RESUMEN
Gonadotropins are highly complex glycoprotein hormones consisting of two noncovalently associated subunits, which are heavily glycosylated. Using the X-ray structure of human choriogonadotropin and structure/activity relationships we aimed to design 'minimized' gonadotropins of reduced complexity. Our results show that it is possible to reduce the size of natural human choriogonadotropin by one-third of its molecular weight while retaining its wild-type biopotency. To our knowledge, such 'mini'-human choriogonadotropins represent the smallest gonadotropins described so far with an lutropin/choriogonadotropin receptor affinity and in vitro biological activity comparable with that of natural human choriogonadotropin. It provides an important step towards the structure/function-based design of small molecule drugs to the human gonadotropin receptors.
Asunto(s)
Gonadotropina Coriónica/química , Gonadotropina Coriónica/farmacología , Animales , Células CHO , Gonadotropina Coriónica/genética , Cricetinae , Diseño de Fármacos , Genes Reporteros , Humanos , Técnicas In Vitro , Luciferasas/genética , Peso Molecular , Mutagénesis Sitio-Dirigida , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/farmacología , Conformación Proteica , Receptores de HL/efectos de los fármacos , Receptores de HL/metabolismo , Relación Estructura-ActividadRESUMEN
The soil amoeba Dictyostelium discoideum is a host cell that provides simple genetics in combination with complex protein synthesis. We show that the complex human heterodimeric gonadotropins can be produced and secreted by this organism. Furthermore, both follicle stimulation hormone and choriogonadotropin produced by D. dictyostelium bind to their human receptors and elicit a biological response comparable to the wild-type hormones. We also show that structure-function analysis using random mutagenesis and screening of recombinant glycoprotein hormones is feasible. Thus, expression of gonadotropins in D. dictyostelium opens the way to the engineering of potential new therapeutic analogues.