Isolation of acetylcholine receptor-- -bungarotoxin complexes from Torpedo californica electroplax

Affinity chromatography has been utilized to purify acetylcholine receptors from Torpedo californica electroplax membranes. These have been isolated as their ¹²⁵I]α-bungarotoxin complexes. The major protein subunit found had a molecular weight of 3.5–4.5 × 10⁴ on gel electrophoresis under denaturing conditions. Other components of higher molecular weight were also present in smaller amounts even in the best preparations. This is interpreted as most likely due to either a multiple subunit structure or to more than one type of receptor in the tissue used.