Development of novel G-protein-coupled receptor 54 agonists with resistance to degradation by matrix metalloproteinase.

Kisspeptin-GPR54 signaling is involved in the suppression of cancer metastasis and regulation of hormonal secretion. Recently, matrix metalloproteinase mediated deactivation of kisspeptins through hydrolysis of the Gly-Leu peptide bond has been reported. In the present report, GPR54 agonistic peptides having several nonhydrolyzable Gly-Leu dipeptide isosteres were designed and synthesized. (E)-Alkene- and hydroxyethylene-type isostere-containing analogues maintained the original activity with higher stability in murine serum and resistance to MMP-9-mediated cleavage.