Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that mediate fast synaptic transmission in the insect nervous system and are targets of a major group of insecticides, the neonicotinoids. They consist of five subunits arranged around a central ion channeL Since the subunit composition determines the functional and pharmacological properties of the receptor the presence o...

Nicotinic acetylcholine receptors are prototypes for the pharmaceutically important family of pentameric ligand-gated ion channels. Here we present atomic resolution structures of nicotine and carbamylcholine binding to AChBP, a water-soluble homolog of the ligand binding domain of nicotinic receptors and their family members, GABAA, GABAC, 5HT3 serotonin, and glycine receptors. Ligand binding ...

We report here the biologically active conformation of acetylcholine when bound to the high-affinity state of the receptor from Torpedo californica. The acetylcholine conformation was determined in the free and bound states by proton NMR two-dimensional nuclear Overhauser effects. In agreement with x-ray crystallographic data, acetylcholine in solution has an extended conformation with an avera...

The rate constants of acetylcholine receptor channels (AChR) desensitization and recovery were estimated from the durations and frequencies of clusters of single-channel currents. Diliganded-open AChR desensitize much faster than either unliganded- or diliganded-closed AChR, which indicates that the desensitization rate constant depends on the status of the activation gate rather than the occup...