CAS 200959-47-3: L-Lysinamide,N2-acetyl-L-arginyl-L-tyrosyl-L-tyrosyl-L-arginyl-L-tryptophyl-

Ac-RYYRWK-NH2 is a delta-opioid receptor agonist. This compound has been shown to uncouple the cerebral cortex from the reproductive system in rats, and to be an endogenous ligand for the delta-opioid receptor. The binding affinity of Ac-RYYRWK-NH2 for the delta opioid receptor was found to be similar to that of naloxone. Ac-RYYRWK-NH2 also inhibits ovulation when administered to rats. Ac-RYYRWK-NH2 is not active against morphine or other opioid receptors, but does have a high affinity for the delta opioid receptor.

Selective NOP receptor partial agonist peptide; Ki=0.71 nM; >4000 nM for μ, δ, κ receptors; boosts food intake in vivo.