α-conotoxin-GI

α-conotoxin GI (alpha-conotoxin GI) is a conopeptide that has been isolated from the venom of the cone snail Conus geographus. α-conotoxin GI is a competitive antagonist of the muscle-type nicotinic acetylcholine receptors (nAChR) such as α-conotoxin MI or d-Turbocurarine. α-conotoxin GI allows to distinguish between the two agonist sites as it binds 10,000-fold more tightly to the α/δ than to the α/γ site excepted in Torpedo which is the reverse.