Postprint version. Published in Biochimica et Biophysica Acta (BBA) - Biomembranes, Volume 1280, Issue 2, April 26, 1996, pages 169-172.
NOTE: At the time of publication, the author John P. Hagen was not yet affiliated with Cal Poly.
The definitive version is available at https://doi.org/10.1016/0005-2736(96)00009-0.
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°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.
Biochemistry | Chemistry