Conformation-dependent hydrophobic photolabeling of the nicotinic receptor: electrophysiology-coordinated photochemistry and mass spectrometry.

ABSTRACT: We characterized the differential accessibility of the nicotinic acetylcholine receptor alpha1 subunit in the open, closed, and desensitized states by using electrophysiology-coordinated photolabeling by several lipophilic probes followed by mass spectrometric analysis. Voltage-clamped oocytes expressing receptors were preincubated with one of the lipophilic probes and were continually exposed to acetylcholine; UV irradiation was applied during 500-ms pulses to + 40 or to -140 mV (which produced closed or approximately 50% open receptors, respectively). In the open state, there was specific probe incorporation within the N-terminal domain at residues that align with the beta8-beta9 loop of the acetylcholine-binding protein. In the closed state, probe incorporation was identified at several

SUBMITTER: Leite JF 

PROVIDER: S-EPMC240743 | biostudies-literature | 2003 Oct

REPOSITORIES: biostudies-literature