Phosphatidylcholine, analysis

O.F. van den Brink, J.J. Boon, P.B. O Connor, M.C. Duursma, and R.M.A. Heeren, Matrix assisted laser desorption/ionization Fourier transform mass spectrometric analysis of oxyge nated triglycerides and phosphatidylcholines in egg tempera paint dosimeters used for environ mental monitoring of museum display conditions, J. Mass Spectrom., 36, 479 492 (2001). 

Gudheti, M. V., Mlodzianoski, ML, and Ffess, S. T. (2007) Imaging and shape analysis of giant unilamellar vesicles (GUVs) as model plasma membranes Effect of fnms-DOPC (dielaidoyl phosphatidylcholine) on membrane properties. Biophys. J. 10.1529/biophysj.106.103374. 

The few examples of deliberate investigation of dynamic processes as reflected by compression/expansion hysteresis have involved monolayers of fatty acids (Munden and Swarbrick, 1973 Munden et al., 1969), lecithins (Bienkowski and Skolnick, 1974 Cook and Webb, 1966), polymer films (Townsend and Buck, 1988) and monolayers of fatty acids and their sodium sulfate salts on aqueous subphases of alkanolamines (Rosano et al., 1971). A few of these studies determined the amount of hysteresis as a function of the rate of compression and expansion. However, no quantitative analysis of the results was attempted. Historically, dynamic surface tension has been used to study the dynamic response of lung phosphatidylcholine surfactant monolayers to a sinusoidal compression/expansion rate in order to mimic the mechanical contraction and expansion of the lungs. 

Marsh, D. (1991). Analysis of the chainlength dependence of lipid phase transition temperatures main and pretransitions of phosphatidylcholines main and non-lamellar transitions of phosphatidylethanolamines, Biochem. Biophys. Acta-Biomembranes, 1062, 1-6. 

G.l.c.—May be used for the analysis of pesticide residues,212 phosphates in water,212 phosphamide in milk and meat,213-214 and phosphatidylcholines.216... 

M. Straume and B. J. Litman, Equilibrium and dynamic structure of large, unilamellar, unsaturated acyl chain phosphatidylcholine vesicles. Higher order analysis of 1,6-diphenyl-... 

Figure 7. Hill plot analysis of PHGPx reaction. PHGPx activity was determined with either dilinoleoyl phosphatidylcholine monohydroperoxide (O) or cardiolipin monohydroperoxide ( ) as a substrate. The amount of PHGPx protein in a reaction mixture was about 0.4 pg.

The ACE analysis of interactions between drugs and phospholipid bilayers of liposomes present as a pseudostationary phase was performed by Zhang et al. (32). The capillaries were treated to eliminate electroendosmosis. Freshly prepared and essentially neutral small unilamellar liposomes composed of egg phosphatidylcholine were sucked into the capillary. These liposomes increased both the retention of four negatively charged drugs and the separation between the substances (Fig. 6). The chromatographic retentions of these drugs on immobilized phosphatidylcholine liposomes, ex-... 

Single-bilayer phosphatidylcholine (14) surfactant vesicles Magnetite prepared from equimolar Fe2+/Fe3+ and NaOH and sonicated with the lipid X-ray analysis established the presence of magnetite in the vesicles 787, 788... 

The application of high-sensitivity ICP-MS detectors coupled to HPLC has enabled the detection of trace arsenic compounds present in marine animals. Thus, arsenocholine has been reported as a trace constituent (<0.1% of the total arsenic) in fish, molluscs, and crustaceans (37) and was found to be present in appreciable quantities (up to 15%) in some tissues of a marine turtle (110). Earlier reports (46,47) of appreciable concentrations of arsenocholine in some marine animals appear to have been in error (32). Phosphatidylarsenocholine 45 was identified as a trace constituent of lobster digestive gland following hydrolysis of the lipids and detection of GPAC in the hydrolysate by HPLC/ICP-MS analysis (70). It might result from the substitution of choline with arsenocholine in enzyme systems for the biogenesis of phosphatidylcholine (111). 

For -LCAT activity the apoA-I proteoliposome emulsion is prepared by evaporating 260 pi of 5 mg/ml egg yolk phosphatidylcholine, 150 pi of 1 mg/ml unesteri-fied cholesterol, and 3 pi of 21 Ci/mmol [7-3H(N)]-cholesterol. The dried lipids are dissolved in 125 pi pure ethanol and injected into 10 ml of analysis buffer and vor-texed. The emulsion is concentrated by ultrafiltration to less than 2.5 ml and then filled up to 2.5 ml. A 300-pL aliquot of this emulsion is incubated with 75-150 mg of apoA-I and 1.1 ml analysis buffer. The optimal amount of apoA-I varies from lot to lot and has to be optimized using normal plasma samples. 

To prepare proteoliposomes, 7 mg egg yolk phosphatidylcholine, 1.16 pg cholesterol, 77.5 pg cholesteryl oleate and 10 pCi [3H]-cholesteryl oleate, all dissolved in chloroform are mixed. After evaporation of chloroform with nitrogen, the lipids are resolved in 400 pi ethanol. The ethanolic solution is injected into 5 ml of a vortex-ing buffer with 39mmol/l sodium phosphate, 0.01% EDTA, 2 mmol/1 NaN3, and 12 mmol/1 sodium cholate (pH 7.4) 3 mg apoA-I is added. The solution is subsequently dialyzed against a buffer with 39 mmol/1 sodium phosphate, 0.01 % EDTA, 2 mmol/1 NaN3, and 12 mmol/1 sodium cholate (pH 7.4) at 4°C. At the end the solution is filled up with analysis buffer containing 39 mmol/1 sodium phosphate,... 

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