Subcellular Localization and Properties of a Cholinergic Receptor Isolated From Housefly Heads

Abstract —Protein(s) possessing the ligand‐binding properties expected of the insect cholinergic receptor were demonstrated in both aqueous and chloroform‐methanol extracts of an 80,000 g supernatant obtained from frozen housefly heads. There is reasonable correlation in both the properties and concentration of the housefly head cholinergic receptor in these radically different extracts. Binding constants for decamethonium, acetylcholine, nicotine and atropine have been determined with aqueous housefly head extracts using an ultrafiltration assay. These observations are taken as further evidence that the cholinergic receptor in the insect central nervous system differs in specificity to the more widely studied nicotinic and muscarinic cholinergic receptors from vertebrates.