Dynamic properties of binary mixtures of phosphatidylcholines and cholesterol

We have observed the paramagnetic resonance spectra of a head group spin-labeled phosphatidylethanolamine (L-alpha-dipalmitoylphosphatidyl-N-ethanolamine) as a function of temperature and cholesterol concentration in binary mixtures of cholesterol and dimyristoylphosphatidylcholine. These spectra bear on two interrelated topics involving mixtures of phosphatidylcholine and cholesterol: (1) lipid phase equilibria and the lateral ordering and diffusion of lipid molecules and (2) model membrane immunochemistry using spin-label lipid haptens.