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Updated: May 13, 2026
Biosensor-based High Throughput Biopanning and Bioinformatics Analysis Strategy for the Global Validation of Drug-protein Interactions
Published on: December 1, 2020
The identification of novel, high affinity AQP9 inhibitors in an intracellular binding site
Sören J Wacker1, Camilo Aponte-Santamaría, Per Kjellbom
1The Max Planck Institute for Biophysical Chemistry, Computational Biomolecular Dynamics Group, Göttingen, Germany.
Background:
The involvement of aquaporin (AQP) water and small solute channels in the etiology of several diseases, including cancer, neuromyelitis optica and body fluid imbalance disorders, has been suggested previously. Furthermore, results obtained in a mouse model suggested that AQP9 function contributes to hyperglycemia in type-2 diabetes. In addition, the physiological role of several AQP family members remains poorly understood. Small molecule inhibitors of AQPs are therefore desirable to further study AQP physiological and pathophysiological functions.
Methods:
The binding of recently established AQP9 inhibitors to a homology model of AQP9 was investigated by molecular dynamics simulations and molecular docking. Putative inhibitor binding sites identified with this procedure were modified by site-directed mutagenesis. Active compounds were measured in a mammalian cell water permeability assay of mutated AQP9 isoforms and tested for changes in inhibitory effects.
Controls:
Three independent cell lines were established for each mutated AQP9 isoform and functionality of mutant isoforms was established.
Principal Findings:
We have identified putative binding sites of recently established AQP9 inhibitors. This information facilitated successful identification of novel AQP9 inhibitors with low micromolar IC50 values in a cell based assay by in silico screening of a compound library targeting specifically this binding site.
Significance:
We have established a successful strategy for AQP small molecule inhibitor identification. AQP inhibitors may be relevant as experimental tools, to enhance our understanding of AQP function, and in the treatment of various diseases.
Insights
Researchers identified new aquaporin-9 (AQP9) inhibitors using computational methods. This strategy advances the study of AQP functions and potential disease treatments.
Area of Science:
- Biochemistry and Molecular Biology
- Pharmacology
Background:
- Aquaporins (AQPs) are implicated in diseases like cancer, neuromyelitis optica, and diabetes.
- AQP9's role in hyperglycemia and the function of other AQPs require further investigation.
- Small molecule AQP inhibitors are crucial for studying AQP roles and developing therapeutics.
Purpose of the Study:
- To identify novel small molecule inhibitors of aquaporin-9 (AQP9).
- To investigate the binding sites of existing AQP9 inhibitors using computational approaches.
- To develop a strategy for discovering new AQP inhibitors.
Main Methods:
- Molecular dynamics simulations and molecular docking were used to analyze AQP9 inhibitor binding.
- Site-directed mutagenesis was employed to modify putative inhibitor binding sites.
- Mammalian cell water permeability assays were conducted on mutated AQP9 isoforms.
Main Results:
- Putative binding sites for AQP9 inhibitors were successfully identified.
- In silico screening identified novel AQP9 inhibitors with low micromolar IC50 values.
- A validated cell-based assay was used to confirm inhibitor activity.
Conclusions:
- A successful strategy for identifying AQP small molecule inhibitors has been established.
- These AQP inhibitors can serve as valuable experimental tools.
- The findings contribute to understanding AQP function and potential therapeutic applications in various diseases.
