Other · Opioid peptide
Deltorphin I
Also known as D-Ala2-Deltorphin I
A natural heptapeptide, Deltorphin I is an exceptionally selective agonist for the delta-opioid receptor, used to probe DOR function in lab models.
- Length
- 7 amino acids
- Half-life
- Not well characterised
- Mechanism
- This peptide functions as a high-affinity and exceptionally selective agonist for the delta-opioid receptor (DOR).
- Studied in
- It is employed in pharmacological studies to characterize DOR-specific signaling pathways, distinct from mu- and kappa-opioid receptor systems.
About Deltorphin I
Deltorphin I is a naturally occurring opioid peptide isolated from the skin of frogs belonging to the *Phyllomedusa* genus. Its sequence, Tyr-D-Ala-Phe-Asp-Val-Val-Gly-NH2, is notable for the presence of a D-alanine at position 2. This D-amino acid substitution is crucial for its remarkable receptor selectivity and provides increased resistance to enzymatic degradation compared to endogenous peptides.
In experimental systems, Deltorphin I serves as a gold standard for activating the delta-opioid receptor (DOR). It exhibits several thousand-fold selectivity for the DOR over the mu-opioid receptor (MOR) and kappa-opioid receptor (KOR). Researchers use it in receptor binding assays, cell-based functional assays measuring G-protein activation or adenylyl cyclase inhibition, and tissue preparations to explore the physiological roles of DOR activation.
Laboratory notes
- The D-alanine at position 2 is the key structural feature responsible for its high delta-opioid receptor selectivity.
- Store stock solutions frozen at -20°C or below, as peptides in solution are less stable than in lyophilised form.
- Use appropriate controls, such as the DOR-selective antagonist naltrindole, to confirm observed effects are DOR-mediated.
Storage and reconstitution basics: storage guide.
Questions about Deltorphin I
What is the source of Deltorphin I?
It is a naturally occurring peptide found in the skin secretions of certain species of South American tree frogs.
Why is Deltorphin I considered a valuable research tool?
Its exceptional selectivity for the delta-opioid receptor allows researchers to study the functions of that specific receptor system without significant cross-activation of mu- or kappa-opioid receptors.
How does it differ from Deltorphin II?
Both are DOR agonists, but they have different amino acid sequences (Deltorphin II has Phe-Glu instead of Phe-Asp). This results in slight differences in their binding affinities and selectivity profiles, with Deltorphin I generally considered more selective.
Is Deltorphin I for human use?
No. It is supplied strictly for in-vitro laboratory research and is not for human or animal consumption.
Related research peptides
All products are sold for laboratory research use only. Not for human consumption, not a medicine, not for diagnosing, treating or preventing any condition.