Opioid-related peptide that acts at the NOP receptor rather than classic opioid receptors.
Also known as: Orphanin FQ · N/OFQ
Part of the Neuropeptides & signaling cluster
Overview
Nociceptin (orphanin FQ) is a 17-amino-acid neuropeptide that binds the NOP receptor, a member of the opioid receptor family. It is studied for its complex roles in pain processing, mood, and stress.
Source & context
Biological / chemical source: Central nervous system; derived from prepronociceptin
Primary research or clinical context: Pain and mood neuroscience research
A distinct opioid-like system
Although related to opioid peptides, nociceptin acts at the NOP (ORL1) receptor rather than mu, delta, or kappa receptors. Its effects on nociception can differ by site of action, making it a nuanced research topic.
Naming origin
The peptide was named 'orphanin FQ' because it was the endogenous ligand for a previously orphan receptor. This page describes that pharmacology for education only.
Sequence
One-letter sequence commonly cited for Nociceptin (educational; isoforms and modifications may differ):
FGGFTGARKSARKLANQ
Residues plotted ~100° apart around an α-helix — clustering of one color reveals an amphipathic face.
FAQ about Nociceptin
What is Nociceptin?+
Nociceptin (orphanin FQ) is a 17-amino-acid neuropeptide that binds the NOP receptor, a member of the opioid receptor family. It is studied for its complex roles in pain processing, mood, and stress.
Is Nociceptin an approved medicine?+
Nociceptin is discussed here as a research / educational topic. Pain and mood neuroscience research. This is not medical advice.
What is the typical length of Nociceptin?+
Nociceptin is commonly described as approximately 17 amino acids (Neuropeptide).