THE HYDROLYSIS OF MONOPHOSPHOINOSITIDE BY EXTRACTS OF BRAIN

1967 ◽  
Vol 45 (6) ◽  
pp. 853-861 ◽  
Author(s):  
W. Thompson
Keyword(s):  
Fatty Acids ◽  
Enzyme Activity ◽  
Calcium Ions ◽  
Brain Extract ◽  
Monovalent Cations ◽  
High Concentration ◽  
Diffusible Factor ◽  
Hydrolysis Of ◽  
The Brain ◽  
Long Chain

The hydrolysis of monophosphoinositide by soluble extracts from rat brain is described. Diglyceride and inositol monophosphate are liberated along with a small amount of free fatty acids. Hydrolysis of the lipid is optimal at pH 5.4 in acetate buffer. The reaction is stimulated by calcium ions or by high concentration of monovalent cations and, to a less extent, by long-chain cationic amphipathic compounds. Enzyme activity is lost on dialysis of the brain extract and can be restored by diffusible factor(s). Some differences in the conditions for hydrolysis of mono- and tri-phosphoinositides are noted.

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.

scholarly journals Determining the Bioenergetic Capacity for Fatty Acid Oxidation in the Mammalian Nervous System

2020 ◽  
Vol 40 (10) ◽  
Author(s):  
Cory J. White ◽  
Jieun Lee ◽  
Joseph Choi ◽  
Tiffany Chu ◽  
Susanna Scafidi ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Nervous System ◽  
Fatty Acid ◽  
Conditional Knockout ◽  
Mammalian Brain ◽  
Metabolic State ◽  
Peripheral Tissues ◽  
Mitochondrial Fatty Acid ◽  
The Brain ◽  
Long Chain

ABSTRACT The metabolic state of the brain can greatly impact neurologic function. Evidence of this includes the therapeutic benefit of a ketogenic diet in neurologic diseases, including epilepsy. However, brain lipid bioenergetics remain largely uncharacterized. The existence, capacity, and relevance of mitochondrial fatty acid β-oxidation (FAO) in the brain are highly controversial, with few genetic tools available to evaluate the question. We have provided evidence for the capacity of brain FAO using a pan-brain-specific conditional knockout (KO) mouse incapable of FAO due to the loss of carnitine palmitoyltransferase 2, the product of an obligate gene for FAO (CPT2B−/−). Loss of central nervous system (CNS) FAO did not result in gross neuroanatomical changes or systemic differences in metabolism. Loss of CPT2 in the brain did not result in robustly impaired behavior. We demonstrate by unbiased and targeted metabolomics that the mammalian brain oxidizes a substantial quantity of long-chain fatty acids in vitro and in vivo. Loss of CNS FAO results in robust accumulation of long-chain acylcarnitines in the brain, suggesting that the mammalian brain mobilizes fatty acids for their oxidation, irrespective of diet or metabolic state. Together, these data demonstrate that the mammalian brain oxidizes fatty acids under normal circumstances with little influence from or on peripheral tissues.

The effect of long-chain polyunsaturated fatty acid and vitamin E supplementation of ewes on neonatal lamb vigour, lamb growth and colostrum parameters

2002 ◽  
Vol 2002 ◽  
pp. 7-7 ◽  
Author(s):  
J. L. Capper ◽  
R. G. Wilkinson ◽  
L. A. Sinclair ◽  
S. E. Pattinson ◽  
A. M. Mackenzie
Keyword(s):  
Fatty Acids ◽  
Vitamin E ◽  
Chain Polyunsaturated Fatty Acid ◽  
Alpha Linolenic Acid ◽  
Chain Pufa ◽  
Ruminant Diets ◽  
The Brain ◽  
Lamb Growth ◽  
Long Chain ◽  
Vitamin E Supplementation

The long-chain polyunsaturated fatty acids (PUFA) docosahexaenoic acid (DHA) and arachidonic acid (AA) are the most abundant fatty acids in the brain and are vital for its correct development and for that of the nervous system (Huang and Craig-Schmidt, 1996). Ruminant diets are low in DHA and its precursor alpha-linolenic acid. In addition, dietary PUFAs are substantially hydrogenated in the rumen. Consequently, it may be argued that the diets of pregnant and lactating ewes may be deficient in DHA and that a response to supplementation may be observed. Studies involving the supplementation of pregnant ewes with supraoptimal levels of vitamin E have shown that lambs born to supplemented dams are more vigorous immediately after birth and have higher liveweight gains (Merrell, 1998). The objective of this experiment was to investigate the effects of dietary long-chain PUFA in combination with vitamin E supplementation of ewes on ewe and lamb performance.

THE METABOLISM OF THE ERYTHROCYTE: X. THE INORGANIC PYROPHOSPHATASE OF THE ERYTHROCYTE

1956 ◽  
Vol 34 (1) ◽  
pp. 121-129 ◽  
Author(s):  
A. Malkin ◽  
O. F. Denstedt
Keyword(s):  
Enzyme Activity ◽  
Calcium Ions ◽  
Human Erythrocyte ◽  
Inorganic Pyrophosphatase ◽  
Magnesium Ions ◽  
Constant Ratio ◽  
Inorganic Pyrophosphate ◽  
Noncompetitive Inhibitor ◽  
Pyrophosphatase Activity ◽  
Hydrolysis Of

The activity of the pyrophosphatase which catalyzes the hydrolysis of inorganic pyrophosphate in the erythrocyte of the human, the rabbit, and the chicken is confined entirely to the cytoplasm of the cell. Following preincubation, the enzyme activity in the human erythrocyte is diminished, but pre-incubation in the presence of cysteine or glutathione prevents the diminution of the enzyme activity. Aging of the hemolyzate of the human erythrocytes results in a marked loss of the inorganic pyrophosphatase activity. The diminished activity can be restored by the addition of cysteine or glutathione to the reaction mixture; but after the hemolyzate has aged for five or six days at 5 °C, the loss in the enzyme activity can no longer be restored with these reagents. Fluoride and calcium ions inhibit the activity of the enzyme, while magnesium ions are essential for its activity. Calcium is a noncompetitive inhibitor, while the inhibition by fluoride is of a "quadratic" nature. If a constant ratio of magnesium to pyrophosphate is maintained, the quadratic inhibition can be converted to the "uncompetitive" type of inhibition.

scholarly journals The occurrence of polyenoic very long chain fatty acids with greater than 32 carbon atoms in molecular species of phosphatidylcholine in normal and peroxisome-deficient (Zellweger's syndrome) brain

1988 ◽  
Vol 253 (3) ◽  
pp. 645-650 ◽  
Author(s):  
A Poulos ◽  
P Sharp ◽  
D Johnson ◽  
C Easton
Keyword(s):  
Fatty Acids ◽  
Molecular Species ◽  
Carbon Chain ◽  
Normal Brain ◽  
Long Chain Fatty Acids ◽  
Brain Physiology ◽  
Chain Lengths ◽  
The Brain ◽  
Long Chain ◽  
Chain Fatty Acids

The n-6 tetra- and pentaenoic fatty acids with carbon chain lengths greater than 32 found in normal brain are located predominantly in a separable species of phosphatidylcholine. A similar phospholipid is found in increased amounts in the brain of peroxisome-deficient (Zellweger's syndrome) patients, but the fatty acid composition differs in that penta- and hexaenoic derivatives predominate. Our data strongly suggest that the polyenoic very long chain fatty acids are confined to the sn-1 position of the glycerol moiety, while the sn-2 position is enriched in saturated, monounsaturated and polyunsaturated fatty acids with less than 24 carbon atoms. It is postulated that these unusual molecular species of phosphatidylcholine may play some, as yet undefined, role in brain physiology.

scholarly journals Lipid remodelling during epididymal maturation of rat spermatozoa. Enrichment in plasmenylcholines containing long-chain polyenoic fatty acids of the n-9 series

1992 ◽  
Vol 283 (1) ◽  
pp. 235-241 ◽  
Author(s):  
M I Aveldaño ◽  
N P Rotstein ◽  
N T Vermouth
Keyword(s):  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Acyl Chain ◽  
Sperm Maturation ◽  
High Concentration ◽  
Lipid Domain ◽  
Choline Glycerophospholipids ◽  
Epididymal Maturation ◽  
Acyl Chains ◽  
Long Chain

In their transit from the caput to the cauda segments of the epididymis, rat spermatozoa undergo significant modifications in lipid content and composition. The amount of lipid phosphorus per cell decreases, and most lipid classes show specific changes in their constituent fatty acids. A depletion of phosphatidylcholine and phosphatidylethanolamine, concomitant with a virtually unchanged amount of the corresponding plasmalogens, are the major alterations, plasmenylcholine thereby becoming the major phospholipid. Diphosphatidylglycerol, sphingomyelin and the phosphoinositides decrease to a lesser extent or do not change at all, also resulting in relative increases with sperm maturation. Concerning the fatty acids, the proportions of oleate (C18:1, n-9) and linoleate (C18:2, n-6) in most lipids decrease on movement of sperm from caput to cauda, augmenting in turn the proportions of longer-chain (C20 to C24) and more unsaturated fatty acids. Docosapentaenoate (C22:5, n-6) is a major acyl chain present in all lipids at both stages, but uncommon long-chain polyenoic fatty acids of the n-9 series are also present, being almost exclusively found in the choline glycerophospholipids. These fatty acids are found to undergo the most significant changes during sperm maturation. They are minor components of plasmenylcholine in immature spermatozoa, but increase severalfold on maturation, representing more than half of the acyl chains of this major lipid in cells from the cauda. The high concentration of n-9 polyenes in mature sperm plasmenylcholine raises intriguing questions on the possible role epididymal cells may play in providing spermatozoa with such an unusual phospholipid. These plasmenylcholines could contribute to the characteristic lipid domain organization of the mature spermatozoa plasma membrane.

Hydrolysis of long-chain, n-3 fatty acid enriched chylomicrons by cardiac lipoprotein lipase

1999 ◽  
Vol 77 (10) ◽  
pp. 813-818 ◽  
Author(s):  
Ryna Levy ◽  
Gene R Herzberg
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Docosahexaenoic Acid ◽  
Stearic Acid ◽  
Eicosapentaenoic Acid ◽  
Free Fatty Acids ◽  
Lipoprotein Lipase ◽  
Alpha Linolenic Acid ◽  
Hydrolysis Of ◽  
Long Chain

The hydrolysis of chylomicrons enriched in long-chain n-3 fatty acids by cardiac lipoprotein lipase was studied. In 60 min, 24.8% of the triacylglycerol fatty acids were released as free fatty acids. The fatty acids were hydrolyzed at different rates. DHA (docosahexaenoic acid, 22:6n-3) and EPA (eicosapentaenoic acid, 20:5n-3) were released at rates significantly less than average. Stearic acid (18:0), 20:1n-9, and alpha-linolenic acid (18:3n-3) were released significantly faster than average. There was no relationship between the rate of release of a fatty acid and the number of carbons or the number of double bonds. Lipoprotein lipase selectively hydrolyzes the fatty acids of chylomicron triacylglycerols. This selectively will result in remnants that are relatively depleted in 18:0, 20:1, and 18:3 and relatively enriched in 20:5 and 22:6.Key words: lipoprotein lipase, chylomicrons, fish oil, eicosapentaenoic acid, docosahexaenoic acid.

Metabolic syndrome: a brain disease

2012 ◽  
Vol 90 (9) ◽  
pp. 1171-1183 ◽  
Author(s):  
Ram B. Singh ◽  
Siddharth Gupta ◽  
Parinita Dherange ◽  
Fabien De Meester ◽  
Agnieszka Wilczynska ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Fatty Acids ◽  
Inflammatory Cytokines ◽  
Arcuate Nucleus ◽  
Fetal Life ◽  
Membrane Phospholipids ◽  
Medline Search ◽  
Chain Pufa ◽  
The Brain ◽  
Long Chain

Recent research indicates an association between brain dysfunction and the pathogenesis of metabolic syndrome. To investigate this, we created a Medline search (up to December 2011) of articles in PubMed. The results indicated that refined carbohydrates, saturated and total fat, high levels of ω-6 fatty acids, and low levels of ω-3 fatty acids and other long chain polyunsaturated fatty acids (PUFA), all in conjunction with sedentary behaviour and mental stress can predispose to inflammation. Increased sympathetic activity, with increased secretion of catecholamine, cortisol, and serotonin can cause oxidative stress, which may damage the arcuate nucleus as well as the hypothalamus and macrophages, and the liver may release pro-inflammatory cytokines. These, in conjunction with an underlying deficiency in long chain PUFA, may damage the arcuate nucleus as well as neuropeptide-Y and pro-opiomelanocortin neurons and insulin receptors in the brain, especially during fetal life, infancy, and childhood, resulting in their dysfunction. Of the fatty acids in the brain, 30%–50% are long chain PUFA, which are incorporated in the cell membrane phospholipids. Hence, ω-3 fatty acids, which are also known to enhance parasympathetic activity and increase the secretion of anti-inflammatory cytokines interleukin (IL)-4 and IL-10 as well as acetylcholine in the hippocampus, may be protective. Therefore, treatment with ω-3 fatty acids may be applied for the prevention of metabolic syndrome.

scholarly journals A continuous fluorescence-displacement assay for triacylglycerol lipase and phospholipase C that also allows the measurement of acylglycerols

1991 ◽  
Vol 276 (1) ◽  
pp. 129-133 ◽  
Author(s):  
D C Wilton
Keyword(s):  
Fatty Acids ◽  
Enzyme Activity ◽  
Fatty Acid ◽  
Phospholipase C ◽  
Initial Rate ◽  
Long Chain Fatty Acids ◽  
Triacylglycerol Lipase ◽  
Displacement Assay ◽  
Long Chain ◽  
Chain Fatty Acids

A new continuous fluorescence-displacement assay for enzymes that release long-chain fatty acids [Wilton (1990) Biochem. J. 266, 435-439] is described in detail for pig pancreatic triacylglycerol lipase. The assay 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 enzyme activity. The assay is surprisingly effective for triacylglycerol lipase, allowing the expression of full activity with low concentrations of substrates in the absence of detergents. The initial rate of decrease in fluorescence is linearly related to enzyme concentration, and activity can be detected in the assay down to concentrations of 10 pg of pure enzyme/ml. The assays demonstrated the quantitative conversion of limiting amounts of substrate into the monacylglycerol. This observation allowed the assay to be used to measure substrates such as triacylglycerols and particularly 1,2-diacylglycerols at concentrations down to about 0.1 microM. Because phospholipase C releases 1,2-diacylglycerols, the coupling of this enzyme to excess lipase allowed the measurement of pure phospholipase C from Bacillus cereus at concentrations down to about 2 ng/ml, and the initial rate of fall in fluorescence in the assay was linearly related to enzyme activity.

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