Identification of the receptor for toxin II alpha from scorpion Leirus quinquestriatus in isolated lobster and squid nerve membranes.

1. Isolated membranes from lobster and squid nerves were labeled with Leirus quinquestriatus toxin II alpha. 2. Dinitrofluorophenylazide 125I-ScTx derivative was synthesized and covalently bound to the membranes. 3. It was found that the membranes of these nonmyelinated nerves present a single polypeptide located at approximately 220-230 Kd range labeled by the ScTx. 4. Rat brain membrane used for comparison presents two polypeptidic zones at 220 and 50 Kd labeled by the toxin.