Skip to Main content Skip to Navigation
Journal articles

Barbiturates Bind in the GLIC Ion Channel Pore and Cause Inhibition by Stabilizing a Closed State

Abstract : Barbiturates induce anesthesia by modulating the activity of anionic and cationic pentameric ligand-gated ion channels (pLGICs). Despite more than a century of use in clinical practice, the prototypic binding site for this class of drugs within pLGICs is yet to be described. In this study, we present the first X-ray structures of barbiturates bound to GLIC, a cationic prokaryotic pLGIC with excellent structural homology to other relevant channels sensitive to general anesthetics and, as shown here, to barbiturates, at clinically relevant concentrations. Several derivatives of barbiturates containing anomalous scatterers were synthesized, and these derivatives helped us unambiguously identify a unique barbiturate binding site within the central ion channel pore in a closed conformation. In addition, docking calculations around the observed binding site for all three states of the receptor, including a model of the desensitized state, showed that barbiturates preferentially stabilize the closed state. The identification of this pore binding site sheds light on the mechanism of barbiturate inhibition of cationic pLGICs and allows the rationalization of several structural and functional features previously observed for barbiturates.
Document type :
Journal articles
Complete list of metadatas

https://hal-pasteur.archives-ouvertes.fr/pasteur-02174609
Contributor : Marie de Tarragon <>
Submitted on : Friday, July 5, 2019 - 11:12:36 AM
Last modification on : Wednesday, September 16, 2020 - 5:51:38 PM

Links full text

Identifiers

Collections

Citation

Zaineb Fourati, Reinis Reinholds Ruza, Duncan Laverty, Emmanuelle Drège, Sandrine Delarue, et al.. Barbiturates Bind in the GLIC Ion Channel Pore and Cause Inhibition by Stabilizing a Closed State. Journal of Biological Chemistry, American Society for Biochemistry and Molecular Biology, 2017, 292 (5), pp.1550-1558. ⟨10.1074/jbc.M116.766964⟩. ⟨pasteur-02174609⟩

Share

Metrics

Record views

120