Dimyristoylphosphatidylcholine lipids

Fig. IV-19. Fluorescence micrographs showing the shape transitions in monolayers of dimyristoylphosphatidylcholine (DMPC) (84%) and dihydrocholesterol (15%) and a lipid containing the dye, Texas Red. (From Ref. 228.)...

Sujak, A., P. Mazurek, and W.I. Gruszecki. 2002. Xanthophyll pigments lutein and zeaxanthin in lipid multibilayers formed with dimyristoylphosphatidylcholine. J. Photochem. Photobiol. B Biol. 68 39 -4. 

Experimental demonstration that the enzyme inside dimyristoylphosphatidylcholine (DMPC) vesicles was active against externally added ADP, yielding lipid vesicle trapped poly (A). 

Fig. 11. Evidence that a membrane-associated immunochemical reaction (complement fixation) depends on the mobility of the target hapten (IX) in the plane of a model membrane. The extent of the immunochemical reaction, complement fixation, is measured by A Absorbance at 413 nm. Temperature is always 32°C, which is above the chainmelting temperature (23°C) of dimyristoylphosphatidylcholine used for the data given in A and below the chain-melting transition temperature (42°C) of dipalmitoylphosphatidyl-choline used for the data in B. Thus A refers to a fluid membrane and B refers to a solid membrane. The numbers by each curve are equal to c, the mole % of spin-label hapten IX in the plane of the lipid membrane. It will be seen that complement fixation, as measured by A Absorbance at 413 nm is far more effective in the fluid membrane than in the solid membrane at low hapten concentrations (i.e., c 0.3 mo e%). In C the lipid membrane host is a 50 50 mole ratio mixture of cholesterol and dipalmitoylphosphatidylcholine. The immunochemical data suggest that this membrane is in a state of intermediate fluidity. Specific affinity-purified IgG molecules were used in these experiments. (For further details, see Ref. 5.)... 

Mabrey S, Sturtevant JM. Investigation of phase-transitions of lipids and lipid mixtures by high sensitivity differential scanning calorimetry. Proc. Natl. Acad. Sci. U.S.A. 1976 73 3862-3866. Lin HN, Huang CH. Eutectic Phase-behavior of l-stearoyl-2-cap-rylphosphatidylcholine and dimyristoylphosphatidylcholine mixtures. Biochim. Biophys. Acta 1988 946 178-184. 

Lipid-peptide mixtures were next investigated. Roughly 10 mg of dimyristoylphosphatidylcholine (DMPC) and 2.5 mg of polyAla were codissolved by 0.5 ml each of various solvent mixtures to form a clear homogeneous solution followed by freezing, and freeze-drying in vacuo. 

Phospho)lipids dimyristoylphosphatidylcholine (DMPC MW 678), dimyristoylphosphatidylglycerol (DMPG MW 689)... 

Fig. 7 A series of different lipids used for the build-up of polymer-tethered interfacial architectures (a) DMPC stands for dimyristoylphosphatidylcholine, a classical synthetic lipid (b) NBD-DMPE is a fluorescently labeled dimyristoylphosphatidyethanolamine derivative and DODA-Ess (c) and CisEse (d) are ethyloxazoline-lipopolymers of different structure...

In a vesicle an aqueous volume (water pool) is entirely enclosed by a membrane that is basically a bilayer of lipid molecules [127-137]. In the case of the unilamellar dimyristoylphosphatidylcholine (DMPC) vesicles (radius = 250 nm) there is only one such bilayer, whereas a multilamellar vesicle (radius 1000 nm) consists of several concentric bilayers. Unilamellar vesicles can be produced from multilamellar vesicles by sonication. In such a system there are two kinds of... 

Amphotericin B is complexed with deoxycholate (C-AMB) and marketed as a lyophilized powder (fungizone) containing 50 mg of amphotericin B that forms a colloid in water. Three lipid formulations of amphotericin B are marketed in the U.S. Amphotericin B colloidal dispersion (ABCD, AMPHOTEC, amphocil) contains equimolar amounts of amphotericin B and cholesteryl sulfate. AMBISOME is a small, unilamellar vesicle formulation that combines amphotericin B (50 mg) with 350 mg of lipid (phosphatidylcholine, cholesterol, and distearoylphosphatidylglycerol, in molar ratio of 10 5 4) in an -10% molar ratio. Amphotericin B lipid complex (ABLC, abelcet) contains dimyristoylphosphatidylcholine and dimyristoylphosphatidylglycerol in a 7 3 mixture with -35 mol% of amphotericin B. 

It is anticipated that oligomerization as well as lattice formation is not always straightforward for a number of membrane proteins overexpressed in a host cell like E. coli, unless identiflcation and incorporation of such specific endogenous lipids to promote the formation of a 2D lattice are seriously taken into account. As a reference system to examine the NMR spectra of such proteins by site-directed NMR approach, it seems to be very important to gain an insight into how the NMR spectra of [3- C]Ala- or [l- C]Val-labeled bR incorporated into neutral lipid bilayers such as egg phosphatidylcholine (PQ, dimyristoylphosphatidylcholine (DMPC) or dipalmytoylphosphatidylcholine (DPPC) are modified by the presence or absence of a 2D crystalline lattice. 

Figure 9.9 Temperature dependence of the maximum wavenumber of the CH2 asymmetric stretching vibrations in (a) dipalmitoylphosphatidylcholine (DPPC)-chol-esterol and (b) dimyristoylphosphatidylcholine (DMPC)-cholesterol at the molar ratios indicated. The temperature dependence for pure lipids (filled circles) is also given (CoTtijo et al., 1982).

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