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Luigi Mondello - One of the best experts on this subject based on the ideXlab platform.
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mass spectrometric elucidation of Triacylglycerol content of brevoortia tyrannus menhaden oil using non aqueous reversed phase liquid chromatography under ultra high pressure conditions
Journal of Chromatography A, 2012Co-Authors: Paola Dugo, Nermeen Fawzy, Paola Donato, Francesco Cacciola, Marco Beccaria, Luigi MondelloAbstract:Abstract A non-aqueous reversed phase high performance liquid chromatography method was developed, and optimized for Triacylglycerol analysis in a Brevoortia tyrannus (menhaden) oil sample. Four columns were serially coupled to tackle such a task, for a total length of 60 cm of shell-packed stationary phase, and operated under ultra high pressure conditions. As detection, positive-ion atmospheric pressure chemical ionization mass spectrometry was used to attain identification of the analyzed sample components. A number of 137 Triacylglycerols containing up to 19 fatty acids, with 14–22 carbon atom alkyl chain length and 0–6 double bonds, were positively identified in the complex lipidic sample. This is the first work that reports an extensive characterization of the Triacylglycerol fraction of menhaden oil.
Valentina Ruizgutierrez - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of molecular species of monoacylglycerols diacylglycerols and Triacylglycerols in human very low density lipoproteins by reversed phase liquid chromatography
Journal of Chromatography B, 2003Co-Authors: Javier S Perona, Valentina RuizgutierrezAbstract:Abstract The aim of the present study was to investigate the applicability of a previously developed method for the analysis of Triacylglycerol molecular species to the simultaneous determination of Triacylglycerols, diacylglycerols and monoacylglycerols of human very-low-density lipoproteins (VLDL). Ten elderly women were recruited for the study. Blood was obtained in fasting conditions and VLDL were isolated by ultracentrifugation. Neutral lipids were separated by solid-phase extraction and were subsequently injected on a reversed-phase HPLC system, with an elution system composed of acetone in acetonitrile. The method allowed the separation of four monoacylglycerols, 18 diacylglycerols and 24 Triacylglycerols, including the resolution of positional isomers of diacylglycerols. Monoacylglycerols were composed of oleic, linoleic, palmitic and stearic acids. The major diacylglycerols were 1,2-dilinoleoyl-glycerol and 1,3-dilinoleoyl-glycerol (14.24±1.02 and 17.93±1.42%, respectively). The main Triacylglycerols quantified were dioleoyl-stearoyl-glycerol (OOS), oleoyl-dipalmitoyl-glycerol (OPP), trilinoleoyl-glycerol (LLL) and linoleoyl-distearoyl-glycerol (LSS), accounting for 11.25±2.15, 10.14±2.05, 9.35±2.30 and 8.56±1.56%, respectively. An inverse relationship between polarity and fatty acid disappearance from Triacylglycerols (r2=0.82, P
Robert V. Farese - One of the best experts on this subject based on the ideXlab platform.
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structure and catalytic mechanism of a human Triacylglycerol synthesis enzyme
Nature, 2020Co-Authors: Kun Wang, Robert V. Farese, Nina L Gluchowski, Shane D Elliott, Maofu Liao, Tobias C WaltherAbstract:Triacylglycerols store metabolic energy in organisms and have industrial uses as foods and fuels. Excessive accumulation of Triacylglycerols in humans causes obesity and is associated with metabolic diseases1. Triacylglycerol synthesis is catalysed by acyl-CoA diacylglycerol acyltransferase (DGAT) enzymes2–4, the structures and catalytic mechanisms of which remain unknown. Here we determined the structure of dimeric human DGAT1, a member of the membrane-bound O-acyltransferase (MBOAT) family, by cryo-electron microscopy at approximately 3.0 A resolution. DGAT1 forms a homodimer through N-terminal segments and a hydrophobic interface, with putative active sites within the membrane region. A structure obtained with oleoyl-CoA substrate resolved at approximately 3.2 A shows that the CoA moiety binds DGAT1 on the cytosolic side and the acyl group lies deep within a hydrophobic channel, positioning the acyl-CoA thioester bond near an invariant catalytic histidine residue. The reaction centre is located inside a large cavity, which opens laterally to the membrane bilayer, providing lipid access to the active site. A lipid-like density—possibly representing an acyl-acceptor molecule—is located within the reaction centre, orthogonal to acyl-CoA. Insights provided by the DGAT1 structures, together with mutagenesis and functional studies, provide the basis for a model of the catalysis of Triacylglycerol synthesis by DGAT. Cryo-electron microscopy structures and functional and mutagenesis studies provide insights into the catalysis of Triacylglycerol synthesis by human acyl-CoA diacylglycerol acyltransferase at its intramembrane active site.
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dgat1 is not essential for intestinal Triacylglycerol absorption or chylomicron synthesis
Journal of Biological Chemistry, 2002Co-Authors: Kimberly K. Buhman, Jinny S Wong, Scot J Stone, Joyce J. Repa, Robert L. Hamilton, Steven J Smith, F. F. Knapp, Betty Jane Burri, Nada A Abumrad, Robert V. FareseAbstract:Abstract Dietary Triacylglycerols are a major source of energy for animals. The absorption of dietary Triacylglycerols involves their hydrolysis to free fatty acids and monoacylglycerols in the intestinal lumen, the uptake of these products into enterocytes, the resynthesis of triacylgylcerols, and the incorporation of newly synthesized Triacylglycerols into nascent chylomicrons for secretion. In enterocytes, the final step in Triacylglycerol synthesis is believed to be catalyzed primarily through the actions of acyl-CoA:diacylglycerol acyltransferase (DGAT) enzymes. In this study, we analyzed intestinal Triacylglycerol absorption and chylomicron synthesis and secretion in DGAT1-deficient (Dgat1 −/−) mice. Surprisingly, DGAT1 was not essential for quantitative dietary Triacylglycerol absorption, even in mice fed a high fat diet, or for the synthesis of chylomicrons. However, Dgat1 −/− mice had reduced postabsorptive chylomicronemia (1 h after a high fat challenge) and accumulated neutral-lipid droplets in the cytoplasm of enterocytes when chronically fed a high fat diet. These results suggest a reduced rate of Triacylglycerol absorption in Dgat1 −/−mice. Analysis of intestine from Dgat1 −/−mice revealed activity for two other enzymes, DGAT2 and diacylglycerol transacylase, that catalyze Triacylglycerol synthesis and apparently help to compensate for the absence of DGAT1. Our findings indicate that multiple mechanisms for Triacylglycerol synthesis in the intestine facilitate Triacylglycerol absorption.
Javier S Perona - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of molecular species of monoacylglycerols diacylglycerols and Triacylglycerols in human very low density lipoproteins by reversed phase liquid chromatography
Journal of Chromatography B, 2003Co-Authors: Javier S Perona, Valentina RuizgutierrezAbstract:Abstract The aim of the present study was to investigate the applicability of a previously developed method for the analysis of Triacylglycerol molecular species to the simultaneous determination of Triacylglycerols, diacylglycerols and monoacylglycerols of human very-low-density lipoproteins (VLDL). Ten elderly women were recruited for the study. Blood was obtained in fasting conditions and VLDL were isolated by ultracentrifugation. Neutral lipids were separated by solid-phase extraction and were subsequently injected on a reversed-phase HPLC system, with an elution system composed of acetone in acetonitrile. The method allowed the separation of four monoacylglycerols, 18 diacylglycerols and 24 Triacylglycerols, including the resolution of positional isomers of diacylglycerols. Monoacylglycerols were composed of oleic, linoleic, palmitic and stearic acids. The major diacylglycerols were 1,2-dilinoleoyl-glycerol and 1,3-dilinoleoyl-glycerol (14.24±1.02 and 17.93±1.42%, respectively). The main Triacylglycerols quantified were dioleoyl-stearoyl-glycerol (OOS), oleoyl-dipalmitoyl-glycerol (OPP), trilinoleoyl-glycerol (LLL) and linoleoyl-distearoyl-glycerol (LSS), accounting for 11.25±2.15, 10.14±2.05, 9.35±2.30 and 8.56±1.56%, respectively. An inverse relationship between polarity and fatty acid disappearance from Triacylglycerols (r2=0.82, P
Paola Donato - One of the best experts on this subject based on the ideXlab platform.
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mass spectrometric elucidation of Triacylglycerol content of brevoortia tyrannus menhaden oil using non aqueous reversed phase liquid chromatography under ultra high pressure conditions
Journal of Chromatography A, 2012Co-Authors: Paola Dugo, Nermeen Fawzy, Paola Donato, Francesco Cacciola, Marco Beccaria, Luigi MondelloAbstract:Abstract A non-aqueous reversed phase high performance liquid chromatography method was developed, and optimized for Triacylglycerol analysis in a Brevoortia tyrannus (menhaden) oil sample. Four columns were serially coupled to tackle such a task, for a total length of 60 cm of shell-packed stationary phase, and operated under ultra high pressure conditions. As detection, positive-ion atmospheric pressure chemical ionization mass spectrometry was used to attain identification of the analyzed sample components. A number of 137 Triacylglycerols containing up to 19 fatty acids, with 14–22 carbon atom alkyl chain length and 0–6 double bonds, were positively identified in the complex lipidic sample. This is the first work that reports an extensive characterization of the Triacylglycerol fraction of menhaden oil.
