Mechanisms of Uptake into Plant Protoplasts

Abstract

Studies on membrane fusion performed using lipid vesicles as model membrane systems have proven a powerful tool in the investigation of the mechanism of membrane interaction at the molecular level. Phospholipid vesicles, called liposomes, are stable structures with a limited permeability to small ions and large molecules and have been described extensively in literature (1, 2, 3). Since the construction of liposomes can be varied from single component systems to mixtures of various lipids differing both in their head group and hydrocarbon chain configuration as well as their charge, questions relating to head group specificity, bilayer fluidity, phase transitions and separations, and temperature dependent phase changes of the lipids can be studied. It is also possible to insert into the membrane other components such as cholesterol, glycolipids and proteins, as well as antibodies. Another advantage of these artificial vesicles is that known membrane-active drugs and molecules which are known to effect membrane fusion can be incorporated into the membrane and their mode of action studied in detail.