Glycerophosphorylcholine

Lyophilization of 1,2-dipalmitoyl-OT-3-glycerophosphorylcholine, n-hexadecan-1 -ol, tyloxapol solution in 0.1 n NaCl. 

Membrane/lipid metabolism/ choline/glycerophosphorylcholine/ Cho/ PCho GPCho/... 

In urea-rich fishes and in the inner medulla of the mammalian kidney, there characteristically is found a set of methylammonium solutes whose effects on proteins are opposite to those of urea (figure 6.6). Different methylamines predominate in different species. For instance, TMAO and glycine betaine are the most prevalent methylamines in elasmobranchs, and glycerophosphorylcholine (GPC) may be especially important in mammalian kidneys (figures 6.1 and 6.2). Despite interspecific differences in the types of methylamines present in cells, a common effect is noted when urea and methylamine solutes are both included in experimental media, an algebraic additivity generally is observed in their influences on proteins. Thus, if urea shifts a property in one direction and a methylamine shifts it in the opposite direction, the net change in the property in a... 

Glycerophosphorylcholine is produced by splitting of phosphatidyl choline (PC). Some of the phosphatidyl choline substrate is synthesized de novo from choline taken up from the blood. Phosphatidyl choline pre-existing in... 

Lyophilizationof l,2-dipalmitoyl-.wj-3-glycerophosphorylcholine, tt-hexadccan-l-ol, tyloxapol solution in O.l n NaCl. 

Sequential removal of the fatty acids by phospholipase action results in the formation of lysolecithin (glycerophosphorylcholine), then hydrolysis to release choline. Acetylcholine is synthesized in neurons using acetyl CoA. 

The partial synthesis may involve several synthetic steps, depending on the basic phospholipid used, the enzyme, the final product desired, and the type and position of the phospholipid constituents to be exchanged. For example, the partial synthesis may avail of the reacylation of 3-5 -glycerophosphorylcholine (GPC). Alternatively, by a deacylation step, GPC can be obtained from PC in soybean lecithin (75). 

PC and PX with the same defined acyl chains at both positions (obtained from glycerophosphorylcholine, GPC) ... 

How does the palmitate arise at position 2 in lung surfactant Current evidence rules out the possibility that an unsaturated fatty acid chain at position 2 is modified in situ to a palmitoyl chain. The two remaining possibilities are (1) direct transfer of palmitoyl chains to positions 1 and 2 of glycerophosphorylcholine and (2) hydrolytic cleavage (removal) of the unsaturated chain at position 2 followed by addition of the palmitoyl chain. 

PC) Phospholipase B choline (lyso-PC) + fatty acid Fatty acids 5/1-3-Glycerophosphorylcholine... 

Phosphatidylethanolamine is usually synthesized from phosphatidic acid or from iodohydrin diesters. The analogous route to that of phosphatidylcholine from glycerophosphorylcholine is not usually used because it is difficult to obtain the substrate in a sufficiently pure state. Care must be taken during the synthesis of phosphatidylethanolamine to protect the unsubstituted amino function. 

Because of its noninvasive nature, MRS is especially suited to in vivo studies of brain. Numerous cerebral metabolites are detectable, particularly with MRS (Figure 6). A few metabolites contribute prominent peaks and these are most easily quantifiable. Naa is predominantly found in the central nervous system, especially in neurons, although its functional role is not fully understood. Dynamic changes in brain Naa concentration have been observed reduced concentration may indicate neuronal dysfunction as well as loss. A prominent peak due to choline (Cho) has contributions from several metabolites including phosphorylcholine and glycerophosphorylcholine. Phosphatidylcholine is synthesized from chohne and is a major constituent of cell membranes being bound, this component is NMR invisible due to a very short T2. Pathologically increased membrane... 

Lipids can be hydrolysed by heating them under reflux with an excess of dilute aqueous ethanolic alkali and the fatty acids, diethyl ether-soluble non-saponifiable materials and any water-soluble hydrolysis products recovered for further analysis. When the water soluble components (such as glycerol, glycerophosphorylcholine, etc.) are required, special procedures must be used and most of these are outwith the scope of this book. The free fatty acids and the non-polar non-saponifiable components are separately recovered in the following procedure ... 

Alkyl-2-acetyl-sn-glycerophosphorylcholine or "platelet-activating factor" (commonly abbreviated to PAF) is present in minute concentrations in platelets and certain other cells, yet exerts profound physiological effects. Its chemistry and biochemistry have been reviewed [353,866]. It is such a polar molecule that HPLC in the adsorption mode is required for its isolation. As the author and others [107,168] have reviewed these methods in some detail. It need only be mentioned here as an example that It elutes between sphingomyelin and lysophosphatidylcholine from a column of silica gel with a gradient of hexane-isopropanol-water in which the water content is increased [110]. No existing method is sufficiently sensitive to demonstrate the... 

L-a Glycerophosphorylcholine cadmium chloride complex was prepared by hydrolyzing egg lecithin which was isolated from egg yolk. 1-Dodecyne, undecylenic acid, 11-bromo undecanoic acid, nonanoic acid, lithium acety-lide ethylenediamine complex, dimethylaminopyridine (DMAP), and dicyclo-hexylcarbodiimide (DCC) were purchased from Aldrich Chemical Co. Milwaukee, WI. Tridecyne was obtained from Farchan Laboratories, Gainesville, FL, and 1,2-dihexanoyl and 1,2-dipalmitoyl PC were purchased from Avanti Polar Lipids, Birmingham, AL. Mixed bed resin AG 501-X8(D) was procured from Bio-Rad Laboratories, Richmond, CA. Chloroform was distilled freshly over phosphorus pentoxide just before the use. Other solvents were used as received. The water was triply distilled and deionized. 

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