Orphan GPCR SP9155 agonist P550 (mouse, rat)

Orphan GPCR SP9155 agonist P550 (mouse, rat) (26RFa (mouse, rat)), a member of the RFamide peptide family with orexigenic effect, is the cognate ligand of the mouse orphan receptor GPR103, also designated SP9155 or AQ27[1][2].

OC(C=C1)=CC=C1C[C@@H](C(N[C@@H](CO)C(N[C@@H](CCCNC(N)=N)C(N[C@@H](CCCNC(N)=N)C(N[C@@H](CCCCN)C(NCC(NCC(N[C@H](C(N[C@@H](CO)C(N[C@H](C(N[C@@H](CCCNC(N)=N)C(N[C@H](C(N)=O)CC2=CC=CC=C2)=O)=O)CC3=CC=CC=C3)=O)=O)CC4=CC=CC=C4)=O)=O)=O)=O)=O)=O)=O)NC([C@H](CO)NC([C@H](CO)NC([C@H](CC(C)C)NC([C@H](CCC(O)=O)NC([C@H](CCC(O)=O)NC([C@H](C)NC([C@H](CC(C)C)NC([C@H]([C@H](O)C)NC(CNC([C@H](CC(C)C)NC([C@H]5N(CCC5)C(CNC([C@H](CO)NC([C@@H](N)C)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O)=O

[1]Chartrel N, et al. Identification of 26RFa, a hypothalamic neuropeptide of the RFamide peptide family with orexigenic activity. Proc Natl Acad Sci U S A. 2003;100(25):15247-15252.|[2]Chartrel N, et al. The Neuropeptide 26RFa (QRFP) and Its Role in the Regulation of Energy Homeostasis: A Mini-Review. Front Neurosci. 2016;10:549. Published 2016 Nov 29.|[3]Egido EM, et al. 26RFa, a novel orexigenic neuropeptide, inhibits insulin secretion in the rat pancreas. Peptides. 2007;28(4):725-730.