Abstract
| Original language | English |
|---|---|
| Pages (from-to) | 21082 - 21095 |
| Number of pages | 14 |
| Journal | Journal of Biological Chemistry |
| Volume | 288 |
| Issue number | 29 |
| DOIs | |
| Publication status | Published - 2013 |
Cite this
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Molecular basis for benzodiazepine agonist action at the type 1 cholecystokinin receptor. / Harikumar, Kaleeckal G; Cawston, Erin E; Lam, Polo C H; Patil, Achyut; Orry, Andrew; Henke, B; Abagyan, Ruben; Christopoulos, Arthur; Sexton, Patrick; Miller, Laurence J.
In: Journal of Biological Chemistry, Vol. 288, No. 29, 2013, p. 21082 - 21095.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Molecular basis for benzodiazepine agonist action at the type 1 cholecystokinin receptor
AU - Harikumar, Kaleeckal G
AU - Cawston, Erin E
AU - Lam, Polo C H
AU - Patil, Achyut
AU - Orry, Andrew
AU - Henke, B
AU - Abagyan, Ruben
AU - Christopoulos, Arthur
AU - Sexton, Patrick
AU - Miller, Laurence J
PY - 2013
Y1 - 2013
N2 - Understanding the molecular basis of drug action can facilitate development of more potent and selective drugs. Here, we explore the molecular basis for action of a unique small molecule ligand that is a type 1 cholecystokinin (CCK) receptor agonist and type 2 CCK receptor antagonist, GI181771X. We characterize its binding utilizing structurally-related radioiodinated ligands selective for CCK receptor subtypes that utilize the same allosteric ligand-binding pocket, using wild type receptors and chimeric constructs exchanging the distinct residues lining this pocket. Intracellular calcium assays were performed to determine biological activity. Molecular models for docking small molecule agonists to the type 1 CCK receptor were developed using a ligand-guided refinement approach. The optimal model was distinct from the previous antagonist model for the same receptor and was mechanistically consistent with the current mutagenesis data. This study revealed a key role for Leu7.39 that was predicted to interact with the isopropyl group in the N1 position of the benzodiazepine that acts as a trigger for biological activity. The molecular model was predictive of binding of other small molecule agonists, effectively distinguishing these from 1065 approved drug decoys with an AUC value of 99 . The model also selectively enriched for agonist compounds, with 130 agonists identified by ROC analysis when seeded in 2175 non-agonist ligands of the type 1 CCK receptor (AUC 78 ). Benzodiazepine agonists in this series docked in consistent pose within this pocket, with a key role played by Leu7.39, while the role of this residue was less clear for chemically-distinct agonists.
AB - Understanding the molecular basis of drug action can facilitate development of more potent and selective drugs. Here, we explore the molecular basis for action of a unique small molecule ligand that is a type 1 cholecystokinin (CCK) receptor agonist and type 2 CCK receptor antagonist, GI181771X. We characterize its binding utilizing structurally-related radioiodinated ligands selective for CCK receptor subtypes that utilize the same allosteric ligand-binding pocket, using wild type receptors and chimeric constructs exchanging the distinct residues lining this pocket. Intracellular calcium assays were performed to determine biological activity. Molecular models for docking small molecule agonists to the type 1 CCK receptor were developed using a ligand-guided refinement approach. The optimal model was distinct from the previous antagonist model for the same receptor and was mechanistically consistent with the current mutagenesis data. This study revealed a key role for Leu7.39 that was predicted to interact with the isopropyl group in the N1 position of the benzodiazepine that acts as a trigger for biological activity. The molecular model was predictive of binding of other small molecule agonists, effectively distinguishing these from 1065 approved drug decoys with an AUC value of 99 . The model also selectively enriched for agonist compounds, with 130 agonists identified by ROC analysis when seeded in 2175 non-agonist ligands of the type 1 CCK receptor (AUC 78 ). Benzodiazepine agonists in this series docked in consistent pose within this pocket, with a key role played by Leu7.39, while the role of this residue was less clear for chemically-distinct agonists.
UR - http://www.jbc.org/content/early/2013/06/10/jbc.M113.480715.full.pdf
U2 - 10.1074/jbc.M113.480715
DO - 10.1074/jbc.M113.480715
M3 - Article
VL - 288
SP - 21082
EP - 21095
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 1083-351X
IS - 29
ER -