Choline phosphate

Phospholipid (Section 26 4) Adiacylglycerol beanng a choline phosphate head group Also known as phosphatidyl choline... 

Detection by LDMS and structural elucidation of other secondary metabolite products, generated in the host during the onset of the parasite disease, is discussed. These molecules may serve as additional biomarkers for rapid malaria diagnosis by LDMS. For instance, choline phosphate (CP) is identified as the source of several low-mass ions observed in parasite-infected blood samples in addition to heme biomarker ions. The CP levels track the sample parasitemia levels. This biomarker can provide additional specificity and sensitivity when compared to malaria detection based on heme ion signals alone. Furthermore the observed elevated CP levels are discussed in the context of Plasmodium metabolism during its intra-erythrocytic life cycle. These data can... 

Choline Phosphate—Another Unique LDMS Biomarker for Malaria Detection... 

Figure 8.7 Low mass (choline phosphate) region of a LD mass spectrum of blood from a P. vivax infected human patient (estimated parasitemia approximately 32,000 parasites/pl). Protocol C is used for sample preparation. A commercial LD TOF system is used laser wavelength 337nm. All one hundred single laser shot spectra, obtained from linear scanning of an individual well, are averaged (no data smoothing). The characteristic ions of detected choline phosphate are denoted.

Figure 8.8 Tentative structures of choline phosphate-related biomarker ions observed by LDMS.

Brundish, D.E. and Baddiley, J. (1968) Pneumococcal C-substance, a ribitol teichoic acid containing choline phosphate. BiochemicalJournal 110, 573-582. 

From the combined evidence, the tentative structure 42 was proposed for the repeating unit of C-substance. The choline phosphate residue is possibly linked to 0-3 of the 2-acetamido-2-deoxy-D-galac-tose. 

The amino alcohol choline is activated for inclusion in phospholipids following a similar principle (see p. 170). Choline is first phos-phorylated by ATP to form choline phosphate (a), which by reaction with CTP and cleavage of diphosphate, then becomes CDPcholine. In contrast to (1), it is not choline that is transferred from CDPcholine, but rather choline phosphate, which with diacylglycerol yields phosphatidylcholine (lecithin). 

This enzyme [EC 2.7.7.15], also referred to as phospho-rylcholine transferase, catalyzes the reaction of CTP with choline phosphate to produce pyrophosphate (or, diphosphate) and CDP-choline. 

This zinc-dependent enzyme [EC 3.1.4.3] (also known as lipophosphodiesterase I, lecithinase C, Clostridium welchii ce-toxin, and Clostridium oedematiens 13- and y-toxins) catalyzes the hydrolysis of a phosphatidylcholine to produce 1,2-diacylglycerol and choline phosphate. The enzyme isolated from bacterial sources also acts on sphingomyelin and phosphatidylinositol however, the enzyme isolated from seminal plasma does not act on phosphatidylinositol. See Micelle... 

Sodium cholate is insoluble in chloroform and in nonpolar solvents in general, but it is very soluble in alcohol and in water. Lecithin, on the contrary, is soluble in chloroform and only swells in water without dissolving in it. These differences in solubility are evidently related to the molecular structure and to the position of the hydrophilic groups in each of these molecules. The lecithin molecule has two important paraffinic chains and a group of hydrophilic functions (choline phosphate) localized at one end. In the presence of water, the lecithin molecules are oriented with their hydrophilic groups toward the water, and they hide their paraffinic chains inside a structure formed of two superposed layers of molecules. Conversely, in a nonpolar solvent the paraffinic chains are turned toward the solvent, while the polar groups are hidden inside the micelle. 

Synthesis of PE and PC from preexisting choline and ethanolamine These synthetic pathways involve the phosphorylation of choline or ethanolamine by kinases, followed by conversion to the activated form, CDP-choline or CDP-ethanolamine. Finally, choline-phosphate or ethanolamine-phosphate is transferred from the nucleotide (leaving CMP) to a molecule of diacylglycerol (see Figure 17.5). 

Fig. 21-5, are also used for formation of both phosphatidylcholine and phosphatidylethanolamine. In both cases, the free base, choline, or ethanolamine180a b is phosphorylated with ATP. Choline phosphate formed in this manner is then converted by reaction with CTP to CDP-choline (Eq. 17-58).181 Phosphatidylcholine is formed from this intermediate1813/b while CDP-ethanolamine is used to form phosphatidylethanolamine (Fig. 21-5). These synthetic reactions occur within cell nuclei as well as on surfaces of cytoplasmic membranes.1810...

Figure 9. Effect of pH on choline phosphate s chemical shift in various matrices. The sample concentration was 150 mg of P/L.

In phosphosphingolipids, the primary hydroxyl group is esterified with choline phosphate. The lipid is known as sphingomyelin. It has the structure ... 

The most common phospholipid, phosphatidylcholine, contains two molecules of fatty acid and one molecule of choline phosphate attached to a glycerol backbone (see Figure 1.11), Like all other phospholipids, it is amphipathic. The water-soluble end features a phosphate group, an amino group, and two keto groups. 

FIGURE I.n Phosphatidylcholine an amphipathic molecule. Phosphatidylcholine is a diglyceride. It contairts a glycerol backbone, two molecules of fatty acid, and a molecule of choline phosphate. The choline phosphate group is not linked to the central carbon of glycenoL... 

Phospholipids may consist of a backbone of glycerol esterified with two fatty acids and one molecule of choline phosphate in the position. Tn other phospholipids, the 3 position may be occupied by a molecule of ethanolamine phosphate, serine phosphate, or inositol phosphate. A phospholipid containing choline phosphate is called phosphatidylcholine one containing ethanolamine phosphate is called phosphatidylethanolamine. Generally, the fatty acids esterified as triglycerides contain up to one double bond, whereas those esterified as phos-... 

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