Effect of fatty acyl chain length and structure on the lamellar gel to liquid-crystalline and lamellar to reversed hexagonal phase transitions of aqueous phosphatidylethanolamine dispersions

Journal Article · Tue Jan 24 00:00:00 EST 1989 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00428a020· OSTI ID:5640343

Lewis, R N.A.H.; Mannock, D A; McElhaney, R N; Turner, D C; Gruner, S M ^[1]

---

1. Univ. of Alberta, Edmonton (Canada)

The lamellar gel/liquid-crystalline and the lamellar liquid-crystalline/reversed hexagonal phase transitions of aqueous dispersions of a number of synthetic phosphatidylethanolamines containing linear saturated, branched chain, and alicyclic fatty acyl chains of varying length were studied by differential scanning calorimetry, {sup 31}P nuclear magnetic resonance spectroscopy, and X-ray diffraction. For any given homologous series of phosphatidylethanolamines containing a single chemical class of fatty acids, the lamellar gel/liquid-crystalline phase transition temperature increases and the lamellar liquid-crystalline/reversed hexagonal phase transition temperature decreases with increases in hydrocarbon chain length. For a series of phosphatidylethanolamines of the same hydrocarbon chain length but with different chemical structures, both the lamellar gel/liquid-crystalline and the lamellar liquid-crystalline/reversed hexagonal phase transition temperatures vary markedly and in the same direction. These results suggest that for any given hydrocarbon chain length, there may be a critical thickness at which the liquid-crystalline phosphatidylethanolamine bilayer becomes unstable with respect to inverted nonbilayer phases such as the H{sub II} phase and that the temperature at which this critical thickness is reached is dependent upon that bilayers proximity to the hydrocarbon chain-melting phase transition temperature.

• DOE Contract Number: FG02-87ER60522
• OSTI ID: 5640343
• Journal Information: Biochemistry; (USA), Vol. 28:2; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
MEMBRANES
CONFORMATIONAL CHANGES
PHOSPHOLIPIDS
PHASE STUDIES
AMINES
AQUEOUS SOLUTIONS
CALORIMETRY
NUCLEAR MAGNETIC RESONANCE
PHOSPHORUS 31
PROTONS
TEMPERATURE DEPENDENCE
X-RAY DIFFRACTION
BARYONS
COHERENT SCATTERING
DIFFRACTION
DISPERSIONS
ELEMENTARY PARTICLES
ESTERS
FERMIONS
HADRONS
ISOTOPES
LIGHT NUCLEI
LIPIDS
MAGNETIC RESONANCE
MIXTURES
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
RESONANCE
SCATTERING
SOLUTIONS
STABLE ISOTOPES
550602* - Medicine- External Radiation in Diagnostics- (1980-)