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Updated: Sep 7, 2025
NMR-Based Fragment Screening in a Minimum Sample but Maximum Automation Mode
Published on: June 4, 2021
Structural Analysis and Development of Notum Fragment Screening Hits
Yuguang Zhao1, William Mahy2, Nicky J Willis2
1Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, The Henry Wellcome Building for Genomic Medicine, Roosevelt Drive, Oxford OX3 7BN, U.K.
Abstract:
The Wnt signaling suppressor Notum is a promising target for osteoporosis, Alzheimer's disease, and colorectal cancers. To develop novel Notum inhibitors, we used an X-ray crystallographic fragment screen with the Diamond-SGC Poised Library (DSPL) and identified 59 fragment hits from the analysis of 768 data sets. Fifty-eight of the hits were found bound at the enzyme catalytic pocket with potencies ranging from 0.5 to >1000 microM. Analysis of the fragments' diverse binding modes, enzymatic inhibitory activities, and chemical properties led to the selection of six hits for optimization, and five of these resulted in improved Notum inhibitory potencies. One hit, 1-phenyl-1,2,3-triazole 7, and its related cluster members, have shown promising lead-like properties. These became the focus of our fragment development activities, resulting in compound 7d with IC50 0.0067 microM. The large number of Notum fragment structures and their initial optimization provided an important basis for further Notum inhibitor development.
Insights
Researchers identified novel inhibitors for Notum, a target for diseases like Alzheimer's and cancer. Fragment screening yielded promising compounds, including 7d with potent inhibitory activity, paving the way for new drug development.
Area of Science:
- Biochemistry
- Medicinal Chemistry
- Structural Biology
Background:
- Notum is a key suppressor of Wnt signaling, implicated in osteoporosis, Alzheimer's disease, and colorectal cancers.
- Developing specific Notum inhibitors is crucial for therapeutic intervention in these diseases.
Purpose of the Study:
- To discover and optimize novel small-molecule inhibitors of Notum using fragment-based drug discovery.
- To characterize the binding modes and inhibitory potencies of identified fragments.
Main Methods:
- X-ray crystallography was employed for fragment screening using the Diamond-SGC Poised Library (DSPL).
- 768 data sets were analyzed to identify fragment hits binding to the Notum catalytic pocket.
- Hit optimization involved structure-activity relationship studies and chemical modifications.
Main Results:
- 59 fragment hits were identified, with 58 binding to the enzyme's catalytic pocket.
- Fragment potencies ranged from 0.5 to >1000 microM, with six selected for optimization.
- Optimization led to compound 7d, exhibiting a potent IC50 of 0.0067 microM and promising lead-like properties.
Conclusions:
- Fragment-based screening is an effective strategy for identifying Notum inhibitors.
- The identified fragment series, particularly compound 7d, provides a strong foundation for further development of Notum-targeted therapeutics.
- Structural insights from fragment binding aid in rational drug design for Notum inhibitors.
