RESUMEN
A general strategy to enzymatically label acyl carrier proteins (ACPs) of polyketide synthases has been developed. Incorporation of a chloromethyl ketone or vinyl ketone moiety into polyketide chain elongation intermediate mimics allows for the synthesis of CoA adducts. These CoA adducts undergo enzymatic reaction with Sfp, a phosphopantetheinyl transferase, to afford labeled CurB carrier proteins.
Asunto(s)
Proteína Transportadora de Acilo/química , Sintasas Poliquetidas/química , Proteínas Bacterianas/metabolismo , Coenzima A/química , Cetonas/química , Sintasas Poliquetidas/metabolismo , Estructura Terciaria de Proteína , Especificidad por Sustrato , Transferasas (Grupos de Otros Fosfatos Sustitutos)/metabolismoRESUMEN
A systematic series of previously inaccessible key C20' urea and thiourea derivatives of vinblastine were prepared from 20'-aminovinblastine that was made accessible through a unique Fe(III)/NaBH(4)-mediated alkene functionalization reaction of anhydrovinblastine. Their examination defined key structural features of the urea-based analogues that contribute to their properties and provided derivatives that match or exceed the potency of vinblastine by as much as 10-fold in cell-based functional assays, which is directly related to their relative tubulin binding affinity. In contrast to expectations based on apparent steric constraints of the tubulin binding site surrounding the vinblastine C20' center depicted in an X-ray cocrystal structure, remarkably large C20' urea derivatives are accommodated.
Asunto(s)
Tubulina (Proteína)/metabolismo , Urea/química , Vinblastina/análogos & derivados , Animales , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , División Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Leucemia Experimental/patología , Ratones , Modelos Moleculares , Unión Proteica , Espectrometría de Masa por Ionización de Electrospray , Espectrofotometría Infrarroja , Vinblastina/química , Vinblastina/farmacologíaRESUMEN
An Fe(III)/NaBH(4)-mediated reaction for the functionalization of unactivated alkenes is described defining the alkene substrate scope, establishing the exclusive Markovnikov addition, exploring a range of free radical traps, examining the Fe(III) salt and initiating hydride source, introducing H(2)O-cosolvent mixtures, and exploring catalytic variants. Its use led to the preparation of a novel, potent, and previously inaccessible C20'-vinblastine analogue.