Orphanin FQ, (Nociceptin)

Orphanin FQ, (Nociceptin) is a synthetic research peptide in the nociceptin/orphanin FQ peptide family. Nociceptin, also called orphanin FQ, is a 17-residue neuropeptide identified independently as the endogenous agonist of the opioid-receptor-like NOP/ORL1 receptor. It resembles classical opioid peptides in sequence yet shows distinct receptor pharmacology. N- and C-terminal truncations and residue-modified analogs have been used to map NOP receptor recognition and activation.

• NOP/ORL1 receptor binding assays
• NOP receptor signaling studies
• nociceptin analog structure-activity experiments
• neuropeptide pharmacology
• analytical peptide controls

For fragments, substituted analogs, labeled peptides, stereochemical variants, or terminally modified forms, experimental behavior should be evaluated for the exact construct rather than assumed to match the native parent peptide. Sequence-dependent solubility, aggregation, adsorption, oxidation, and stability should be considered when establishing reconstitution, storage, and assay conditions.

1. Orphanin FQ: a neuropeptide that activates an opioidlike G protein-coupled receptor
2. Isolation and structure of the endogenous agonist of opioid receptor-like ORL1 receptor