Toward Regulation of Gonadal Function by a Synthetic Hybrid Molecule Composed of Gonadotropin and Fc Fragment of Immunoglobulin G

Abstract

A conjugate of human chorionic gonadotropin (HCG) and Fc fragment of immunoglobulin G was prepared by covalent cross-linking using the heterobifunctional reagent, N-succinimidyl 3-(2-pyridyldithio) propionate. Mouse Leydig tumor cells expressing receptors for luteinizing hormone were specifically lysed in vitro as a consequence of complement fixation via the Fc component of the hybrid molecule. Furthermore, administration of HCG-Fc to rams caused an acute depression in circulatory testosterone. This novel concept of targeted inhibition of gonadal function could prove to have future applications in control of reproductive processes.