Phosphoryl choline

The different phosphoglycerides are often named by placing the constituent attached to the phosphate group after phosphatidyl , e.g. phosphatidyl choline (3-in-phosphatidylcholine or l,2-diacyl-sn-glycero-3-phosphoryl-choline). There are many phosphoglycerides because of the possible variation in the fatty acid chains, and when the full chemical structure is known, it should be used (e.g. l-palmitoyl-2-oleoyl-phosphatidylcholine). Nomenclature that entails the use of the DL system should be avoided. 

This enzyme [EC 2.7.S.2] (also known as CDP-choline l,2-diacylglycerol cholinephosphotransferase, diacylglycerol cholinephosphotransferase, phosphoryl-choline glyceride transferase, alkylacylglycerol cholinephosphotransferase, and l-alkyl-2-acetylglycerol cholinephosphotransferase) catalyzes the reaction of CDP-choline with 1,2-diacylglycerol to produce CMP and a phosphatidylcholine. l-Alkyl-2-acylglycerol derivatives can also serve as substrates. 

Dimyristoyl- and dipalmitoyllecithin were synthesized by acylation of sn-glycero-3-phosphorylcholine with fatty acid anhydrides as described by Cubero Robles and van den Berg (23). The sn-glycero-3-phosphoryl-choline was prepared by deacylation of egg-yolk lecithin according to... 

Having shown that dibutyryl PC is monomeric under the enzyme assay conditions, we found that the phospholipase A2, which acts poorly on PE in mixed micelles, is activated by dibutyryl PC which is itself an even poorer substrate. 31p-NMR spectroscopy was employed to show that only PE is hydrolyzed in mixtures of various compositions of these two phospholipids. The fully activated enzyme hydrolyzes PE at a similar rate to its optimal substrate, PC containing long-chain fatty acid groups. Because dibutyryl PC is not incorporated into the micelles, these results are consistent with a mechanism of direct activation of the enzyme by phosphoryl-choline-containing lipids (either monomeric or micellar) rather than a change in the properties of the interface being responsible for the activation of phospholipase A2. Therefore, two functional sites on the enzyme have to be assumed an activator site and a catalytic site (6). 

Abbreviations PBMA, poly (ethylene-co-butyl methacrylate) PC, phosphoryl choline PEVAc, poly (ethylene-co-vinyl autate) PLGA, poly (lactide-co-glycolide) SIBS, styrene-isobutylene-styrene SS,. ... 

The adsorption of block copolymers can be controlled by different stimuli, in particular by the pH since most of the brushes formed by block copolymers adsorption are polyelectrolyte brushes [129, 130], The group of Armes, for instance, studied the pH-controlled adsorption of a series of block copolymers [131, 132], In the case of copolymers bearing hydrophobic 2-(diethylamino)ethyl methacrylate groups (DEA) and a water-soluble zwiterionic poly(2-methacryloyl phosphoryl-choline) (MPC) block, they showed that at low pH the cationic DEA flatted to the anionic silicon surface while the MPC was in contact with the solution [132], At around neutral pH, micelles were formed in solution and adsorbed onto the surface because the DEA core was still weakly cationic. The MPC block formed the micelle coronas. Nevertheless, at higher pH the micelles became less cationic and the adsorption rate decreased. 

The enzymatic radioassay method for the analysis of acetylcholine and choline in brain tissue has been reported by Reid et al. [210]. The method describes the determination of nanogram amounts of acetylcholine and choline in as little as 10 mg of brain tissue, involves isolation of acetylcholine by high-voltage paper electrophoresis, alkaline hydrolysis of acetylcholine to choline, and conversion of this into [32P]-phosphoryl choline in the presence of choline kinase and [y32P] ATP. The labeled derivative is isolated by column chromatography on Bio-Rad AG1-X8 resin, using Tris buffer solution as the eluent. Cerenkov radiation from 32P is counted (at 33% efficiency) in a liquid scintillation spectrometer. The amount of phosphorylcholine is proportional to the amount of choline over the range of 0.08-8.25 nmol. 

Waku, K. and Nakagawa, Y. (1972) Hydrolyses of 1-O-alkyl, 1-O-alkenyl and l-acyl-2-(l-14C)linoleoyl-glycero-3-phosphoryl choline by various phospholipases, J. Biochem. 72, 149-155. 

Acid sphingomyelinase is a lysosomal enzyme that catalyzes the breakdown of sphingomyelin to ceramide and phosphoryl-choline.A deficiency of this enzyme leads to lysosomal accumulation of sphingomyelin in patients with Niemann-Pick disease. Recent data indicate that correct intracellular targeting of acid sphingomyelinase to lysosomes is dependent on the mannose 6-phosphate-mediated pathway. Does this imply that the I-cell patient will present with Niemann-Pick symptoms Can I-cell disease be viewed as a constellation of many lysosomal storage diseases ... 

Sphingomyelin has a phosphoryl choline attached to the third carbon —OH. It is the only phospho-sphingolipid. 

Figure 33.11. Binding of a Small Antigen. The structure of a complex between an Fj j, fragment of an antibody and its target in this case, phosphoryl-choline. Residues from the antibody interact with phosphorylcholine through...

Other materials have also been studied for their ability to reduce protein adsorption onto surfaces. Because many cell membranes are based on phospholipids, polymers containing phospholipid-type head groups have been utilized for this purpose. Poly(2-methacroylethyl phosphoryl choline) could be plasma deposited onto silicone rubber and the adhesion of albumin reduced by factors of up to 80 (Fig. 

Initially recorded with rare paraproteins (B23), mainly of the IgA class, this has also been associated with IgG and IgM. Usually the total serum cholesterol is raised, but in one case it has been within normal limits curiously it is subnormal in most patients with IgA-myelomatosis without xanthoma (S7). The xanthomata are typically of the soft eruptive variety and contain complexes of the paraprotein and /8-Iipo-protein. Beaumont (B8) has collected evidence suggesting that the paraproteins are antibodies to the 8-apoprotein. Occasionally excess complexes can result in viscosity syndrome (Section 7.5.6). If a lipid stain is used, the paraprotein band is positive. In such cases, regrettably. Potter has been unable to relate the antibody activity to phosphoryl-choline (P13). Cytotoxic treatment can reduce the serum levels of lipid and paraprotein. 

P13. Potter, M., and Lieberman, R., Common individual antigenic determinants in five of eight BALB/c IgA myeloma proteins that bind phosphoryl choline. J. Exp. Med. 132, 737-751 (1970). 

There are numerous other compounds in milk. In skimmed cow s milk the only other detectable species is glyceryl phosphoryl choline 346 however, in milk from other species remarkable variations in spectra and hence phosphorous compounds may be observed350 (Fig. 9). When cow s milk is concen-... 

Homogeneous reduction of the unsaturated phosphoryl choline containing polymer (1), using Wilkinson s catalyst and an insufficient quantity of H2 T2 mixture to reduce fully the acetylenic triple bond, gives rise to a mixture of... 

Choline kinase phosphorylates choline to give a phosphocholine and participates in glycine, serine and threonine metabolism and glycerophospholipid metabolism. Hemicholinium-7 is the prototypical tool compound used to inhibit CHK. Based on inhibitor studies, it has been proposed that CHK is important for the regulation of cell proliferation. Inhibition of choline kinase is also used to target plasmodium and develop novel antimalarials. A series of papers on pyridinium based inhibitors have been published, but no disclosures of more drug-like molecules have been made. 

GTPase-activating protein Glycerol 3-phosphoryl-choline... 

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