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High-resolution Spatiotemporal Analysis of Receptor Dynamics by Single-molecule Fluorescence Microscopy
Published on: July 25, 2014
The two-state dimer receptor model: a general model for receptor dimers
Rafael Franco1, Vicent Casadó, Josefa Mallol
1Dept. Bioquimica i Biologia Molecular, Universitat de Barcelona, Av. Diagonal 645, 08028 Barcelona, Spain. rfranco@ub.edu
Molecular Pharmacology
|February 28, 2006
Summary
The two-state dimer receptor model effectively analyzes agonist binding to dimeric G-protein-coupled receptors. This model accurately fits binding data, regardless of Scatchard plot linearity, demonstrating its versatility in receptor research.
Area of Science:
- Biochemistry
- Molecular Biology
- Pharmacology
Background:
- Nonlinear Scatchard plots are common for G-protein-coupled receptor (GPCR) agonist binding.
- Receptor dimerization is established, suggesting binding site cooperativity.
- A "two-state dimer receptor model" was recently developed to explain these phenomena.
Purpose of the Study:
- To evaluate the performance of the "two-state dimer receptor model" in fitting binding data.
- To analyze agonist binding to A(1) adenosine receptors and dopamine D(1) receptors.
- To assess the model's applicability to estrogen receptor binding data.
Main Methods:
- Fitting agonist binding data to the "two-state dimer receptor model".
- Analyzing agonist/antagonist competition data for dopamine D(1) receptors.
- Comparing the "two-state dimer receptor model" with the "two-independent-site receptor model" using discrimination tests.
Main Results:
- The model successfully fitted concave downward Scatchard plots for A(1) adenosine receptors.
- The "two-state dimer receptor model" provided a simpler and better fit than the "two-independent-site receptor model" for dopamine D(1) receptors.
- The model robustly fitted concave upward Scatchard plots for estrogen receptors, predicting positive cooperativity in dimers.
Conclusions:
- The "two-state dimer receptor model" is effective for analyzing binding data of dimeric receptors.
- The model can interpret linear, concave upward, and concave downward Scatchard plots.
- This model provides a unified framework for understanding ligand binding to dimeric receptors.
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