The action of botulinum toxin on cholinergic nerve terminals isolated from the electric organ of Torpedo marmorata. Detection of a putative toxin receptor.

Botulinum neurotoxin type A (BoNTx) inhibits the release of acetylcholine (ACh) from Torpedo electric organ synaptosomes. We have studied several biochemical and morphological aspects in order to characterize the molecular interactions of BoNTx intoxication in our preparation. 1. We are describing for the first time an electrophoretic band from cholinergic presynaptic plasma membrane (PSPM) that is recognized by 125I-BoNTx as a putative BoNTx receptor. 2. Furthermore we describe direct interaction of botulinum toxin-gold complexes with synaptic vesicles through the three-step model of the BoNTx intoxication.