Intestinal microsomes: polyunsaturated fatty acid metabolism and regulation of enterocyte transport properties

1990 ◽  
Vol 68 (5) ◽  
pp. 636-641 ◽  
Author(s):  
M. L. Garg ◽  
M. Keelan ◽  
A. B. R. Thomson ◽  
M. T. Clandinin
Keyword(s):  
Acyl Chain ◽  
Lipid Synthesis ◽  
Fatty Acyl ◽  
Fine Tuning ◽  
Membrane Properties ◽  
Head Group ◽  
Fatty Acyl Chain ◽  
Polar Head Group ◽  
Intestinal Microsomes ◽  
Main Determinants

Recent evidence has suggested that transport of nutrients from the lumen to the interior of the gastrointestinal epithelium and exit of nutrients from the enterocyte to the circulation is governed by physicochemical properties of brush border and basolateral membranes, respectively. The main determinants of membrane properties are phospholipid, cholesterol, and fatty acyl chain composition (chain length and degree of unsaturation). Lipid synthesis occurs in enterocyte microsomes and the fine tuning of lipid composition is done at other subcellular sites by deacylation–reacylation or by changing the polar head group (e.g., by phosphatidylethanolamine methyltransferase). The present paper will focus on the mechanisms by which enterocyte membranes adapt functional properties in response to external stimuli. It is proposed that under the influence of internal or external stress, the enzymes of lipid metabolism in microsomes are modulated. These changes in lipid synthesis are reflected in other subcellular membranes, changing their physicochemical status and thus transport phenomena. One of the initial events appears to be alteration in desaturase enzyme activity. Our results suggest that desaturase activity and the fatty acyl profiles of the intestinal mucosal phospholipid rapidly respond to physiological conditions such as fasting and dietary fat treatment.Key words: polyunsaturated fatty acids, desaturases, enterocyte, intestinal microsomes, adaptation.

scholarly journals Profile of Phosphatidylserine Modifications under Nitroxidative Stress Conditions Using a Liquid Chromatography-Mass Spectrometry Based Approach

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 107 ◽  
Author(s):  
Bruna Neves ◽  
Pedro Domingues ◽  
Maria Oliveira ◽  
Maria Domingues ◽  
Tânia Melo
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Acyl Chain ◽  
Fatty Acyl ◽  
Head Group ◽  
Fatty Acyl Chain ◽  
Polar Head Group ◽  
Derivatives Of

Nitrated lipids have been detected in vitro and in vivo, usually associated with a protective effect. While nitrated fatty acids have been widely studied, few studies reported the nitration and nitroxidation of the phospholipid classes phosphatidylcholine, and phosphatidylethanolamine. However, no information regarding nitrated and nitroxidized phosphatidylserine can be found in the literature. This work aims to identify and characterize the nitrated and nitroxidized derivatives of 1-palmitoyl-2-oleoyl-sn-3-glycero-phosphoserine (POPS), obtained after incubation with nitronium tetrafluoroborate, by liquid chromatography (LC) coupled to mass spectrometry (MS) and tandem MS (MS/MS). Several nitrated and nitroxidized products were identified, namely, nitro, nitroso, nitronitroso, and dinitro derivatives, as well as some nitroxidized species such as nitrosohydroxy, nitrohydroxy, and nitrohydroperoxy. The fragmentation pathways identified were structure-dependent and included the loss of HNO and HNO2 for nitroso and nitro derivatives, respectively. Combined losses of PS polar head group plus HNO or HNO2 and carboxylate anions of modified fatty acyl chain were also observed. The nitrated POPS also showed antiradical potential, demonstrated by the ability to scavenge the ABTS●+ and DPPH● radicals. Overall, this in vitro model of nitration based on LC-MS/MS provided additional insights into the nitrated and nitroxidized derivatives of PS and their fragmentation fingerprinting. This information is a valuable tool for targeted analysis of these modified PS in complex biological samples, to further explore the new clues on the antioxidant potential of nitrated POPS.

Lipid restructuring does not contribute to elevated activities of Na(+)/K(+)-ATPase in basolateral membranes from the gill of seawater-acclimated eel (Anguilla rostrata)

1999 ◽  
Vol 202 (17) ◽  
pp. 2385-2392
Author(s):  
E.L. Crockett
Keyword(s):  
Atpase Activity ◽  
Time Course ◽  
Sea Water ◽  
Acyl Chain ◽  
Fatty Acyl ◽  
Membrane Properties ◽  
Phospholipid Content ◽  
Fatty Acyl Chain ◽  
Anguilla Rostrata ◽  
Basolateral Membranes

In teleost fishes, increases in gill Na(+)/K(+)-ATPase activity accompanying the transition from fresh water to sea water may be attributed to changes in either the numbers of enzyme molecules present or to turnover number (k(cat)). The sensitivity of Na(+)/K(+)-ATPase to its chemical/physical environment in the membrane makes it plausible that modulation of enzyme activity may be driven, in part, by changes in membrane properties. In the current study, I test the hypothesis that lipid compositional changes (restructuring) contribute to the modulation of gill Na(+)/K(+)-ATPase activity. An enriched preparation of basolateral membranes was prepared from the gills of freshwater- and seawater-acclimated American eel (Anguilla rostrata). Phospholipid class distribution, fatty acyl chain compositions and cholesterol contents were determined. Phosphatidylcholine, the most abundant phospholipid present in gill basolateral membranes, makes up more than 60 % of the total phospholipid content in both freshwater- and seawater-acclimated animals. The contents of other phospholipids and major fatty acyl chains are also similar for the two acclimation groups. Cholesterol/phospholipid molar ratios are 0.28 for freshwater and 0.29 for seawater animals. The similarity between lipid compositions in membranes from freshwater- and seawater-acclimated eels indicates that lipid restructuring is not a mechanism for modulation of gill Na(+)/K(+)-ATPase activity in Anguilla rostrata, at least during the acclimation time course used in the present study.

Uncoupling of cardiac cells by doxyl stearic acids specificity and mechanism of action

1989 ◽  
Vol 256 (4) ◽  
pp. C913-C924 ◽  
Author(s):  
J. M. Burt
Keyword(s):  
Single Channel ◽  
Methyl Esters ◽  
Acyl Chain ◽  
Fatty Acyl ◽  
Cardiac Cells ◽  
Neonatal Rat ◽  
Head Group ◽  
Fatty Acyl Chain ◽  
Heart Cells ◽  
Dependent Manner

The influence of doxyl stearic acids (DSAs) on gap junctional conductance (gj) between pairs of neonatal rat heart cells was studied. DSAs are spin probes that perturb the membrane at different depths depending on position of the doxyl group on the fatty acyl chain. 16-DSA and 12-DSA rapidly and reversibly reduced gj to unmeasureable levels in a dose- and time-dependent manner. Single channel events observed when gj was low were of the same unitary size as those observed under control conditions. The methyl esters of 16- and 12-DSA, stearic acid itself, and TEMPO, an analogue of the doxyl group that has no fatty acyl chain, had no effect on gj. Protonation of the carboxyl head group (by acidifying the solution) reduced the potency of 16- or 12-DSA. Spontaneous beating activity and action potentials were observed at concentrations of the DSAs 15-20 times that necessary for uncoupling. These results indicate that uncoupling by the DSAs requires the presence of the charged carboxyl group and localized perturbation of the channel at the lipid-channel interface by the doxyl group. Furthermore, they predict that unsaturated free fatty acids, which accumulate during ischemia, may exert their arrhythmogenic effect by reducing gj, and thereby slowing conduction.

The influence of fatty acyl chain length and head group on the size of multilamellar vesicles

1989 ◽  
Vol 49 (4) ◽  
pp. 271-288 ◽  
Author(s):  
Thomas J. Racey ◽  
Michael A. Singer ◽  
Leonard Finegold ◽  
Paul Rochon
Keyword(s):  
Chain Length ◽  
Acyl Chain ◽  
Fatty Acyl ◽  
Head Group ◽  
Fatty Acyl Chain ◽  
Multilamellar Vesicles ◽  
Acyl Chain Length

scholarly journals HILIC-ESI-FTMS with All Ion Fragmentation (AIF) Scans as a Tool for Fast Lipidome Investigations

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2310
Author(s):  
Giovanni Ventura ◽  
Mariachiara Bianco ◽  
Cosima Damiana Calvano ◽  
Ilario Losito ◽  
Tommaso R. I. Cataldi
Keyword(s):  
Structural Information ◽  
Acyl Chain ◽  
Fatty Acyl ◽  
Dermal Fibroblasts ◽  
Head Group ◽  
Fatty Acyl Chain ◽  
Ion Fragmentation ◽  
Lipid Species ◽  
Acyl Chains ◽  
Scan Data

Lipidomics suffers from the lack of fast and reproducible tools to obtain both structural information on intact phospholipids (PL) and fatty acyl chain composition. Hydrophilic interaction liquid chromatography with electrospray ionization coupled to an orbital-trap Fourier-transform analyzer operating using all ion fragmentation mode (HILIC-ESI-FTMS-AIF MS) is seemingly a valuable resource in this respect. Here, accurate m/z values, HILIC retention times and AIF MS scan data were combined for PL assignment in standard mixtures or real lipid extracts. AIF scans in both positive and negative ESI mode, achieved using collisional induced dissociation for fragmentation, were applied to identify both the head-group of each PL class and the fatty acyl chains, respectively. An advantage of the AIF approach was the concurrent collection of tandem MS-like data, enabling the identification of linked fatty acyl chains of precursor phospholipids through the corresponding carboxylate anions. To illustrate the ability of AIF in the field of lipidomics, two different types of real samples, i.e., the lipid extracts obtained from human plasma and dermal fibroblasts, were examined. Using AIF scans, a total of 253 intact lipid species and 18 fatty acids across 4 lipid classes were recognized in plasma samples, while FA C20:3 was confirmed as the fatty acyl chain belonging to phosphatidylinositol, PI 38:3, which was found to be down-regulated in fibroblast samples of Parkinson’s disease patients.

Fatty acyl chain structure, orientational order, and the lipid phase transition in Acholeplasma laidlawii B membranes. A review of recent 19F nuclear magnetic resonance studies

1984 ◽  
Vol 62 (11) ◽  
pp. 1134-1150 ◽  
Author(s):  
P. M. Macdonald ◽  
B. D. Sykes ◽  
R. N. McElhaney
Keyword(s):  
Phase Transition ◽  
Fatty Acids ◽  
Nuclear Magnetic Resonance ◽  
Acyl Chain ◽  
Orientational Order ◽  
Membrane Lipid ◽  
Fatty Acyl ◽  
Fatty Acyl Chain ◽  
Lipid Phase ◽  
Lipid Phase Transition

The orientational order parameters of monofluoropalmitic acids biosynthetically incorporated into membranes of Acholeplasma laidlawii B in the presence of a large excess of a variety of structurally diverse fatty acids have been determined via 19F nuclear magnetic resonance (19F NMR) spectroscopy. It is demonstrated that these monofluoropalmitic acids are relatively nonperturbing membrane probes based upon physical (differential scanning calorimetry), biochemical (membrane lipid analysis), and biological (growth studies) criteria. 19F NMR is shown to convey the same qualitative and quantitative picture of membrane lipid order provided by 2H-NMR techniques and to be sensitive to the structural characteristics of the membrane fatty acyl chains, as well as to the lipid phase transition. Representatives of each naturally occurring class of fatty acyl chain structures, including straight-chain saturated, methyl-branched, monounsaturated, and alicyclic-ring-substituted fatty acids, were studied and the 19F-NMR order parameters were correlated with the lipid phase transitions (determined calorimetrically). The lipid phase transition was the prime determinant of overall orientational order regardless of fatty acid structure. Effects upon orientational order attributable to specific structural substituents were discernible, but were secondary to the effects of the lipid phase transition. In the gel state, relative overall order was directly proportional to the temperature of the particular lipid phase transition. Not only the overall order, but also the order profile across the membrane was sensitive to the presence of particular structural substituents. In particular, in the gel state specific fatty acyl structures demonstrated a characteristic disordering effect in the membrane order profile. These various observations can be merged to provide a unified picture of the manner in which fatty acyl chain chemistry modulates the physical state of membrane lipids.

scholarly journals The Role of Ceramide Metabolism and Signaling in the Regulation of Mitophagy and Cancer Therapy

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2475
Author(s):  
Megan Sheridan ◽  
Besim Ogretmen
Keyword(s):  
Cancer Therapy ◽  
Acyl Chain ◽  
Fatty Acyl ◽  
Fatty Acyl Chain ◽  
Cancer Cell Proliferation ◽  
Bioactive Lipids ◽  
Cellular Functions ◽  
Proliferation Response ◽  
Ceramide Synthases

Sphingolipids are bioactive lipids responsible for regulating diverse cellular functions such as proliferation, migration, senescence, and death. These lipids are characterized by a long-chain sphingosine backbone amide-linked to a fatty acyl chain with variable length. The length of the fatty acyl chain is determined by specific ceramide synthases, and this fatty acyl length also determines the sphingolipid’s specialized functions within the cell. One function in particular, the regulation of the selective autophagy of mitochondria, or mitophagy, is closely regulated by ceramide, a key regulatory sphingolipid. Mitophagy alterations have important implications for cancer cell proliferation, response to chemotherapeutics, and mitophagy-mediated cell death. This review will focus on the alterations of ceramide synthases in cancer and sphingolipid regulation of lethal mitophagy, concerning cancer therapy.

Effect of Acylglycerol Composition and Fatty Acyl Chain Length on Lipid Digestion in pH-Stat Digestion Model and SimulatedIn VitroDigestion Model

2015 ◽  
Vol 81 (2) ◽  
pp. C317-C323
Author(s):  
Jin F. Qi ◽  
Cai H. Jia ◽  
Jung A. Shin ◽  
Jeong M. Woo ◽  
Xiang Y. Wang ◽  
...  
Keyword(s):  
Chain Length ◽  
Acyl Chain ◽  
Fatty Acyl ◽  
Fatty Acyl Chain ◽  
Lipid Digestion ◽  
Acyl Chain Length ◽  
Ph Stat

scholarly journals Acyltransferase-mediated selection of the length of the fatty acyl chain and of the acylation site governs activation of bacterial RTX toxins

2020 ◽  
Vol 295 (28) ◽  
pp. 9268-9280 ◽  
Author(s):  
Adriana Osickova ◽  
Humaira Khaliq ◽  
Jiri Masin ◽  
David Jurnecka ◽  
Anna Sukova ◽  
...  
Keyword(s):  
Acyl Chain ◽  
Fatty Acyl ◽  
Biologically Active ◽  
Fatty Acyl Chain ◽  
Acyl Carrier Proteins ◽  
E Coli ◽  
Rtx Toxins ◽  
Wide Range ◽  
Lysine Residues ◽  
Acyl Chains

In a wide range of organisms, from bacteria to humans, numerous proteins have to be posttranslationally acylated to become biologically active. Bacterial repeats in toxin (RTX) cytolysins form a prominent group of proteins that are synthesized as inactive protoxins and undergo posttranslational acylation on ε-amino groups of two internal conserved lysine residues by co-expressed toxin-activating acyltransferases. Here, we investigated how the chemical nature, position, and number of bound acyl chains govern the activities of Bordetella pertussis adenylate cyclase toxin (CyaA), Escherichia coli α-hemolysin (HlyA), and Kingella kingae cytotoxin (RtxA). We found that the three protoxins are acylated in the same E. coli cell background by each of the CyaC, HlyC, and RtxC acyltransferases. We also noted that the acyltransferase selects from the bacterial pool of acyl–acyl carrier proteins (ACPs) an acyl chain of a specific length for covalent linkage to the protoxin. The acyltransferase also selects whether both or only one of two conserved lysine residues of the protoxin will be posttranslationally acylated. Functional assays revealed that RtxA has to be modified by 14-carbon fatty acyl chains to be biologically active, that HlyA remains active also when modified by 16-carbon acyl chains, and that CyaA is activated exclusively by 16-carbon acyl chains. These results suggest that the RTX toxin molecules are structurally adapted to the length of the acyl chains used for modification of their acylated lysine residue in the second, more conserved acylation site.

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