Phospholipid choline containing

Dukhovich, A. F., et al. (1988). Choline-containing phospholipids as specific activators and stabilizers of firefly luciferase. Dokl. Akad. Nauk SSSR 298 1257-1260. 

There is also inside-outside (transverse) asymmetry of the phospholipids. The choline-containing phospholipids (phosphatidylcholine and sphingomyelin) are located mainly in the outer molecular layer the aminophospholipids (phosphatidylserine and phos-phatidylethanolamine) are preferentially located in the inner leaflet. Obviously, if this asymmetry is to exist at all, there must be limited transverse mobility (flip-flop) of the membrane phospholipids. In fact, phospholipids in synthetic bilayers exhibit an extraordinarily slow rate of flip-flop the half-life of the asymmetry can be measured in several weeks. However, when certain membrane proteins such as the erythrocyte protein gly-cophorin are inserted artificially into synthetic bilayers, the frequency of phospholipid flip-flop may increase as much as 100-fold. 

The choline-containing phospholipids, PC and Sph, predominate in the outer leaflet and the amino-containing phospholipids (PE and PS) in the inner leaflet. 

Choline-containing phospholipids Potassium iodide-bismuth subnitrate (phosphatidylcholine and Dragendorff reagent... 

Transversely, mammalian biomembranes exhibit a general pattern for preferential localization of choline-containing phospholipids [such as phosphatidylcholine (PC) and... 

Choline-containing phospholipids Phospholipase D Choline oxidase 51... 

Choline-containing phospholipids have been determined in human serum using an IMER consisting of coimmobilized phospholipase D and choline oxidase [51]. Recently, immobilized glutamate oxidase was used to determine L-glutamic acid in culture media [52],... 

It can be seen from Figure 1 that the choline-containing phospholipids, phosphatidylcholine and sphingomyelin are localized predominantly in the outer monolayer of the plasma membrane. The aminophospholipids, conprising phosphatidylethanolamine and phosphatidylserine, by contrast, are enriched in the cytoplasmic leaflet of the membrane (Bretcher, 1972b Rothman and Lenard, 1977 Op den Kamp, 1979). The transmembrane distribution of the minor membrane lipid components has been determined by reaction with lipid-specific antibodies (Gascard et al, 1991) and lipid hydrolases (Biitikofer et al, 1990). Such studies have shown that phosphatidic acid, phosphatidylinositol and phosphatidylinositol-4,5-fc -phosphate all resemble phosphatidylethanolamine in that about 80% of the phospholipids are localized in the cytoplasmic leaflet of the membrane. 

Hypoxic or ischemic conditions led to an immediate release of free choline via the breakdown of choline-containing phospholipids in rat hippocampus slices. Klein et d. [198] showed that bilobalide inhibited the hypoxia-induced choline release in a dose-dependent manner both in vitro (EC,0 0.38 /rM) and ex vivo (2-20 mg/kg, p.o.). Asimilar reduction of choline release was confirmed after administration of EGb (200 mg/kg, p.o.). Bilobalide also inhibits die //-methyl-D-aspartate-induced, P LA,-dependent release of choline from hippocampal phospholipids both in vitro (10-100/rM) and in vivo (20 mg/kg, ip.) [199]. 

M Wada, K Nakashima, N Kuroda, S Akiyama, K Imai. Sensitive flow-injection method with peroxy-oxalate chemiluminescence detection combined with preparative high performance hquid chromatography for determination of choline-containing phospholipids in human serum. J Chromatogr B 678 129-136, 1996. 

Solvent I (chloroform-methanol 1 1, v/v). In 10 column volumes, all of the choline-containing phospholipids should have passed through. Then, start the following ... 

Solvent II (ethanol-chloroform-water, 5 2 2, v/v). This will elute the remaining non-choline-containing phospholipids again in approximately 10 column volumes of solvent. 

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