scholarly journals Function of human mitochondrial 2,4-dienoyl-CoA reductase and rat monofunctional Δ3-Δ2-enoyl-CoA isomerase in β-oxidation of unsaturated fatty acids

1999 ◽  
Vol 344 (3) ◽  
pp. 903-914 ◽  
Author(s):  
Aner GURVITZ ◽  
Leila WABNEGGER ◽  
Ahmed I. YAGI ◽  
Maximilian BINDER ◽  
Andreas HARTIG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Fatty Acids ◽  
Oleic Acid ◽  
Unsaturated Fatty Acids ◽  
Petroselinic Acid ◽  
Yeast Cells ◽  
C Terminus ◽  
Peroxisomal Targeting ◽  
Targeting Signals ◽  
Coa Reductase

Human 2,4-dienoyl-CoA reductase (2,4-reductase; DECR) and rat monofunctional ∆3-∆2-enoyl-CoA isomerase (rat 3,2-isomerase; ECI) are thought to be mitochondrial auxiliary enzymes involved in the β-oxidation of unsaturated fatty acids. However, their function during this process has not been demonstrated. Although they lack obvious peroxisomal targeting signals (PTSs), both proteins have been suggested previously to also occur in the mammalian peroxisomal compartment. The putative function and peroxisomal location of the two mammalian proteins can be examined in yeast, since β-oxidation of unsaturated fatty acids is a compartmentalized process in Saccharomyces cerevisiae requiring peroxisomal 2,4-dienoyl-CoA reductase (Sps19p) and peroxisomal 3,2-isomerase (Eci1p). A yeast sps19∆ mutant expressing human 2,4-reductase ending with the native C-terminus could not grow on petroselinic acid [cis-C18:1(6)] medium but could grow when the protein was extended with a PTS tripeptide, SKL (Ser-Lys-Leu). We therefore reason that the human protein is a physiological 2,4-reductase but that it is probably not peroxisomal. Rat 3,2-isomerase expressed in a yeast eci1∆ strain was able to re-establish growth on oleic acid [cis-C18:1(9)] medium irrespective of an SKL extension. Since we had shown that ∆2,4 double bonds could not be metabolized extra-peroxisomally to restore growth of the sps19∆ strain, we postulate that rat 3,2-isomerase acted on the ∆3 unsaturated metabolite of oleic acid by replacing the mutant's missing activity from within the peroxisomes. Immunoblotting of fractionated yeast cells expressing rat 3,2-isomerase in combination with electron microscopy supported our proposal that the protein functioned in peroxisomes. The results presented here shed new light on the function and location of human mitochondrial 2,4-reductase and rat monofunctional 3,2-isomerase.

Effects of unsaturated fatty acid deprivation on neutral lipid synthesis in Saccharomyces cerevisiae

1982 ◽  
Vol 152 (2) ◽  
pp. 747-756
Author(s):  
T M Buttke ◽  
A L Pyle
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Cell Growth ◽  
Unsaturated Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Lipid Synthesis ◽  
Yeast Cells

The effects of unsaturated fatty acid deprivation on lipid synthesis in Saccharomyces cerevisiae strain GL7 were determined by following the incorporation of [14C]acetate. Compared to yeast cells grown with oleic acid, unsaturated fatty acid-deprived cells contained 200 times as much 14C label in squalene, with correspondingly less label in 2,3-oxidosqualene and 2,3;22,23-dioxidosqualene. Cells deprived of either methionine or cholesterol did not accumulate squalene, demonstrating that the effect of unsaturated fatty acid starvation on squalene oxidation was not due to an inhibition of cell growth. Cells deprived of olefinic supplements displayed additional changes in lipid metabolism: (i) an increase in 14C-labeled diacylglycerides, (ii) a decrease in 14C-labeled triacylglycerides, and (iii) increased levels of 14C-labeled decanoic and dodecanoic fatty acids. The changes in squalene oxidation and acylglyceride metabolism in unsaturated fatty acid-deprived cells were readily reversed by adding oleic acid. Pulse-chase studies demonstrated that the [14C]squalene and 14C-labeled diacylglycerides which accumulated during starvation were further metabolized when cells were resupplemented with oleic acid. These results demonstrate that unsaturated fatty acids are essential for normal lipid metabolism in yeasts.

Evidence for a novel pathway for the targeting of a Saccharomyces cerevisiae peroxisomal protein belonging to the isomerase/hydratase family

2000 ◽  
Vol 113 (3) ◽  
pp. 533-544
Author(s):  
I.V. Karpichev ◽  
G.M. Small
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Beta Oxidation ◽  
Peroxisomal Protein ◽  
Intracellular Targeting ◽  
Targeting Signals ◽  
Peroxisome Targeting Signals

We, and others, have identified a novel Saccharomyces cerevisiae peroxisomal protein that belongs to the isomerase/hydratase family. The protein, named Dci1p, shares 50% identity with Eci1p, a delta(3)-cis-delta(2)-trans-enoyl-CoA isomerase that acts as an auxiliary enzyme in the beta-oxidation of unsaturated fatty acids. Both of these proteins are localized to peroxisomes, and both contain motifs at their amino- and carboxyl termini that resemble peroxisome targeting signals (PTS) 1 and 2. However, we demonstrate that the putative type 1 signaling motif is not required for the peroxisomal localization of either of these proteins. Furthermore, the correct targeting of Eci1p and Dci1p occurs in the absence of the receptors for the type 1 or type 2 peroxisome targeting pathway. Together, these data suggest a novel mechanism for the intracellular targeting of these peroxisomal proteins.

scholarly journals Inhibition of steroid 5α-reductase by specific aliphatic unsaturated fatty acids

1992 ◽  
Vol 285 (2) ◽  
pp. 557-562 ◽  
Author(s):  
T Liang ◽  
S Liao
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Unsaturated Fatty Acids ◽  
Binding Assay ◽  
Reductase Activity ◽  
Undecylenic Acid ◽  
Gamma Linolenic Acid ◽  
Enzymic Assay

Human or rat microsomal 5 alpha-reductase activity, as measured by enzymic conversion of testosterone into 5 alpha-dihydrotestosterone or by binding of a competitive inhibitor, [3H]17 beta-NN-diethulcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([3H]4-MA) to the reductase, is inhibited by low concentrations (less than 10 microM) of certain polyunsaturated fatty acids. The relative inhibitory potencies of unsaturated fatty acids are, in decreasing order: gamma-linolenic acid greater than cis-4,7,10,13,16,19-docosahexaenoic acid = cis-6,9,12,15-octatetraenoic acid = arachidonic acid = alpha-linolenic acid greater than linoleic acid greater than palmitoleic acid greater than oleic acid greater than myristoleic acid. Other unsaturated fatty acids such as undecylenic acid, erucic acid and nervonic acid, are inactive. The methyl esters and alcohol analogues of these compounds, glycerols, phospholipids, saturated fatty acids, retinoids and carotenes were inactive even at 0.2 mM. The results of the binding assay and the enzymic assay correlated well except for elaidic acid and linolelaidic acid, the trans isomers of oleic acid and linoleic acid respectively, which were much less active than their cis isomers in the binding assay but were as potent in the enzymic assay. gamma-Linolenic acid had no effect on the activities of two other rat liver microsomal enzymes: NADH:menadione reductase and glucuronosyl transferase. gamma-Linolenic acid, the most potent inhibitor tested, decreased the Vmax. and increased Km values of substrates, NADPH and testosterone, and promoted dissociation of [3H]4-MA from the microsomal reductase. gamma-Linolenic acid, but not the corresponding saturated fatty acid (stearic acid), inhibited the 5 alpha-reductase activity, but not the 17 beta-dehydrogenase activity, of human prostate cancer cells in culture. These results suggest that unsaturated fatty acids may play an important role in regulating androgen action in target cells.

scholarly journals Antioxidant and fatty acid profile of gabiroba seed (Campomanesisa Xanthocarpa Berg)

2012 ◽  
Vol 32 (2) ◽  
pp. 234-238 ◽  
Author(s):  
Marli da Silva Santos ◽  
Obdulio Gomes Miguel ◽  
Carmen Lúcia Oliveira Petkowicz ◽  
Lys Mary Bileski Cândido
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Fatty Acid Profile ◽  
Unsaturated Fatty Acids ◽  
Ethanol Extract ◽  
Solvent Polarity ◽  
Antioxidant Potential ◽  
Total Phenolic ◽  
Total Phenolic Compounds

This study aimed to evaluate the antioxidant potential and fatty acid profile of gabiroba (Campomanesia xanthocarpa Berg) seeds. In order to obtain the extract, the seeds were dried, crushed, and subjected to sequential extraction by maceration and percolation in a modified soxhlet extractor using solvent polarity gradient composed of hexane, chloroform, ethyl acetate, and alcohol, respectively. The extraction time was six hours. The ethanol extract showed the highest antioxidant potential, given by the EC50 value and the amount of total phenolic compounds. High amounts of unsaturated fatty acids were found in the oil studied, especially the oleic acid.

scholarly journals Effect of nitrogen and potassium fertilization on the production and quality of oil in Jatropha curcas L. under the dry and warm climate conditions of Colombia

2014 ◽  
Vol 32 (2) ◽  
pp. 255-265 ◽  
Author(s):  
Omar Montenegro R. ◽  
Stanislav Magnitskiy ◽  
Martha C. Henao T.
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Jatropha Curcas ◽  
Oil Content ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Fruit Production ◽  
Biodiesel Production ◽  
Oil Composition

This study was conducted to assess fruit and seed yield, oil content and oil composition of Jatropha curcas fertilized with different doses of nitrogen and potassium in Espinal (Tolima, Colombia). The yields ranged from 4,570 to 8,800 kg ha-1 of fruits and from 2,430 to 4,746 kg ha-1 of seeds. These yields showed that the fertilizer dose of 150 kg ha-1 N + 120 kg ha-1K increased fruit production by 92% and seed production by 95%, which represents an increase of about 100% in oil production, which increased from 947 to 1,900 kg ha-1. The total oil content in the seeds ranged from 38.7 to 40.1% (w/w) with a high content of the unsaturated fatty acids oleic (> 47%) and linoleic acid (> 29%). The highest content of oleic acid in the seed oil was from the unfertilized control plants and plants with an application of 100 kg ha-1 of N and 60 kg ha-1 of K, with an average of 48%. The lowest content of oleic acid was registered when a low dose of nitrogen and a high level of potassium were applied at a ratio of 1:2.4 and doses of 50 kg ha-1 N + 120 kg ha-1 K, respectively. Low contents of the saturated fatty acids palmitic (13.4%) and stearic (7.26%) were obtained, making this oil suitable for biodiesel production. The nitrogen was a more important nutrient for the production and quality of oil in J. curcas than potassium under the studied conditions of soil and climate.

scholarly journals Antagonism Between Saturated and Unsaturated Fatty Acids in ROS Mediated Lipotoxicity in Rat Insulin-Producing Cells

2015 ◽  
Vol 36 (3) ◽  
pp. 852-865 ◽  
Author(s):  
Wiebke Gehrmann ◽  
Wiebke Würdemann ◽  
Thomas Plötz ◽  
Anne Jörns ◽  
Sigurd Lenzen ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Palmitic Acid ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
H2o2 Production ◽  
Β Cell ◽  
Specific Expression ◽  
Insulin Producing Cells ◽  
H2o2 Formation

Background/Aims: Elevated levels of non-esterified fatty acids (NEFAs) are under suspicion to mediate β-cell dysfunction and β-cell loss in type 2 diabetes, a phenomenon known as lipotoxicity. Whereas saturated fatty acids show a strong cytotoxic effect upon insulin-producing cells, unsaturated fatty acids are not toxic and can even prevent toxicity. Experimental evidence suggests that oxidative stress mediates lipotoxicity and there is evidence that the subcellular site of ROS formation is the peroxisome. However, the interaction between unsaturated and saturated NEFAs in this process is unclear. Methods: Toxicity of rat insulin-producing cells after NEFA incubation was measured by MTT and caspase assays. NEFA induced H2O2 formation was quantified by organelle specific expression of the H2O2 specific fluorescence sensor protein HyPer. Results: The saturated NEFA palmitic acid had a significant toxic effect on the viability of rat insulin-producing cells. Unsaturated NEFAs with carbon chain lengths >14 showed, irrespective of the number of double bonds, a pronounced protection against palmitic acid induced toxicity. Palmitic acid induced H2O2 formation in the peroxisomes of insulin-producing cells. Oleic acid incubation led to lipid droplet formation, but in contrast to palmitic acid induced neither an ER stress response nor peroxisomal H2O2 generation. Furthermore, oleic acid prevented palmitic acid induced H2O2 production in the peroxisomes. Conclusion: Thus unsaturated NEFAs prevent deleterious hydrogen peroxide generation during peroxisomal β-oxidation of long-chain saturated NEFAs in rat insulin-producing cells.

Studies on the Metabolism of Unsaturated Fatty Acids. VIII. Induction of 2,4-Dienoyl-CoA Reductase in Escherichia coli on the Addition of Unsaturated Fatty Acids1

1982 ◽  
Vol 91 (4) ◽  
pp. 1453-1456 ◽  
Author(s):  
Michinao MIZUGAKI ◽  
Tomoko NISHIMAKI ◽  
Hirotaka YAMAMOTO ◽  
Sumiko NISHIMURA ◽  
Mataichi SAGI ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Coa Reductase

ERUCIC ACID AND CHOLESTEROL EXCRETION IN THE RAT

1956 ◽  
Vol 34 (1) ◽  
pp. 981-991 ◽  
Author(s):  
K. K. Carroll ◽  
R. L. Noble
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Erucic Acid ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Fraction ◽  
Cholesterol Concentration ◽  
Acid Fraction ◽  
Cholesterol Excretion ◽  
Fecal Cholesterol

Erucic acid has been found to increase the excretion of endogenously produced cholesterol in the rat with little change in the cholesterol concentration in the carcass except for increased concentrations in the adrenals and liver. The fecal cholesterol was identified by melting point and infrared spectrum after isolation by chromatography on alumina. It does not appear to originate in the liver since no increase was observed in the biliary excretion of cholesterol. Other homologues of oleic acid, namely eicosenoic and nervonic acid, produced similar changes in fecal cholesterol excretion, although oleic acid itself had little effect. A series of saturated fatty acids from butyric (C4) to behenic (C22) were tested and the longer chain members found to cause some increase in cholesterol excretion. Ester cholesterol accounted for much of the observed increases but varied greatly in the experiments with unsaturated fatty acids. A preparation of cerebrosides from beef spinal cord also increased the amount of cholesterol excreted in the feces. The fatty acid fraction from this preparation gave a similar result, although the cerebrosides gave rise mainly to free cholesterol and the fatty acid fraction to ester cholesterol.

Sign in / Sign up

Export Citation Format

Share Document