Organosilicon molecules bind to the intrinsically disordered protein NUPR1 by clamping its hot-spots

The nuclear protein 1, or NUPR1, is an intrinsically disordered protein (IDP) involved in the development and progression of pancreatic ductal adenocarcinoma (PDAC). We have previously developed drugs capable of binding at the two hot-spot regions of NUPR1, around residues Ala33 and Thr68, hampering...

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Detalles Bibliográficos
Autores: Peña, LF, Estaras, M, González-Andrés, P, Díez-Poza, C, Rizzuti, B, Abian, O, Velazquez-Campoy, A, Iovanna, JL, Santofimia-Castaño, P, Neira, JL, Barbero, A
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)
Repositorio:r-FISABIO. Repositorio Institucional de Producción Científica
OAI Identifier:oai:dnet:r-fisabio___::867fc96a3d064c28f4bdf743bcbe3028
Acceso en línea:https://fisabio.portalinvestigacion.com/publicaciones/21016
Access Level:acceso abierto
Palabra clave:Organosilanes
Intrinsically disordered proteins
Protein-protein interactions
Organic synthesis
Descripción
Sumario:The nuclear protein 1, or NUPR1, is an intrinsically disordered protein (IDP) involved in the development and progression of pancreatic ductal adenocarcinoma (PDAC). We have previously developed drugs capable of binding at the two hot-spot regions of NUPR1, around residues Ala33 and Thr68, hampering its interactions in cellulo. In this work, we synthesized new organosilicon molecules targeting those key hot-spots. The compounds were obtained by an acid-catalyzed intramolecular cyclization of a starting alkenol that contains a silyl group attached to the double bond. Binding between the silyl compounds and NUPR1 involved the two hot-spots, as shown by 2D H-1-N-15 HSQC NMR. Molecular simulations clarified that the binding relies on a loose clamp mechanism of the ligands towards the hot-spots. The dissociation constants (K-d) were around 20 mu M, as measured by several biophysical techniques. However, studies in cellulo with PDAC cells did not show a decrease of cell viability upon treatment with the compounds; furthermore, proximity ligation assays in cellulo with a natural partner protein of NUPR1, G3BP, did not show a significant level of interfering in such interaction when silyl compounds were present, probably due to the high hydrophobicity of the designed compounds. Thus, in the case of NUPR1, moderate-to-high drug binding affinities (K-d < 10 mu M) in vitro and a higher hydrophilicity are necessary to hamper protein-protein interactions in cellulo. As a more general conclusion, in vitro binding of ligands to the protein hot-spots is a necessary condition in the drug design targeting IDPs, but it is not enough to guarantee inhibition of their interactions in cellulo.