The biosynthesis and functional role of cardiolipin.

Since our last comprehensive review on multi-dimensional mass spectrometry-based shotgun lipidomics (Mass Spectrom. Rev. 24 (2005), 367), many new developments in the field of lipidomics have occurred. These developments include new strategies and refinements for shotgun lipidomic approaches that use direct infusion, including novel fragmentation strategies, identification of multiple new informative dimensions for mass spectrometric interrogation, and the development of new bioinformatic approaches for enhanced identification and quantitation of the individual molecular constituents that comprise each cell's lipidome. Concurrently, advances in liquid chromatography-based platforms and novel strategies for quantitative matrix-assisted laser desorption/ionization mass spectrometry for lipidomic analyses have been developed. Through the synergistic use of this repertoire of new mass spectrometric approaches, the power and scope of lipidomics has been greatly expanded to accelerate progress toward the comprehensive understanding of the pleiotropic roles of lipids in biological systems.

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Multi-dimensional mass spectrometry-based shotgun lipidomics and novel strategies for lipidomic analyses.

It has been suggested that anandamide (N-arachidonoylethanolamine), an endogenous cannabinoid substance, may be produced through Ca2+-stimulated hydrolysis of the phosphatidylethanolamine (PE) derivative N-arachidonoyl PE. The presence of N-arachidonoyl PE in adult brain tissue and the enzyme pathways that underlie its biosynthesis are, however, still undetermined. We report here that rat brain tissue contains both anandamide (11 +/- 7 pmol/gm wet tissue) and N-arachidonoyl PE (22 +/- 16 pmol/gm), as assessed by gas chromatography/mass spectrometry. We describe a N-acyltransferase activity in brain that catalyzes the biosynthesis of N-arachidonoyl PE by transferring an arachidonate group from the sn-1 carbon of phospholipids to the amino group of PE. We also show that sn-1 arachidonoyl phospholipids are present in brain, where they constitute approximately 0.5% of total phospholipids. N-acyltransferase activity is Ca2+ dependent and is enriched in brain and testis. Within the brain, N-acyltransferase activity is highest in brainstem; intermediate in cortex, striatum, hippocampus, medulla, and cerebellum; and lowest in thalamus, hypothalamus, and olfactory bulb. Pharmacological inhibition of N-acyltransferase activity in primary cultures of cortical neurons prevents Ca2+-stimulated N-arachidonoyl PE biosynthesis. Our results demonstrate, therefore, that rat brain tissue contains the complement of enzymatic activity and lipid substrates necessary for the biosynthesis of the anandamide precursor N-arachidonoyl PE. They also suggest that biosynthesis of N-arachidonoyl PE and formation of anandamide are tightly coupled processes, which may concomitantly be stimulated by elevations in intracellular Ca2+ occurring during neural activity.

https://www.druglibrary.org/crl/receptors/endogenous/Cadas%20et.al%2097%20Biosynthesis_%20JNeurosci.pdf

Occurrence and Biosynthesis of Endogenous Cannabinoid Precursor,N-Arachidonoyl Phosphatidylethanolamine, in Rat Brain

Increased Biosynthesis of Platelet-activating Factor in Activated Human Eosinophils*

Publisher Summary This chapter discusses the metabolism of molecular species of diacylglycerophospholipids. The glycerolipid composition of cell membranes and lipoproteins is metabolically adjusted to meet specific requirements, and it does not merely reflect the supply of different fatty acids in the diet or in the cell culture medium. However, adequate adjustment cannot always be possible, and under such conditions, the cellular activity can take place in a suboptimal physicochemical environment and characteristic symptoms of a disease state can appear. As the cellular lipid composition is subject to considerable dietary and pharmacological manipulation, there can be therapeutic alterations in the composition of the molecular species of the tissues and other animal species. The metabolism of the molecular species of the glycerophospholipids is intimately involved with the activity of the acyl transferases. Therapeutic alterations in the composition of the molecular species of the glycerolipids can be feasible and can yield beneficial results in the treatment of membrane diseases.

Metabolism of molecular species of diacylglycerophospholipids.

A quantitative method for the simultaneous determination of alk-l-enyl- and alkyl-glyceryl ethers is described. Complete hydrogenolysis of carboxylate and phosphate esters of neutral lipids and phospholipids was achieved with lithium aluminum hydride. The hydrogenolysis products of the glyceryl ether containing lipids, alk-l-enyl- and alkyl-glyceryl ethers and alcohols, were identified by thin-layer chromatography (TLC), gas-liquid chromatography (GLC), and infrared spectroscopy. The alk-l-enyl- and alkyl-glyceryl ethers were quantitated by TLC photodensitometry. The specificity of this method can also be extended when used in conjunction with GLC, ion-complexing TLC, zonal scanning, and autoradiography to study composition, isomeric form, and the biosynthesis of glyceryl ethers in neutral and phospholipids.

Quantitative determination of alk‐1‐enyl‐ and alkyl‐glyceryl ethers in neutral lipids and phospholipids

Tumor lipids: Metabolic relationships derived from structural analyses of acyl, alkyl, and alk-1-enyl moieties of neutral glycerides and phosphoglycerides☆

Randall Wood

Papers

Quantitative determination of alk‐1‐enyl‐ and alkyl‐glyceryl ethers in neutral lipids and phospholipids

Tumor lipids: Metabolic relationships derived from structural analyses of acyl, alkyl, and alk-1-enyl moieties of neutral glycerides and phosphoglycerides☆

Structural analyses of rat liver phosphoglycerides

Structural studies of neutral glycerides and phosphoglycerides of rat liver.

Tumor lipids: biosynthesis of plasmalogens.