Incorporation of Phospholipid Analogs into the Plasma Membrane Affects ATP-Induced Vesiculation of Human Erythrocyte Ghosts

The influence of various spin-labelled phospholipid analogues on the ATP-dependent vesiculation of human erythrocyte ghosts at 37°C was investigated by monitoring the acetylcholinesterase activity. After incorporation of analogues into the outer leaflet a decline of endocytic vesiculation was observed. However, suppression was arrested after about 20 min when ghosts have been labelled with a phosphatidylserine analogue known to redistribute rapidly to the inner leaflet. These data suggest that vesiculation of erythrocyte ghosts is affected by differential expansion of the inner and outer leaflet.