Serine, phosphatidyl

The work of Hubscher (1962) and Borkenhagen, Kennedy and Fielding (1961) indicates that in mammalian tissues phosphatidyl serine (IX) is not formed by the transfer of (9-phosphoserine from CDP-serine to D-cx,j8-diglyceride by a reaction analogous to those already described for the formation of lecithin and phosphatidyl ethanolamine (Reactions 12 and 19). Apparently free serine and not 0-phosphoserine is the immediate precursor of phosphatidyl serine. Serine displaces ethanolamine from phosphatidyl ethanolamine in an enzymic reaction activated by Ca and not requiring ATP  

There is evidence that in certain enzyme preparations the addition of CMP and ATP may be necessary for the formation of serine-containing phospholipids, suggesting that phosphatidyl serine also may be formed by a second pathway as yet not defined (Artom and Wainer 1963, Miras, Mantzos and Levis 1964). 

The conversion of serine to ethanolamine by brain and liver preparations has been known for a long time (see Wilson, Gibson and Udenfriend 1960). 

Reference has been made already to the recent findings of Kanfer and Kennedy (1964), who showed that in cell-free extracts of E, coli phosphatidyl serine is formed by a different pathway. A phosphatidyl group is transferred from CDP-diglyceride to L-serine by a highly specific enzyme L-serine-CMP phosphatidyl-transferase (Reaction 21). In this organism most of the phosphatidyl serine so formed is decarboxylated to yield phosphatidyl ethanolamine (Reaction 22). 

Phosphatidyl inositol (XIII) occurs in a wide variety of tissues, but the concentration in brain is particularly high (see Hawthorne and Kemp 1964, for a review of brain phosphoinositides). Poljnnannosides of phosphatidyl inositol occur in Mycobacterium tuberculosis (Ballou, Vilkas and Lederer 1963) and phosphatidyl inositol derivatives of various types probably have quite a wide distribution in nature (Carter et al. 1958, Klenk and Hendricks 1961). 

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Malcolm (1973, 1975) reported possible observable differences between the pressure-area curves of poly(L-alanine) mixed with poly(D-a-amino-n-butyric acid) and the corresponding mixture containing poly(D-alanine). Shafer (1974) observed differences in the film pressure between (/ )-phosphatidyl serine with poly-L-lysine and the corresponding film with poly-D-lysine injected under the film. 

Membrane associations can occur by selective protein binding to lipid head groups. One example is spectrin, which binds to phosphatidylinositol-4,5-bisphosphate by means of a pleckstrin-homology (PH) domain [5] (Fig. 2-5). and also to phosphatidyl serine [6] (Fig. 2-6). 

Figure 22. The average dimensionless area per molecule (left ordinate) and the phosphate - phosphate distance in lattice units across the bilayer (right ordinate) of phosphatidyl serine bilayers as a function of the square root of the ionic strength...

Phosphatidyl serines (or threonine) nh3 —ch2ch.cooh Widely distributed but in small amounts. Is a major component of brain and red cell lipids Usually isolated as salts with K+, Ca2+, Na+ or Mg2+... 

Phosphatidic acid Phosphatidyl ethanolamine Phosphatidyl serine Phosphatidyl choline Phosphatidyl inositol Sphingomyelin. 

Ninhydrin 2 g 1 1 in acetone Containing free amino groups Purple spots appear with phosphatidyl ethanolamine and phosphatidyl serine, for instance, after heating at 100°C... 

By preparing planar lipid monolayers or bilayers on hydrophobically derivatized or native hydrophilic glass, respectively, the adsorption equilibrium constants of a blood coagulation cascade protein, prothrombin, have been examined by TIRF on a surface that more closely models actual cell surfaces and is amenable to alterations of surface charge. It was found that membranes of phosphatidylcholine (PC) that contain some phosphatidyl-serine (PS) bind prothrombin more strongly than pure PC membranes/83... 

ArdaU, D., Lerme, F., and Louisot P., 1991, Involvement of contact sites in phosphatidyl-serine import into hver mitochondria. 7. Biol. Chem., 266 7978-7981. 

Abood and coworkers (IJ-IS) have reported that acidic lipids, in particular phosphatidyl serine (PS), enhanced binding of opiates to membranous components of brain. Furthermore, PS has been shown to bind opiates stereospecifically whereas other acidic lipids bind to a lesser extent and neutral lipids bind very little (1 1). Loh and coworkers (14-16,) have reported that cerebroside Issued as N.R.C.C. Publication No. 17068. 

Figure 3. The pH dependence of Ti of [3-[2-C-13]glycine]methionine enkephalin (1.1 mg) in presence of phosphatidyl serine (78.5 mg). Spectra were run at...

The anandamide precursor, phosphatidylethanol amine, is present in membranes almost always accompanied by phophatidylserine. It seemed reasonable to expect the formation of anandamide from its precursor will be paralleled by formation of N-arachidinoylserine from phosphatidyl serine. Indeed, A -arachidonoyl-L-serine (ARA-S) was found to be formed alongside anandamide (Fig. 4). This compound was isolated from bovine brain and its structure was elucidated by comparison with synthetic ARA-S. Contrary to anandamide, ARA-S binds very weakly to the known cannabinoid CBi and CB2 or vanilloid TRPVl receptors. However, it produces endothelium-dependent vasodilation of rat isolated mesenteric... 

A method for analyzing protein structure based on limited proteolysis. This method is especially useful in investigations of membrane proteins whose membrane association limits the repertoire of techniques that can be gainfully applied to infer structural features. For example, Davis et al used four proteases to assess the topology of yeast H -ATPase reconstituted into phosphatidyl-serine vesicles. Limited proteolysis by trypsin and a-chymotrypsin inactivates the enzyme and produces stable, membrane-bound fragments. Sequence analyses of... 

Apoptosis Nuclear condensation and lobulation, caspase activation, phosphatidyl serine externalization, annexin, immuno-cytochemistry, DNA fragmentation and labeled-dUTP incorporation by terminal deoxynucleotidyl transferase... 

On surface of platelet membrane phospholipid, phosphatidyl serine forms tenase and prothrombinase complexes... 

The second important regulatory function of diacylglycerol is stimulation of protein kinase C (see 7.7). Protein kinase C is a protein kinase occurring in almost all cells, and has a regulating effect on many reactions of the cell. Characteristic for protein kinase C is its stimulation by Ca, diacylglycerol and phosphatidyl serine. 

BLM surface tensions have been determined by the application of an ultrasmall hydrostatic pressure to one side of the membrane and measuring the resultant curvature changes by optical interferometry (Fig. 61). Typical values of 0.2-Q.3 mNm 1 were obtained for y for glyceryl monooleate and phosphatidyl-serine BLMs [413]. 

Tetragonia tetragonoides (Pall.) O. Kuntz. Fan Xing (leaf, stem)60 Phosphatidylcholine, phosphatidyl-ethanolamine, phosphatidyl-serine, phosphatidyl-inositol, tetragonin, trigonelline, choline, adenine.56 A remedy for carcinoma, treat ventriculi, stomach ulcers, leukemia. 

Species Phosphatidyl- choline Phosphatidyl- ethanolamine Phosphatidyl- serine Phosphatidyl- inositol Sphingomyelin Lysophospho- lipids0... 

Droplets of different density and lipid protein ratios ranging from about 1.5 1 to 40 1 have been isolated from bovine mammary gland. Triglycerides are the major lipid class in droplets of all sizes and represent increasingly greater proportions of total droplet mass in increasingly less dense droplet preparations. Surface coat material of droplets contains cholesterol and the major phospholipid classes found in milk, i.e. sphingomyelin, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidyl-serine. 

Figure 3.2 The molecular arrangement of the cell membrane (A) integral proteins (B) glycoprotein (C) pore formed from integral protein (D) various phospholipids with saturated fatty acid chains (E) phospholipids with unsaturated fatty acid chains (F) network proteins (G) cholesterol (H) glycolipid (I) peripheral protein. There are four different phospholipids phosphatidyl serine phosphatidyl choline phosphatidyl ethanolamine and sphingomyelin represented as , o. The stippled area of the protein represents the hydrophobic portion. Source From Ref. 1.

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