Dimyristoylphosphatidylcholine DMPC

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.)...

Conformational changes in BmorPBP were also studied in the presence of model membranes using CD spectroscopy. Conformational changes more pronounced than those observed at low pH were detected in the presence of anionic vesicles of dimyristoylphosphatidylglycerol (DMPG), whereas the effect of neutral phospholipids vesicles, dimyristoylphosphatidylcholine (DMPC) was... 

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

Recently, the investigation of monolayer models of biological membranes by neutron reflectometry has received some attention. For example, the changes in the structure of monolayers of dimyristoylphosphatidylglycerol (DMPG) and dimyristoylphosphatidylcholine (DMPC), which accompany the transition from an expanded to a condensed state, were reported by Bayerl et al. (1990). Monolayers composed of a mixture of perdeuterated DMPC and DMPG in the ratio 7 3 were deposited on D2O and ACMW subphases to... 

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. 

Fig. 8. Ability of apolipoprotein E-dimyristoylphosphatidylcholine (DMPC) complexes of the three major isoforms to compete with human I-labeled LDL for binding to normal human fibroblasts. Cells incubated in medium containing 10% human lipoprotein-deficient serum received 1 ml of the same medium with 2 of 1-labeled...

Fluorescence quenching studies showed that chlorophyll a molecules are solubilized by dimyristoylphosphatidylcholine (DMPC) only up to concentrations of around 1 mol %. Excess molecules precipitate almost exclusively in domains containing chlorophyll. Pheophytin a solubility in liquid DMPC amounts to about 10 mol %. 

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

In 1991, Johnson et al. reported one of the first NR studies of phospholipid bilayers at the solid-solution interface [46]. Although these measurements were not the first to employ NR to study molecules adsorbed at the solid-hquid interface, they did constitute the first measurements of a supported bilayer using NR. A bilayer of dimyristoylphosphatidylcholine (DMPC) was spread on a quartz surface by the fusion and rupturing of smaU unilamellar vesicles. The very smooth, singlecomponent substrate aUowed a complex model of the interface to be constructed from layers corresponding to (i) the quartz, (ii) a thin film of water on the quartz... 

Log D membrane, or log D em/ is another way of measuring the lipophilicity of a compound, which is less frequently used than the octanol/water partition system. Log Dmem utilizes liposomes prepared from the synthetic phospholipids dimyristoylphosphatidylcholine (DMPC), and although the system is more physiologically relevant than octanol, it suffers from a lack of predictability. This method requires 1 mg of the compound, whereby a solution of the compound is equilibrated with a solution of DMPC liposomes at 37°C for two hours. The free and liposome-bound compounds are then separated by centrifugation, and the solutions are analyzed by high-performance liquid chromatography (HPLC). 

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... 

Entrapment of drug substances in liposomes and micelles can lead to changes in their stability. When entrapment reduces the degradation rate, it can be used as a method for stabilizing pharmaceuticals. Aspirin can be partially stabilized by incorporation in L-a-dimyristoylphosphatidylcholine (DMPC)-based liposomes.489-491 Anesthetics such as procaine are also stabilized by incorporation in liposomes.490 Physostigmine salicylate in a phospholipid emulsion is stabilized through interaction with phospholipids at the oil-water interface and through incorporation into the internal phase of the emulsion (Fig. 131).549... 

---