Solubilization and characterization of the acceptor for Clostridium botulinum type B neutroxin from rat brain synaptic membranes

The acceptor for Clostridium botulinum type B neurotoxin was solubilized from rat brain synaptic membrane with nonionic detergent, nonanoyl-N-methylglucamide (MEGA-9). The solubilized acceptor was assayed for the binding activity by precipitating the acceptor with acetone in the presence of phosphatidylcholine. ¹²⁵Ilabeled neutroxin specifically bound to the lipid vesicles having incorporated the acceptor together with gangliosided. The lipid vesicles having incorporated either the acceptor or gangliosides alone showed extremely low binding activity. The treatment of the solubilized acceptor with lysyl endopeptidase and accompanying an N-linked carbohydrate moiety. The observations suggest also that a protein acceptor/ganglioside complex may be required to form the functional toxin receptor.