High pressure 2H nuclear magnetic resonance study of the gel phases of dipalmitoylphosphatidylcholine

✍ Scribed by Daniel A. Driscoll; Jiri Jonas; Ana Jonas

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 504 KB
• Volume: 58
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(91)90115-r

✦ Synopsis

The 2H-NMR lineshapes of dipalmitoylphosphatidylcholine perdeuterated in the acyl chains were studied in a 15% dispersion in water as a function of pressure from 1 bar to 5 kbar over the temperature range from 7 degrees C to 75 degrees C. Increasing pressure in the gel state had the same effect as lowering the temperature: the lineshape gradually changed from a motionally averaged to a rigid lattice type spectrum with much of the intensity in the shoulders at +/- 63 kHz. At very high pressures and low temperatures (7 degrees C, 2.5 kbar; 25 degrees C, 5 kbar) even the methyl portion of the spectrum became a rigid lattice type spectrum at +/- 21 kHz. In addition to the liquid crystalline phase, five gel phases were detected. Using different techniques to determine the phase transitions, a general pressure-temperature phase diagram was constructed.