scholarly journals The synthesis of medium-chain fatty acids by lactating-rabbit mammary gland studied in vitro (Short Communication)

1973 ◽  
Vol 132 (1) ◽  
pp. 121-123 ◽  
Author(s):  
Christopher R. Strong ◽  
Eric M. Carey ◽  
Raymond Dils
Keyword(s):  
Fatty Acids ◽  
Molecular Weight ◽  
Mammary Gland ◽  
Fatty Acid ◽  
Short Communication ◽  
Acyl Chain ◽  
Fatty Acid Synthetase ◽  
Supernatant Fraction ◽  
Weight Factor

The proportion of C8:0 and C10:0 fatty acids synthesized by the microsomal plus particle-free supernatant fraction from lactating rabbit mammary gland is enhanced at high protein concentrations. This fraction appears to contain a soluble high-molecular-weight factor that modifies the specificity of the fatty acid synthetase complex for termination of the growing acyl chain.

The possible involvement of a fatty acyl thioesterase in the termination of the synthesis of fatty acids in a psychrophilic bacterium, Vibrio sp. strain ABE-1

1993 ◽  
Vol 39 (10) ◽  
pp. 994-998
Author(s):  
Naoki Morita ◽  
Hidetoshi Okuyama
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Acyl Chain ◽  
Fatty Acid Synthetase ◽  
Fatty Acyl ◽  
Carrier Proteins ◽  
Acyl Carrier Proteins ◽  
Cytosol Fraction ◽  
Acyl Chain Length

In Vibrio sp. strain ABE-1, very long chain fatty acids with up to 30 carbon atoms were synthesized in vitro in the form of acyl-acyl carrier protein by a fatty acid synthetase that had been prepared from the cytosol fraction precipitated between 55 and 75% saturation with ammonium sulfate. In contrast, fatty acids with 10–18 carbon atoms, which are the usual acyl components in this bacterium, were synthesized in vitro when the unfractionated cytosol fraction was used as the source of catalytic activity. When partially purified fatty acid synthetase was used together with a subfraction that had been prepared from the cytosol fraction precipitated between 0 and 55% saturation with ammonium sulfate, 16-carbon fatty acids were recovered as the dominant free fatty acids, and fatty acids with more than 20 carbon atoms were not synthesized in vitro. Acyl-acyl carrier proteins and acyl-CoAs with 16-carbon fatty acids were preferentially hydrolyzed when this subfraction was used as the source of catalytic activity. These results suggest that (a) fatty acyl thioesterase(s) with high specificity for acyl-acyl carrier proteins with 16-carbon fatty acids regulate(s) acyl chain length. This activity could explain the high levels of 16-carbon fatty acids in this bacterium.Key words: acyl chain length regulation, fatty acyl thioesterase, acyl-ACP, fatty acid synthetase, psychrophilic bacteria, Vibrio sp.

TetR-family transcriptional repressor Thermus thermophilus FadR controls fatty acid degradation

Microbiology ◽  
2011 ◽  
Vol 157 (6) ◽  
pp. 1589-1601 ◽  
Author(s):  
Yoshihiro Agari ◽  
Kazuko Agari ◽  
Keiko Sakamoto ◽  
Seiki Kuramitsu ◽  
Akeo Shinkai
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Target Genes ◽  
Thermus Thermophilus ◽  
Acyl Chain ◽  
Metabolic Energy ◽  
Straight Chain ◽  
Fatty Acid Degradation ◽  
Acid Degradation

In the extremely thermophilic bacterium Thermus thermophilus HB8, one of the four TetR-family transcriptional regulators, which we named T. thermophilus FadR, negatively regulated the expression of several genes, including those involved in fatty acid degradation, both in vivo and in vitro. T. thermophilus FadR repressed the expression of the target genes by binding pseudopalindromic sequences covering the predicted −10 hexamers of their promoters, and medium-to-long straight-chain (C10–18) fatty acyl-CoA molecules were effective for transcriptional derepression. An X-ray crystal structure analysis revealed that T. thermophilus FadR bound one lauroyl (C12)-CoA molecule per FadR monomer, with its acyl chain moiety in the centre of the FadR molecule, enclosed within a tunnel-like substrate-binding pocket surrounded by hydrophobic residues, and the CoA moiety interacting with basic residues on the protein surface. The growth of T. thermophilus HB8, with palmitic acid as the sole carbon source, increased the expression of FadR-regulated genes. These results indicate that in T. thermophilus HB8, medium-to-long straight-chain fatty acids can be used for metabolic energy under the control of FadR, although the major fatty acids found in this strain are iso- and anteiso-branched-chain (C15 and 17) fatty acids.

scholarly journals Molecular weight and subunit size of fatty acid synthetase from rabbit mammary gland

1976 ◽  
Vol 159 (1) ◽  
pp. 181-184 ◽  
Author(s):  
N Paskin ◽  
R J Mayer
Keyword(s):  
Molecular Weight ◽  
Mammary Gland ◽  
Fatty Acid ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Fatty Acid Synthetase ◽  
Subunit Size

Fatty acid synthetase purified from the mammary gland of the rabbit has a mol. wt. of 968000 as determined by gel filtration. The enzyme gave one band, corresponding to a mol.wt. of approx. 35000, on polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate and phenylmethanesulphonyl fluoride.

scholarly journals Transacylation as a chain-termination mechanism in fatty acid synthesis by mammalian fatty acid synthetase. Synthesis of butyrate and hexanoate by lactating cow mammary gland fatty acid synthetase

1980 ◽  
Vol 186 (1) ◽  
pp. 287-294 ◽  
Author(s):  
J K Hansen ◽  
J Knudsen
Keyword(s):  
Fatty Acids ◽  
Mammary Gland ◽  
Fatty Acid ◽  
Fatty Acid Synthetase ◽  
Short Chain Fatty Acids ◽  
Acid Synthesis ◽  
Chain Termination ◽  
Short Chain ◽  
Esterified Fatty Acids ◽  
A Chain

1. Purified cow mammary gland fatty acid synthetase synthesized long-chain unesterified and short-chain esterified fatty acids. 2. A direct relationship was observed between the amount of short-chain products synthesized and the concentration of acetyl-CoA in the incubation medium. 3. The short-chain products were identified as butyryl-CoA and hexanoyl-CoA. 4. Inhibition of the terminating thioester hydrolase of the fatty acid synthetase complex with phenylmethanesulphonyl fluoride did not inhibit the synthesis of short-chain products. 5. It is suggested that the synthesis of short-chain fatty acids involves the reverse of the ‘loading’ reaction.

scholarly journals Molecular weight and subunit size of rabbit mammary-gland fatty acid synthetase

1978 ◽  
Vol 173 (3) ◽  
pp. 929-933 ◽  
Author(s):  
I Grunnet ◽  
J Knudsen
Keyword(s):  
Molecular Weight ◽  
Mammary Gland ◽  
Fatty Acid ◽  
Sucrose Gradient ◽  
Gradient Centrifugation ◽  
Fatty Acid Synthetase ◽  
Mammary Glands ◽  
Sucrose Gradient Centrifugation ◽  
Molecular Weights ◽  
Subunit Size

1. The molecular weights of fatty acid synthetases isolated from lactating rabbit, rat, cow and goat mammary glands were estimated by sucrose gradient centrifugation and compared by chromatography on Sepharose 6B. 2. The values obtained for all four enzymes were in the same range (0.40 × 10(6)-0.55 × 10(6)) as that found for other mammalian and avian fatty acid synthetases. The molecular weight found for the rabbit mammary enzyme therefore differs from published values of approx. 0.9 × 10(6). 3. The molecular weights of the subunits of these four synthetases were 225000-242000. Again, the value for the rabbit mammary enzyme differs from published values.

scholarly journals Transacylation as a chain-termination mechanism in fatty acid synthesis by mammalian fatty acid synthetase. Synthesis of medium-chain-length (C8-C12) acyl-CoA esters by goat mammary-gland fatty acid synthetase

1982 ◽  
Vol 202 (1) ◽  
pp. 139-143 ◽  
Author(s):  
J Knudsen ◽  
I Grunnet
Keyword(s):  
Fatty Acids ◽  
Mammary Gland ◽  
Fatty Acid ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Medium Chain Length ◽  
A Chain ◽  
Chain Fatty Acids

1. Ruminant mammary-gland fatty acid synthetases can, in contrast with non-ruminant mammary enzymes, synthesize medium-chain fatty acids. 2. Medium-chain fatty acids are only synthesized in the presence of a fatty acid-removing system such as albumin, beta-lactoglobulin or methylated cyclodextrin. 3. The short- and medium-chain fatty acids synthesized were released as acyl-CoA esters from the fatty acid synthetase.

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.

Lipogenesis in the sand rat (Psammomys obesus)

1983 ◽  
Vol 244 (5) ◽  
pp. E480-E486 ◽  
Author(s):  
B. Kalderon ◽  
J. H. Adler ◽  
E. Levy ◽  
A. Gutman
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthetase ◽  
Epididymal Adipose Tissue ◽  
Albino Rats ◽  
Hepatic Lipogenesis ◽  
Very Low Density Lipoproteins ◽  
Sand Rat

Synthesis of fatty acids was measured in the liver and in epididymal adipose tissue of sand rats and albino rats. In chow-fed sand rats the rate of hepatic lipogenesis, as measured by the incorporation of 3H2O into fatty acids, was four- to sevenfold higher than in albino rats and in sand rats on a low-calorie saltbush diet. The contribution of [14C]glucose to lipogenesis in sand rat liver was lower than in albino rats. In fed sand rats lipogenesis incorporating 3H2O was stimulated by casein but not by glucose. In adipose tissue, lipogenesis measured 1 h after administration of 3H2O was much lower in sand rats than in albino rats. In vitro incorporation of [14C]glucose or acetate into adipose tissue fatty acids was negligible. In adipose tissue, uptake of very-low-density lipoproteins (VLDL) and lipoprotein lipase activity were sevenfold higher than in albino rats. Activities of NADP-malate dehydrogenase, acetyl CoA carboxylase, and fatty acid synthetase were considerably higher in the liver of chow-fed sand rats than in albino rats. It was concluded that obesity in sand rats originates from hepatic lipogenesis without a significant contribution of local fatty acid synthesis in adipose tissue.

scholarly journals Triacylglycerol synthesis in goat mammary gland. The effect of ATP, Mg2+ and glycerol 3-phosphate on the esterification of fatty acids synthesized de novo

1984 ◽  
Vol 220 (2) ◽  
pp. 513-519 ◽  
Author(s):  
H O Hansen ◽  
I Grunnet ◽  
J Knudsen
Keyword(s):  
Fatty Acids ◽  
Mammary Gland ◽  
Fatty Acid ◽  
De Novo ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Medium Chain ◽  
Medium Chain Fatty Acids ◽  
Triacylglycerol Synthesis ◽  
Chain Fatty Acids

Goat mammary-gland microsomal fraction by itself induces synthesis of medium-chain-length fatty acids by goat mammary fatty acid synthetase and incorporates short- and medium-chain fatty acids into triacylglycerol. Addition of ATP in the absence or presence of Mg2+ totally inhibits triacylglycerol synthesis from short- and medium-chain fatty acids, and severely inhibits synthesis de novo of medium-chain fatty acids. The inhibition by ATP of fatty acid synthesis and triacylglycerol synthesis de novo can be relieved by glycerol 3-phosphate. The effect of ATP could not be mimicked by the non-hydrolysable ATP analogue, adenosine 5′-[beta, gamma-methylene]triphosphate and could not be shown to be caused by inhibition of the diacylglycerol acyltransferase by a phosphorylation reaction. Possible explanations for the mechanism of the inhibition by ATP are discussed, and a hypothetical model for its action is outlined.

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