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1.
Bioorg Med Chem Lett ; 47: 128113, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-33991628

RESUMEN

Through an internal virtual screen at GlaxoSmithKline a distinct class of 2-phenylimidazo[1,2-a]pyridine-6-carboxamide H-PGDS inhibitors were discovered. Careful evaluation of crystal structures and SAR led to a novel, potent, and orally active imidazopyridine inhibitor of H-PGDS, 20b. Herein, describes the identification of 2 classes of inhibitors, their syntheses, and their challenges.


Asunto(s)
Descubrimiento de Drogas , Inhibidores Enzimáticos/farmacología , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Humanos , Oxidorreductasas Intramoleculares/antagonistas & inhibidores , Oxidorreductasas Intramoleculares/metabolismo , Estructura Molecular , Relación Estructura-Actividad
2.
Bioorg Med Chem ; 28(23): 115791, 2020 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-33059303

RESUMEN

GlaxoSmithKline and Astex Pharmaceuticals recently disclosed the discovery of the potent H-PGDS inhibitor GSK2894631A 1a (IC50 = 9.9 nM) as part of a fragment-based drug discovery collaboration with Astex Pharmaceuticals. This molecule exhibited good murine pharmacokinetics, allowing it to be utilized to explore H-PGDS pharmacology in vivo. Yet, with prolonged dosing at higher concentrations, 1a induced CNS toxicity. Looking to attenuate brain penetration in this series, aza-quinolines, were prepared with the intent of increasing polar surface area. Nitrogen substitutions at the 6- and 8-positions of the quinoline were discovered to be tolerated by the enzyme. Subsequent structure activity studies in these aza-quinoline scaffolds led to the identification of 1,8-naphthyridine 1y (IC50 = 9.4 nM) as a potent peripherally restricted H-PGDS inhibitor. Compound 1y is efficacious in four in vivo inflammatory models and exhibits no CNS toxicity.


Asunto(s)
Compuestos Aza/química , Inhibidores Enzimáticos/química , Quinolinas/química , Animales , Sitios de Unión , Encéfalo/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cristalografía por Rayos X , Estabilidad de Medicamentos , Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/farmacología , Humanos , Oxidorreductasas Intramoleculares/antagonistas & inhibidores , Oxidorreductasas Intramoleculares/metabolismo , Cinética , Masculino , Ratones , Ratones Endogámicos C57BL , Simulación de Dinámica Molecular , Músculo Esquelético/química , Músculo Esquelético/metabolismo , Ratas , Relación Estructura-Actividad
3.
Protein Expr Purif ; 73(2): 167-76, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20457255

RESUMEN

Phosphoinositide 3-kinases have been targeted for therapeutic research because they are key components of a cell signaling cascade controlling proliferation, growth, and survival. Direct activation of the PI3Kalpha pathway contributes to the development and progression of solid tumors in breast, endometrial, colon, ovarian, and gastric cancers. In the context of a drug discovery effort, the availability of a robust crystallographic system is a means to understand the subtle differences between ATP competitive inhibitor interactions with the active site and their selectivity against other PI3Kinase enzymes. To generate a suitable recombinant design for this purpose, a p85alpha-p110alpha fusion system was developed which enabled the expression and purification of a stoichiometrically homogeneous, constitutively active enzyme for structure determination with potent ATP competitive inhibitors (Raha et al., in preparation) [56]. This approach has yielded preparations with activity and inhibition characteristics comparable to those of the full-length PI3Kalpha from which X-ray diffracting crystals were grown with inhibitors bound in the active site.


Asunto(s)
Fosfatidilinositol 3-Quinasas Clase II/metabolismo , Cristalografía por Rayos X , Inhibidores Enzimáticos/farmacología , Adenosina Trifosfato/metabolismo , Animales , Fusión Artificial Génica , Baculoviridae/metabolismo , Sitios de Unión , Células Cultivadas , Fosfatidilinositol 3-Quinasas Clase II/química , Fosfatidilinositol 3-Quinasas Clase II/genética , Fosfatidilinositol 3-Quinasa Clase Ia/genética , Diseño de Fármacos , Concentración 50 Inhibidora , Modelos Moleculares , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/aislamiento & purificación , Proteínas Recombinantes de Fusión/metabolismo , Spodoptera/citología , Spodoptera/metabolismo , Difracción de Rayos X
4.
Bioorg Med Chem Lett ; 19(17): 4993-5, 2009 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-19640712

RESUMEN

During our ongoing efforts to develop a small molecule inhibitor targeting the beta-amyloid cleaving enzyme (BACE-1), we discovered a class of compounds bearing an aminoimidazole motif. Initial optimization led to potent compounds that have high Pgp efflux ratios. Crystal structure-aided design furnished conformationally constrained compounds that are both potent and have relatively low Pgp efflux ratios. Computational studies performed after these optimizations suggest that the introduction of the constraint enhances potency via additional hydrophobic interactions rather than conformational restriction.


Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Imidazoles/química , Inhibidores de Proteasas/química , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Sitios de Unión , Dominio Catalítico , Cristalografía por Rayos X , Diseño de Fármacos , Humanos , Imidazoles/síntesis química , Imidazoles/farmacología , Conformación Molecular , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/farmacología , Estructura Terciaria de Proteína
5.
Bioorg Med Chem Lett ; 19(11): 2977-80, 2009 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-19409780

RESUMEN

We have developed a novel series of heteroaromatic BACE-1 inhibitors. These inhibitors interact with the enzyme in a unique fashion that allows for potent binding in a non-traditional paradigm. In addition to the elucidation of their binding profile, we have discovered a pH dependent effect on the binding affinity as a result of the intrinsic pK(a) of these inhibitors and the pH of the BACE-1 enzyme binding assay.


Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Inhibidores Enzimáticos/química , Compuestos Heterocíclicos/química , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Cristalografía por Rayos X , Diseño de Fármacos , Inhibidores Enzimáticos/farmacología , Compuestos Heterocíclicos/farmacología , Concentración de Iones de Hidrógeno , Unión Proteica , Relación Estructura-Actividad
7.
J Med Chem ; 48(7): 2282-93, 2005 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-15801822

RESUMEN

Optimization of a previously reported thrombin inhibitor, 9-hydroxy-9-fluorenylcarbonyl-l-prolyl-trans-4-aminocyclohexylmethylamide (1), by replacing the aminocyclohexyl P1 group provided a new lead structure, 9-hydroxy-9-fluorenylcarbonyl-l-prolyl-2-aminomethyl-5-chlorobenzylamide (2), with improved potency (K(i) = 0.49 nM for human thrombin, 2x APTT = 0.37 microM in human plasma) and pharmacokinetic properties (F = 39%, iv T(1/2) = 13 h in dogs). An effective strategy for reducing plasma protein binding of 2 and improving efficacy in an in vivo thrombosis model in rats was to replace the lipophilic fluorenyl group in P3 with an azafluorenyl group. Systematic investigation of all possible azafluorenyl P3 isomers and azafluorenyl-N-oxide analogues of 2 led to the identification of an optimal compound, 3-aza-9-hydroxyfluoren-9(R)-ylcarbonyl-l-prolyl-2-aminomethyl-5-chlorobenzylamide (19b), with high potency (K(i) = 0.40 nM, 2x APTT = 0.18 microM), excellent pharmacokinetic properties (F = 55%, T(1/2) = 14 h in dogs), and complete efficacy in the in vivo thrombosis model in rats (inhibition of FeCl(3)-induced vessel occlusions in six of six rats receiving an intravenous infusion of 10 microg/kg/min of 19b). The stereochemistry of the azafluorenyl group in 19b was determined by X-ray crystallographic analysis of its N-oxide derivative (23b) bound in the active site of human thrombin.


Asunto(s)
Fluorenos/síntesis química , Prolina/análogos & derivados , Prolina/síntesis química , Trombina/antagonistas & inhibidores , Administración Oral , Animales , Disponibilidad Biológica , Proteínas Sanguíneas/metabolismo , Cristalografía por Rayos X , Perros , Fluorenos/química , Fluorenos/farmacología , Semivida , Humanos , Técnicas In Vitro , Macaca mulatta , Masculino , Microsomas Hepáticos/metabolismo , Modelos Moleculares , Prolina/química , Prolina/farmacología , Unión Proteica , Ratas , Ratas Sprague-Dawley , Estereoisomerismo , Relación Estructura-Actividad
8.
J Med Chem ; 47(26): 6447-50, 2004 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-15588077

RESUMEN

We describe the development of cell-permeable beta-secretase inhibitors that demonstratively inhibit the production of the secreted amino terminal fragment of an artificial amyloid precursor protein in cell culture. In addition to potent inhibition in a cell-based assay (IC50 < 100 nM), these inhibitors display impressive selectivity against other biologically relevant aspartyl proteases.


Asunto(s)
Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Etilaminas/síntesis química , Sulfonamidas/síntesis química , Secretasas de la Proteína Precursora del Amiloide , Ácido Aspártico Endopeptidasas/química , Sitios de Unión , Línea Celular , Permeabilidad de la Membrana Celular , Cristalografía por Rayos X , Diseño de Fármacos , Etilaminas/química , Etilaminas/farmacología , Humanos , Modelos Moleculares , Relación Estructura-Actividad , Sulfonamidas/química , Sulfonamidas/farmacología
9.
J Med Chem ; 47(12): 2995-3008, 2004 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-15163182

RESUMEN

In an effort to discover potent, clinically useful thrombin inhibitors, a rapid analogue synthetic approach was used to explore the P(1) region. Various benzylamines were coupled to a pyridine/pyrazinone P(2)-P(3) template. One compound with an o-thiadiazole benzylic substitution was found to have a thrombin K(i) of 0.84 nM. A study of ortho-substituted five-membered-ring heterocycles was undertaken and subsequently demonstrated that the o-triazole and tetrazole rings were optimal. Combination of these potent P(1) aryl heterocycles with a variety of P(2)-P(3) groups produced a compound with an extraordinary thrombin inhibitory activity of 1.4 pM. It is hoped that this potency enhancement in P(1) will allow for more diversification in the P(2)-P(3) region to ultimately address additional pharmacological concerns.


Asunto(s)
Compuestos Heterocíclicos/síntesis química , Trombina/antagonistas & inhibidores , Bencilaminas/síntesis química , Bencilaminas/química , Sitios de Unión , Compuestos Heterocíclicos/química , Modelos Moleculares , Pirazinas/síntesis química , Pirazinas/química , Piridinas/síntesis química , Piridinas/química , Relación Estructura-Actividad , Tetrazoles/síntesis química , Tetrazoles/química , Tiadiazoles/síntesis química , Tiadiazoles/química , Trombina/química , Triazoles/síntesis química , Triazoles/química
10.
Bioorg Med Chem Lett ; 17(3): 823-7, 2007 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-17107793

RESUMEN

Several simple scoring methods were examined for 2 series of beta-secretase (BACE-1) inhibitors to identify a docking/scoring protocol which could be used to design BACE-1 inhibitors in a drug discovery program. Both the PLP1 score and MMFFs interaction energy (E(inter)) performed as well or better than more computationally intensive methods for a set of substrate-based inhibitors, while the latter performed well for both sets of inhibitors.


Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Cristalografía por Rayos X , Cinética , Modelos Moleculares , Conformación Molecular
11.
Bioorg Med Chem Lett ; 17(6): 1788-92, 2007 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-17257835

RESUMEN

A series of low-molecular weight 2,6-diamino-isonicotinamide BACE-1 inhibitors containing an amine transition-state isostere were synthesized and shown to be highly potent in both enzymatic and cell-based assays. These inhibitors contain a trans-S,S-methyl cyclopropane P(3) which bind BACE-1 in a 10s-loop down conformation giving rise to highly potent compounds with favorable molecular weight and moderate to high susceptibility to P-glycoprotein (P-gp) efflux.


Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Niacinamida/síntesis química , Niacinamida/farmacología , Animales , Baculoviridae/efectos de los fármacos , Baculoviridae/enzimología , Disponibilidad Biológica , Células Cultivadas , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Conformación Molecular , Peso Molecular , Niacinamida/farmacocinética , Ratas , Relación Estructura-Actividad
12.
Bioorg Med Chem Lett ; 16(3): 641-4, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16263281

RESUMEN

We have synthesized and evaluated a series of conformationally biased P3 amide replacements based on an isophthalamide lead structure. The studies resulted in the identification of the beta-secretase inhibitor 7m which has an in vitro IC(50)=35 nM. The synthesis and biological activities of these compounds are described.


Asunto(s)
Amidas/química , Endopeptidasas/metabolismo , Inhibidores de Proteasas/síntesis química , Amidas/farmacología , Secretasas de la Proteína Precursora del Amiloide , Diseño de Fármacos , Concentración 50 Inhibidora , Modelos Moleculares , Ácidos Ftálicos/química , Inhibidores de Proteasas/farmacología , Relación Estructura-Actividad
13.
Bioorg Med Chem Lett ; 16(14): 3635-8, 2006 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-16690314

RESUMEN

A series of beta-site amyloid precursor protein cleaving enzyme (BACE-1) inhibitors containing a psi(CH2NH) reduced amide bond were synthesized. Incorporation of this reduced amide isostere as a non-cleavable peptide surrogate afforded inhibitors possessing low nanomolar potencies in both an enzymatic and cell-based assay.


Asunto(s)
Amidas/química , Endopeptidasas/metabolismo , Inhibidores de Proteasas/síntesis química , Secretasas de la Proteína Precursora del Amiloide , Sitios de Unión , Inmunoensayo , Péptidos/química , Inhibidores de Proteasas/farmacología , Relación Estructura-Actividad
14.
Anal Biochem ; 342(1): 144-51, 2005 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-15958191

RESUMEN

The deposition of beta-amyloid peptides (A beta42 and A beta40) in neuritic plaques is one of the hallmarks of Alzheimer's disease (AD). A beta peptides are derived from sequential cleavage of amyloid precursor protein (APP) by beta- and gamma-secretases. BACE-1 has been shown to be the major beta-secretase and is a primary therapeutic target for AD. In this article, two novel assays for the characterization of BACE-1 inhibitors are reported. The first is a sensitive 96-well HPLC biochemical assay that uses a unique substrate containing an optimized peptide cleavage sequence, NFEV, spanning from the P2-P2' positions This substrate was processed by BACE-1 approximately 10 times more efficiently than was the widely used substrate containing the Swedish (NLDA) sequence. As a result, the concentration of the enzyme required for the assay can be as low as 100 pM, permitting the evaluation of inhibitors with subnanomolar potency. The assay has also been applied to related aspartyl proteases such as cathepsin D (Cat D) and BACE-2. The second assay is a homogeneous electrochemiluminescence assay for the evaluation of BACE-1 inhibition in cultured cells that assesses the level of secreted amyloid EV40_NF from HEK293T cells stably transfected with APP containing the novel NFEV sequence. To illustrate the use of these assays, the properties of a potent, cell-active BACE-1 inhibitor are described.


Asunto(s)
Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Inhibidores de Proteasas/química , Sulfonamidas/farmacología , Secretasas de la Proteína Precursora del Amiloide , Precursor de Proteína beta-Amiloide/genética , Catepsina D/antagonistas & inhibidores , Línea Celular , Cromatografía Líquida de Alta Presión , Endopeptidasas , Humanos , Oligopéptidos/metabolismo , Oligopéptidos/farmacología , Sensibilidad y Especificidad , Transfección
15.
J Biol Chem ; 280(18): 17792-7, 2005 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-15737955

RESUMEN

Extracellular deposits of aggregated amyloid-beta (Abeta) peptides are a hallmark of Alzheimer disease; thus, inhibition of Abeta production and/or aggregation is an appealing strategy to thwart the onset and progression of this disease. The release of Abeta requires processing of the amyloid precursor protein (APP) by both beta- and gamma-secretase. Using an assay that incorporates full-length recombinant APP as a substrate for beta-secretase (BACE), we have identified a series of compounds that inhibit APP processing, but do not affect the cleavage of peptide substrates by BACE1. These molecules also inhibit the processing of APP and Abeta by BACE2 and selectively inhibit the production of Abeta(42) species by gamma-secretase in assays using CTF99. The compounds bind directly to APP, likely within the Abeta domain, and therefore, unlike previously described inhibitors of the secretase enzymes, their mechanism of action is mediated through APP. These studies demonstrate that APP binding agents can affect its processing through multiple pathways, providing proof of concept for novel strategies aimed at selectively modulating Abeta production.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/antagonistas & inhibidores , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Secretasas de la Proteína Precursora del Amiloide , Ácido Aspártico Endopeptidasas/metabolismo , Sitios de Unión/efectos de los fármacos , Sitios de Unión/fisiología , Relación Dosis-Respuesta a Droga , Endopeptidasas , Células HeLa , Humanos , Inhibidores de Proteasas/metabolismo , Inhibidores de Proteasas/farmacología , Inhibidores de Proteasas/uso terapéutico
16.
Biochemistry ; 41(10): 3520-8, 2002 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-11876660

RESUMEN

Quinolinate phosphoribosyltransferase (QAPRTase, EC 2.4.2.19) catalyzes the formation of nicotinate mononucleotide, carbon dioxide, and pyrophosphate from 5-phosphoribosyl 1-pyrophosphate (PRPP) and quinolinic acid (QA, pyridine 2,3-dicarboxylic acid). The enzyme is the only type II PRTase whose X-ray structure is known. Here we determined the kinetic mechanism of the enzyme from Salmonella typhimurium. Equilibrium binding studies show that PRPP and QA each form binary complexes with the enzyme, with K(D) values (53 and 21 microM, respectively) similar to their K(M) values (30 and 25 microM, respectively). Although neither PP(i) nor NAMN products bound well to the enzyme, 130-fold tighter binding of PP(i) (K(D) = 75 microM) and NAMN (K(D) = 6 microM) in a ternary complex was observed. Phthalic acid (K(D) = 21 microM) and PRPP each caused a 2.5-fold tightening of the other's binding. Isotope trapping experiments indicated that the E.QA complex is catalytically competent, whereas the E.PRPP complex could not be trapped. Pre-steady-state kinetics gave a linear rate of NAMN formation, indicating that on-enzyme phosphoribosyl transfer chemistry is rate-determining. Isotope trapping from the steady state revealed that nearly all QA and about one-third of PRPP in ternary enzyme.QA.PRPP complexes could be trapped as the product. Substrate inhibition by PRPP was observed. These data demonstrate a predominantly ordered kinetic mechanism in which productive binding of quinolinic acid precedes that of PRPP. An E.PRPP complex exists as a nonproductive side branch.


Asunto(s)
Pentosiltransferasa/metabolismo , Isótopos , Cinética , Ácidos Ftálicos/metabolismo , Proteínas Recombinantes/metabolismo , Especificidad por Sustrato
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