Fig. 5.

Vti1a-β copurified with synaptic vesicles. Synaptosomes (P2) were isolated from rat brain homogenate (H). The synaptosomes were osmotically lysed and separated into a low-speed membrane fraction (LP1) containing synaptic plasma membranes and a high-speed pellet (LP2) with synaptic vesicles. The synaptic vesicles were further purified by sucrose density gradient centrifugation and chromatography on a CPG column yielding the highly enriched fraction CPG3. Vti1a-β copurified with the synaptic vesicle marker synaptobrevin (Syb). Vti1b was present in synaptic vesicles but was not enriched compared with homogenate.