Abstract:
:The three phases of dipalmitoylphosphatidylcholine-water dispersions, occurring below the main transition are studied by a moment analysis of 1H-nuclear magnetic resonance (NMR) spectra. The subtransition, recently detected by Chen, S. C., J. M. Sturtevant, and B. J. Gaffney, 1980, Pro. Natl. Acad. Sci. USA, 77:5060-5063, is characterized by a sharp drop in the second moment at 12 degrees C as a result of increasing the temperature. Interesting features of this phase transition are a hysteresis of 11 K and extremely slow kinetics. It is interpreted as the onset of a flip-flop of the hydrocarbon chains about their long axis. At the pretransition, this type of motion is assumed to change into a fast rotation. The proposed models for the three phases are confirmed by computer calculations of theoretical values for the second and fourth moments of the corresponding NMR signals.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Trahms L,Klabe WD,Boroske Edoi
10.1016/S0006-3495(83)84396-3subject
Has Abstractpub_date
1983-06-01 00:00:00pages
285-93issue
3eissn
0006-3495issn
1542-0086pii
S0006-3495(83)84396-3journal_volume
42pub_type
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