Fig. 7. Comparison of V-ATPase in the synaptosomal plasma membrane and synaptic vesicles. After biotinylation of intact synaptosomes, the biotinylated plasma membrane (B) was isolated on streptavidin-coated beads. Its antigenic content was compared with that of purified synaptic vesicles (sv). Samples were adjusted to contain similar VAMP-2 amounts. C, background binding of unbiotinylated synaptosomal membranes to streptavidin beads.