scholarly journals The distribution of oleic acid between chylomicron-like emulsions, phospholipid bilayers, and serum albumin. A model for fatty acid distribution between lipoproteins, membranes, and albumin.

1990 ◽  
Vol 265 (21) ◽  
pp. 12650-12655
Author(s):  
P J Spooner ◽  
D L Gantz ◽  
J A Hamilton ◽  
D M Small
1990 ◽  
Vol 68 (9) ◽  
pp. 1255-1260 ◽  
Author(s):  
V. Durocher ◽  
M. Miller ◽  
M. A. Rodriguez

Glycerolphosphate acyltransferase activity in microsomes from rat adipose tissue is shown to decrease with time upon incubation with adipose tissue cytosolic fraction. The inactivation can be prevented with serum albumin and seems to be caused by an increase in endogenous free fatty acid as a consequence of the action of cytosolic lipase(s) on the membrane lipids. Similar inactivation can be observed after short incubation of microsomes with oleic acid at micromolar concentrations. Diacylglycerol acyltransferase is also inhibited by oleic acid, although to a lesser degree. In contrast, glucose-6-phosphatase and NADPH – cytochrome reductase activities are not changed. The oleic acid effect appears to occur upon binding to the microsomal membranes and can be prevented by bovine serum albumin at protein/fatty acid molar ratios above one. These results suggest that free fatty acids may be involved in the modulation of triacylglycerol synthetic enzymes.Key words: glycerolphosphate acyltransferase, fatty acids, microsomal enzymes, lipid synthesis.


2005 ◽  
Vol 19 (2) ◽  
pp. 109-117 ◽  
Author(s):  
Giovanna Vlahov

The fatty acid distribution between the 1,3- and 2-positions of triglycerides was determined in the olive oil set sampled in the Marche region, by using the13C NMR method which applies the DEPT pulse sequence. The results confirmed that the oleic and linoleic acids were not randomly distributed at the 2-position of triacylglycerols but were lower for oleic acid and higher for linoleic acid compared to the theoretical values expected for a random distribution. Moreover, the unsaturated acids deviated from the 2-random distribution at different extents according to the acid concentration of triglyceride.The13C NMR results, they were obtained for three olive oil samples characterized by high, medium and low oleic acid at 2-position (Ofound) corresponding to a low, medium, high deviation rate from the 2-random pattern, were compared to those calculated by the computer program based on the 1,3-random-2-random distribution of fatty acids in the triglycerides.The molar concentrations of the triglyceride species LLL and OLL were calculated from the molar concentrations of oleic and linoleic acids at the 2- and 1,3-positions obtained by using13C NMR and the computer method. The LLL and OLL triglycerides determined by the computer method were found to be markedly higher in the “high Ofound” oil as compared to NMR. No differences were detected between the two methods for both triglyceride species in the “low Ofound” oil.


1947 ◽  
Vol 86 (3) ◽  
pp. 215-228 ◽  
Author(s):  
Bernard D. Davis ◽  
René J. Dubos

Serum albumin is a protective bacterial growth factor; by binding traces of fatty acid in the media it permits initiation of growth by the smallest possible inocula of tubercle bacilli. Each molecule of albumin binds 3 to 6 molecules of oleic acid (1 to 2 per cent of the weight of the albumin) tightly enough to prevent bacteriostasis, and 9 molecules of oleic acid in equilibrium with a saturated neutral solution. The property requires undenatured albumin. Crystalline ß-lactoglobulin has a smaller capacity, and a number of other proteins no perceptible capacity to bind oleic acid. The inhibitory effect of the commercial product Tween 80 (polyoxyethylene sorbitan monooleate) on the growth of small inocula of tubercle bacilli in liquid media is caused by its content of unesterified oleic acid (0.6 per cent by weight). Purified Tween 80, freed of this contaminating fatty acid, not only permits growth of small inocula, but protects against small amounts of added oleic acid. The implications of the binding capacity of albumin for its possible physiological significance in the animal body (transport; protection against cytotoxins), and for the structure of the protein, are briefly discussed.


1988 ◽  
Vol 250 (2) ◽  
pp. 443-446 ◽  
Author(s):  
J H M Dröge ◽  
L H M Janssen ◽  
J Wilting

The binding of oleic acid to human serum albumin causes progressive changes in (a) the pK of some amino acid residues, as detected by pH-stat titration and (b) the induced molar ellipticities of albumin-bound drugs (diazepam and oxyphenbutazone), as measured by c.d. It is concluded that albumin undergoes several conformational transitions as the amount of oleic acid bound increases from 0 to about 9 molecules/molecule of protein. At least three different conformations of the protein seem to be involved. These conformations can be linked with the three classes of oleic acid-binding sites on albumin.


1984 ◽  
Vol 217 (3) ◽  
pp. 709-714 ◽  
Author(s):  
B Lederer ◽  
H G Hers

We confirmed that, as reported by Sooranna & Saggerson [(1982) Biochem. J. 202, 753-758], the affinity of 6-phosphofructo-1-kinase (PFK) for fructose 6-phosphate in an adipocyte extract was increased after incubation of the cells in the presence of noradrenaline. The participation of fructose 2,6-bisphosphate in this kinetic modification could be excluded, because the noradrenaline effect persisted after extensive gel filtration of the extracts and also because the treatment did not cause any change in the concentration of fructose 2,6-bisphosphate in the adipocytes. Oleic acid was found to be another potent positive effector of PFK in an adipocyte extract, with a Ka of 10 microM. Its effect was synergistic with that of fructose 2,6-bisphosphate and AMP, and was counteracted by serum albumin. Palmitic acid had a similar effect. We conclude that the large increase in fatty acid concentration caused by noradrenaline treatment is an explanation for the activation of phosphofructokinase at low fructose 6-phosphate concentrations in an adipocyte extract.


1986 ◽  
Vol 56 (01) ◽  
pp. 057-062 ◽  
Author(s):  
Martine Croset ◽  
M Lagarde

SummaryWashed human platelets were pre-loaded with icosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or EPA + DHA and tested for their aggregation response in comparison with control platelets. In fatty acid-rich platelets, an inhibition of the aggregation could be observed when induced by thrombin, collagen or U-46619. The strongest inhibition was observed with DHA-rich platelets and it was reduced when DHA was incorporated in the presence of EPA.Study of fatty acid distribution in cell lipids after loading showed that around 90% of EPA or DHA taken up was acylated into phospholipids and a very small amount (less than 2%) remained in their free and hydroxylated forms. DHA was more efficiently acylated into phosphatidylethanolamine (PE) than into phosphatidylinositol (PI) in contrast to what observed with EPA, and both acids were preferentially incorporated into phosphatidylcholine (PC). EPA inhibited total incorporation of DHA and increased its relative acylation into PE at the expense of PC. In contrast, DHA did not affect the acylation of EPA. Upon stimulation with, thrombin, EPA was liberated from phospholipids and oxygenated (as judged by the formation of its monohydroxy derivative) whereas DHA was much less metabolized, although consistently transferred into PE.It is concluded that EPA and DHA might affect platelet aggregation via different mechanisms when pre-loaded in phospholipids. Whereas EPA is known to alter thromboxane A2 metabolism from endogenous arachidonic acid, by competing with it, DHA might act directly at the membrane level for inhibiting aggregation.


2016 ◽  
Vol 2 (1) ◽  
pp. 37-42 ◽  
Author(s):  
J.M. Pino Moreno ◽  
A. Ganguly

In the present paper we have determined the fatty acid content of some edible insects of Mexico. A comparative analysis of the insect species studied in this research showed that caproic acid was present in a minimal proportion which ranged between 0.01 for Periplaneta americana (nymphs) and 0.06 (g/100 g, dry basis) for Euschistus strenuus. The highest proportion of caprilic acid (0.09) was found in Tenebrio molitor (adults). Atta sp. had the highest amount of capric acid (0.26). Polistes sp. was found to be rich in lauric acid (0.77) and for myristic acid it had the highest content (5.64). Dactylopius sp. and E. strenuus were rich in palmitic acid (14.89). Euschistus taxcoensis had the highest quantity of palmitoleic acid (12.06). Llaveia axin exhibited the highest quantity of stearic acid (22.75). Polistes sp. was found to be rich in oleic acid (38.28). The highest quantity of linoleic acid was observed in T. molitor (larvae) (10.89), and in L. axin the highest content of linolenic acid (7.82) was obtained. A comparison between the species under the present investigation revealed that, in general, the insects are poor in caproic, caprilic, capric, lauric, myristic, palmitoleic and linolenic acids, because the quantities were either minimal or could not be detected at all. They had moderate quantities of stearic, palmitic and linoleic acids and had high quantities of oleic acid. Finally it was concluded that although a particular insect species is unable to fulfil the total fatty acid need for a human, if consumed in combination they could definitely be able to supply a good amount of this highly valued nutrient.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1245
Author(s):  
Naoufal Lakhssassi ◽  
Valéria Stefania Lopes-Caitar ◽  
Dounya Knizia ◽  
Mallory A. Cullen ◽  
Oussama Badad ◽  
...  

Soybean is the second largest source of oil worldwide. Developing soybean varieties with high levels of oleic acid is a primary goal of the soybean breeders and industry. Edible oils containing high level of oleic acid and low level of linoleic acid are considered with higher oxidative stability and can be used as a natural antioxidant in food stability. All developed high oleic acid soybeans carry two alleles; GmFAD2-1A and GmFAD2-1B. However, when planted in cold soil, a possible reduction in seed germination was reported when high seed oleic acid derived from GmFAD2-1 alleles were used. Besides the soybean fatty acid desaturase (GmFAD2-1) subfamily, the GmFAD2-2 subfamily is composed of five members, including GmFAD2-2A, GmFAD2-2B, GmFAD2-2C, GmFAD2-2D, and GmFAD2-2E. Segmental duplication of GmFAD2-1A/GmFAD2-1B, GmFAD2-2A/GmFAD2-2C, GmFAD2-2A/GmFAD2-2D, and GmFAD2-2D/GmFAD2-2C have occurred about 10.65, 27.04, 100.81, and 106.55 Mya, respectively. Using TILLING-by-Sequencing+ technology, we successfully identified 12, 8, 10, 9, and 19 EMS mutants at the GmFAD2-2A, GmFAD2-2B, GmFAD2-2C, GmFAD2-2D, and GmFAD2-2E genes, respectively. Functional analyses of newly identified mutants revealed unprecedented role of the five GmFAD2-2A, GmFAD2-2B, GmFAD2-2C, GmFAD2-2D, and GmFAD2-2E members in controlling the seed oleic acid content. Most importantly, unlike GmFAD2-1 members, subcellular localization revealed that members of the GmFAD2-2 subfamily showed a cytoplasmic localization, which may suggest the presence of an alternative fatty acid desaturase pathway in soybean for converting oleic acid content without substantially altering the traditional plastidial/ER fatty acid production.


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