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PubMed · 8639690

Critical pressures in multicomponent lipid monolayers.

J P Hagen·H M McConnell
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Abstract

Epifluorescence microscopy has been used previously to study coexisting liquid phases in lipid monolayers of dihydrocholesterol and dimyristoylphosphatidylcholine at the air/water interface. This binary mixture has a critical point at room temperature (22 degrees C), a monolayer pressure of approx. 10 mN/m, and a composition in the vicinity of 20-30 mol% dihydrocholesterol. It is reported here that this critical pressure can be lowered, raised, or maintained constant by systematically replacing molecules of this phosphatidylcholine with molecules of a phosphatidylethanolamine, or an unsaturated phosphatidylcholine, or mixtures of the two, while maintaining the dihydrocholesterol concentration at 20 mol%. Thus, even complex mixtures of lipids may be characterized by a single, well-defined second-order phase transition. In principle, such transitions might be found in biological membranes.

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CholestanolMicroscopy, FluorescenceModels, ChemicalPhospholipidsJournal ArticleResearch Support, U.S. Gov't, Non-P.H.S.

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J P Hagen, H M McConnell. 1996-04-26. Critical pressures in multicomponent lipid monolayers.. https://doi.org/10.1016/0005-2736(96)00009-0

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