Ac-Arg-Tyr-Tyr-Arg-Ile-Lys-NH2

Ac-RYYRIK-NH2 is a potent and partial agonist on ORL1 transfected in CHO cells (Kd=1.5 nM) and behaves as a endogenous ligand of ORL1. Ac-RYYRIK-NH2 is a specific antagonist for the activation of G protein and competitively antagonizes the stimulation of [35S]-GTPgS binding to G proteins by nociceptin/orphanin FQ (noc/OFQ) in membranes and sections of rat brain[1].

Ac-RYYRIK-NH2 is a potent ORL1 partial agonist as an endogenous ligand of ORL1 in CHO cells (Kd=1.5 nM). Ac-RYYRIK-NH2 is a specific antagonist of G protein activation and competitively antagonizes noc/OFQ-stimulated [35S]-GTPgS-binding G protein in rat meninges and brain sections.

[1] H Berger, et al. Antagonism by acetyl-RYYRIK-NH2 of G protein activation in rat brain preparations and of chronotropic effect on rat cardiomyocytes evoked by nociceptin/orphanin FQ. Br J Pharmacol. 1999 Feb;126(3):555-8. DOI:10.1038/sj.bjp.0702353
[2] H Berger, et al. The nociceptin/orphanin FQ receptor ligand acetyl-RYYRIK-amide exhibits antagonistic and agonistic properties.Peptides. 2000 Jul;21(7):1131-9. DOI:10.1016/s0196-9781(00)00251-5
[3] C T Dooley, et al. Binding and in vitro activities of peptides with high affinity for the nociceptin/orphanin FQ receptor, ORL1. J Pharmacol Exp Ther.1997 Nov;283(2):735-41. PMID:9353393