Adenosine Triphosphatase Activity Associated with Purified Cholinergic Synaptic Vesicles of Torpedo marmorata

Abstract
A rapid method for purifying Torpedo electric organ vesicles is described, which employs an isoosmotic continuous sucrose-glycine gradient followed by chromatography on CPG-10-3000 porous glass beads. Synaptic vesicles have a buoyant density of 1.057 g/ml. Purified vesicles are free of cholinesterase, lactate dehydrogenase and Na+,K+-stimulated ATPase activity. They contain a ouabain-insensitive Na+,K+-inhibited, Mg2+, Ca2+-stimulated ATPase activity. This is further stimulated by acetylcholine but not by choline.