Skip to Main content Skip to Navigation
Journal articles

A Novel Bifunctional Alkylphenol Anesthetic Allows Characterization of gamma-Aminobutyric Acid, Type A (GABAA), Receptor Subunit Binding Selectivity in Synaptosomes.

Abstract : Propofol, an intravenous anesthetic, is a positive modulator of the GABAA receptor, but the mechanistic details, including the relevant binding sites and alternative targets, remain disputed. Here we undertook an in-depth study of alkylphenol-based anesthetic binding to synaptic membranes. We designed, synthesized, and characterized a chemically active alkylphenol anesthetic (2-((prop-2-yn-1-yloxy)methyl)-5-(3-(trifluoromethyl)-3H-diazirin-3-yl)phenol, AziPm-click (1)), for affinity-based protein profiling (ABPP) of propofol-binding proteins in their native state within mouse synaptosomes. The ABPP strategy captured approximately 4% of the synaptosomal proteome, including the unbiased capture of five alpha or beta GABAA receptor subunits. Lack of gamma2 subunit capture was not due to low abundance. Consistent with this, independent molecular dynamics simulations with alchemical free energy perturbation calculations predicted selective propofol binding to interfacial sites, with higher affinities for alpha/beta than gamma-containing interfaces. The simulations indicated hydrogen bonding is a key component leading to propofol-selective binding within GABAA receptor subunit interfaces, with stable hydrogen bonds observed between propofol and alpha/beta cavity residues but not gamma cavity residues. We confirmed this by introducing a hydrogen bond-null propofol analogue as a protecting ligand for targeted-ABPP and observed a lack of GABAA receptor subunit protection. This investigation demonstrates striking interfacial GABAA receptor subunit selectivity in the native milieu, suggesting that asymmetric occupancy of heteropentameric ion channels by alkylphenol-based anesthetics is sufficient to induce modulation of activity.
Document type :
Journal articles
Complete list of metadata

https://hal.archives-ouvertes.fr/hal-01497996
Contributor : Jérôme Hénin Connect in order to contact the contributor
Submitted on : Wednesday, March 29, 2017 - 4:03:30 PM
Last modification on : Wednesday, February 9, 2022 - 3:46:13 AM

Links full text

Identifiers

Citation

Kellie A. Woll, Sruthi Murlidaran, Benika J. Pinch, Jérôme Hénin, Xiaoshi Wang, et al.. A Novel Bifunctional Alkylphenol Anesthetic Allows Characterization of gamma-Aminobutyric Acid, Type A (GABAA), Receptor Subunit Binding Selectivity in Synaptosomes.. Journal of Biological Chemistry, American Society for Biochemistry and Molecular Biology, 2016, 291, pp.20473--86. ⟨10.1074/jbc.M116.736975⟩. ⟨hal-01497996⟩

Share

Metrics

Record views

44