significantly increased after 0,6,12,18 and 24 hours of fasting. Therefore, a chronic insulin-like activity on lipid metabolism of hamsters is associated with plerocercoid infection.

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 Synthesis of fatty acids in the perfused mouse liver

1974 ◽  
Vol 142 (3) ◽  
pp. 611-618 ◽  
Author(s):  
D. Michael W. Salmon ◽  
Neil L. Bowen ◽  
Douglas A. Hems
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
De Novo ◽  
Saturated Fatty Acids ◽  
Carbon Sources ◽  
Acid Synthesis ◽  
Hepatic Glycogen ◽  
Total Rate ◽  
Glucose Carbon

1. Fatty acid synthesis de novo was measured in the perfused liver of fed mice. 2. The total rate, measured by the incorporation into fatty acid of3H from3H2O (1–7μmol of fatty acid/h per g of fresh liver), resembled the rate found in the liver of intact mice. 3. Perfusions with l-[U-14C]lactic acid and [U-14C]glucose showed that circulating glucose at concentrations less than about 17mm was not a major carbon source for newly synthesized fatty acid, whereas lactate (10mm) markedly stimulated fatty acid synthesis, and contributed extensive carbon to lipogenesis. 4. The identification of 50% of the carbon converted into newly synthesized fatty acid lends further credibility to the use of3H2O to measure hepatic fatty acid synthesis. 5. The total rate of fatty acid synthesis, and the contribution of glucose carbon to lipogenesis, were directly proportional to the initial hepatic glycogen concentration. 6. The proportion of total newly synthesized lipid that was released into the perfusion medium was 12–16%. 7. The major products of lipogenesis were saturated fatty acids in triglyceride and phospholipid. 8. The rate of cholesterol synthesis, also measured with3H2O, expressed as acetyl residues consumed, was about one-fourth of the basal rate of fatty acid synthesis. 9. These results are discussed in terms of the carbon sources of hepatic newly synthesized fatty acids, and the effect of glucose, glycogen and lactate in stimulating lipogenesis, independently of their role as precursors.

scholarly journals A low-protein, high-carbohydrate diet increases de novo fatty acid synthesis from glycerol and glycerokinase content in the liver of growing rats

2013 ◽  
Vol 33 (6) ◽  
pp. 494-502 ◽  
Author(s):  
Andreza Lúcia Menezes ◽  
Mayara Peron Pereira ◽  
Samyra Lopes Buzelle ◽  
Maísa Pavani dos Santos ◽  
Suélem Aparecida de França ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
De Novo ◽  
Acid Synthesis ◽  
High Carbohydrate Diet ◽  
Carbohydrate Diet ◽  
High Carbohydrate ◽  
Growing Rats ◽  
Low Protein

scholarly journals [Corrigendum] A combination of inhibitors of glycolysis, glutaminolysis and de�novo fatty acid synthesis decrease the expression of chemokines in human colon cancer cells

2020 ◽  
Author(s):  
Alejandro Schcolnik‑Cabrera ◽  
Guadalupe Dominguez‑G�mez ◽  
Alma Ch�vez‑Blanco ◽  
Marisol Ram�rez‑Yautentzi ◽  
Roc�o Morales‑B�rcenas ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Fatty Acid ◽  
Cancer Cells ◽  
Fatty Acid Synthesis ◽  
De Novo ◽  
Human Colon ◽  
Acid Synthesis ◽  
Colon Cancer Cells ◽  
Human Colon Cancer ◽  
Human Colon Cancer 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.

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