Identification and in Vivo and in Vitro Characterization of Long Acting and Melanocortin 4 Receptor (MC4-R) Selective α-Melanocyte-Stimulating Hormone (α-MSH) Analogues

Abstract

We report in vitro and in vivo data of new α-melanocyte-stimulating hormone (α-MSH) analogues which are N-terminal modified with a long chain fatty acid derivative. While keeping the pharmacophoric motif (d-Phe-Arg-Trp) fixed, we tried to improve selectivity and physicochemical parameters like solubility and stability of these analogues by replacing amino acids further away from the motif. Receptor specific changes in binding affinity to the melanocortin receptors were observed between the acetyl derivatives and the fatty acid analogues. Furthermore, amino acids at the N-terminal of α-MSH (Ser-Tyr-Ser) not considered to be part of the pharmacophore were found to have an influence on the MC4/MC1 receptor selectivity. While the acetyl analogues have an in vivo effect for around 7 h, the long chain fatty acid analogues have an effect up to 48 h in an acute feeding study in male Sprague-Dawley rats after a single subcutaneous administration.

Bench-top to clinical therapies: A review of melanocortin ligands from 1954 to 2016

“…In development by Novo Nordisk, MC4-NN2-0453 is a α-MSH analog with an N-terminal fatty acid extension [286]. The modified peptide, 16-(tetrazol-5-yl)hexadecanoyl-Oeg-Gly-Ser-Gln-His-Dap[bis(carboxymethyl)amino]acetyl-Nle-c[Glu-Hyp-DPhe-Arg-Trp-Lys]-NH 2 (Figure 6), has K i of 2700, 71, 0.58, and 13 nM at the hMC1R, hMC3R, hMC4R, hMC5R, respectively [286].…”

Design, Synthesis, Structural and Functional Characterization of Novel Melanocortin Agonists Based on the Cyclotide Kalata B1

“…Three-dimensional structures were calculated from the recorded two-dimensional spectra using CYANA as described previously (52). Structures were analyzed using Molprobity and PROMOTIF (53) and displayed using MolMol (54) and PyMol (55) Melanocortin Assays-Melanocortin receptor binding assays were conducted as described previously (56). Each assay was performed in duplicate, and three assays were done on each receptor.…”

“…The cAMP activity assays were conducted on baby hamster kidney cells expressing the MC4R, using the FlashPlate TM assay as described previously (56). Cells and peptide (100 fM to 10 M to) were incubated and shaken for 30 min at room temperature.…”

“…The data analyses from the receptor assays were performed as described previously (56), using the program GraphPad Prism, GraphPad Software. IC 50 values were calculated using a nonlinear regression model, and K i values were calculated from the IC 50 values.…”

Melanocortin-4 Receptor Modulators for the Treatment of Obesity: a Patent Analysis (2008–2014)

“…Compound 4 which exhibited partial activity in a low expressing MC4R functional assay was found to decrease food intake and body weight gain in a rat model and stimulate erectile behavior in male rats. Novo Nordisk disclosed lipidated cyclic peptides such as MC4-NN2-0453 (5) with greater than 1000-fold selectivity for MC4R over Melanocortin-4 receptor modulators for the treatment of obesity Patent Review MC1R (MC4R Ki = 0.0006 μM; MC1R Ki = 2.7 μM), enhanced aqueous solubility and extended half-lives in rodent models [43,44]. Compound 5 exhibited full agonist activity in a cAMP functional assay and was shown to significantly decrease food intake in rodent models over a 48-h period.…”