Nicotinic acetylcholine receptors(nAChR)are ligand-gated ion channels that are involved in fast synaptic transmission and mediated physiological activities in the nervous system.α-Conotoxin IM1 exhibits subtype-specific nicotinic acetylcholine reeptor blockade,preferential inhibition of homomeric α7 and α9 receptors.In this study,a method was established to build α7 nicotinic acetylcholine receptor and α-IM1 dimer complex model using AMBER16.Two different force field parameters are applied to this method,breaking the force field boundary between protein and organic molecules.In this way,organic molecules and peptides are integrated together for molecular dynamic simulations.The constructed model not only reveals the high activity and high selectivity of the α-IM1 dimer to the α7 nicotinic acetylcholine receptor at molecular level,but also is useful as guidance for design of more selective conotoxin dimers used as neurochemical tools.