The effect of incorporation of phosphonic acid dibutyl ester in POPC model membranes on the hydration force
β Scribed by F. Stallmach; U. Dietrich; G. Klose
- Book ID
- 103037739
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 514 KB
- Volume
- 74
- Category
- Article
- ISSN
- 0009-3084
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β¦ Synopsis
The hydration and swelling properties of lipid model membranes formed by mixtures of l-palmitoyl-2-oleoylglycerophosphatidyl-choline (POPC) and different molar ratios Ra/l of dodecyl phosphonic acid dibutyl ester (PAB~2) in water were studied at 25Β°C. It is shown by X-ray diffraction and 3~p NMR spectroscopy that the system exists in a fluid lamellar phase at R~/~ = 0.25 and 0.5 over a wide range of water concentration. Intermembrane forces were determined by the osmotic stress technique. The hydration repulsion was found to decrease exponentially with increasing intermembrane water layer thickness. The values of the pre-exponential factor of the hydration forces which slightly decrease with increasing R~l were discussed according to the theory of water polarization near structured water/lipid interfaces (Cevc).
π SIMILAR VOLUMES
Mixtures of egg yolk lecithin and phosphonic acid diethyl or dibutyl esters of the general type RP(O) (OR'): with R = hexane or dodecane were studied at low water concentration using 3~p. and :H-NMR. (1) The esters cause a phase transition Lo--H H at room temperature. This cannot be observed in pure
The semi-empirical PCILO (Perturbative Configuration Interaction using Localized Orbitals) method has been used to study intermolecular hydrogen bonding and proton transfer in the acetic acid -imidazole system. The effect of specific hydration on the proton potential functions was investigated (with