Glucose and Weight Control in Mice with a Designed Ghrelin O-Acyltransferase Inhibitor

Ghrelin is a gastric peptide hormone that stimulates weight gain in vertebrates. The biological activities of ghrelin require octanoylation of the peptide on Ser³, an unusual posttranslational modification that is catalyzed by the enzyme ghrelin O-acyltransferase (GOAT). Here, we describe the design, synthesis, and characterization of GO-CoA-Tat, a peptide-based bisubstrate analog that antagonizes GOAT. GO-CoA-Tat potently inhibits GOAT in vitro, in cultured cells, and in mice. Intraperitoneal administration of GO-CoA-Tat improves glucose tolerance and reduces weight gain in wild-type mice but not in ghrelin-deficient mice, supporting the concept that its beneficial metabolic effects are due specifically to GOAT inhibition. In addition to serving as a research tool for mapping ghrelin actions, GO-CoA-Tat may help pave the way for clinical targeting of GOAT in metabolic diseases.