Curvature stress and polymorphism in membranes

A simple means of quantitating the curvature energy of membrane constituents is proposed based on the concept that the enthalpic curvature stress or stress relief that an isolated membrane constituent imparts upon a bilayer matrix is reflected by changes in the transition temperature between the bilayer and inverted hexagonal structures. Thermodynamic and shape arguments are used to critically review the effects of membrane constituents on this transition. An index of the propensity for curvature of over 150 compounds is presented ill tabular form.