Sickled erythrocytes: A model to study the stabilization of the phospholipid bilayer in the red cell membrane

The (human) erythrocyte membrane is characterized by a high degree of asymmetry in distribution of the various phospholipid classes over both halves of the bilayer. Studies on sickled erythrocytes, as well as those on chemically modified normal red cells, strongly suggest that the cytoskeleton plays an important role in the stabilization of the lipid bilayer, particularly as far as it concerns the glycero-phospholipids herein. Both their asymmetric orientation in the membrane, as well as their slow transbilayer movements, seem to be conrolled by - direct interactions with - the cytoskeletal network. Structural changes in this network, on the other hand, do not affect the orientation of SM in the membrane, which suggests that the orientation of this sphingo-phospholipid is governed by interactions with other membrane constituents.