Linking the acetylcholine receptor-channel agonist-binding sites with the gate.

ABSTRACT: The gating isomerization of neuromuscular acetylcholine receptors links the rearrangements of atoms at two transmitter-binding sites with those at a distant gate region in the pore. To explore the mechanism of this reversible process, we estimated the gating rate and equilibrium constants for receptors with point mutations of alpha-subunit residues located between the binding sites and the membrane domain (N95, A96, Y127, and I49). The maximum energy change caused by a side-chain substitution at alphaA96 was huge (approximately 8.6 kcal/mol, the largest value measured so far for any alpha-subunit amino acid). A Phi-value analysis suggests that alphaA96 experiences its change in energy (structure) approximately synchronously with residues alphaY127 and alphaI49, but after the agonist molecu

SUBMITTER: Cadugan DJ 

PROVIDER: S-EPMC2913195 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature