RESUMEN
Targeting specific protein-protein interactions (PPIs) is an attractive concept for drug development, but hard to implement since intracellular antibodies do not penetrate cells and most small-molecule drugs are considered unsuitable for PPI inhibition. A potential solution to these problems is to select intracellular antibody fragments to block PPIs, use these antibody fragments for target validation in disease models and finally derive small molecules overlapping the antibody-binding site. Here, we explore this strategy using an anti-mutant RAS antibody fragment as a competitor in a small-molecule library screen for identifying RAS-binding compounds. The initial hits are optimized by structure-based design, resulting in potent RAS-binding compounds that interact with RAS inside the cells, prevent RAS-effector interactions and inhibit endogenous RAS-dependent signalling. Our results may aid RAS-dependent cancer drug development and demonstrate a general concept for developing small compounds to replace intracellular antibody fragments, enabling rational drug development to target validated PPIs.
Asunto(s)
Sitios de Unión de Anticuerpos , Fragmentos de Inmunoglobulinas/química , Transducción de Señal , Anticuerpos/química , Biomarcadores/metabolismo , Línea Celular Tumoral , Supervivencia Celular , Cristalografía por Rayos X , Células HEK293 , Humanos , Mutación , Unión Proteica , Dominios Proteicos , Proteínas Recombinantes/química , Bibliotecas de Moléculas Pequeñas , Resonancia por Plasmón de Superficie , Proteínas ras/químicaRESUMEN
Lp-PLA2 has been explored as a target for a number of inflammation associated diseases, including cardiovascular disease and dementia. This article describes the discovery of a new fragment derived chemotype that interacts with the active site of Lp-PLA2. The starting fragment hit was discovered through an X-ray fragment screen and showed no activity in the bioassay (IC50 > 1 mM). The fragment hit was optimized using a variety of structure-based drug design techniques, including virtual screening, fragment merging, and improvement of shape complementarity. A novel series of Lp-PLA2 inhibitors was generated with low lipophilicity and a promising pharmacokinetic profile.
Asunto(s)
Inhibidores Enzimáticos/farmacología , Lactamas/farmacología , 1-Alquil-2-acetilglicerofosfocolina Esterasa , Administración Oral , Animales , Disponibilidad Biológica , Cristalografía por Rayos X , Perros , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Humanos , Lactamas/administración & dosificación , Lactamas/síntesis química , Lactamas/química , Modelos Moleculares , Estructura Molecular , Ratas , Relación Estructura-Actividad , Distribución TisularRESUMEN
Elevated levels of human lipoprotein-associated phospholipase A2 (Lp-PLA2) are associated with cardiovascular disease and dementia. A fragment screen was conducted against Lp-PLA2 in order to identify novel inhibitors. Multiple fragment hits were observed in different regions of the active site, including some hits that bound in a pocket created by movement of a protein side chain (approximately 13 Å from the catalytic residue Ser273). Using structure guided design, we optimized a fragment that bound in this pocket to generate a novel low nanomolar chemotype, which did not interact with the catalytic residues.
Asunto(s)
1-Alquil-2-acetilglicerofosfocolina Esterasa/antagonistas & inhibidores , Descubrimiento de Drogas , Inhibidores Enzimáticos/farmacología , Pirazoles/farmacología , Tiazoles/farmacología , 1-Alquil-2-acetilglicerofosfocolina Esterasa/metabolismo , Sitios de Unión/efectos de los fármacos , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Humanos , Modelos Moleculares , Estructura Molecular , Pirazoles/síntesis química , Pirazoles/química , Relación Estructura-Actividad , Tiazoles/síntesis química , Tiazoles/químicaRESUMEN
The DDR1 and DDR2 receptor tyrosine kinases are activated by extracellular collagen and have been implicated in a number of human diseases including cancer. We performed a fragment-based screen against DDR1 and identified fragments that bound either at the hinge or in the back pocket associated with the DFG-out conformation of the kinase. Modeling based on crystal structures of potent kinase inhibitors facilitated the "back-to-front" design of potent DDR1/2 inhibitors that incorporated one of the DFG-out fragments. Further optimization led to low nanomolar, orally bioavailable inhibitors that were selective for DDR1 and DDR2. The inhibitors were shown to potently inhibit DDR2 activity in cells but in contrast to unselective inhibitors such as dasatinib, they did not inhibit proliferation of mutant DDR2 lung SCC cell lines.
RESUMEN
A highly stereocontrolled total synthesis of the cytotoxic marine macrolide aplyronine C is described. The route exploits aldol methodology to install the requisite stereochemistry and features a crucial boron-mediated aldol coupling of an N-vinylformamide-bearing methyl ketone with a macrocyclic aldehyde to introduce the full side chain. The synthesis of two novel C21-C34 side chain analogs is also reported.
Asunto(s)
Antineoplásicos/síntesis química , Macrólidos/síntesis química , Compuestos de Vinilo/química , Antineoplásicos/química , Boro/química , Macrólidos/química , Estructura Molecular , EstereoisomerismoRESUMEN
Diastereomeric 2-methoxycyclopentyl analogues of a natural quorum sensing signaling molecule from Pseudomonas aeruginosa were synthesized and screened in pigment production assays with P. aeruginosa and Serratia strain ATCC39006.