Vasopressin/oxytocin receptor-targeting peptide (CHEMBL1817756)
A small lab-made peptide that latches onto the vasopressin and oxytocin receptors, the body's controls for blood pressure, water balance, and social bonding. Research tool only, not a medicine.
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
CHEMBL1817756 is a 7-residue synthetic peptide (sequence CIQNCPG) catalogued in the ChEMBL bioactivity database as a ligand at the vasopressin/oxytocin receptor family. It is not a marketed drug and is not associated with a clinical program — it is a research-stage compound characterized in a medicinal-chemistry effort to design selective peptidic agonists of the V1a vasopressin receptor (Wiśniewski 2011). The two cysteines in the sequence indicate the molecule is designed to cyclize through a disulfide bridge, which is the canonical scaffold shared by vasopressin and oxytocin; that ring geometry is what allows binding to this receptor family at all.
What it does
In cell-based assays summarised in ChEMBL, CHEMBL1817756 binds the vasopressin V2 receptor with an EC50 of approximately 955 nM. The platform card also lists activity (or assay coverage) at V1a, V1b, and the oxytocin receptor, reflecting the cross-reactivity that is typical of compounds built on the vasopressin/oxytocin ring scaffold. The published series from which this compound is drawn was specifically aimed at producing V1a-selective, short-acting peptidic agonists for further pharmacological study (Wiśniewski 2011) — the compound is a probe of receptor pharmacology, not a therapeutic.
Evidence
- Human: No human studies. This is a ChEMBL-catalogued research peptide; there are no clinical trials and no published in-vivo human data tied to this specific compound.
- In vitro: Receptor-binding/functional activity at V2 (EC50 ≈ 955 nM) is documented in ChEMBL (CHEMBL1817756). The parent medicinal-chemistry series targeting V1a-selective short-acting agonists is described by Wiśniewski and colleagues (2011, Journal of Medicinal Chemistry).
- Animal: None recorded in the dossier for this specific compound.
Related peptides
The vasopressin/oxytocin receptor family is one of the most extensively studied peptide-receptor systems in pharmacology. The clinically used members of this family are:
- Vasopressin (/card/pep-04424) — the endogenous nonapeptide hormone (Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Arg-Gly-NH₂) that regulates water balance via V2 and vascular tone via V1a; ICU drug for vasodilatory shock and central diabetes insipidus.
- Oxytocin — the closely related nonapeptide (differs from vasopressin at two positions) acting primarily at the oxytocin receptor.
CHEMBL1817756 sits in the same chemical neighbourhood — a disulfide-cyclised peptide acting at this receptor family — but is a research compound with low potency and no clinical role.
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.
Does CIQNCPG last longer in blood than vasopressin because it lacks the site where enzymes normally cut the hormone apart?
Vasopressin infusions used in septic shock and surgery require continuous delivery because the hormone degrades in minutes. A more stable analog could work as a less frequent injection or even a patch, reducing intensive-care burden and improving outcomes for critically ill patients.
Could locking the peptide into a tighter double-ring structure using its terminal proline make it survive digestion and work as an oral medicine?
All existing vasopressin-type drugs must be injected or given as a nasal spray, which is inconvenient for long-term use. If this structural tweak leads to a tablet that reaches the bloodstream intact, it could transform treatment of conditions like low blood pressure disorders and nighttime bedwetting into a simple daily pill.
Is the asparagine at position 5 the key switch that steers this peptide toward the V1a receptor and away from V2?
V1a and V2 receptors have opposite roles, V1a controls blood vessel tone and V2 regulates kidney water retention. A drug that cleanly separates them could treat hypertension or hemorrhage without the water-retention side effects that complicate current vasopressin therapies.
▸full evidence table1 metrics
| metric | value | tool |
|---|---|---|
| EC50 | 954.99 nM | GPCRDB/ChEMBL |
▸3-letter notation
▸recipeboltz-2 2.2.1
| parameter | value |
|---|---|
| model | boltz-2 2.2.1 |
| weights | — |
| hardware | vast_v100_32gb |
| mlx version | — |
| python | — |
| random seed | 1 |
| msa strategy | colabfold_local |
| runtime | — |
| predicted by | — |
| predicted at | 2026-05-22 |
▸citationbibtex
@peptide{pep10300,
sequence = {CIQNCPG},
target = {avpr1a},
author = {peptidemodel},
year = {2026},
status = {bioassayed}
}