Partial purification of the Glycera convoluta venom components responsible for its presynaptic effects

The crude extract of glands appended to the jaws of the polychaete annelid Glycera convoluta induces an important increase in the spontaneous quantal transmitter release on frog and crayfish neuromuscular junctions and on Torpedo nerve-electroplaque junctions. The venom similarly triggers acetylcholine (ACh) release from synaptosomes purified from Torpedo electric organ. At the frog neuromuscular junction, the reproducibility, the reversibility and the dose-dependence of the venom action permit a quantitative evaluation of the effect. The crude venom extract has been fractionated by gel-filtration. The effect on transmitter release has been found in a high molecular weight fraction distinct from those which contain the protease and phospholipase activities.