Related Experiment Video
Updated: Aug 17, 2026

Using an α-Bungarotoxin Binding Site Tag to Study GABA A Receptor Membrane Localization and Trafficking
Published on: March 28, 2014
Brain regional heterogeneity of pH effects on GABA(A) receptor-associated [35s]TBPS binding
Mikko Uusi-Oukari1, Paula Kosonen, Gregg E Homanics
1Department of Pharmacology and Clinical Pharmacology, University of Turku, Turku, Finland. mikko.uusi-oukari@utu.fi
Abstract:
We have utilized quantitative autoradiography with the GABA(A) receptor chloride channel blocker [35S]t-butylbicyclophosphorothionate ([35S]TBPS) in rodent brain sections to investigate if differential proton modulation of various GABA(A) receptor subtypes expressed in various brain regions are differentially sensitive to pH alternations. Acidic and basic pHs decreased the binding, the mean values at pH 5.4 and pH 9.4 being 17% and 76% of the binding at pH 7.4, respectively. The regional profiles of the pH effects could be divided into two types. In regions with high basal binding at pH 7.4. the pH profile was usually 'bell-shaped,' with maximal binding at pH 7.4 (type 1). In regions with low basal binding at pH 7.4, the pH profile (type 2) revealed very low binding at pH 5.4, lower sensitivity to high pH, and usually maximal binding at pH 8.4. In brain regions with type 1 pH modulation alpha1 and beta2 subunits are abundantly expressed, whereas alpha2 and beta3 subunits are abundant in type 2 regions. Therefore the alpha1beta2gamma2 and alpha2beta3gamma2 receptor subtypes are suggested to be preferentially responsible for brain regional heterogeneity of the pH modulation of [35S]TBPS binding.
More Related Videos
Related Concept Videos
GPCR Desensitization
Ligand-Gated Ion Channel Receptor: Gating Mechanism
The Two-State Receptor Model
The binding affinity of a drug determines its interaction with one...
Factors Affecting Protein-Drug Binding: Drug-Related Factors
One crucial factor in drug-protein binding is the drug's lipophilicity or its affinity for fat. More lipophilic drugs tend to have higher binding extents. For example, highly lipophilic drugs like cloxacillin exhibit substantial protein binding, with as much as 95% of the drug binding to proteins. In contrast,...

