Phosphatidylglycerol phosphatidic acid

PHOSPHATIDES Phosphatidylcholine Phosphatidylethanolamine Phosphatidyl-N-acetylethanolamine Phosphatidylserine Phosphatidylinositol Phosphatidylglycerol Phosphatidic acid... 

Phosphatidylcholine Sphingomyelin Phosphatidylserine Phosphatidylinositol Phosphatidylglycerol Phosphatidic Acid Cardiolipin... 

Glycerol-containing phospholipids are used for the preparation of liposomes and vesicles phosphatidylcholine (13.1), phosphatidylserine, phosphatidylethanol-amine, phosphatidylanisitol, phosphatidylglycerol, phosphatidic acid and cholesterol. In most preparations, a mixture of lipids is used to obtain the optimum structure. 

Liposomes are multilamellar structures consisting of several bilayers of lipids (several pm) - they are produced by simply shaking an aqueous solution of phospholipids, e.g. egg lecithin. When sonicated, these multilayer structures produce unilamellar structures (with size range of 25-5 nm) that are referred to as liposomes. A schematic picture of liposomes and vesicles is given in Fig. 1.40. Glycerol-containing phospholipids are used for the preparation of liposomes and vesicles phosphatidylcholine phosphat-idylserine phosphatidylethanolamine phosphatidylanisitol phosphatidylglycerol phosphatidic acid cholesterol. In most preparations, a mixture of lipids are used to obtain the most optimum structure. 

Six two-component models were tested under sink conditions (models 5.1-10.1 in Table 7.3), employing three negatively charged lipids (dodecylcarboxylic acid, phosphatidic acid, and phosphatidylglycerol). These models were also tested in the absence of the sink condition (models 5.0-10.0 in Table 7.3). 

Figure 21-3 Major pathways of synthesis of fatty acids and glycerolipids in the green plant Arabidopsis. The major site of fatty acid synthesis is chloroplasts. Most is exported to the cytosol as oleic acid (18 1). After conversion to its coenzyme A derivative it is converted to phosphatidic acid (PA), diacylglycerol (DAG), and the phospholipids phosphatidylcholine (PC), phosphatidylinositol (PI), phosphatidylglycerol (PG), and phosphatidylethanolamine (PE). Desaturation also occurs, and some linoleic and linolenic acids are returned to the chloroplasts. See text also. From Sommerville and Browse.106 See also Figs. 21-4 and 21-5. Other abbreviations monogalactosyldiacylglycerol (MGD), digalactosyldiacylglycerol (DGD), sulfolipid (SL), glycerol 3-phosphate (G3P), lysophosphatidic acid (LPA), acyl carrier protein (ACP), cytidine diphosphate-DAG (CDP-DAG).

Glycerophospholipids contain a glycerol skeleton to which two fatty acids are esterified saturated fatty acids occupy mostly sn-position 1, whereas unsaturated fatty acids are mainly present on sn-position 2. The third hydroxyl is linked to a phosphate group to which an organic base is mostly esterified (Fig. 1). The most important components of soybean lecithin are phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylinositol (PI). Phosphatidic acid (PA) may become important due to the presence of phospholipase D this enzyme slowly converts PC into PA in vegetable lecithins. Phosphatidylserine (PS), phosphatidylglycerol (PG), and lyso-phosphatidylcholine (LPC) are known as minor components lysophospholipids contain only one acyl group per molecule. Besides, ether phospholipids occur in which one or both fatty acyl... 

Lipid synthesis is unique in that it is almost exclusively localized to the surface of membrane structures. The reason for this restriction is the amphipathic nature of the lipid molecules. Phospholipids are biosynthesized by acylation of either glycerol-3-phosphate or dihydroxyacetone phosphate to form phosphatidic acid. This central intermediate can be converted into phospholipids by two different pathways. In one of these, phosphatidic acid reacts with CTP to yield CDP-diacylglycerol, which in bacteria is converted to phosphatidylserine, phosphatidylglycerol, or diphos-... 

Fig. 25 (a) DNA release from EDOPC-DNA lipoplexes after addition of negatively charged lipid dispersion, as monitored by FRET (CM, oleic acid DOPA, dioleoyl phosphatidic acid DOPG, dioleoyl phosphatidylglycerol CL, cardiolipin DOPS, dioleoyl phosphatidylserine PI, phospha-tidylinositol). (b) Fraction of released DNA from EDOPC lipoplexes 10 min after addition of the respective anionic liposomes (c) X-ray diffraction patterns of mixtures of EDOPC and anionic liposome dispersions the respective structures are shown schematically on the left side (reproduced with permission from [98] copyright (2004) Biophysical Society)... 

Phosphatidic acids Phosphatidylcholines Phosphatidylserines Phosphatidylglycerols Phosphatidylethanol amines Phosphatidyl inositols Phosphatidylinositides Cardiolipins... 

Platelet Activating Factor (PAF) and PAF Analogs, Lysophosphatidic Acid and Phosphatidic Acid, Phosphatidylglycerol Cardiolipin, Sphingosine-1 -P... 

Phospholipase A2 (snake venom) will attack phosphatidylglycerol smoothly and to completion under conditions previously described in chapter 4. One mole of fatty acid is released per mole of lipid phosphorus. This result supports an sn-3 configuration for the phosphatidic acid portion of the molecule. 

One-dimensional thin-layer chromatography has been used to a limited extent. It will not cleanly separate phosphatidic acid, phosphatidylglycerol, and cardiolipin from each other in a neutral solvent system. However, it can be of value in evaluating the purity of cardiolipin-rich fractions as demonstrated by Smaal et al. (1985). 

DMPC dimyristoyl phosphatidylcholine DOPC dioleoyl phosphatidylcholine DPPC dipalpalmitoylphosphatidylcholine DMPG dimyristoyl phosphatidylglycerol PAPC l-palmitoyl,2-arachidonoyl PC PDPC l-palmitoyl,2-docosahexaenoyl PC PA phosphatidic acid PE phosphatidylethanolamine PS phosphatidylserine... 

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