Table 1.
Amino acid sequences of selected human endogenous opioid peptides.
| Precursor | Opioid Peptide | Copies of Peptide | Structure | Other Peptides |
|---|---|---|---|---|
| Proenkephalin (PENK) |
[Leu]5enkephalin | 1 | Tyr-Gly-Gly-Phe-Leu | Synenkephalin |
| [Met]5enkephalin | 4 | Tyr-Gly-Gly-Phe-Met | ||
| [Met]5enkephalin-Arg6-Gly7-Leu8(Octapeptide) | 1 | Tyr-Gly-Gly-Phe-Met-Arg-Gly-Leu | ||
| [Met]5enkephalin-Arg6-Phe7 (Heptapeptide) |
1 | Tyr-Gly-Gly-Phe-Met-Arg-Ph | ||
| Prodynorphin (PDYN) |
Dynorphin A1-17 | 1 | Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-Pro-Lys-Leu-Lys-Trp-Asp-Asn-Gln | α-neoendorphin, β-neoendorphin, Big dynorphin, Leumorphin |
| Dynorphin B1-13 | 1 | Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Gln-Phe-Lys-Val-Val-Thr | ||
| Pro-opiomelanocortin (POMC) |
βh-Endorphin1-31 | 1 | Tyr-Gly-Gly-Phe-Met-Thr-Ser-Glu-Lys-Ser-Gln-Thr-Pro-Leu-Val-Thr-Leu-Phe-Lys-Asn-Ala-Ile-Ile-Lys-Asn-Ala-Tyr-Lys-Lys-Gly-Glu | γ-MSH, ACTH, α-MSH, CLIP, β-LPH, γ-LPH, β-MSH |
| Unknown | Endomorphin-1 | Tyr-Pro-Trp-Phe-NH2 | ||
| Endomorphin-2 | Tyr-Pro-Phe-Phe-NH2 |
MSH: melanocyte stimulating hormone; ACTH: adrenocorticotropic hormone; CLIP: corticotropin-like intermediate lobe peptide; LPH: lipotropin.