Acylation of lysophosphatidylcholine in liver microsomes of thermally acclimated trout

1988 ◽  
Vol 255 (6) ◽  
pp. R923-R928
Author(s):  
R. C. Livermore ◽  
J. R. Hazel
Keyword(s):  
Fatty Acids ◽  
Chain Length ◽  
Liver Microsomes ◽  
Salmo Gairdneri ◽  
Acclimation Temperature ◽  
Membrane Phospholipids ◽  
Degree Of Unsaturation ◽  
Acyl Coenzyme A ◽  
Docasahexaenoic Acid ◽  
Substrate Concentrations

The specificity of acyl-coenzyme A (CoA): lysophosphatidylcholine acyltransferase (LPCAT; EC 2.3.1.23) was determined for a range for acyl-CoA substrates differing with respect to chain length and degree of unsaturation in liver microsomes of thermally acclimated (5 and 20 degrees C) rainbow trout, Salmo gairdneri. Absolute levels of oleate incorporation into phosphatidylcholine (PC) were determined at substrate concentrations in the physiological range (12 microM) and higher (64 microM). The specificity of LPCAT was determined by the extent to which competing substrates decreased the incorporation of oleate. LPCAT specificity was significantly influenced by both assay and acclimation temperature at total substrate concentrations of both 72 and 256 microM. A clear preference for 14- and 16-carbon monoenes was exhibited by LPCAT from 20 but not 5 degrees C-acclimated trout. Furthermore, LPCAT from 5 degrees C-acclimated trout preferentially incorporated long chain and polyunsaturated fatty acids (eicosadienoyl, arachidonoyl, erucoyl) and excluded 18-carbon unsaturates at an assay temperature of 5 degrees C compared with 20 degrees C; at 20 degrees C, 18-carbon unsaturates were incorporated more readily than 20-carbon species. Linolenic acid (18:3N3) was generally excluded from incorporation, reflecting a possible mechanism by which this precursor of docasahexaenoic acid (22:6N3, n - 3) remains available for modification. These results indicate that trout liver LPCAT preferentially incorporates fatty acids into PC on the basis of both chain length and degree of unsaturation in a manner consistent with the temperature-induced restructuring of membrane phospholipids.

scholarly journals Effect of fatty acid chain length and saturation on the gastrointestinal handling and metabolic disposal of dietary fatty acids in women

1999 ◽  
Vol 81 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Amanda E. Jones ◽  
Michael Stolinski ◽  
Ruth D. Smith ◽  
Jane L. Murphy ◽  
Stephen A. Wootton
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Chain Length ◽  
Time Course ◽  
Absorbed Dose ◽  
Dietary Fatty Acids ◽  
Fatty Acid Chain ◽  
Degree Of Unsaturation

The gastrointestinal handling and metabolic disposal of [1-13C]palmitic acid, [1-13C]stearic acid and [1-13C]oleic acid administered within a lipid–casein–glucose–sucrose emulsion were examined in normal healthy women by determining both the amount and nature of the13C label in stool and label excreted on breath as13CO2. The greatest excretion of13C label in stool was in the stearic acid trial (9.2 % of administered dose) whilst comparatively little label was observed in stool in either the palmitic acid (1.2 % of administered dose) or oleic acid (1.9 % of administered dose) trials. In both the palmitic acid and oleic acid trials, all of the label in stool was identified as being present in the form in which it was administered (i.e. [13C]palmitic acid in the palmitic acid trial and [13C]oleic acid in the oleic acid trial). In contrast, only 87 % of the label in the stool in the stearic acid trial was identified as [13C]stearic acid, the remainder was identified as [13C]palmitic acid which may reflect chain shortening of [1-13C]stearic acid within the gastrointestinal tract. Small, but statistically significant, differences were observed in the time course of recovery of13C label on breath over the initial 9 h of the study period (oleic acid = palmitic acid > stearic acid). However, when calculated over the 24 h study period, the recovery of the label as13CO2was similar in all three trials (approximately 25 % of absorbed dose). These results support the view that chain length and degree of unsaturation may influence the gastrointestinal handling and immediate metabolic disposal of these fatty acids even when presented within an emulsion.

FATTY ACID INHIBITION OF CHOLESTEROL SYNTHESIS

1956 ◽  
Vol 34 (1) ◽  
pp. 861-868 ◽  
Author(s):  
J. D. Wood ◽  
B. B. Migicovsky
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Length ◽  
Rat Liver ◽  
Cholesterol Synthesis ◽  
Rapid Decrease ◽  
Acid Inhibition ◽  
Degree Of Unsaturation ◽  
Liver Homogenates ◽  
Fatty Acid Inhibition

Fatty acids inhibit cholesterol synthesis by rat liver homogenates. Inhibition occurs with acids containing either an even or an odd number of carbon atoms in the chain, and with saturated and unsaturated acids, the inhibition increasing with the degree of unsaturation of the acid. In the case of acids with an even number of carbon atoms the inhibition increases with chain length to a maximum at 12 carbons after which a rapid decrease occurs. The presence of fatty acid during cholesterol synthesis increases the acetate incorporated into fatty acids to a slight extent. This increase is small compared with the decrease in the amount incorporated into cholesterol. A possible mechanism for the inhibition is discussed.

FATTY ACID INHIBITION OF CHOLESTEROL SYNTHESIS

1956 ◽  
Vol 34 (5) ◽  
pp. 861-868 ◽  
Author(s):  
J. D. Wood ◽  
B. B. Migicovsky
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Length ◽  
Rat Liver ◽  
Cholesterol Synthesis ◽  
Rapid Decrease ◽  
Acid Inhibition ◽  
Degree Of Unsaturation ◽  
Liver Homogenates ◽  
Fatty Acid Inhibition

Fatty acids inhibit cholesterol synthesis by rat liver homogenates. Inhibition occurs with acids containing either an even or an odd number of carbon atoms in the chain, and with saturated and unsaturated acids, the inhibition increasing with the degree of unsaturation of the acid. In the case of acids with an even number of carbon atoms the inhibition increases with chain length to a maximum at 12 carbons after which a rapid decrease occurs. The presence of fatty acid during cholesterol synthesis increases the acetate incorporated into fatty acids to a slight extent. This increase is small compared with the decrease in the amount incorporated into cholesterol. A possible mechanism for the inhibition is discussed.

THE FERMENTATION OF LONG-CHAIN COMPOUNDS BY TORULOPSIS MAGNOLIAE: I. STRUCTURES OF THE HYDROXY FATTY ACIDS OBTAINED BY THE FERMENTATION OF FATTY ACIDS AND HYDROCARBONS

1962 ◽  
Vol 40 (7) ◽  
pp. 1326-1338 ◽  
Author(s):  
A. P. Tulloch ◽  
J. F. T. Spencer ◽  
P. A. J. Gorin
Keyword(s):  
Fatty Acids ◽  
Carbon Atom ◽  
Chain Length ◽  
Hydroxy Fatty Acid ◽  
Hydroxyl Group ◽  
Fatty Esters ◽  
Degree Of Unsaturation ◽  
Chain Compounds ◽  
Chain Lengths ◽  
Long Chain

The yield of extracellular glycolipid produced by Torulopsis magnoliae is increased three-to five-fold by the addition of suitable compounds to the growing culture. The supplement, which can be a long-chain acid, ester, hydrocarbon, or glyceride, is hydroxylated and converted to hydroxy fatty acid sophorosides. Fatty esters of all chain lengths from C16 to C22, including several unsaturated esters, and even-numbered hydrocarbons from C16 to C24 are readily fermented. Shorter-chain compounds are used poorly or not at all. With compounds of 16 to 18 carbon atoms, hydroxylation occurs at the terminal or penultimate carbon atom, depending on degree of unsaturation and chain length. Substrates of more than 18 carbon atoms are mainly reduced in chain length by one or more two-carbon units and hydroxylated, giving C17 or C18 acids with the hydroxyl group on the penultimate carbon atom. The various enzymic reactions which occur during the fermentation are discussed.

Influence of thermal acclimation on membrane lipid composition of rainbow trout liver

1979 ◽  
Vol 236 (1) ◽  
pp. R91-R101 ◽  
Author(s):  
J. R. Hazel
Keyword(s):  
Fatty Acids ◽  
Rainbow Trout ◽  
Polyunsaturated Fatty Acids ◽  
Cold Acclimation ◽  
Saturated Fatty Acids ◽  
Total Content ◽  
Membrane Lipid ◽  
Salmo Gairdneri ◽  
Acclimation Temperature ◽  
Induced Changes

Rainbow trout (Salmo gairdneri) acclimated to 5 degrees C possessed larger livers and less neutral lipid per gram of liver than 20 degrees C-acclimated animals; quantities of liver glycolipid, phospholipid, and cholesterol did not vary significantly with acclimation temperature. The relative proportions of phosphatidylethanolamine increased significantly following cold exposure, whereas the quantities of sphingomyelin and cardiolipin declined. For all phosphatides examined (phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, lysolecithin, cardiolipin, sphingomyelin) cold acclimation resulted in 1) an increase in the quantity of polyunsaturated fatty acids, 2) a reduction in the level of saturated fatty acids, and 3) little change in the total content of monoenes and dienes. The increased content of polyunsaturated fatty acids in choline and ethanolamine phosphatides following cold acclimation was confined to the 2-position and occurred at the expense of monoenes and dienes. The relative proportions of n - 3 fatty acids, and less frequently n - 6 fatty acids, increased in phosphatides of cold-acclimated trout, whereas the relative proportions of n - 9 fatty acids declined. These data suggest a preferential incorporation of fatty acids belonging to the linolenic acid family at reduced temperatures. Temperature-induced changes in the chemical composition of trout liver phospholipids counteracted the effects of acute temperature change on nonelectrolyte permeability of isolated liposomes.

scholarly journals Evaluation of Acyl Coenzyme A Oxidase (Aox) Isozyme Function in the n-Alkane-Assimilating YeastYarrowia lipolytica

1999 ◽  
Vol 181 (17) ◽  
pp. 5140-5148 ◽  
Author(s):  
Huijie J. Wang ◽  
Marie-Thérèse Le Dall ◽  
Yves Waché ◽  
Céline Laroche ◽  
Jean-Marc Belin ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Chain Length ◽  
Coenzyme A ◽  
Short Chain Fatty Acids ◽  
Activity Levels ◽  
Chain Acyl ◽  
Acyl Coa Oxidase ◽  
A Chain ◽  
Acyl Coenzyme A ◽  
Chain Lengths

ABSTRACT We have identified five acyl coenzyme A (CoA) oxidase isozymes (Aox1 through Aox5) in the n-alkane-assimilating yeastYarrowia lipolytica, encoded by the POX1through POX5 genes. The physiological function of these oxidases has been investigated by gene disruption. Single, double, triple, and quadruple disruptants were constructed. Global Aox activity was determined as a function of time after induction and of substrate chain length. Single null mutations did not affect growth but affected the chain length preference of acyl-CoA oxidase activity, as evidenced by a chain length specificity for Aox2 and Aox3. Aox2 was shown to be a long-chain acyl-CoA oxidase and Aox3 was found to be active against short-chain fatty acids, whereas Aox5 was active against molecules of all chain lengths. Mutations in Aox4 and Aox5 resulted in an increase in total Aox activity. The growth of mutant strains was analyzed. In the presence of POX1 only, strains did not grow on fatty acids, whereas POX4 alone elicited partial growth, and the growth of the double POX2-POX3-deleted mutant was normal excepted on plates containing oleic acid as the carbon source. The amounts of Aox protein detected by Western blotting paralleled the Aox activity levels, demonstrating the regulation of Aox in cells according to the POX genotype.

Effect of fatty acid structure on esterification by the small intestine in vitro

1963 ◽  
Vol 204 (5) ◽  
pp. 821-824 ◽  
Author(s):  
Alvin M. Gelb ◽  
Jacques I. Kessler
Keyword(s):  
Fatty Acids ◽  
Small Intestine ◽  
Fatty Acid ◽  
Small Bowel ◽  
Chain Length ◽  
Degree Of Unsaturation ◽  
Fatty Acid Structure ◽  
Acid Structure

The effect of chain length and degree of unsaturation of fatty acids (FA) on in vitro esterification by slices of hamster small intestine was observed in a medium containing C14-labeled FA. After incubation, lipids were extracted and separated and the radioactivity in the esterified lipids was measured. Comparative experiments, in which results were expressed as per cent of substrate esterified per 100 mg tissue, indicate that for saturated FA, maximal esterification occurred with myristic acid, 14 carbons. As chain length was either increased or decreased, percentage esterification decreased. FA with 8 carbons or less were only minimally esterified. Among 18-carbon FA, two unsaturated bonds significantly decreased percentage esterification, although one unsaturated bond did not. These results suggest that, at least in vitro, the small bowel esterifies FA at varying rates depending upon chain length and degree of unsaturation. These differences are in the same direction as differences in absorption and partition of FA in vivo previously reported by others.

Sign in / Sign up

Export Citation Format

Share Document