RESUMEN
Nicotinamide N-methyltransferase (NNMT) has been linked to obesity and diabetes. We have identified a novel nicotinamide (NA) analog, compound 12 that inhibited NNMT enzymatic activity and reduced the formation of 1-methyl-nicotinamide (MNA), the primary metabolite of NA by â¼80% at 2â¯h when dosed in mice orally at 50â¯mg/kg.
Asunto(s)
Inhibidores Enzimáticos/farmacología , Niacinamida/farmacología , Nicotinamida N-Metiltransferasa/antagonistas & inhibidores , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Humanos , Estructura Molecular , Niacinamida/síntesis química , Niacinamida/química , Nicotinamida N-Metiltransferasa/metabolismo , Relación Estructura-ActividadRESUMEN
Nicotinamide N-methyltransferase (NNMT) is a S-adenosyl-l-methionine (SAM)-dependent enzyme that catalyzes N-methylation of nicotinamide (NA) and other pyridines to form N-methyl pyridinium ions. Here we report the first ternary complex X-ray crystal structures of monkey NNMT and mouse NNMT in bound form with the primary endogenous product, 1-methyl nicotinamide (MNA) and demethylated cofactor, S-adenosyl-homocysteine (SAH) determined at 2.30 Å and 1.88 Å respectively. The structural fold of these enzymes is identical to human NNMT. It is known that the primary endogenous product catalyzed by NNMT, MNA is a specific inhibitor of NNMT. Our data clearly indicates that the MNA binds to the active site and it would be trapped in the active site due to the formation of the bridge between the pole (long helix, α3) and long C-terminal loop. This might explain the mechanism of MNA acting as a feedback inhibitor of NNMT.
Asunto(s)
Retroalimentación Fisiológica , Niacinamida/análogos & derivados , Nicotinamida N-Metiltransferasa/química , S-Adenosilmetionina/química , Secuencia de Aminoácidos , Animales , Dominio Catalítico , Clonación Molecular , Cristalografía por Rayos X , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Macaca mulatta , Ratones , Modelos Moleculares , Niacinamida/química , Niacinamida/metabolismo , Nicotinamida N-Metiltransferasa/antagonistas & inhibidores , Nicotinamida N-Metiltransferasa/genética , Nicotinamida N-Metiltransferasa/metabolismo , Unión Proteica , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Dominios y Motivos de Interacción de Proteínas , Estructura Terciaria de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , S-Adenosilmetionina/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Especificidad por SustratoRESUMEN
Nicotinamide N-methyltransferase (NNMT) is a cytosolic enzyme that catalyzes the transfer of a methyl group from the co-factor S-adenosyl-L-methionine (SAM) onto the substrate, nicotinamide (NA) to form 1-methyl-nicotinamide (MNA). Higher NNMT expression and MNA concentrations have been associated with obesity and type-2 diabetes. Here we report a small molecule analog of NA, JBSNF-000088, that inhibits NNMT activity, reduces MNA levels and drives insulin sensitization, glucose modulation and body weight reduction in animal models of metabolic disease. In mice with high fat diet (HFD)-induced obesity, JBSNF-000088 treatment caused a reduction in body weight, improved insulin sensitivity and normalized glucose tolerance to the level of lean control mice. These effects were not seen in NNMT knockout mice on HFD, confirming specificity of JBSNF-000088. The compound also improved glucose handling in ob/ob and db/db mice albeit to a lesser extent and in the absence of weight loss. Co-crystal structure analysis revealed the presence of the N-methylated product of JBSNF-000088 bound to the NNMT protein. The N-methylated product was also detected in the plasma of mice treated with JBSNF-000088. Hence, JBSNF-000088 may act as a slow-turnover substrate analog, driving the observed metabolic benefits.
Asunto(s)
Inhibidores Enzimáticos/uso terapéutico , Enfermedades Metabólicas/tratamiento farmacológico , Enfermedades Metabólicas/enzimología , Nicotinamida N-Metiltransferasa/metabolismo , Animales , Peso Corporal/efectos de los fármacos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/enzimología , Dieta Alta en Grasa/efectos adversos , Masculino , Ratones , Ratones Endogámicos C57BL , Nicotinamida N-Metiltransferasa/antagonistas & inhibidoresRESUMEN
[reaction: see text] Regioselective and stereoselective inverse-electron-demand Diels-Alder reaction of N-sulfonyl-1-aza-1,3-butadiene with fulvenes are described. The methodology provides an efficient and novel route to tetrahydro-[1]pyrindine systems.