Some binary mixtures of cholesterol and phospholipids in monolayers have thermodynamic phase diagrams with two upper miscibility critical points. This feature has been interpreted in terms of 'condensed complexes' between the phospholipid and cholesterol. The present work gives evidence for the formation of complexes with a common simple integral stoichiometry in binary mixtures of cholesterol and a series of five sphingomyelins where the amide-linked acyl chain length is varied. This indicates that these complexes have a distinct geometry even though they form a liquid phase.
Bibliographical noteFunding Information:
We are indebted to Thomas Anderson for helpful discussions concerning condensed complexes and the Penrose tiling of a plane. This work was supported by the NIH 5R01AI13587-25 (H.M.M.) and the NIGMS 45928 (R.E.B.).
- Critical point
- Liquid mixture
- Phase diagram