Theory of superstructures in lipid monolayer phase transitions

D. J. Keller, H. M. McConnell, Vincent T. Moy

Research output: Contribution to journalArticle

136 Citations (Scopus)

Abstract

We present a theory which explains the thermodynamically controlled striplike shapes of two-dimensional solid "crystal" domains observed in phospholipid monolayers in the presence of trace amounts of cholesterol. In the theory, dipole-dipole repulsions between lipid molecules favor the elongation of the domains into long strips, but this elongation is opposed by increasing interfacial free energy (line tension) associated with the perimeter of the domains. The width of the striplike domains is determined by a balance of dipolar and line tension forces and is found to vary exponentially with the ratio X/A where X is the line tension and Δμ is the difference in dipole density between the solid and fluid phases. We then derive an expression for the dependence of the line tension on the concentration of cholesterol molecules in the monolayer and use this relation to compare the predictions of the theory to experimental measurements of the width of the domains as a function of monolayer compression. The theory is found to agree well at high compression but deviates from experiment at low compression, where the domains are short and end effects neglected in the theory become important.

Original languageEnglish
Pages (from-to)2311-2315
Number of pages5
JournalThe Journal of Physical Chemistry®
Volume90
Issue number11
StatePublished - Dec 1 1986
Externally publishedYes

Fingerprint

Lipids
lipids
Monolayers
Phase transitions
Cholesterol
Elongation
Molecules
Phospholipids
cholesterol
dipoles
Free energy
elongation
Crystals
Fluids
solid phases
molecules
strip
Experiments
free energy
fluids

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Theory of superstructures in lipid monolayer phase transitions. / Keller, D. J.; McConnell, H. M.; Moy, Vincent T.

In: The Journal of Physical Chemistry®, Vol. 90, No. 11, 01.12.1986, p. 2311-2315.

Research output: Contribution to journalArticle

Keller, D. J. ; McConnell, H. M. ; Moy, Vincent T. / Theory of superstructures in lipid monolayer phase transitions. In: The Journal of Physical Chemistry®. 1986 ; Vol. 90, No. 11. pp. 2311-2315.
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