Neuropeptide Y (NPY) and pancreatic polypeptide (PP) control central and peripheral processes by activating the G protein coupled receptors Y xR (x = 1, 2, 4, 5). We present analogs of the C-terminal fragments 25-36 and 32-36 of NPY and PP containing (1R,2S)-cyclobutane (βCbu) or (1R,2S)-cyclopentane (βCpe) β-amino acids, which display exclusively Y4R affinity. In particular, [βCpe34]-NPY-(25-36) is a Y4R selective partial agonist (EC50 41 ± 6 nM, Emax 71%) that binds Y4R with a Ki of 10 ± 2 nM and a selectivity >100-fold relative to Y1R and Y2R and >50-fold relative to Y5R. Comparably, [Y 32, βCpe34]-NPY(PP)-(32-36) selectively binds and activates Y4R (EC50 94 ± 21 nM, Emax 73%). The NMR structure of [βCpe34]-NPY-(25-36) in dodecylphosphatidylcholine micelles shows a short helix at residues 27-32, while the C-terminal segment R33βCpe34R35Y 36 is extended. The biological properties of the βCbu- or βCpe-containing NPY and PP C-terminal fragments encourage the future application of these β-amino acids in the synthesis of selective Y 4R ligands. © 2013 American Chemical Society.
|Journal||Journal of Medicinal Chemistry|
|Publication status||Published - 14 Nov 2013|