Kinetic basis of partial agonism at NMDA receptors.

ABSTRACT: Activation of ligand-gated channels is initiated by the binding of small molecules at extracellular sites and culminates with the opening of a membrane-embedded pore. To investigate how perturbations at ligand-binding domains influence the gating reaction, we examined current traces recorded from individual NMDA receptors in the presence of several subunit-specific partial agonists. We found that low-efficacy agonists acting at either the glycine-binding or the glutamate-binding NMDA receptor subunits had very similar effects on the receptor's activation reaction, possibly reflecting a high degree of coupling between the two subunit types during gating. In addition, we found that partial agonists increased the height of all energy barriers encountered by NMDA receptors during activation. T

SUBMITTER: Kussius CL 

PROVIDER: S-EPMC2739723 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature