Deltorphin I

Deltorphin I is a heptapeptide, a chain of seven amino acids, that is naturally produced in the skin of certain species of frogs. It is one of the most potent opioid peptides known, with a high affinity for delta opioid receptors in the central nervous system.

Structure and Synthesis

Deltorphin I has the amino acid sequence Tyr-D-Ala-Phe-Asp-Val-Val-Gly-NH2. The D-Ala in the second position is a D-amino acid, which is less common in nature than L-amino acids. The synthesis of Deltorphin I involves the stepwise addition of these amino acids in a process known as peptide synthesis.

Biological Activity

Deltorphin I is a potent agonist at the delta opioid receptor, meaning it binds to this receptor and activates it. This receptor is one of three main types of opioid receptors in the brain, the others being the mu opioid receptor and the kappa opioid receptor. Activation of the delta receptor by Deltorphin I can lead to analgesia, or pain relief, as well as other effects such as changes in mood and behavior.

Pharmacology

The pharmacokinetics of Deltorphin I, including its absorption, distribution, metabolism, and excretion, are not well understood. However, it is known that the peptide can cross the blood-brain barrier, allowing it to exert its effects in the central nervous system. The delta opioid receptor is a G protein-coupled receptor, and activation by Deltorphin I leads to inhibition of adenylate cyclase, reducing levels of the second messenger cyclic AMP.

Clinical Significance

While Deltorphin I itself is not used clinically, it has been the subject of research due to its potent opioid activity. It may serve as a lead compound for the development of new analgesics and other drugs acting on the delta opioid receptor.

See Also

• Deltorphin II
• Dermorphin
• Opioid peptide
• Delta opioid receptor