Specificity of α-Bungarotoxin binding to Torpedo californica electroplax

Abstract

Binding of [ 125I]α-Bungarotoxin to Triton X-100 extracts of Torpedo californica electroplax membranes has been studied. Major and minor binding components have been observed; these differ in their apparent Stokes radii and in their behaviour in sucrose density gradients. The concentrations of both toxin binding components agree with previous studies of cholinergic ligand binding to membrane particles of the related species Torpedo marmorata. Some physical parameters of the major binding component compare with those previously determined for a toxin-binding macromolecule from Electrophorus electricus.