An Updated Structure of Oxybutynin Hydrochloride.
Jieye LinGuanhong BuJohan UngeTamir GonenPublished in: Advanced science (Weinheim, Baden-Wurttemberg, Germany) (2024)
Oxybutynin (Ditropan), a widely distributed muscarinic antagonist for treating the overactive bladder, has been awaiting a definitive crystal structure for ≈50 years due to the sample and technique limitations. Past reports used powder X-ray diffraction (PXRD) to shed light on the possible packing of the molecule however their model showed some inconsistencies when compared with the 2D chemical structure. These are largely attributed to X-ray-induced photoreduction. Here microcrystal electron diffraction (MicroED) is used to successfully unveil the experimental 3D structure of oxybutynin hydrochloride showing marked improvement over the reported PXRD structure. Using the improved model, molecular docking is applied to investigate the binding mechanism between M 3 muscarinic receptor (M 3 R) and (R)-oxybutynin, revealing essential contacts/residues and conformational changes within the protein pocket. A possible universal conformation is proposed for M 3 R antagonists, which is valuable for future drug development and optimization. This study underscores the immense potential of MicroED as a complementary technique for elucidating unknown pharmaceutical structures, as well as for protein-drug interactions.
Keyphrases
- crystal structure
- molecular docking
- molecular dynamics simulations
- high resolution
- electron microscopy
- binding protein
- molecular dynamics
- squamous cell carcinoma
- emergency department
- protein protein
- high glucose
- single molecule
- radiation therapy
- computed tomography
- transcription factor
- small molecule
- human health
- climate change
- endothelial cells
- mass spectrometry
- electronic health record