Effect of diacylglycerols on calcium-induced fusion of phosphatidylserine/phosphatidylcholine vesicles.

forming lipids are removed and thus the constraints on formation of non-bilayer structures are reduced. The action of cryopreservatives, based on these effects of temperature and water activity on thc phase behaviour o f membrane lipids, may be predicted to affect membrane lipids in such a way as t o preserve the phase bchaviour close t o that prevailing at physiological temperatures. Thus cryoprotective agents would act t o lower the lamellar-non-bilayer phase transition temperature of thc bilaycr-forming lipids. Furthermore, by reducing thc temperature at which ice crystallizes, formation o f lamellar gel phases comprised o f non-bilayer lipids may be prevented and the action o f acidic lipids can be manifested at lower temperatures.