Melanocortin 4 receptors interact with antimicrobial frog peptide analogues

• Published in: Biochemical and biophysical research communications Vol. 343; no. 4; pp. 1094 - 1100
• Main Authors: Do, Ernest U., Jo, Eun Bae, Choi, Gyu, Piao, Long Zhu, Shin, Jaekyoon, Seo, Min-Duk, Kang, Su-Jin, Lee, Bong-Jin, Ho Kim, Kang, Bum Kim, Jae, Kim, Su-il
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 19.05.2006
• Subjects: Agonists and antagonists; alpha-MSH - analogs & derivatives; alpha-MSH - pharmacology; Animals; Antimicrobial Cationic Peptides - pharmacology; Binding, Competitive; Cell Line; Cyclic AMP - metabolism; Fluorescence Polarization; Gaegurin; Genes, Reporter; High-throughput screening; Human melanocortin 4 receptors; Humans; Ligands; Melanocyte-Stimulating Hormones - pharmacology; Oligopeptides - pharmacology; Plant Extracts - pharmacology; Rana rugosa; Ranidae; Rank order of potency; Receptor, Melanocortin, Type 4 - agonists; Receptor, Melanocortin, Type 4 - antagonists & inhibitors; Receptor, Melanocortin, Type 4 - metabolism; Recombinant Proteins - agonists; Recombinant Proteins - antagonists & inhibitors; Recombinant Proteins - metabolism; High-throughput screening; Fluorescence polarization; Human melanocortin 4 receptors; Agonists and antagonists; Gaegurin; Rank order of potency
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2006.03.082

We have developed fluorescence polarization (FP) assays of human melanocortin 4 receptor (MC4R) in 384-well microtiter plates using TAMRA-NDP-MSH as a tracer. The rank order of potency of agonists and antagonists agrees well relative to the published assays: SHU9119 > MTII > NDP αMSH > αMSH. We have screened libraries of Korean plant extracts and frog peptide analogues in search of MC4R ligands using FP assays and cell-based CRE luciferase reporter assays. We report that FLGFLFKVASK, FLGWLFKVASK, FLGALFKWASK, and FLGWLFKWASK are the peptide analogues, which bind to human MC4R receptor with good affinity in vitro. FLGWLFKVASK and FLGWLFKWASK stimulated CRE-driven reporter gene via MC4R. In luciferase reporter assays, they possess the pharmacological and functional profiles of full agonists. We demonstrate the interaction of MC4R with 11-residue antimicrobial peptides derived from the Korean frog, Rana rugosa. The results suggest that MC4R interacts promiscuously with bioactive analogues of antimicrobial peptide, gaegurin-5.