Polymorphic phase behavior of lysophosphatidylethanolamine dispersions. A thermodynamic and spectroscopic characterization.
We have investigated the phase behavior of aqueous dispersions of a series of synthetic lysophosphatidylethanolamines as a function of the acyl chain length. Lysophosphatidylethanolamines exhibit phase polymorphism encompassing a well-ordered crystalline phase which may arise either from a metastable interdigitated lamellar gel phase or a metastable micellar phase. The time course of interconversion between these various phases have been outlined by observing the low temperature incubation time dependence of the calorimetric thermograms. We have determined differences in structure of these phases by Raman spectroscopy and 31P nuclear magnetic resonance spectroscopy. It appears that a principal contribution to this polymorphic phase behavior lies in the nature of headgroup hydration and headgroup-headgroup interactions.
Department of Biochemistry and Biophysics Program, University of Virginia School of Medicine, Charlottesville 22908.
J L
JL
Slater
C H
CH
Huang
R G
RG
Adams
I W
IW
Levin
D002151:Calorimetry; D008051:Lipid Bilayers; D008246:Lysophospholipids; D009682:Magnetic Resonance Spectroscopy; D008962:Models, Theoretical; D013329:Structure-Activity Relationship; D013816:Thermodynamics
D008051:Lipid Bilayers; D008246:Lysophospholipids; C008301:lysophosphatidylethanolamine