RESUMEN
A novel class of pyridinyl aminohydantoins was designed and prepared as highly potent BACE1 inhibitors. Compound (S)-4g showed excellent potency with IC(50) of 20 nM for BACE1. X-ray crystallography indicated that the interaction between pyridine nitrogen and the tryptophan Trp76 was a key feature in the S2' region of the enzyme that contributed to increased potency.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Ácido Aspártico Endopeptidasas/antagonistas & inhibidores , Ácido Aspártico Endopeptidasas/metabolismo , Hidantoínas/farmacología , Piridinas/farmacología , Secretasas de la Proteína Precursora del Amiloide/química , Ácido Aspártico Endopeptidasas/química , Cristalografía por Rayos X , Humanos , Hidantoínas/química , Modelos Moleculares , Unión Proteica , Piridinas/química , Relación Estructura-ActividadRESUMEN
The proteolytic enzyme beta-secretase (BACE-1) produces amyloid beta (Abeta) peptide, the primary constituent of neurofibrillary plaques, implicated in Alzheimer's disease, by cleavage of the amyloid precursor protein. A small molecule inhibitor of BACE-1, (diaminomethylene)-2,5-diphenyl-1H-pyrrole-1-acetamide (1, BACE-1 IC(50)=3.7 microM), was recently described, representing a new small molecule lead. Initial SAR investigation demonstrated the potential of accessing the nearby S(3) and S(1)(') substrate binding pockets of the BACE-1 enzyme by building substituents off one of the phenyl substituents and guanidinyl functional group. We report here the optimization of guanidinyl functional group substituents on 1, leading to potent submicromolar BACE-1 inhibitors.
Asunto(s)
Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Guanidina/farmacología , Pirroles/química , Enfermedad de Alzheimer/enzimología , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Animales , Células CHO , Cricetinae , Cricetulus , Inhibidores Enzimáticos/química , Guanidina/química , HumanosRESUMEN
BACE1 is an aspartyl protease responsible for cleaving amyloid precursor protein to liberate Abeta, which aggregates leading to plaque deposits implicated in Alzheimer's disease. We have identified small-molecule acylguanidine inhibitors of BACE1. Crystallographic studies show that these compounds form unique hydrogen-bonding interactions with the catalytic site aspartic acids and stabilize the protein in a flap-open conformation. Structure-based optimization led to the identification of potent analogs, such as 10d (BACE1 IC(50) = 110 nM).