Crystallographic fragment screening reveals ligand hotspots in TRIM21 PRY-SPRY domain

Tripartite motif-containing protein 21 (TRIM21), and particularly its PRY-SPRY protein interaction domain, plays a critical role in the immune response by recognizing intracellular antibodies targeting them for degradation. In this study, we performed a crystallographic fragment screening (CFS) campaign to identify potential small molecule binders targeting the PRY-SPRY domain of TRIM21. Our screen identified a total of 109 fragments binding to TRIM21 that were distributed across five distinct binding sites. These fragments have been designed to facilitate straightforward follow-up chemistry, making them ideal starting points for further chemical optimization. A subsequent fragment merging approach demonstrated improved activity. To enable functional validation of compounds with full length human TRIM21, we established a NanoBRET assay suitable for measuring target engagement to the main Fc binding site in life cells. The high-resolution structural data and observed binding modes across the different sites highlight the versatility of the PRY-SPRY domain as a target for small-molecule intervention. The presented data provide a solid foundation for structure-guided ligand design, enabling the rational design of more potent and selective compounds, with the goal to develop bivalent molecules such as Proteolysis Targeting Chimeras (PROTACs).

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Publication Details

Journal
Communications Chemistry
Published
2025-06-13
DOI
https://doi.org/10.1038/s42004-025-01574-3
Citations
2
Primary Topic
interferon and immune responses
Type
article
Field-Weighted Citation Impact
1.59

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article

Crystallographic fragment screening reveals ligand hotspots in TRIM21 PRY-SPRY domain

Stefan Knapp, Yeojin Kim, Krishna Saxena, Christopher Lenz et al.
2 citations
Communications Chemistry
interferon and immune responses
1.59
article

Crystallographic fragment screening reveals ligand hotspots in TRIM21 PRY-SPRY domain

Stefan Knapp, Yeojin Kim, Krishna Saxena, Christopher Lenz, Martin P. Schwalm, F. von Delft, Aleksandar Lučić, J.C. Aschenbrenner, Thomas Hanke, Frederic Farges, D. Fearon, Andreas Krämer, Peter Marples
article en
2 citations

Abstract

Tripartite motif-containing protein 21 (TRIM21), and particularly its PRY-SPRY protein interaction domain, plays a critical role in the immune response by recognizing intracellular antibodies targeting them for degradation. In this study, we performed a crystallographic fragment screening (CFS) campaign to identify potential small molecule binders targeting the PRY-SPRY domain of TRIM21. Our screen identified a total of 109 fragments binding to TRIM21 that were distributed across five distinct binding sites. These fragments have been designed to facilitate straightforward follow-up chemistry, making them ideal starting points for further chemical optimization. A subsequent fragment merging approach demonstrated improved activity. To enable functional validation of compounds with full length human TRIM21, we established a NanoBRET assay suitable for measuring target engagement to the main Fc binding site in life cells. The high-resolution structural data and observed binding modes across the different sites highlight the versatility of the PRY-SPRY domain as a target for small-molecule intervention. The presented data provide a solid foundation for structure-guided ligand design, enabling the rational design of more potent and selective compounds, with the goal to develop bivalent molecules such as Proteolysis Targeting Chimeras (PROTACs).

Communications ChemistryVol. 8(1)
Goethe University Frankfurt (DE), Discovery Centre (CA), Diamond Light Source (GB), Structural Genomics Consortium (CA), Research Complex at Harwell (GB), German Cancer Society (DE), German Marine Research Consortium (DE), Oxford Centre for Diabetes, Endocrinology and Metabolism (GB), Frankfurt Cancer Institute (DE)
Bristol-Myers Squibb, Pfizer, Bayer, McGill University, Genome Canada, Diamond Light Source, Ontario Genomics, European Federation of Pharmaceutical Industries and Associations, Ontario Genomics Institute, Deutsche Forschungsgemeinschaft, Genentech
Openalex Percentile: Top 16%
interferon and immune responses
1.59
DOIOpen Access PDFOpenAlex
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