ABSENCE OF CHIRAL DOMAINS IN MIXTURES OF DIPALMITOYLPHOSPHATIDYLCHOLINE MOLECULES OF OPPOSITE CHIRALITY

We present calorimetric data for liposome mixtures of l-dipalmitoylpho sphatidylcholine with perdeuterated hydrocarbon chains (I-DPPC-d(62)) and d-DPPC at varying molar concentrations and excess water (less than or equal to 30% by wt.) conditions. The data are consistent with a bi nary system whose components exhibit complete mutual solid solubility. Therefore, the asymmetric ripples observed in racemic dimyristoylphos phatidylcholine bilayers in the P-beta' phase [Katsaras and Raghunatha n, Phys. Rev. Lett. 74, 2022 (1995)] are not the result of pure enanti omer domains.