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Adenosine receptor modeling: what does the A2A crystal structure tell us?
Diego Dal Ben1, Catia Lambertucci, Gabriella Marucci
1School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, 62032 Camerino (MC), Italy. diego.dalben@unicam.it
Current Topics in Medicinal Chemistry
|April 8, 2010
Summary
Structural data for adenosine receptors (ARs) were limited until the human adenosine A(2A) receptor (AA(2A)R) crystal structure provided a reliable template. This structure facilitates homology modeling and validates previous docking studies for AR subtypes.
Area of Science:
- Structural biology
- Pharmacology
- Computational chemistry
Background:
- Historically, homology modeling was the primary method for studying adenosine receptor (AR) structure-function relationships due to a lack of experimental data.
- Early modeling efforts relied on templates like bacteriorhodopsin and rhodopsin, with bovine rhodopsin's crystal structure being a significant advancement for eukaryotic G protein-coupled receptors (GPCRs).
- Rhodopsin-based homology modeling became standard for ARs, aiding in interpreting mutagenesis data and guiding molecular docking.
Purpose of the Study:
- To evaluate the utility of different templates for adenosine receptor (AR) homology modeling.
- To assess the impact of newly available crystal structures on AR structural modeling and drug design.
- To validate previous hypotheses regarding AR structure and ligand interactions using updated structural information.
Main Methods:
- Homology modeling using various templates, including rhodopsin and adrenergic receptors.
- Analysis of crystal structures of related G protein-coupled receptors (GPCRs).
- Molecular docking studies and validation against experimental data.
Main Results:
- The crystal structure of the human adenosine A(2A) receptor (AA(2A)R), published in late 2008, emerged as a superior template for AR homology modeling.
- The AA(2A)R structure demonstrated high similarity to other AR subtypes, enabling more accurate modeling.
- This structure facilitated ligand docking analyses and allowed for the verification of hypotheses derived from earlier modeling and docking studies.
Conclusions:
- The crystal structure of the human adenosine A(2A) receptor (AA(2A)R) is a crucial resource for understanding adenosine receptor (AR) structure.
- AA(2A)R provides a high-fidelity template for homology modeling of other AR subtypes.
- The availability of the AA(2A)R structure has advanced molecular docking and structure-based drug design for ARs.
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