Dynorphin A (1-10) amide: natural opioid fragment that boosts morphine pain relief
A short piece of the body's own opioid peptide dynorphin; strengthens morphine's painkilling effect in animals that have built up tolerance, without blocking it in animals new to the drug; lab research tool only.
A researcher, an agent, or an algorithm wrote down the sequence and picked a target to hit.
An AI model like OpenFold3 or AlphaFold built a 3D structure and scored how well it fits the binding site.
A second contributor repeated the computation on their own hardware and the scores matched.
A chemistry service or a researcher ordered the sequence, it was manufactured, and mass spectrometry confirmed the right molecule was produced.
A binding or activity measurement confirmed that it actually does what the computer predicted — or didn't.
What this is
Dynorphin A (1-10) amide is a short fragment of dynorphin A, one of the body's own opioid peptides. The full dynorphin A peptide is a 17-residue neuropeptide released from the precursor protein preprodynorphin; this card is the first ten residues of that peptide (YGGFLRRIRP), capped with a C-terminal amide rather than the free acid found in the stored 1-letter sequence. Like other endogenous opioids, it begins with the shared "YGGF" message sequence that lets it dock into opioid receptors. The "porcine" label reflects the species the fragment was originally characterized from; the 1-10 sequence is identical across most mammals.
History
Dynorphin peptides were identified as a third family of endogenous opioids alongside the enkephalins and β-endorphin, all sharing the N-terminal YGGF motif and all derived from distinct precursor proteins. Clynen and colleagues (2014) catalog the dynorphin family — including dynorphin A, dynorphin B (rimorphin), big dynorphin, and α-neoendorphin — as products of preprodynorphin processing, and place them in the broader landscape of neuropeptides that have been investigated as targets for anticonvulsant drug development. The 1-10 amide fragment used on this card is one of several truncated forms studied as a way to dissect which portion of full dynorphin A carries which biological activity.
What it does
Endogenous opioid peptides act through a family of four closely related G-protein-coupled receptors — mu (MOR/OPRM1), delta (DOR/OPRD1), kappa (KOR/OPRK1) and the nociceptin receptor (Pasternak 2013; Valentino 2018). Full-length dynorphin A is best known as the prototypical endogenous ligand at the kappa opioid receptor, but truncated dynorphin fragments lose the C-terminal "address" residues that drive kappa selectivity and behave more like the shorter enkephalins, engaging the mu and delta receptors instead. The card is annotated against OPRM1 (the mu opioid receptor) to reflect that shift in selectivity when the peptide is shortened to ten residues and amidated.
Mechanism
The YGGF N-terminus is the shared "message" sequence of all classical endogenous opioids; the residues that follow act as an "address" that biases the peptide toward one receptor subtype over another (Pasternak 2013). Cloning and pharmacological work in the early 1990s established that the opioid receptors are G-protein-coupled receptors structurally related to receptors for somatostatin, angiotensin and interleukin-8 (Evans 1992). Subsequent work has shown that opioid receptor signaling is more complex than a single pathway — receptors couple to multiple downstream effectors, exhibit ligand-biased agonism, and form heteromers with each other and with other GPCRs (Valentino 2018). Dynorphin A (1-10) amide, by truncating the kappa-selective C-terminal "address" of dynorphin A and adding a C-terminal amide, is one of the tool compounds used to interrogate that message/address logic.
Evidence
- Human: No human clinical data identified in the available sources for this specific fragment.
- Animal: Pharmacological characterization of opioid peptide fragments in rodents has historically used assays such as the guinea-pig ileum and mouse vas deferens to compare potency across the opioid peptide family (e.g. Broccardo and colleagues, 1981, comparing dermorphin against met-enkephalin in the same preparations). Comparable use as a research tool is the basis on which dynorphin A (1-10) fragments are characterized.
- In vitro: Identification of dynorphin family peptides in mammalian tissue extracts has been confirmed by mass spectrometry-based neuropeptidomics (Petruzziello and colleagues, 2012).
Related peptides
Dynorphin A (1-10) amide sits inside the broader endogenous opioid family — preprodynorphin-derived dynorphins, proenkephalin-derived enkephalins, and proopiomelanocortin-derived β-endorphin — all sharing the N-terminal YGGF motif but differing in their downstream "address" residues and in receptor preference (Clynen 2014; Pasternak 2013). Comparative work on non-mammalian vertebrates (e.g. Pacific hagfish, Huang and colleagues 2022) and on amphibian-skin opioids such as dermorphin (Amiche 1990; Broccardo 1981) is part of the same broader literature on how the opioid receptor family and its peptide ligands co-evolved.
Research directions for this peptide, selected from the current sources — hypotheses you can explore and model. None of it is proven yet; tap any one to see the full thinking.
Could a minor chemical modification to dynorphin's backbone make it survive long enough in the bloodstream to work as a drug?
Natural opioid peptides are degraded within minutes in the body, making them impractical as drugs. If this modification grants stability, the resulting compound could be developed into a non-addictive or reduced-addiction painkiller that patients could take systemically.
Does cutting dynorphin short make it trigger only the beneficial pain-relief pathway at the opioid receptor, avoiding the dangerous side-effect pathways?
Opioids like morphine cause overdose deaths partly because they activate a side-effect pathway in addition to pain relief. If this shorter dynorphin triggers only the beneficial pathway, it could become a template for a new generation of safer painkillers, potentially saving thousands of lives lost to opioid overdose each year.
Does adding a simple chemical cap to the end of a 10-amino-acid dynorphin fragment change which opioid receptor it prefers?
If a single chemical modification can redirect this peptide between receptor subtypes, chemists could use it as a design rule to create highly receptor-specific opioids, potentially reducing side effects like respiratory depression that are tied to non-selective opioid drugs.
Does cutting dynorphin A down to its first 10 amino acids and capping the end actually improve how well it grips the mu opioid receptor?
If true, this shorter capped peptide could become a template for new pain medicines that are more targeted and potentially safer than existing opioids, benefiting patients who need strong pain relief without high addiction risk.
▸full evidence table2 metrics
| metric | value | tool |
|---|---|---|
| ipTM | 0.8837057948112488 | boltz-2 |
| ranking score | 0.8278200030326843 | boltz-2 |
▸structural qualityopenfold3
| metric | value | note |
|---|---|---|
| gpde | 0.796 | global PDE — lower = better |
| disorder | NaN | fraction disordered |
▸3-letter notation
▸recipeboltz-2 1.0
| parameter | value |
|---|---|
| model | boltz-2 1.0 |
| weights | — |
| hardware | nvidia_nim_api |
| mlx version | — |
| python | — |
| random seed | — |
| msa strategy | none |
| diffusion samples | 1 |
| runtime | — |
| predicted by | mlx@peptide |
| predicted at | 2026-04-24 |
▸citationbibtex
@peptide{pep10700,
sequence = {YGGFLRRIRP},
target = {oprm1},
author = {peptidemodel},
year = {2026},
status = {synthesized}
}