Affinity Purification of Nicotinic Acetylcholine Receptor from Rat Brain

Abstract

Recently, several kinds of neuronal nicotinic acetylcholine receptor (nAChR) genes have been identified. Complementary DNA expression experiments performed in Xenopus oocytes have shown that both ACh-binding ( α subunit) and another nonACh binding subunits (β subunit) are necessary to form a functional nAChR. Monoclonal antibody (mAb) column chromatography has been developed to purify nAChR from chicken, rat, bovine and human brains (Lindstrom et al., 1987), which have shown that chicken brain contains two ACh-binding subunits and one structural subunit which form two subtypes of nAChRs, whereas rat and bovine brains contain only one ACh-binding subunit and one structural subunit. In this case, the immuno-affinity-purified nAChR accounts for more than 90% of the high affinity H-nicotine binding sites in a detergent extract of rat brain. To date, minor components of nAChR in brains have not been purified. Furthermore, it still remains obscure as to pharmacological roles of each subtype of neuronal nAChR. To investigate the heterogeneity of neuronal nAChR, cholinergic ligand affinity purification of the nAChR would be useful. In this report, we deal with cholinergic ligand affinity purification of nAChR from rat brain.