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Measuring G-protein-coupled Receptor Signaling via Radio-labeled GTP Binding
Published on: June 9, 2017
Modeling G Protein-Coupled Receptors: a Concrete Possibility.
Chimica Oggi
|January 22, 2011
Summary
Accurate G protein-coupled receptor (GPCR) models can be built using homology modeling and molecular docking, especially when using new crystal structures. While transmembrane bundles are modeled well, ligand binding prediction is challenging, and loop modeling remains problematic.
Area of Science:
- Biochemistry
- Structural Biology
- Pharmacology
Background:
- G protein-coupled receptors (GPCRs) are crucial membrane proteins regulating physiological functions and are key drug targets.
- Homology modeling is widely used for GPCR structure prediction due to limited experimental structures.
- Rhodopsin was the primary template, but recent crystallographic advances provide new structural data.
Purpose of the Study:
- To evaluate the accuracy of homology modeling and molecular docking for constructing GPCR-ligand complex models.
- To assess the reliability of predicted GPCR structures and ligand binding modes.
- To identify limitations in current GPCR modeling techniques.
Main Methods:
- Homology modeling utilizing newly available GPCR crystal structures.
- Fully flexible molecular docking for ligand-receptor complex simulation.
- Validation through a blind assessment coordinated with the adenosine A(2A) receptor X-ray structure determination.
Main Results:
- Accurate models of GPCR transmembrane helical bundles were achieved.
- Ligand binding mode prediction was demonstrated to be feasible but challenging.
- Modeling of extracellular and intracellular loops presented significant difficulties.
Conclusions:
- Homology modeling combined with flexible docking provides accurate GPCR models, particularly for the transmembrane core.
- Ligand binding site prediction is improving but requires further refinement.
- Further research is needed to enhance the modeling accuracy of GPCR extracellular and intracellular loops.
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G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
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