title: Structure-activity relationships of beta-MSH derived melanocortin-4 receptor peptide agonists.
abstract: The recent emergence of obesity as a major health threat in the industrialized world has intensified the search for novel and effective pharmacologic treatment. The proopiomelanocortin (POMC)-melanocortin 4 receptor (MC4R) axis has been shown to regulate food intake and energy homeostasis and is considered among the most promising antiobesity targets. Our initial efforts in this area have focused on affinity and selectivity directed optimization of the native beta-MSH(5-22) sequence and resulted in the discovery of a potent MC4R agonist: Ac-Tyr-Arg-[Cys-Glu-His-D-Phe-Arg-Trp-Cys]-NH(2) (10). Subcutaneous administration of this peptide produced an excellent in vivo efficacy in reducing food intake and increasing fat metabolism. Additionally, suppression of food intake was observed in wild type but not in MC4R deficient mice, suggesting that the effects observed in the wild type mice were mediated through MC4R signaling. Subsequent optimization efforts led to the identification of a novel series of disulfide constrained hexapeptides as exemplified by Ac-[hCys-His-D-Phe-Arg-Trp-Cys]-NH(2) (100). These cyclic hexapeptides showed a further improved potency in binding MC4R and an enhanced selectivity over MC1R. At a dose of 0.07 mg/kg analog 102 reduced food intake by 38% and increased fat utilization by 58% in rats. These cyclic peptides provide novel and enhanced reagents for the elucidation of melanocortin receptors biology and may find applications in the treatment of obesity and related metabolic disorders.
authors.affiliation: Lilly Research Laboratories, A Division of Eli Lilly & Company, Lilly Corporate Center, Indianapolis, IN 46285, USA. yan_liang_zeng@lilly.com
authors.forename: Liang Zeng
authors.initials: LZ
authors.lastname: Yan
authors.forename: Hansen M
authors.initials: HM
authors.lastname: Hsiung
authors.forename: Mark L
authors.initials: ML
authors.lastname: Heiman
authors.forename: Robert A
authors.initials: RA
authors.lastname: Gadski
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Emmerson
authors.forename: JeAnne
authors.initials: J
authors.lastname: Hertel
authors.forename: David
authors.initials: D
authors.lastname: Flora
authors.forename: Patrick
authors.initials: P
authors.lastname: Edwards
authors.forename: Dave
authors.initials: D
authors.lastname: Smiley
authors.forename: Lianshan
authors.initials: L
authors.lastname: Zhang
authors.forename: Saba
authors.initials: S
authors.lastname: Husain
authors.forename: Steven D
authors.initials: SD
authors.lastname: Kahl
authors.forename: Richard D
authors.initials: RD
authors.lastname: DiMarchi
authors.forename: John P
authors.initials: JP
authors.lastname: Mayer
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D003198:Computer Simulation; D004220:Disulfides / Q000737:chemistry; D006801:Humans; D044105:Receptor, Melanocortin, Type 4 / Q000819:agonists* / Q000378:metabolism; D013329:Structure-Activity Relationship; D019824:beta-MSH / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D000596:Amino Acids; D004220:Disulfides; D044105:Receptor, Melanocortin, Type 4; D019824:beta-MSH