Palmitoyl oleoyl phosphatidylcholine POPC

Two popular vesicle-forming surfactants are shown in Figure 9.20, fatty acids and palmitoyl-oleoyl-phosphatidylcholine (POPC). In both cases, the hydrophobic parts are emphasized. Oleate, as for most long-chain fatty acids, forms vesicle spontaneously, on simple addition of its concentrated aqueous or methanol solution into water POPC and other lipids also form hposomes spontaneously when added to water from an alcoholic solution, or by first preparing a lipid him from an organic soluhon (by evaporahon), then adding water and stirring so as to induce a vortex. 

FIGURE 2.11 A bilayer of phosphatidylcholine. Palmitoyl-oleoyl-phosphatidylcholine (POPC) molecules spontaneously form bilayer structures in water. These bilayers are closed on themselves so that water molecules are trapped inside the vesicle. Note that the association of a saturated acyl chain in R1 and an unsaturated one in R2... 

Figure 6 Results for lipid raft systems with varying amounts of POPC (palmitoyl-oleoyl-phosphatidylcholine), SM, and cholesterol (42), which shows plots for one leaflet from above. The top row for the system is a 1 1 1 mixture of POPC, SM, and cholesterol. The middle row shows data for Sg (2 1 1 for POPC SM cholesterol), and the bottom row shows data for Sq (62 1 1 for POPC SM cholesterol). The first column on the left shows data for the acyl chain order parameter (Sqq) averaged over selected carbons in POPC and SM chains. The second and third columns depict the in-plane electron densities of cholesterol and the selected chain carbons, respectively.

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... 

More recent studies showed that liposomes from POPC (a double-chain amphiphile, 1-palmitoyl-2-oleoyl-phosphatidylcholine) could also be utilized for such experiments. In these studies, the liposomes containing the enzyme were made semipermeable by adding sodium cholate, a well-described detergent. By using this technique, liposomes containing the appropriate enzyme (and template if... 

Abstract. The urea-urease system is a pH dependent enzymatic reaction that was proposed as a convenient model to study pH oscillations in vitro here, in order to determine the best conditions for oscillations, a two-variable model is used in which acid and substrate, urea, are supplied at rates kh and ks from an external medium to an enzyme-containing compartment. Oscillations were observed between pH 4 and 8. Thus the reaction appears a good candidate for the observation of oscillations in experiments, providing the necessary condition that kh > ks is met. In order to match these conditions, we devised an experimental system where we can ensure the fast transport of acid to the encapsulated urease, compared to that of urea. In particular, by means of the droplet transfer method, we encapsulate the enzyme, together with a suitable pH indicator, in a l-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) lipid membrane, where differential diffusion of H+ and urea is ensured by the different permeability (Pm) of membranes to the two species. Here we present preliminary tests for the stability of the enzymatic reaction in the presence of lipids and also the successful encapsulation of the enzyme into lipid vesicles. 

In order to provide quantitative information on the elfeets of pressure on eross-peak intensities, we earned out 2D-NOESY experiments on pure POPC (l-palmitoyl-2-oleoyl-x -glyeero-3-phosphatidylcholine (Ci6 o, Cig c )) and DMPC (l,2-dimyristoyl-OT-glyeero-3-phosphatidylcholine (di-Ci4 o)) lipid bilayers.As an example, we present data on POPC, a phospholipid which is also a very important eomponent of animal cell membranes. It has an... 

Figure 14 Structures of zwitterionic phospholipids commonly used in the formation of liposomes and lipid bilayers. Shown are l-palmitoyl-2-oleoyl-in-glycero-3-phosphocholine (POPC), l,2-ipalmitoyl-in-glycero-3-phosphocholine (DPPC), and 1,2-dioleoyl-iw-glycero-3-phosphoethanolamine (DOPE). As is the case with POPC and DPPC, the acyl chains attached to the polar phosphatidylcholine head group may correspond to various fatty acids, which can be interchanged. DOPE, on the other hand, is comprised of the same acyl chains as DPPC and POPC but differs in the headgroup.

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