Pyrazole-Based Transthyretin Kinetic Stabilizers Identified Using a Covalent Fluorescent Probe Assay for Selectivity Profiling in Human Serum.
Kim, K.A., Lee, C., Lim, N., Kim, K.W., Lee, Y.H., Choe, J., Kim, S.J., Jeong, J.W., Jeon, E.H., Son, D.H., Park, S.J., Kang, N.S., Shin, H.C., Koo, T.S., Choi, S.(2025) J Med Chem 68: 26448-26465
- PubMed: 41362238 Search on PubMed
- DOI: https://doi.org/10.1021/acs.jmedchem.5c02576
- Primary Citation Related Structures: 
9WPB - PubMed Abstract: 
Transthyretin (TTR) amyloidosis arises from the extracellular aggregation of misfolded TTR monomers into β-sheet-rich fibrils, leading to progressive tissue damage. To inhibit this process, we designed and synthesized pyrazole-based kinetic stabilizers targeting the thyroxine-binding sites of TTR. Structure-activity relationship studies revealed that derivatives with hydrophobic trans-alkene linkers and 3,5-substituted pyrazole rings showed enhanced stabilizing potency, particularly those bearing carboxylic acid, amide, or sulfonamide groups. A covalent fluorescent probe derived from trans-styrylpyrazole was developed to selectively react with Lys15, enabling fluorescence probe exclusion and native PAGE assays to evaluate stabilizer selectivity in human serum. Among these, 3,5-dichloropyrazole derivatives exhibited efficacy comparable to that of tafamidis and acoramidis. X-ray crystallography of the TTR- 17 complex confirmed hydrogen bonding with Ser117/117' and electrostatic interactions with Lys15. Pharmacokinetic studies of compounds 16 and 17 demonstrated favorable exposure, bioavailability, and metabolic stability, supporting their preclinical development for hereditary- and wild-type TTR amyloidosis.
- Department of New Drug Discovery and Development, Chungnam National University, Daejeon 34134, Republic of Korea.
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