On the mechanism of vesicle release from @entity855 -depleted XXXX red blood cells.

@entity1 @entity2366 @entity8435 @entity3167 @entity17420 @entity1098 @entity855
The release of spectrin-free vesicles from @entity855 -depleted @entity1 red blood cells (Lutz et al. (1977) J. Cell. Biol. 73, 548) can be considered the final step of a shape change from discocytes to echinocytes. The study of physical and chemical properties of released vesicles suggests that vesicle release is not merely a consequence of charge alterations within either monolayer of the budding membrane. Fresh membranes and released vesicles have within experimental error the same @entity3167 content per surface area and the same electrophoretic mobilities. Vesicle release cannot be stimulated by doubling the charge density on the outer monolayer by means of a phospholipase D-treatment, but correlates with a breakdown of @entity17420 to @entity2366 on the inner monolayer. This breakdown does not lead to a significant change in the negative charge density on the inner monolayer, because an increased @entity8435 content compensates for this alteration. Furthermore, @entity17420 breakdown and @entity2366 production are not the rate-limiting step in vesicle release from @entity855 -depleting red blood cells. This is evident from the fact that 10 mM @entity1098 inhibits vesicle release to 75% without affecting @entity17420 breakdown and @entity2366 production. Hence, @entity2366 formation may be sufficient for membrane budding as suggested earlier (Allan et al. (1976) Nature 261, 58), but vesicle release requires a second, as yet unidentified process.
