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Updated: Oct 2, 2026

Genetically-encoded Molecular Probes to Study G Protein-coupled Receptors
Published on: September 13, 2013
Reconstitution of partially purified opioid receptors with a GTP-binding protein
1Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan.
Abstract:
Partially purified opioid receptors, obtained from rat brains using an affinity resin, AF-Amino Toyopearl with [D-Ala2, Leu5]enkephalin, were reconstituted with an inhibitory GTP-binding protein (Gi). In the reconstituted system, the displacement curve for the binding of a delta-agonist, [D-Ala2, D-Leu5]enkephalin, showed two states, high and low affinity binding ones, with different affinities for the agonist. The high affinity binding was eliminated by the addition of a guanine nucleotide analog to the system. These results directly showed that opioid receptors, at least the delta-type, could interact with Gi.
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