Lysophosphatidyl choline

Lysophosphatidyl choline (Sigma, St. Louis, MO). For assays in which fixation and permeabilization are performed in a single step, lysophosphatidyl choline is prepared as a stock solution of 1 mg/mL in 37% formalin. For assays in which fixation and permeabilization are performed as separate steps, the lysophosphatidyl choline is prepared as a stock solution of 1 mg/mL in PBS (see Note 2). 

Add chemoattractant (10 pL of 10 FMLP) to designated tubes, and mix the samples. Fix and permeabilize the samples in a single step with addition of 100 pL of 37% formalin containing 1 mg/mL of lysophosphatidyl choline at specified times after activation. Fix the cells for at least 5 min at... 

Samples may be fixed at step 2 of Subheading 3.2.1. by the addition of 100 pL of 37% formalin, and stored at 4°C until it is convenient to continue with the staining and analysis. After refrigerated storage, the samples are per-meabilized by the addition of 100 pL of 1 mg/mL lysophosphatidyl choline in PBS, and processed identically as described in steps 3-6 of Subheading 3.2.1. 

For calculation it was assumed that these five phospholipids together accounted for all of the phospholipids of the membrane. In the actual analyses, other phospholipids (primarily lysophosphatidyl choline and lysophosphatidyl ethanolamine) were found to account for less than 5% of the total. The heavy and light microlipid droplet fractions were obtained by sucrose density gradient centrifugation. Heavy fractions were collected between 0.5 and 1.0 M sucrose and light fractions banded at the 0.5 M sucrose-buffer interface. 

Portman, O.W., Alexander, M. 1976. Influence of lysophosphatidyl choline on the metabolism of plasma lipoproteins. Biochim. Biophys. Acta 450, 322-334. 

Weltzien, H.U. 1979. Cytolytic and membrane-perturbing properties of lysophosphatidyl choline. Biochim. Biophys. Acta 559, 259-287. 

Abbreviations PLGA poly(lactide-co-glycolide) P(CPP CEFB) poly[l,3-bis(p-carboxy-phenoxy) propane-co-p-(carboxyethylformamido) benzoic anhydride] chitosan-TBA chitosan-4-thiobutylamidine conjugate LPC lysophosphatidyl choline hGH human growth hormone GDC glycodeoxycholate sodium STDHF ... 

The relative F-actin changes in neutrophils are quantified by exposing the cells to a chemoattractant stimulus, and the reactions are stopped by formalin fixation of the cells. The cells are permeabilized by the addition of lysophosphatidyl choline to the samples, and fluorescently conjugated phallotoxin is added, which specifically labels F-actin, but not G-actin. After staining, the cells are washed to remove unbound phallotoxin, resuspended in phosphate-buffered saline (PBS), and analyzed for fluorescence intensity with a flow cytometer. All samples are compared with control, unstimulated (resting) neutrophils. The mean channel fluorescence (MCF) intensity of stimulated samples is divided by the MCF of resting cells and expressed as a relative F-actin ratio. Since phallotoxins bind well to both large and small F-actin polymers, but do not bind to monomeric G-actin, the fluorescence intensity of each cell is directly proportional to its F-actin content. 

Fatty Acid Composition of Sphingomyelins, Lysophosphatidyl Cholines,... 

Fatty Acid Composition of the sn-1 and sn-2 Position Obtained from the Corresponding Lysophospholipid Fraction (lysophosphatidyl-cholines [lysoPC] and lysophosphatidylethanolamines [lysoPE]) after Phospholipase Aj Hydrolysis the Fatty Acid Composition of PC and PE Fraction Are Given for a Comparison (mol%)... 

The second example represents a large-scale human metabolomics study that was performed with LC/MS [54]. The aim of this study was to identify potential biomarkers from lipid profiles of some 600 human plasma samples. Lipids were extracted from plasma samples and subjected to LC/ESI-MS analysis. Several different classes of lipids, such as phosphatidylcholines, lysophosphatidyl-cholines, triglycerides, diglycerides, sphingomyelins, and cholesterol esters were the target of this study. To detect small differences in metabolic profiles, statistical methods were used to process this large set of data. Partial least-squares discriminant analysis of the data could locate potential biomarkers. 

Phosphatidylcholine can be completely hydrolysed with aqueous acid to produce fatty acids, glycerol, phosphoric acid and choline. With alkali, the fatty esters are preferentially hydrolysed, leaving the glycero-phosphoryl-cholines, which can in turn hydrolyse slowly into glycerophosphoric acid and choline. Enzymatic hydrolysis occurs selectively at different ester sites by several phospholipases to produce a range of products. Phospholipases A1 and A2 are obtained commercially from snake venom. They hydrolyse the fatty acid at the -1 and sn-2 positions respectively, to produce lysophosphatidyl-choline. Phospholipase C catalyses the hydrolysis of the phosphate moiety to give 1,2-diacylglycerols and phosphorylcholine. Phospholipase D found in plant tissues mainly catalyses hydrolysis of the phosphate ester to produce choline and phosphatidic acids (1). 

Although the nuclear membrane s proteins have been fractionated by gel electrophoresis and their amino acid composition has been studied, their function remains unknown. However, it is certain that they are not histones. Although the quantitative content of phospholipids in the nuclear membrane is not certain, it is estimated that 50-60% of the phospholipids found in the nucleus are associated with the membrane. They include cardiolipin, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl inositol, phosphatidyl choline, sphingomyelin, and lysophosphatidyl choline. Of course, as in most cellular membranes, their function remains to be determined. 

Unlike their short-chain counterparts, long-chain fatty acids are not absorbed directly from the rumen. When they reach the small intestine they are mainly saturated and unesterified, but some - in the bacterial lipids - are esterified. Monoacylglycerols, which play an important role in the formation of mixed micelles in non-ruminants, are replaced in ruminants by lysophosphatidyl choline. 

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