RESUMEN
All reported GnRH receptor mutants (causing human hypogonadotropic hypogonadism) are misfolded proteins that cannot traffic to the plasma membrane. Pharmacoperones correct misfolding and rescue mutants, routing them to the plasma membrane where they regain function. Because pharmacoperones are often peptidomimetic antagonists, these must be removed for receptor function after rescue; in vivo this necessitates pulsatile pharmacoperone administration. As an antecedent to in vivo studies, we determined whether pharmacoperones need to be present at the time of synthesis or whether previously misfolded proteins could be refolded and rescued. Accordingly, we blocked either protein synthesis or intra-cellular transport. Biochemical and morphological studies using 12 mutants and 10 pharmacoperones representing three different chemical classes show that previously synthesized mutant proteins, retained by the quality control system (QCS), are rescued by pharmacoperones, showing that pharmacoperone administration in vivo likely need not consider whether the target protein is being synthesized at the time of drug administration.
Asunto(s)
Chaperonas Moleculares/farmacología , Pliegue de Proteína , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Receptores Acoplados a Proteínas G/metabolismo , Receptores LHRH/metabolismo , Animales , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Células COS , Chlorocebus aethiops , Evaluación Preclínica de Medicamentos , Células HeLa , Humanos , Indoles/farmacología , Inositol/farmacología , Imitación Molecular , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Transporte de Proteínas/efectos de los fármacos , Piridinas/farmacología , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/genética , Receptores LHRH/química , Receptores LHRH/genética , TransfecciónRESUMEN
Structure-activity relationships of a 4-aminoquinoline MCH1R antagonist lead series were explored by synthesis of analogs with modifications at the 2-, 4-, and 6-positions of the original HTS hit. Improvements to the original screening lead included lipophilic groups at the 2-position and biphenyl, cyclohexyl phenyl, and hydrocinnamyl carboxamides at the 6-position. Modifications of the 4-amino group were not well tolerated.