Molecular modelling of the nicotinic acetylcholine receptor transmembrane region in the open state.

A model of the nicotinic acetylcholine receptor transmembrane region has been constructed which may represent the channel in its open-state. The positions of helices flanking the ion channel match those observed by electron microscopy and previously reported by others. Residues labelled, mutated or by other means known to have a strong influence on ion flux are each accessible from the lumen of the modelled channel. The model provides new insights into our current understanding of the ion channel structure, and suggests some novel explanations for the results of labelling and mutation studies such as those involving ion channel blockers and residue-dependent changes in ion selectivity.