Dimyristoyl-phosphatidylcholine

Figure Bl.20.11. Force curves of DMPC/DPPE (dimyristoyl phosphatidylcholine and dipalmitoyl phosphatidylethanolainine) bilayers across a solution of PEG at different concentrations. Clearly visible is a concentration-dependent depletion attraction, with pennission from [17],...

DGDG digalactosyl diacylglycerol DHPC dihexadecyl phosphatidylcholine DMPC dimyristoyl phosphatidylcholine DOPC dioleoyl phosphatidylcholine DPPC dipalmitoyl phosphatidylcholine EYPC egg yolk phosphatidylcholine POPC 1-palmitoyl 2-oleoyl-phosphatidylcholine SBPC soya bean phosphatidylcholine... 

Plots of t0/t for varying [Q]T are first otained for different concentrations of lipid. Then, form the slope and intercept of a plot of k pp against am, the value of the partition coefficient is obtained. This method has been applied to the partitioning of lindane into lipid bilayers.(102 103) An example is shown in Figure 5.4 for the quenching of DPH by 5-DOXYL-decane in dimyristoyl-phosphatidylcholine vesicles(104) the increase in the partition coefficient as the... 

Figure 5.4. EfTect of the phase transition on the partition coefficient of 5-DOXYL-decane calculated on the basis of its ability to quench the fluorescence of DPH in dimyristoyl-phosphatidylcholine vesicles. The fluorescence anisotropy of the DPH is also shown. (From Ref. 104, with permission.)...

CH, cholesterol DLPC, dilaurylphosphatidylcholine DMPC, dimyristoyl-phosphatidylcholine DMPG, dimyristoylphosphatidylglycerol DPPC, dipal-mitoylphosphatidylcholine DPPG, dipalmitoylphosphatidylglycerol, DSPC, distearoylphosphatidylcholine DSPG, distearoylphosphatidylglycerol MLV, multilameller vesicle PA, phosphatidic acid PC, phosphatidylcholine TA, triamcinolone acetonide. 

Aqueous phase (2.7 mm3) was placed in the thin lower compartment of the microcell and the Dil dodecane solution (63 mm3) was added on top of the aqueous layer. Fluorescence of the interfacial Dil was observed in the range of 571-575 nm. The influence of two kinds of surfactants, sodium dodecyl sulfate (SDS) and dimyristoyl phosphatidylcholine (DMPC), on the lateral diffusion dynamics of single molecules at the interface was investigated. DMPC was dissolved in chloroform, and the solution was mixed with pure diethyl ether at a ratio of 1 19 (chloroform diethyl ether) by volume. Pure water was placed in the lower container, and the DMPC solution was subsequently (5 mm3) spread carefully on the water. After evaporation of chloroform and diethyl ether, the Dil dodecane solution was added on the DMPC layer. Since Dil has a high... 

Griffin, M.C.A., Infante, R.B., Klein, R.A. 1984. Structural domaines of K-casein show different interaction with dimyristoyl phosphatidylcholine monolayers. Chem. Phys. Lips. 36, 91-98. 

DMPC dimyristoyl phosphatidylcholine DOPC dioleoyl phosphatidylcholine DPPC dipalpalmitoylphosphatidylcholine DMPG dimyristoyl phosphatidylglycerol PAPC l-palmitoyl,2-arachidonoyl PC PDPC l-palmitoyl,2-docosahexaenoyl PC PA phosphatidic acid PE phosphatidylethanolamine PS phosphatidylserine... 

A 9-methoxyellipticine (2)-low density lipoprotein (LDL) complex was formulated by Soula and co-workers (742) and found to be 10 times more active than 2 against L1210 and P388 leukemia in vitro. This activity seems to depend on the LDL high-affinity receptor since LDL reduces the antitumor activity. The complex was prepared by adding 2 to a dimyristoyl phosphatidylcholine, cho-lesteryl oleate-stabilized microemulsion and then fusing with human LDL. 

CG density gradient centrifugation DMPC dimyristoyl phosphatidylcholine... 

The hinged-domain hypothesis was developed from the characterization of discoidal particles formed between apoA-I and dimyristoyl-phosphatidylcholine (Brouillette et al., 1984). At different proteintDMPC molar ratios, several discretely sized particles were found in complexes containing a constant number of apoA-I molecules per particle. The stepsize between the particles was constant and the change in circumference of the discoidal particles was found equal to the diameter of two a helices (Brouillette et ai, 1984). Thus it was proposed that conformational changes in apoA-I that result in the all-or-none binding of complete a-helical domains controlled particle sizes formed. This size quantization of particle classes has since been shown to be a general characteristic of human apoA-I-lipid complexes reconstituted with a variety of phospholipids in the presence and absence of cholesterol. 

Hendrich et al. [155] investigated the mechanism of incorporation of phe-nothiazines in the membrane bilayer lipids. They studied the influence of a particular phenothiazine derivative, TFZ, on the thermal properties of dimyristoyl phosphatidylcholine and dimyristoyl phosphatidylethanolamine by microcalorimetry. The main phase transition of both lipids was affected by this drug, depending on its concentration. The results suggest that TFZ was probably incorporated into both dimyristoyl phosphatidylcholine and dimyristoyl phosphatidylethanolamine bilayers. The phase separation was presumably induced by the different modes of the drug-bilayer interactions of protonated and unprotonated forms of TFZ. Only phosphatidylcholine, which possesses polar heads less densely packed in bilayers than phosphatidylethanolamine ones, was able to distinguish between the different protonated forms of TFZ. 

Anantharamaiah GM, Jones JL, Brouillette CG, Schmidt CF, Chung BH, Hughes TA, Bhown AS, Segrest JP (1985) Studies of synthetic peptide analogs of the amphipathic helix. Structure of complexes with dimyristoyl phosphatidylcholine. J Biol Chem 260 10248-10255... 

Milon, A., Wolff, G., Ourisson, G. et al. (1986). Organisation of carotenoid-phospholipid bilayer systems incorporation of zeaxanthin, astaxanthin, and their C50 homologues into dimyristoyl-phosphatidylcholine vesicles. Helvetica Chimica Acta, 69,... 

Schultz, T.W. and Seward, J.R. (2000) Dimyristoyl phosphatidylcholine/water partitioning-dependent modeling of narcotic toxicity to Tetrahymena pyriformis. Quant. Struct. -Act. Rdat.,... 

Fig. 6 Plot of membrane tension t as a function of dilation for a wide range of copolymer amphiphiles as extracted from MD simulations. The computational models, derived from systematic coarse-graining (black symbols), show nearly the same dilational behavior marked by the solid line. The slope of the line, ka, is very close to experimental measurements performed on giant vesicles 0colored symbols). Experimental data for a dimyristoyl phosphatidylcholine lipid membrane are also shown. The point of membrane lysis as observed experimentally for selected lipid and polymersome systems is also shown in the plot with green and red stars, respectively. Reprinted by permission from Macmillan Publishers Ltd Nature Materials, Ref. [85], copyright (2004)...

The thermotropic phase transition temperature of a vesicle composed of a mixture of dipalmitoyl and dimyristoyl phosphatidylcholine (DPPC and DMPC, respectively) is intermediate between the phase transition temperatures of the single lipid vesicles and reflects the relative concentrations of the two lipids in the vesicle. This can be used to determine the rate of exchange of phosphatidylcholine between two unilamellar vesicles of initially pure phospholipid. 

Helmkamp (1980a) studied the effect of the fatty acid composition of the acceptor lipid on the stimulation of phosphatidylinositol transfer from rat liver microsomes to phosphatidylcholine vesicles by bovine brain exchange protein. Acceptor vesicles containing egg phosphatidylcholine or dioleoyl phosphatidylcholine gave approximately the same transfer activity, whereas dielaidoyl phosphatidylcholine or dimyristoyl phosphatidylcholine vesicles produced lower transfer rates. Zborowski and Demel (1982) used the same protein and measured the rate of transfer of phosphatidylinositol from a monolayer to phosphatidylcholine vesicles. Vesicles of egg, dioleoyl, dielaidoyl, and dipalmitoyl phosphatidylcholine, even below its phase transition temperature, all gave equivalent transfer rates. However, a reduced rate was found when dimyristoyl and dilin-oleoyl phosphatidylcholine, and other phosphatidylcholines with two polyunsaturated fatty acids, were used. Table IV shows a comparison of the transfer activities measured in the two assays. The transfer rates are expressed as a percent of the transfer rate obtained with egg phosphatidylcholine acceptor vesicles. 

Kasper and Helmkamp (1981) used egg and dimyristoyl phosphatidylcholine vesicles as acceptor membranes in a transfer assay. By varying the temperature of the exchange reaction and thereby the physical state of the vesicles, they showed that the protein interacts preferentially with vesicles in the liquid-crystalline state. 

DMPC dimyristoyl phosphatidylcholine HDL high-density lipoprotein... 

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