In vitro selection of a peptide antagonist of growth hormone secretagogue receptor using cDNA display.
G protein-coupled receptors (GPCRs) are major drug targets, and their ligands are currently being explored and developed by many pharmaceutical companies and independent researchers. Class A (rhodopsin-like) GPCRs compose a predominant GPCR family; therefore, class A GPCR ligands are in demand. Growth hormone secretagogue receptor (GHS-R) is a class A GPCR that stimulates food intake by binding to its peptide ligand, ghrelin. Therefore, antagonists of GHS-R are expected to exert antiobesity function. In this article, we describe the use of cDNA display to screen for successfully and identify an antagonistic peptide of GHS-R. The antagonistic peptide inhibited the ghrelin-induced increase in intracellular Ca(2+) in vitro (IC(50) = approximately 10 μM) and repressed the contraction of isolated animal stomach in response to ghrelin. Furthermore, peripheral administration of the peptide inhibited the food intake of mice. This work provides new insight into the development of antiobesity drugs and describes a method for the discovery of unique peptide ligands for class A GPCRs.
Department of Regulation Biology, Faculty of Science, Saitama University, Sakura-ku, Saitama 338-8570, Japan.
Shingo
S
Ueno
Sayaka
S
Yoshida
Anupom
A
Mondal
Kazuya
K
Nishina
Makoto
M
Koyama
Ichiro
I
Sakata
Kenju
K
Miura
Yujiro
Y
Hayashi
Naoto
N
Nemoto
Koichi
K
Nishigaki
Takafumi
T
Sakai
D000818:Animals; D019440:Anti-Obesity Agents / Q000494:pharmacology; D016466:CHO Cells; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D018076:DNA, Complementary / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015723:Gene Library; D054439:Ghrelin / Q000378:metabolism; D066298:In Vitro Techniques; D020128:Inhibitory Concentration 50; D008024:Ligands; D008297:Male; D051379:Mice; D008954:Models, Biological; D010455:Peptides / Q000737:chemistry; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000378:metabolism; D054440:Receptors, Ghrelin / Q000378:metabolism*
D019440:Anti-Obesity Agents; D018076:DNA, Complementary; D054439:Ghrelin; D008024:Ligands; D010455:Peptides; D012333:RNA, Messenger; D054440:Receptors, Ghrelin; D002118:Calcium