Konno_1991_Proc.Biol.Sci_244_69

Reference

Title : Rings of anionic amino acids as structural determinants of ion selectivity in the acetylcholine receptor channel - Konno_1991_Proc.Biol.Sci_244_69
Author(s) : Konno T , Busch C , Von Kitzing E , Imoto K , Wang F , Nakai J , Mishina M , Numa S , Sakmann B
Ref : Proc Biol Sci , 244 :69 , 1991
Abstract :

To gain an insight into the molecular basis of the weak but significant selectivity among alkali metal cations of the nicotinic acetylcholine receptor (AChR) channel, we have determined single-channel conductance and permeability ratios for alkali metal cations on specifically mutated Torpedo californica AChR channels expressed in Xenopus oocytes. The mutations involved charged and polar side chains in the three anionic rings (extracellular, intermediate and cytoplasmic ring) which have previously been found to determine the rate of K+ transport through the AChR channel. The results obtained reveal that mutations in the intermediate ring exert much stronger effects on ion selectivity than do mutations in the extracellular and the cytoplasmic ring. The experimental results, together with simulations of the channel's energy profile, suggest that the amino acid residues forming the intermediate ring come into close contact with permeating cations and possibly represent part of the physical correlate of the postulated selectivity filter in the AChR channel.

PubMedSearch : Konno_1991_Proc.Biol.Sci_244_69
PubMedID: 1679551

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Citations formats

Konno T, Busch C, Von Kitzing E, Imoto K, Wang F, Nakai J, Mishina M, Numa S, Sakmann B (1991)
Rings of anionic amino acids as structural determinants of ion selectivity in the acetylcholine receptor channel
Proc Biol Sci 244 :69

Konno T, Busch C, Von Kitzing E, Imoto K, Wang F, Nakai J, Mishina M, Numa S, Sakmann B (1991)
Proc Biol Sci 244 :69