Membrane skeleton detachment in spherical and cylindrical microexovesicles

We observed that amphiphile-induced microexovesicles may be spherical or cy lindrical, depending on the species of the added amphiphile. The spherical microexovesicle corresponds to an extreme local difference between the two monolayer areas of the membrane segment with a fixed area, while the cylind rical microexovesicle corresponds to an extreme local area difference if th e area of the budding segment is increased due to lateral influx of anisotr opic membrane constituents. Protein analysis showed that both types of vesi cles are highly depleted in the membrane skeleton. It is suggested that a p artial detachment of the skeleton in the budding region is favoured due to accumulated skeleton shear deformations in this region. (C) 1999 Society fo r Mathematical Biology.