Function and Biosynthesis of Lipids

This volume contains the proceedings of the International Symposium on Function and Biosynthesis of Lipids held November 1976 at Sierra de la Ventana, Argentina. The conference was organized by the Argentine Biochemical Society and co-sponsored by the International Union of Biochemistry and the Pan American Association of Biochemical Societies. The Symposium's great success is owed to all the participants, most of whom were actively involved in the interesting and stimu­ lating discussions that followed every single lecture and communi­ cation delivered. Many thanks also to Drs. R. Anderson, S. Bonting, K. K. Carroll, B. Cecarelli, M. A. Crawford, R. T. Holman, J. Mead, R. H. Michell, G. Porcellati, W. Stoffel, W. Thompson, and H. Wiegandt for chairing Symposium sessions. The contributions are organized in four sections, preceded by the opening lecture on the role of dolichol phosphate in glyco­ protein biosynthesis delivered by Dr. Luis F. Leloir. The first section, on aspects of lipid involvement in the biogenesis of mem­ branes, covers the biosynthesis of saturated and unsaturated fatty acids, including enzymology, biosynthetic pathways, and regulation and modifications during development, in the fetus and in tumor~ cells. Papers on the composition and assembly of membrane compo­ nents, lipid interactions with proteins and enzymes, developmental changes of lipids, and newer approaches to survey the organization and biogenesis of cellular membranes complete this section. New information as well as reviews of current concepts about structural specificity, biosynthesis, and function of glycosphingo­ lipids are included in the second section.

In memoriam―Professor Werner Seubert.- A short history of the biochemistry of lipids in Argentina (Opening address).- Opening Lecture.- The role of dolichol in protein glycosylation.- I. Lipid Involvement in the Biogenesis of Membranes.- (A) Biosynthesis of fatty acids.- The role of lipid in stearyl CoA desaturation.- Biosynthetic pathways of polyunsaturated fatty acids.- The specificity of mammalian desaturases.- Regulation of the ?9 desaturation.- Regulatory function of ?6 desaturase―Key enzyme of polyunsaturated fatty acid synthesis.- Saturated and mono-unsaturated fatty acid biosynthesis in brain: relation to development in normal and dysmyelinating mutant mice.- Protein factor involved in fatty acid desaturation of linoleic acid.- Biosynthesis of lipids in tumoral cells.- Specificity of ?6 desaturase. Effect of chain length and number of double bonds.- Fetal accumulation of long-chain polyunsaturated fatty acids.- Materno-fetal transfer of 14C linoleic and arachidonic acids.- (B) Biogenesis and organization of cellular membranes.- On the asymmetric composition of plasma membranes.- Influence of the lipid environment on the properties of rhodopsin in the photoreceptor membrane.- Approaches to the biochemistry of regeneration in the central nervous system.- 3-D-(?)Hydroxybutyrate dehydrogenase from rat liver mitochondria ― Purification and interaction with phospholipids.- The role of phospholipids in Na-K ATPase.- Interactions with phospholipid monolayers of lipids and water-soluble compounds that induce membrane fusion.- The lipid composition and Ca transport function of sarcoplasmic reticulum (SR) membranes during development in vivo and in vitro.- Lipid metabolism during development in insects.- Composition and metabolism of phospholipids during early stages of vertebrate embryonic development.- II. Glycosphingolipids―Gangliosides.- Structural specificity of gangliosides.- The biosynthesis of brain gangliosides―Evidence for a “transient pool” and an “end product pool” of gangliosides.- Effects of brain gangliosides on reinnervation of fast-twitch rat skeletal muscle.- Studies on the functions of gangliosides in the central nervous system.- The biosynthesis of gangliosides and sialoglycoproteins in bovine retina.- Possible presence of psychosine in brain.- III. Lipids in Neural Tissue.- (A) Biosynthesis and turnover.- Transformations of the polyunsaturated fatty acids in the brain.- The significance of base-exchange reactions in lipid metabolism.- Metabolism of phosphatidylcholine in the central nervous system.- Metabolic studies on ethanolamine phosphoglycerides in neuronal and glial cells.- Metabolic relation between phosphatidic acids, CDP-diglycerides, and phosphoinositides.- Neobiosynthesis of phosphatidylinositol and of other glycerolipids in the entire cattle retina.- Phosphatidate, phosphatidylinositol, diacylglycerols, and free fatty acids in the brain following electroshock, anoxia, or ischemia.- Acyl groups, molecular species, and labeling by 14C-glycerol and 3H-arachidonic acid of vertebrate retina glycerolipids.- (B) Functions.- Effect of phospholipid liposomes on the regulation of cerebral metabolism.- Metabolism of phosphatidic acid and phosphatidylinositol in relation to transmitter release from synaptosomes.- Metabolism and role of phosphatidylinositol in acetylcholine-stimulated membrane function.- The possible involvement of phosphatidylinositol breakdown in the mechanism of stimulus-response coupling at receptors which control cell-surface calcium gates.- The biosynthesis of prostaglandins and thromboxanes by nervous tissue.- The relationship between cholinergic proteolipid and proteodetergent in Torpedo electroplax membranes.- Effects of divalent cations, K+, and X-537A on glycerolipid metabolism in the cattle retina.- Effects of temperature, ionic environment, and light flashes on the glycerolipid neosynthesis in the toad retina.- Muscarinic cholinergic stimulation of phosphatidylinositol turnover in the CNS.- Selective lipid alterations during experimental allergic encephalomyelitis―An interpretation of the changes.- IV. Essential Fatty Acids in Nutrition.- Essential fatty acids in human nutrition.- Essential fatty acids: what level in the diet is most desirable?.- The relationship between membrane fatty acids and the development of the rat retina.- Dietary essential fatty acids, brain polyunsaturated fatty acids, and prostaglandin biosynthesis.- Essential fatty acids in testes.- Membrane structure and function with different lipid-supplemented diets.- Effect of thyroxine on ?6 and ?9 desaturation activity.- Biosynthesis of polyunsaturated fatty acids from the linoleic acid family in cultured cells.