Rapid, sensitive fluorometric determination of serum triglyceride by measuring lipase-liberated fatty acids

1994 ◽  
Vol 40 (1) ◽  
pp. 14-17 ◽  
Author(s):  
J E Voysey ◽  
D C Wilton
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Serum Triglyceride ◽  
Time Interval ◽  
Serum Samples ◽  
Fluorescence Change ◽  
Displacement Assay ◽  
Catalyzed Reactions ◽  
Hydrolysis Of

Abstract A continuous fluorescence displacement assay was developed for the measurement of long-chain fatty acids and utilized in the study of triglyceride lipase-catalyzed reactions (Wilton, DC. Biochem J 1991;276:129-33). We now describe a method for the rapid measurement of triglyceride in serum with the fluorescence displacement assay. The method involves the hydrolysis of a diluted sample equivalent to 0.1 microL of original serum with excess lipase (EC 3.1.1.3) from Rhizopus arrhizus and measuring the fatty acid released after a set time interval, normally 1 min. Under the conditions of the timed assay, about 2 mol of fatty acid are released per mole of triglyceride. The released fatty acid is monitored by fluorescence change and is proportional to the concentration of triglyceride in the original serum sample. The effective range of serum triglyceride concentration that could be measured was 0.5-10 mmol/L (0.44-8.8 g/L), based on triolein standard. The assay is unique in that it measures lipase-liberated fatty acids rather than liberated glycerol and as such is not subject to many of the criticisms of the glycerol-based methods. Comparison of fasted serum samples established a high correlation between the fatty acid and glycerol methods.

scholarly journals The reaction of phosphoglycolipids and other lipids with hydrofluoric acid

1974 ◽  
Vol 143 (2) ◽  
pp. 461-464 ◽  
Author(s):  
N. Shaw ◽  
A. Stead
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Structure Determination ◽  
Hydrofluoric Acid ◽  
Good Yield ◽  
Glycosidic Linkage ◽  
Cyclopropane Fatty Acids ◽  
Hydrolysis Of

1. The use of HF as a dephosphorylating reagent for phospholipids was examined. 2. Hydrolysis of phosphatidylethanolamine at 0°C for 24h with 60% HF gives a good yield of diglyceride. Under similar conditions phosphatidyldiglucosyl diglyceride gives diglyceride and diglucosyl diglyceride. 3. The glycolipid is also obtained from hydrolysis of glycerylphosphoryldiglucosyl diglyceride. No lyso derivative of the glycolipid could be detected and the glycosidic linkage was also stable. 4. Triglycerides, unsaturated and cyclopropane fatty acids were unaffected by the reagent. 5. 1,2-Diglycerides and 1,3-diglycerides were partially isomerized and also gave small amounts of free fatty acid and monoglyceride. 6. Monoglycerides underwent extensive rearrangement to form 1,2- and 1,3-diglycerides. 7. Lysophosphatidylethanolamine also gave 1,2- and 1,3-diglycerides as well as monoglycerides. 8. The application of this procedure to the structure determination of various phosphoglycolipids is discussed.

scholarly journals A continuous fluorescence displacement assay for the measurement of phospholipase A2 and other lipases that release long-chain fatty acids

1990 ◽  
Vol 266 (2) ◽  
pp. 435-439 ◽  
Author(s):  
D C Wilton
Keyword(s):  
Fatty Acids ◽  
Enzyme Activity ◽  
Fatty Acid ◽  
Phospholipase A2 ◽  
Long Chain Fatty Acids ◽  
Fatty Acid Binding ◽  
Displacement Assay ◽  
Hydrolysis Of ◽  
Long Chain ◽  
Chain Fatty Acids

1. A new continuous fluorescence assay for phospholipase A2 is described which involves the displacement of the highly fluorescent fatty-acid probe 11-(dansylamino)undecanoic acid from rat liver fatty-acid-binding protein by long-chain fatty acids released as a result of phospholipase A2-catalysed hydrolysis of phospholipids. The initial rate of decrease in fluorescence is linearly related to enzyme activity. 2. The assay will detect enzyme activity down to about 10 pmol/min per ml and gives a linear response up to about 10 nmol/min per ml. 3. The assay will work with all phospholipids that have been tested including phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol and phosphatidylglycerol. Substrates carrying a net negative charge showed the highest rates of hydrolysis. 4. The assay will work, in principle, with an enzyme catalysing the release of long-chain fatty acids from a fatty-acylated substrate. This has been confirmed with pancreatic lipase and cholesterol esterase.

In vivo study of the biosynthesis of long-chain fatty acids using deuterated water

1995 ◽  
Vol 269 (2) ◽  
pp. E247-E252 ◽  
Author(s):  
H. O. Ajie ◽  
M. J. Connor ◽  
W. N. Lee ◽  
S. Bassilian ◽  
E. A. Bergner ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
De Novo ◽  
Chain Elongation ◽  
Deuterated Water ◽  
De Novo Synthesis ◽  
Isotopomer Distribution ◽  
Long Chain ◽  
Mass Isotopomer

To determine the contributions of preexisting fatty acid, de novo synthesis, and chain elongation in long-chain fatty acid (LCFA) synthesis, the synthesis of LCFAs, palmitate (16:0), stearate (18:0), arachidate (20:0), behenate (22:0), and lignocerate (24:0), in the epidermis, liver, and spinal cord was determined using deuterated water and mass isotopomer distribution analysis in hairless mice and Sprague-Dawley rats. Animals were given 4% deuterated water for 5 days or 8 wk in their drinking water. Blood was withdrawn at the end of these times for the determination of deuterium enrichment, and the animals were killed to isolate the various tissues for lipid extraction for the determination of the mass isotopomer distributions. The mass isotopomer distributions in LCFA were incompatible with synthesis from a single pool of primer. The synthesis of palmitate, stearate, arachidate, behenate, and lignocerate followed the expected biochemical pathways for the synthesis of LCFAs. On average, three deuterium atoms were incorporated for every addition of an acetyl unit. The isotopomer distribution resulting from chain elongation and de novo synthesis can be described by the linear combination of two binomial distributions. The proportions of preexisting, chain elongation, and de novo-synthesized fatty acids as a percentage of the total fatty acids were determined using multiple linear regression analysis. Fractional synthesis was found to vary, depending on the tissue type and the fatty acid, from 47 to 87%. A substantial fraction (24-40%) of the newly synthesized molecules was derived from chain elongation of unlabeled (recycled) palmitate.

scholarly journals Evidence for the regulation of guinea-pig heart microsomal phosphatidylcholine-hydrolysing phospholipase A1 by guanosine 5′-[γ-thio]triphosphate

1992 ◽  
Vol 288 (3) ◽  
pp. 965-968 ◽  
Author(s):  
K Badiani ◽  
X Lu ◽  
G Arthur
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Guinea Pig ◽  
Molecular Species ◽  
Inhibitory Effect ◽  
Phospholipase A1 ◽  
Guinea Pig Heart ◽  
Substrate Specificities ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

We have recently characterized lysophospholipase A2 activities in guinea-pig heart microsomes and postulated that these enzymes act sequentially with phospholipases A1 to release fatty acids selectively from phosphatidylcholine (PC) and phosphatidylethanolamine, thus providing an alternative route to the phospholipase A2 mode of release. In a further investigation of the postulated pathway, we have characterized the PC-hydrolysing phospholipase A1 in guinea-pig heart microsomes. Our results show that the enzyme may have a preference for substrates with C16:0 over C18:0 at the sn-1 position. In addition, although the enzyme cleaves the sn-1 fatty acid, the rate of hydrolysis of PC substrates with C16:0 at the sn-1 position was influenced by the nature of the fatty acid at the sn-2 position. The order of decreasing preference was C18:2 > C20:4 = C18:1 > C16:0. The hydrolyses of the molecular species were differentially affected by heating at 60 degrees C. An investigation into the effect of nucleotides on the activity of the enzyme showed that guanosine 5′-[gamma-thio]triphosphate (GTP[S]) inhibited the hydrolysis of PC by phospholipase A1 activity, whereas GTP, guanosine 5′-[beta-thio]diphosphate (GDP[S]), GDP, ATP and adenosine 5′-[gamma-thio]triphosphate (ATP[S]) did not affect the activity. The inhibitory effect of GTP[S] on phospholipase A1 activity was blocked by preincubation with GDP[S]. A differential effect of GTP[S] on the hydrolysis of different molecular species was also observed. Taken together, the results of this study suggest the presence of more than one phospholipase A1 in the microsomes with different substrate specificities, which act sequentially with lysophospholipase A2 to release linoleic or arachidonic acid selectively from PC under resting conditions. Upon stimulation and activation of the G-protein, the release of fatty acids would be inhibited.

Rapid in vivo hydrolysis of fatty acid ethyl esters, toxic nonoxidative ethanol metabolites

1997 ◽  
Vol 273 (1) ◽  
pp. G184-G190 ◽  
Author(s):  
M. Saghir ◽  
J. Werner ◽  
M. Laposata
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Fatty Acid Ethyl Esters ◽  
Ethyl Esters ◽  
Ethanol Ingestion ◽  
Gi Tract ◽  
Apparent Lack ◽  
Hydrolysis Of

Fatty acid ethyl esters (FAEE), esterification products of fatty acids and ethanol, are in use as fatty acid supplements, but they also have been implicated as toxic mediators of ethanol ingestion. We hypothesized that hydrolysis of orally ingested FAEE occurs in the gastrointestinal (GI) tract and in the blood to explain their apparent lack of toxicity. To study the in vivo inactivation of FAEE by hydrolysis to free fatty acids and ethanol, we assessed the hydrolysis of FAEE administered as an oil directly into the rat stomach and when injected within the core of low-density lipoprotein particles into the circulation of rats. Our studies demonstrate that FAEE are rapidly degraded to free fatty acids and ethanol in the GI tract at the level of the duodenum with limited hydrolysis in the stomach. In addition, FAEE are rapidly degraded in the circulation, with a half-life of only 58 s. Thus the degradation of FAEE in the GI tract and in the blood provides an explanation for the apparent lack of toxicity of orally ingested FAEE.

scholarly journals Fatty acid composition of night-scented stock (Matthiola bicornis (Sibth. & Sm.) DC.) raw materials

2021 ◽  
Vol 34 (1) ◽  
pp. 34-41
Author(s):  
Viktoriia O. Pinkevych ◽  
Moeen F. Dababneh ◽  
Nadiia Ye. Burda ◽  
Iryna O. Zhuravel
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Acid Composition ◽  
Raw Materials ◽  
Similar Fatty Acid Composition ◽  
Domestic Plant ◽  
Plant Sources

Abstract Introduction. With due consideration of the properties of fatty acids, as well as their importance for normal life activity and human development, research into the fatty acid composition of poorly studied plants and the search for new domestic plant sources of polyunsaturated fatty acids is a mainstream trend in modern pharmacy. Aim. Aim of research – determination of fatty acid qualitative composition and content in threshed grass, stalks, roots and seeds of Night-scented stock ‘Queen of Night’ and ‘Evening Scent’ cultivars as grown in Ukraine. Methods. Gas chromatography. Results. Both cultivars of Night-scented stock taken for analysis had similar fatty acid composition – 5 saturated, 5 (4 for seeds) monounsaturated and 2 polyunsaturated fatty acids, Quantitatively, in all tested parts of the herb polyunsaturated and monounsaturated fatty acid dominated, making in total 88.92% and 88.62% in the seeds of Queen of Night and Evening Scent cultivars, respectively, and averaging 65% in other parts of the tested cultivars. Linolenic and linoleic acids prevailed among the polyunsaturated fatty acids, whereas oleic acid prevailed among the monounsaturated. Conclusion. Night-scented stock can be utilized as a source of polyunsaturated fatty acids for the development of drugs and for standardization of tested raw materials.

Lipids of the fin whale (Balaenoptera physalus) from North Atlantic waters. IV. Fin whale milk

1968 ◽  
Vol 46 (3) ◽  
pp. 197-203 ◽  
Author(s):  
R. G. Ackman ◽  
C. A. Eaton ◽  
S. N. Hooper
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Total Lipid ◽  
Iodine Value ◽  
North Atlantic ◽  
Methyl Esters ◽  
Short Chain Fatty Acids ◽  
Fin Whale ◽  
Hydrolysis Of

Fatty acid compositions were determined for total lipid (17.5% of the milk and > 95% triglycerides), 2-monoglyceride obtained by enzymatic hydrolysis of isolated triglyceride, and isolated phospholipid (~1% of total lipids). The total lipid fatty acids of the milk had a composition similar to fin whale depot fat but were enriched in hexadecanoic acid and polyunsaturated fatty acids at the expense of monoethylenic acids; correspondingly the iodine value of 136 (methyl esters) was higher than the normal range (105–120) of North Atlantic fin whale blubber oils. Over 80% of the fatty acids in the 2-position of the triglycerides were accounted for by relatively short chain fatty acids, especially hexadecanoic (54.6%), tetradecanoic (13.7%), and hexadecenoic (11.2%), so that the ester iodine value was only 48. The milk phospholipids had a fatty acid composition basically similar to that of liver phospholipids (methyl ester iodine value 120) with somewhat more polyunsaturated fatty acids and accordingly an iodine value of 144 for methyl esters.

Enzymic colorimetric determination of phosphatidylglycerol in amniotic fluid.

1984 ◽  
Vol 30 (4) ◽  
pp. 534-537 ◽  
Author(s):  
J D Artiss ◽  
M W McGowan ◽  
D R Strandbergh ◽  
E Epstein ◽  
B Zak
Keyword(s):  
Amniotic Fluid ◽  
Fetal Lung ◽  
Aqueous Sample ◽  
Colorimetric Determination ◽  
Glycerol Phosphate ◽  
Ionic Detergent ◽  
Catalyzed Reactions ◽  
Enzyme Catalyzed Reactions ◽  
Hydrolysis Of

Abstract We describe a procedure for the enzymic, colorimetric determination of phosphatidylglycerol in amniotic fluid. After extraction into chloroform:methanol (2:1 by vol) and evaporation, the phospholipid-containing residue is redissolved in a non-ionic detergent, which thus provides an aqueous sample. The subsequent enzymic reaction sequence involves phospholipase-catalyzed hydrolysis of glycerol from its phospholipid. Subsequent enzyme-catalyzed reactions phosphorylate this glycerol and oxidize the resulting glycerol phosphate to produce hydrogen peroxide, which is reacted to produce an intense red chromogen in the peroxidase-catalyzed coupling of 4-aminoantipyrine and 2-hydroxy-3,5-dichlorobenzenesulfonate. When used in conjunction with previously reported enzymic techniques for determination of lecithin and sphingomyelin, this procedure may provide an accurate and precise "lung profile" for assessment of fetal lung maturity.

scholarly journals Characterization of the oils present in acid and fermented silages produced from Tilapia filleting residue

2011 ◽  
Vol 40 (2) ◽  
pp. 240-244 ◽  
Author(s):  
Rose Meire Vidotti ◽  
Maria Teresa Bertoldo Pacheco ◽  
Giovani Sampaio Gonçalves
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Nutritional Value ◽  
Lipid Fraction ◽  
Monounsaturated Fatty Acids ◽  
Degree Of Saturation ◽  
Degree Of Hydrolysis ◽  
Animal Feeding ◽  
Hydrolysis Of

The objective of this study was to determine the quality and composition of fatty acid in the lipid fraction of silages obtained from the residue of tilapia processing. Stratification of the lipid layer of the silages occurred at different times among the two types of silage (acid and fermented) and the greatest volume of oil was observed in acid silage (8.67% p/p). Although acid silage was more oxidized, it showed lower contents of free fatty acids probably because the degree of hydrolysis of its components is lower than that of fermented silage. Fatty acid composition did not differ among processes inasmuch as level of ϖ-3 was slightly higher in fermented silage. According to the degree of saturation, monounsaturated fatty acids stood out as the predominant category in acid and fermented silages with values of 39.69% and 33.39%, respectively. The use of antioxidants in the silage is needed because the process of production is carried out at temperatures higher than room temperature. The oil in the silages has excellent nutritional value and contains fatty acids essential for animal feeding.

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