SEARCH · Search PubMed

Results for “STEARIC ACID”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,243 records · Page 69Linked to original sources

PubMed1998

Is the cytoprotective effect of trimetazidine associated with lipid metabolism?

Trimetazidine is an anti-ischemic compound devoid of hemodynamic effect, which was recently suspected to induce cardioprotection at the cellular level by a mechanism involving lipid metabolism. The effect on trimetazidine was evaluated in vivo by determination of rat cardiac fatty acid composition, and in vitro by investigation of the phospholipid metabolism in cultured rat cardiomyocytes. In rats, a 4-week trimetazidine treatment induced a significant decrease in the phospholipid content in linoleic acid, balanced by a small increase in oleic and stearic acids. These changes were not correlated with similar alterations in plasma fatty acid composition. In isolated cells, the time-dependent incorporation of labeled precursors of membrane phospholipid ([3H]inositol, [14C]ethanolamine, [14C]choline, [3H]glycerol, [14C]arachidonic acid, and [14C]linoleic acid 10 micromol/L) was compared in trimetazidine-treated cells and control cells. In trimetazidine-treated cells, arachidonic acid incorporation was increased in the phospholipid, but not in other lipid fractions. This enhanced fatty acid utilization elicited a net increase in the total arachidonic acid uptake. The incorporation of [14C] inositol in phosphatidylinositol was strongly stimulated by trimetazidine, although the uptake of inositol was not altered. The difference was significant within 30 minutes, and reached +70%(in trimetazidine-treated cells) after 150 minutes. A similar result was obtained with ethanolamine as phosphatidylethanolamine precursor, where turnover increased by 50% in trimetazidine-treated cells. Conversely, the incorporation of choline in phosphatidylcholine was not significantly affected by the presence of trimetazidine. In conclusion, trimetazidine appears to interfere with the metabolism of phospholipids in cardiac myocytes in a manner that could indicate an increased phosphatidylinositol turnover and a redirection of cytidine triphosphate (CTP) utilization toward phosphatidylethanolamine instead of phosphatidylcholine turnover. This overall phospholipid turnover increase may contribute to a reorganization of the fatty acid utilization balance in the heart, which could lead to a lowered availability of fatty acids for energy production.

Animals↗

PubMed1993

In vivo effect of chronic ethanol consumption on the fatty acid composition of phosphatidylinositols in resting and anti-CD3-activated lymphocytes.

Fatty acid composition of phosphatidylinositols was analyzed in peripheral blood lymphocytes from nine alcoholic patients who were well nourished and without severe acute and chronic liver disease, before and after stimulation with anti-CD3 antibody. Six comparable nondrinkers were studied as controls. A reduction in unsaturated fatty acid (mainly arachidonic) and an increase in palmitic and stearic acid molar content were observed in phosphatidylinositol (PI), phosphatidylinositol-4-phosphate (PIP), and phosphatidylinositol-4,5-bisphosphate (PIP2) in unstimulated samples from alcoholic patients in comparison with normal subjects, leading to a significant decrease in the saturated/unsaturated ratio. In controls, anti-CD3 stimulation caused a marked decrease in arachidonic acid relative molar content counterbalanced by an increase in other polyunsaturated fatty acid relative molar content in PI, PIP, and PIP2 fractions. Interestingly, after anti-CD3 stimulation, alcoholic patients show the same trend of modification in the fatty acid composition resulting in a sharp reduction of arachidonic acid relative molar content. These results support the hypothesis of an alteration in nutrients being responsible for immune derangement in alcoholics.

Adult↗

PubMed1991

Ion permeability through bilayer lipid membranes for biosensor development: control by chemical modification of interfacial regions between phase domains.

Based on the results of studies on cystic fibrosis, which implicated hydroxystearic acid (HSA) as a contributing factor in altered biomembrane function, solvent-free bilayer lipid membranes (BLMs) and monolayer films were prepared from a lipid mixture containing (by mass) 34% phosphatidylcholine, 19% dipalmitoylphosphatidyl serine, 47% cholesterol and variable amounts of 10- and 12-HSA (0-50%). Ion currents, resulting from K+ permeation through BLMs that were supported in 0.1 mol dm-3 KCl solutions buffered to pH 7.4, were monitored with use of a d.c. circuit. The structures of monolayer films at the air-water interface of a Langmuir-Blodgett trough were studied by pressure-area correlations and by further correlation with microscopic phase separation as revealed by fluorescence microscopy. In order to elucidate the role of the hydroxyl moieties in ion permeability, the transmembrane ion current was corrected for the effect of the negative surface charge of the carboxylic acid by replacement of the HSA component with stearic acid. The ion current was found to increase with the molar proportion of the HSAs. Two models for ion conduction through BLMs were considered: 'hopping' via hydrophilic sites within the hydrophobic zone of the BLMs, introduced by the hydroxyl moiety of 10- or 12-HSA; and transport through interfacial regions between phase domains that represent areas of low steric density and low structural order within monolayers. Although the two mechanisms are not distinct, the ion permeability results indicate a change in the response of ion current to HSA concentration at 35 mol-%, suggesting a change in the relative proportion of the mechanisms.(ABSTRACT TRUNCATED AT 250 WORDS)

Biosensing Techniques↗

PubMed1990

Alteration of the cellular fatty acid profile and the production of eicosanoids in human monocytes by gamma-linolenic acid.

We administered borage seed oil (9 capsules/day) for 12 weeks to 7 normal controls and to 7 patients with active rheumatoid arthritis. The therapy provided 1.1 gm/day of gamma-linolenic acid (GLA). GLA administration resulted in increased proportions of its first metabolite, dihomo-gamma-linolenic acid (DGLA), in circulating mononuclear cells. The ratios of DGLA to arachidonic acid and DGLA to stearic acid increased significantly in these cells. Significant reductions in prostaglandin E2, leukotriene B4, and leukotriene C4 produced by stimulated monocytes were seen after 12 weeks of GLA supplementation. The antiinflammatory effects of GLA administration observed in animal models, and the apparent clinical improvement experienced by 6 or 7 rheumatoid arthritis patients given borage seed oil in this open, uncontrolled study may be due in part to reduced generation of arachidonic acid oxygenation products.

Administration, Oral↗

PubMed1996

Lipid and antioxidant blood levels in vegetarians.

Parameters of lipid metabolism (triacylglycerols TG, cholesterol CH, HDL-CH, LDL-CH, atherogenic index AI, profile of fatty acids) were measured in blood samples of 81 healthy lacto and lacto-ovo vegetarians (42 males, 39 females; age range 19-39 years). The average period of being on a vegetarian diet was 6.2 years. Low levels of TG, CH, LDL-CH, AI and HDL-CH values on the borderline between standard and reduced risk (1.4 mmol.l-1) can be considered as favourable from the atherosclerosis prevention aspect. Compared with non-vegetarians (n = 62), the levels of TG, CH, LDL-CH, and AI are significantly reduced in the vegetarian group. As opposed to non-vegetarians, vegetarians showed a higher total sum of polyunsaturated fatty acids, a significantly higher content of linoleic acid (C 18:2) and linolenic acid (C 18:3), unchanged content of oleic acid (C 18:1), stearic acid (C 18:0) and other polyunsaturated fatty acids. The process of lipoperoxidation (with polyunsaturated fatty acids as substrate) is involved in the etiology of cardiovascular and oncological diseases. Favourable values of prooxidative-antioxidative parameters demonstrated a reduced risk of lipoperoxidation in vegetarians, compared to non-vegetarians (significantly reduced content of conjugated dienes of fatty acids in plasma, significantly higher plasma levels of vitamin C, beta-carotene, vitamin E/cholesterol ratio--and indicator of LDL protection, vitamin E/triacylglycerols ratio--an indicator of fatty acid protection--, selenium and glutathione-peroxidase activity).

Adult↗

PubMed1991

The GTPase stimulatory activities of the neurofibromatosis type 1 and the yeast IRA2 proteins are inhibited by arachidonic acid.

Three proteins, GTPase activating protein (GAP), neurofibromatosis 1 (NF1) and the yeast inhibitory regulator of the RAS-cAMP pathway (IRA2), have the ability to stimulate the GTPase activity of Ras proteins from higher animals or yeast. Previous studies indicate that certain lipids are able to inhibit this activity associated with the mammalian GAP protein. Inhibition of GAP would be expected to biologically activate Ras protein. In these studies arachidonic acid is shown also to inhibit the activity of the catalytic fragments of the other two proteins, mammalian NF1 and the yeast IRA2 proteins. In addition, phosphatidic acid (containing arachidonic and stearic acid) was inhibitory for the catalytic fragment of NF1 protein, but did not inhibit the catalytic fragments of GAP or IRA2 proteins. These observations emphasize the biochemical similarity of these proteins and provide support for the suggestion that lipids might play an important role in their biological control, and therefore also in the control of Ras activity and cellular proliferation.

Arachidonic Acid↗

PubMed1998

Physicochemical and immunochemical properties of recombinant human serum albumin from Pichia pastoris.

We analyzed and compared the physicochemical and immunochemical properties of recombinant human serum albumin (rHSA) from Pichia pastoris with those of plasma-derived human serum albumin (pHSA). The second virial coefficient of rHSA, obtained from colloid osmotic pressure measurements at pH 6.7 +/- 0.1 was not significantly different from that of pHSA (P > 0.05). A 25% rHSA solution exhibited Newtonian flow, and the viscosity of 25% rHSA at 20 +/- 0.02 degrees C was not significantly different from that of 25% pHSA (P > 0.05). We analyzed the long- and medium-chain fatty acid composition of rHSA by reverse-phase HPLC using 9-anthryldiazomethane as the fluorescent labeling reagent. The total amount of fatty acid was higher for pHSA than for rHSA. The fatty acid composition of the rHSA preparation was the same as that of the pHSA preparation. However, the amounts of palmitic acid (C16:0) and stearic acid (C18:0) in rHSA were much lower than those in pHSA. Interestingly, we found that P. pastoris produced linolenic acid (C18:3) because it was detected in rHSA. The immunochemical properties of rHSA were analyzed by a parallel line assay method using anti-pHSA polyclonal antibody, and were identical to those of pHSA (P > 0.05).

Amino Acid Sequence↗

PubMed1997

Trypanosoma cruzi: nitrogenous-base-containing phosphatides in trypomastigote forms--isolation and chemical analysis.

In trypanosomatids, little is known about the biosynthetic pathways involved in the metabolism of ethanolamine. In an attempt to clarify this point, an exhaustive analysis of the chloroform:methanol extract of T. cruzi trypomastigotes metabolically labeled with [14C]ethanolamine, in comparison with the lipids from [3H]palmitic acid-incorporated parasites, was performed. In both cases, phosphatidylethanolamine and lysophosphatidylethanolamine were detected, while phosphatidylcholine and lysophosphatidylcholine were only labeled with the fatty acid precursor. However, dimethylphosphatidylethanolamine was isolated from parasites labeled with the base precursor, indicating the ability of trypanosomes to methylate phosphatidylethanolamine to dimethylphosphatidylethanolamine. Fatty acids of the labeled phospholipids were analyzed by reverse-phase thin-layer chromatography and fluorography. Interestingly, phospholipids from the trypomastigote stage show palmitic acid (C16:0) and stearic acid (C18:0) as the only labeled components. The same saturated fatty acids were found free and as components of the radioactive triglycerides. No unsaturated fatty acids were detected, in accordance with the results obtained with inositolphospholipids. Conversely, when the fatty acids of phospholipids purified from nonlabeled parasites were analyzed by gas-liquid chromatography and gas-liquid chromatography-mass spectrometry, C18:1 was also detected. A striking finding was the presence of a considerable amount of free lignoceric acid (C24:0). Also, the C24:0 fatty acid was identified in the triglyceride fraction and as a component of phosphatidylcholine. The limited capacity of trypomastigote forms to elongate fatty acids was determined. In contrast with the results reported for other noninfective forms of the parasite, the absence of unsaturated fatty acids due to a low activity of desaturases was observed.

Animals↗

PubMed1987

Lipid composition and fatty acid pattern of the gerbil brain after exposure to perchloroethylene.

Continuous inhalation of perchloroethylene (PCE) (320 ppm) for 3 months by Mongolian gerbils resulted in an altered fatty acid pattern of a brain phospholipid. A minor decrease in the brain weight was also observed. In ethanolamine phosphoglyceride of the cerebral cortex and the hippocampus, a decrease was found among the minor fatty acids derived from linolenic acid with a corresponding increase in several fatty acids of the linoleic acid family. Linoleic acid itself was decreased. Stearic acid was also decreased in both the cerebral cortex and the hippocampus. These changes in the fatty acid pattern indicate increased desaturation. PCE might alter the desaturase activity either directly by interfering with the protein moieties of the enzyme system, or indirectly by changing the properties of the lipid matrix. The observed changes in fatty acid composition are also consistent with the current hypothesis that solvents and anesthetics perturb the lipid matrix of membranes, possibly inducing complex compensatory changes in the membrane lipid composition.

Animals↗

PubMed1977

[Determination of the ethyl esters of long chain fatty acids in wine distillate, brandy, and wine. II. (author's transl)].

Free fatty acids are able to interfere the determination of the ethyl esters by gas chromatography on Carbowax 20 M. Therefore series of tests were made to remove the fatty acids. Sodium hydrogen carbonate was found to be more suitable than sodium carbonate. A method is described to determine the ethyl esters of fatty acids of caproic to stearic acid and of the unsaturated fatty acids with 16 and 18 carbon atoms.

Alcoholic Beverages↗

PubMed1979

De novo fatty acid synthesis and fatty acid elongation catalyzed by subcellular fractions from hog and human aorta.

De novo synthesis and mitochondrial elongation of fatty acids have been demonstrated in subcellular fractions from hog and human aorta. Microsomal fatty acid elongation has been shown in hog aorta. The activity catalyzing the formation of fatty acids from acetyl and malonyl CoA was associated with a high molecular weight complex in the 6 x 10(6) g x min supernatant fraction. The principal product was palmitic acid. Some myristic and stearic acids were also formed. One elongation system was associated with protein which sedimented between 4500 g x min and 150,000 g x min. It used acetyl CoA but not malonyl CoA, and NADH was the preferred reducing agent. Radioactivity from acetyl CoA was incorporated into many fatty acids. In hog aorta a second elongation system was found associated with protein which sedimented at 6 x 10(6) g x min. It used malonyl CoA preferentially as substrate and either NADH or NADPH as reducing agent.

Acetyl Coenzyme A↗

PubMed1991

Erythrocyte and platelet fatty acids in retinitis pigmentosa.

The fatty acid composition and the glutathione-peroxidase activity (GSH-Px) of erythrocytes and platelets, the production of malondialdehyde (MDA) by platelets and the activity of the main systems of transmembrane cation transport in erythrocyte have been studied in 12 patients (5 males and 7 females) affected by retinitis pigmentosa (RP). A remarkable increase of saturated fatty acids (SFA), particularly of stearic acid (C18:0), has been noted in these patients. The reduced unsaturated/saturated fatty acids ratio (PUFA/SFA) observed in both erythrocytes and platelets and the decrease of arachidonic acid in platelets may depend by an active peroxidation process as documented by the increase of MDA. Platelet glutathione-peroxidase (PTL-GSH-PX) and plasma retinol were in the normal range, whereas erythrocyte glutathione-peroxidase (E-GSH-PX), MDA and plasma alfa-toco-pherol were increased in patients with RP. The activities of Na(+)-K+ pump, cotransport and Na(+)-Li+ countertransport were normal in RP erythrocytes.

Adult↗

PubMed1997

Volume-sensitive chloride current activated by hyposmotic swelling in antral gastric myocytes of the guinea-pig.

The characteristics of volume-sensitive chloride current (ICl) induced by osmotic cell swelling were studied using the whole-cell patch-clamp technique and cell diameters of antral circular guinea-pig myocytes were simultaneously measured under isosmotic and hyposmotic conditions by using a video image analysis system. At -60 mV, osmotic cell swelling (200 mosmol/l) activated a sustained inward current. Instantaneous current/voltage (I-V) relations obtained by step voltage pulses showed an outward rectification. At potentials above +40 mV, the current exhibited time-dependent decay. The outward current amplitude was decreased and the reversal potential was shifted to more positive potentials by replacement of external Cl- with gluconate-, while the current amplitude and the I/V relation were not affected by replacing extracellular Na+ with N-methyl-D-glucamine. The anion permeability sequence of the swelling-induced current was I- (1.80) > Br- (1.31) > Cl- (1) > F- (0.85) > gluconate- (0.18). The ICl was effectively inhibited by the Cl- channel blockers, 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS, 100 microM), and niflumic acid (10 microM). DIDS suppressed outward current more effectively than inward current. Also, the ICl was dose-dependently inhibited by arachidonic acid, an unsaturated fatty acid and also inhibited by other unsaturated fatty acids (linoleic acid and oleic acid) but not by stearic acid, a saturated fatty acid. The inhibitory effect of arachidonic acid on ICl was not prevented by indomethacin, a cyclo-oxygenase inhibitor and chelerythrine, a protein kinase C inhibitor. Under whole-cell patch-clamp conditions, the cell diameter was continuously measured using video image analysis, which reflects the change in cell volume. A hyposmotic-stimulation-induced increase of cell diameter was followed by ICl activation. In intact single gastric myocytes, relatively severe hyposmotic (176 mosmol/l) superfusing solution increased the cell diameter and the pretreatment with DIDS or with niflumic acid significantly potentiated the above effect of hyposmotic superfusion. These results suggest that volume-sensitive outwardly rectifying chloride current (ICl) is present in guinea-pig gastric myocyte and the ICl may play a role in smooth muscle cell volume regulation.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

PubMed2004

Selective increase in pinolenic acid (all-cis-5,9,12-18:3) in Korean pine nut oil by crystallization and its effect on LDL-receptor activity.

The aims of this study were to obtain concentrated pinolenic acid (5,9,12-18:3) from dietary Korean pine (Pinus koraiensis) nut oil by urea complexation and to investigate its cholesterol-lowering effect on the LDL-receptor activity of human hepatoma HepG2 cells. Pine nut oil was hydrolyzed to provide a low-pinolenic acid-containing FA extract (LPAFAE), followed by crystallization with different ratios of urea in ethanol (EtOH) or methanol (MeOH) as a solvent to produce a high-pinolenic acid-containing FA extract (HPAFAE). The profiles of HPAFAE obtained by urea complexation showed different FA compositions compared with LPAFAE. The long-chain saturated FA palmitic acid (16:0) and stearic acid (18:0) were decreased with urea/FA ratios (UFR) of 1:1 (UFR1), 2:1 (UFR2), and 3:1 (UFR3). Linoleic acid (9,12-18:2) was increased 1.3 times with UFR2 in EtOH, and linolenic acid (9,12,15-18:3) was increased 1.5 times with UFR3 in MeOH after crystallization. The crystallization with UFR3 in EtOH provided the highest concentration of pinolenic acid, which was elevated by 3.2-fold from 14.1 to 45.1%, whereas that of linoleic acid (9,12-18:2) was not changed, and that of oleic acid (9-18:1) was decreased 7.2-fold. Treatment of HepG2 cells with HPAFE resulted in significantly higher internalization of 3,3'-dioctadecylindocarbocyanine-LDL (47.0 +/- 0.15) as compared with treatment with LPAFAE (25.6 +/- 0.36) (P< 0.05). Thus, we demonstrate a method for the concentration of pinolenic acid and suggest that this concentrate may have LDL-lowering properties by enhancing hepatic LDL uptake.

Animals↗

PubMed1987

Iron-binding lipids of rabbit duodenal brush-border membrane.

Rabbit duodenal brush-border membrane contains chloroform/methanol (2:1, v/v) extractable Fe-binding lipids (27.2 +/- 6.7 nmol/mg protein, mean +/- S.E. (n = 5)). Thin-layer chromatography in two solvent systems reveals that the major Fe-binding component(s) co-migrate with free fatty acids. Fe-binding by pure lipids reveals that phosphatidic acid, phosphatidylserine, oleic and stearic acids all show apparent Fe-binding in filtration assays, although oleic acid shows the highest apparent binding (5-10-fold) on a molar basis. The free fatty acid content of brush-border membrane vesicles is sufficient to account for the chloroform/methanol extractable Fe-binding observed in vesicle preparations. The pH dependence of Fe-binding by oleic acid is similar to that reported for the detergent extractable Fe-binding lipid which has been implicated in transport of Fe from Fe/ascorbate solutions by rabbit duodenal brush-border membrane vesicles (Simpson, R.J. and Peters, T.J. (1986) Biochim. Biophys. Acta 859, 227-236).

Animals↗

PubMed1987

Quinidine and melittin both decrease the fluidity of liver plasma membranes and both inhibit hormone-stimulated adenylate cyclase activity.

Increasing concentrations of either quinidine or melittin gave a dose-dependent inhibition of both the glucagon- and fluoride-stimulated activities of adenylate cyclase in the liver plasma membranes. At similar concentrations these agents increased the order of liver plasma membranes as detected by a fatty acid ESR probe, doxyl stearic acid. This increase in bilayer order (decrease in 'fluidity') is suggested to explain the inhibitory action of quinidine on adenylate cyclase activity but only in part contributes to the inhibitory action of melittin on adenylate cyclase. Arrhenius plots of fluoride-stimulated activity became non-linear in the presence of either quinidine or melittin, with a single well-defined break occurring at around 12 degrees C in each instance. Arrhenius plots of the glucagon-stimulated activity also exhibited such a novel break at around 12 degrees C when either quinidine or melittin were present as well as exhibiting a break at around 28 degrees C, as was seen in the absence of these ligands. The fatty acid spin probe inserted into liver plasma membranes detected a novel lipid phase separation occurring at around 12 degrees C when either quinidine or melittin was present and showed that the lipid phase separation occurring at around 28 degrees C in native membranes was apparently unaffected by these ligands.

Adenylyl Cyclases↗

PubMed1994

Behaviour of complex oligosaccharides at a bilayer membrane surface: probed by 2H-NMR.

Deuterium wideline NMR was used in an attempt to directly assess oligosaccharide arrangement and motional characteristics of complex glycosphingolipids dispersed as minor components in phospholipid membranes. A convenient, general synthetic approach was developed which involved replacement of the acetate group of amido sugars with deuteroacetate (-COCD3). This provided excellent signal-to-noise when applied to the terminal GalNAc residue of globoside, and the terminal NANA residue of GM1. Simultaneously, globoside and GM1 fatty acids were replaced with stearic acid deuterated at C-2- a probe location sensitive to glycolipid hydrophobic backbone orientation and rigid body motion. Deuterated GM1 and globoside were studied by 2H-NMR in bilayers of 1-palmitoyl-2-oleoyl phosphatidylcholine, in the presence and absence of physiological quantities of cholesterol. The monoglycosyl glycosphingolipid, glucosyl ceramide, which is the common skeleton of many complex glycosphingolipids including those studied here, was also deuterated at fatty acid C-2 for comparative study in the same matrices. Correlation with spectra of the complex glycolipids demonstrated that, for a given temperature and membrane composition, ceramide backbone conformation was very similar amongst the species studied. Spectral features of GM1 deuterated on terminal NANA and assembled at a membrane surface, were found to be highly consistent with the oligosaccharide conformation determined in studies of GM1 in solution. In contrast, globoside deuterated in the terminal GalNAc residue gave spectra very different from those predicted on the basis of the conformation considered to exist in solution. It seems likely that this result reflects a combination of greater oligosaccharide chain flexibility relative to GM1, and the presence of the membrane environment. Interestingly, although there was highly significant spatial geometry associated with the complex oligosaccharide chains, and although temperature and the presence of cholesterol exert measurable effects on the membrane-inserted portion, these factors had very little impact on the measured spectral parameters associated with the NANA residue of GM1 or the terminal GalNAc residue of globoside. This seems to indicate lack of sensitivity of the complex oligosaccharide chains to conformation and internal motions of the hydrophobic chain segments in these fluid and semi-fluid membranes; and has important implications for mechanisms of crypticity.

Carbohydrate Sequence↗

PubMed1977

Some characteristics of soluble fatty acid synthesis in germinating pea seeds.

Soluble fractions from germinating pea synthesize palmitic acid de novo and stearic acid by elongation. Malonyl CoA, acyl carrier protein and NADPH are required for both reactions. In contrast to some other plant systems, no requirement was found for divalent cations. On the other hand, the formation of both stearate and palmitate was inhibited by sulphydryl reagents and palmitate elongation was sensitive to arsenite. The products of the reactions were examined and found to be principally acyl-acyl carrier proteins and unesterified fatty acids. Unlike the pea microsomal fractions, the soluble enzymes are stimulated only slightly by the addition of exogenous lipids. The substrate for palmitate elongation is palmitoylacyl carrier protein, which is quantitatively elongated to stearate. Comparisons are made with membrane-localised fatty acid synthesis from the same tissue.

Arsenic↗