Gating at the mouth of the acetylcholine receptor channel: energetic consequences of mutations in the alphaM2-cap.

ABSTRACT: Gating of nicotinic acetylcholine receptors from a C(losed) to an O(pen) conformation is the initial event in the postsynaptic signaling cascade at the vertebrate nerve-muscle junction. Studies of receptor structure and function show that many residues in this large, five-subunit membrane protein contribute to the energy difference between C and O. Of special interest are amino acids located at the two transmitter binding sites and in the narrow region of the channel, where C<-->O gating motions generate a low<-->high change in the affinity for agonists and in the ionic conductance, respectively. We have measured the energy changes and relative timing of gating movements for residues that lie between these two locations, in the C-terminus of the pore-lining M2 helix of the alpha subunit ('

SUBMITTER: Bafna PA 

PROVIDER: S-EPMC2429975 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature