Intramembrane particle aggregation in erythrocyte membranes and band 3-lipid recombinants.
The low pH-induced aggregation of intramembrane particles in human erythrocyte membranes was studied in native membranes and in a reconstituted model system. A significant difference in such aggregation was found when samples of freshly prepared ghosts were compared to ghosts receiving pretreatments that removed most of spectrin-actin from underneath the membrane. All conditions effective in aggregating particles are equally effective in precipitating extracted mixtures of spectrin and actin. In Band 3-lipid recombinants, the pH-induced aggregation of particles was duplicated only in samples containing spectrin-actin that equilibrated with these recombinants in sucrose gradients. Therefore, it was proposed that spectrin-actin components, through their associations with the underlying intramembrane particles, could impede particle lateral mobility and also determine particle redistribution in erythrocyte membrane.
Intramembrane particle aggregation in erythrocyte membranes and band 3-lipid recombinants. The low pH-induced aggregation of intramembrane particles in human erythrocyte membranes was studied in native membranes and in a reconstituted model system. A significant difference in such aggregation was found when samples of freshly prepared ghosts were compared to ghosts receiving pretreatments that removed most of spectrin-actin from underneath the membrane. All conditions effective in aggregating particles are equally effective in precipitating extracted mixtures of spectrin and actin. In Band 3-lipid recombinants, the pH-induced aggregation of particles was duplicated only in samples containing spectrin-actin that equilibrated with these recombinants in sucrose gradients. Therefore, it was proposed that spectrin-actin components, through their associations with the underlying intramembrane particles, could impede particle lateral mobility and also determine particle redistribution in erythrocyte membrane.