scholarly journals Evidence for a single non-arachidonic acid-specific fatty acyl-CoA synthetase in heart which is regulated by Mg2+

1996 ◽  
Vol 313 (3) ◽  
pp. 849-853 ◽  
Author(s):  
Christine SAUNDERS ◽  
Jeffrey M. VOIGT ◽  
Margaret T. WEIS

Previous reports indicated that arachidonic acid is incorporated into the isolated perfused rabbit heart in preference to other fatty acids, and that incorporation of arachidonic acid, but not other fatty acids, is inhibited during Mg2+ depletion. In this study, we have not been able to demonstrate an arachidonic acid-specific fatty acyl-CoA synthetase in rat or rabbit heart by hydroxyapatite chromatography. Kinetic evidence was consistent with a single enzyme, as the slopes of pseudo-Hill plots were not significantly different from -1. The single fatty acyl-CoA synthetase present appears to prefer C18:0 unsaturated fatty acids to arachidonate, and had about the same affinity for C10:0–C14:0 saturated fatty acids as for arachidonate. At 35 μM arachidonate, enzyme velocity increased as the total Mg2+ was increased from 3 to 80 mM. Calculated [MgATP] indicated that the MgATP complex was not rate-limiting. At low concentrations, Mn2+ and Ni2+ supported activity, but Cu2+ and Zn2+ did not. Low Ca2+ concentrations activated only oleic acid conversion. Kinetic analysis indicated that the Vmax of the enzyme was increased with increasing concentrations of ionized Mg2+ for both oleic acid and arachidonic acid. The data are consistent with the hypothesis that Mg2+ has a direct effect on fatty acyl-CoA synthetase activity, and suggest that preference for oleic acid and arachidonic acid can be influenced by the ionic milieu.

2014 ◽  
Vol 32 (2) ◽  
pp. 255-265 ◽  
Author(s):  
Omar Montenegro R. ◽  
Stanislav Magnitskiy ◽  
Martha C. Henao T.

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.


2015 ◽  
Vol 36 (3) ◽  
pp. 852-865 ◽  
Author(s):  
Wiebke Gehrmann ◽  
Wiebke Würdemann ◽  
Thomas Plötz ◽  
Anne Jörns ◽  
Sigurd Lenzen ◽  
...  

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.


2007 ◽  
Vol 97 (1) ◽  
pp. 62-69 ◽  
Author(s):  
X. Sun ◽  
D. Zhou ◽  
P. Zhang ◽  
E. G. Moczydlowski ◽  
G. G. Haddad

In this study, we examined the effect of arachidonic acid (AA) on the BK α-subunit with or without β-subunits expressed in Xenopus oocytes. In excised patches, AA potentiated the hSlo-α current and slowed inactivation only when β2/3 subunit was co-expressed. The β2-subunit–dependent modulation by AA persisted in the presence of either superoxide dismutase or inhibitors of AA metabolism such as nordihydroguaiaretic acid and eicosatetraynoic acid, suggesting that AA acts directly rather than through its metabolites. Other cis unsaturated fatty acids (docosahexaenoic and oleic acid) also enhanced hSlo-α + β2 currents and slowed inactivation, whereas saturated fatty acids (palmitic, stearic, and caprylic acid) were without effect. Pretreatment with trypsin to remove the cytosolic inactivation domain largely occluded AA action. Intracellularly applied free synthetic β2-ball peptide induced inactivation of the hSlo-α current, and AA failed to enhance this current and slow the inactivation. These results suggest that AA removes inactivation by interacting, possibly through conformational changes, with β2 to prevent the inactivation ball from reaching its receptor. Our data reveal a novel mechanism of β-subunit–dependent modulation of BK channels by AA. In freshly dissociated mouse neocortical neurons, AA eliminated a transient component of whole cell K+ currents. BK channel inactivation may be a specific mechanism by which AA and other unsaturated fatty acids influence neuronal death/survival in neuropathological conditions.


1963 ◽  
Vol 9 (5) ◽  
pp. 530-543 ◽  
Author(s):  
Bernard J Katchman ◽  
Robert E Zipf ◽  
James P F Murphy

Abstract The kinetic effect of palmitate, stearate, oleate, linoleate, and linolenate upon in vitro endogenous respiration of rat chloromyeloid leukemic cells has been investigated. Inhibition of respiration has been correlated with the ability of fatty acids to cause decreased cell viability and cell count; in the bioassay of fatty acid-treated tumor inocula, the increase in animal life span is correlated to the degree of dilution of the inocula due to cell lysis. The degree of lysis is dependent upon the chemical structure of the fatty acid, concentration, and duration of contact; unsaturated fatty acids are more effective than saturated fatty acids. Tumor cells, when incubated at low concentrations of fatty acids, show stimulation of O2 uptake; however, in the bioassay these fatty acid-treated inocula showed no loss in tumor activity. The nature of the physiochemical interaction between fatty acids and tumor cells is discussed.


1965 ◽  
Vol 97 (2) ◽  
pp. 371-374 ◽  
Author(s):  
JD Sink ◽  
CK Huston ◽  
JW Shigley

1. The effect of diethylstilboestrol on the fatty acid composition of adipose-tissue lipids of the ox (Bos taurus) was studied. 2. The capsula adiposa (perirenal) was shown to contain more total saturated fatty acids, whereas more total unsaturated fatty acids were found in the panniculus adiposus (subcutaneous). 3. Significantly more stearic acid and linolenic acid were obtained from the capsula adiposa, whereas the panniculus adiposus contained more myristoleic acid, palmitoleic acid and oleic acid. 4. Implanting diethylstilboestrol significantly increased the deposition of the saturated fatty acids, particularly stearic acid. 5. A decrease in the deposition of total unsaturated fatty acids, myristoleic acid, palmitoleic acid and linoleic acid can also be attributed to the diethylstilboestrol treatment.


1991 ◽  
Vol 260 (3) ◽  
pp. C439-C448 ◽  
Author(s):  
J. M. Burt ◽  
K. D. Massey ◽  
B. N. Minnich

The permeability and conductance of gap junctions between pairs of neonatal rat heart cells were rapidly and reversibly decreased by oleic acid in a dose- and time-dependent manner. Other unsaturated fatty acids (C-18: cis 6, 9, or 11, and C-18, 16, and 14, cis 9), saturated fatty acids (C-10, 12, and 14), and saturated fatty alcohols (C-8, 10, and 12) also caused uncoupling. The most effective compounds of the unsaturated and saturated fatty acid and saturated fatty alcohol series caused essentially complete uncoupling at comparable aqueous concentrations. However, oleic acid uncoupled cells at membrane concentrations as low as 1 mol%, whereas decanoic acid required upwards of 35 mol%. The channels that support the action potential remained functional at these same membrane concentrations. The data are discussed in terms of the possible mechanism by which these compounds cause uncoupling and the possible role of uncoupling by nonesterified free fatty acids in the initiation of arrhythmias during and after ischemic insults.


2008 ◽  
Vol 8 (16) ◽  
pp. 4683-4690 ◽  
Author(s):  
O. Vesna ◽  
S. Sjogren ◽  
E. Weingartner ◽  
V. Samburova ◽  
M. Kalberer ◽  
...  

Abstract. Unsaturated fatty acids are important constituents of the organic fraction of atmospheric aerosols originating from biogenic or combustion sources. Oxidative processing of these may change their interaction with water and thus affect their effect on climate. The ozonolysis of oleic and arachidonic acid aerosol particles was studied under humid conditions in a flow reactor at ozone exposures close to atmospheric levels, at concentrations between 0.5 and 2 ppm. While oleic acid is a widely used proxy for such studies, arachidonic acid represents polyunsaturated fatty acids, which may decompose into hygroscopic products. The hygroscopic (diameter) growth factor at 93% relative humidity (RH) of the oxidized arachidonic particles increased up to 1.09 with increasing RH during the ozonolysis. In contrast, the growth factor of oleic acid was very low (1.03 at 93% RH) and was almost invariant to the ozonolysis conditions, so that oleic acid is not a good model to observe oxidation induced changes of hygroscopicity under atmospheric conditions. We show for arachidonic acid particles that the hygroscopic changes induced by humidity during ozonolysis are accompanied by about a doubling of the ratio of carboxylic acid protons to aliphatic protons. We suggest that, under humid conditions, the reaction of water with the Criegee intermediates might open a pathway for the formation of smaller acids that lead to more significant changes in hygroscopicity. Thus the effect of water to provide a competing pathway during ozonolysis observed in this study should be motivation to include water, which is ubiquitously present in and around atmospheric particles, in future studies related to aerosol particle aging.


2020 ◽  
Vol 11 (2) ◽  
pp. 8904-8914

The objective of this study to compare the fatty acids composition in cooking oil from repeated frying without added turmeric extract and added. The research design is testing the composition of fatty acids in repeated cooking oil using two types of treatment, namely cooking oil from frying without adding turmeric extract and cooking oil from frying with 0.03% turmeric extract added with 10 times frying repeat because it is suspected that repeated frying will increase the composition of fatty acids in cooking oil. The analysis of fatty acids was conducted using gas chromatography. Based on these results that the fatty acid components were produced of saturated fatty acids, namely lauric acid, myristic acid, palmitic acid, and stearic acid, whereas unsaturated fatty acids also detected such as elaidic acid, oleic acid, linoleic acid, cis-11-eicosadienoic acid, linolenic acid, and cis-11,14-eicosadienoic acid. The highest saturated fatty acid content in cooking oil before frying is palmitic acid (30.88%), whereas unsaturated fatty acid was oleic acid (35.86%). The highest content of saturated fatty acids in cooking oil has been added turmeric extract before frying is palmitic acid (28.5%), while unsaturated fatty acid of oleic acid was 32.97%.


2001 ◽  
Vol 358 (3) ◽  
pp. 757-761 ◽  
Author(s):  
David W. JIANG ◽  
Paul T. ENGLUND

As part of our investigation of fatty acid metabolism in Trypanosoma brucei, we have expressed four acyl-CoA synthetase (TbACS) genes in Esherichia coli. The recombinant proteins, with His-tags on their C-termini, were purified to near homogeneity using nickel-chelate affinity chromatography. Although these enzymes are highly homologous, they have distinct specificities for fatty acid chain length. TbACS1 prefers saturated fatty acids in the range C11:0 to C14:0 and TbACS2 prefers shorter fatty acids, mainly C10:0. TbACS3 and 4, which have 95% sequence identity, have similar specificities, favouring fatty acids between C14:0 and C17:0. In addition, TbACS1, 3 and 4 function well with a variety of unsaturated fatty acids.


2020 ◽  
Vol 1000 ◽  
pp. 210-219
Author(s):  
Dedison Gasni ◽  
Ikhsanul Fikri ◽  
Muhammad Latif

The purpose of this study was to investigate the influence of oleic acid as an additive in palm and coconut oils on tribological properties. Palm and coconut oils are vegetable oils that are consisted of free fatty acid, which one of the materials used as a source of environmental lubricant. Fatty acids in vegetable oil consist of saturated fatty acids and unsaturated fatty acids. Palm and coconut oils are rich in palmitic acid, which is categorized as saturated fatty acids. Whereas oleic acid is unsaturated fatty acids, and it has good lubricity as a lubricant. The effect of variation of oleic acid (10wt%, 20wt%, and 30wt%) in palm and coconut oils was investigated on tribological properties. The tribological properties were investigated by using a pin on disc apparatus and a ball bearing test rig. The results show that the effect of 10%wt oleic acids in coconut oil significantly increased its tribological properties with Δ scar width around 96 μm and 154 μm for the inner race and outer race, respectively.


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