 | |
| Names | |
|---|---|
| IUPAC name L-Tyrosyl-L-prolyl-L-phenylalanyl-L-phenylalaninamide | |
| Identifiers | |
3D model (JSmol) | |
| ChemSpider | |
| UNII | |
| |
| |
| Properties | |
| C32H37N5O5 | |
| Molar mass | 571.667 g/mol |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Endomorphin-2 (EM-2) is anendogenousopioid peptide and one of the twoendomorphins.[1] It has theamino acid sequence Tyr-Pro-Phe-Phe-NH2. It is a highaffinity, highly selectiveagonist of theμ-opioid receptor, and along with endomorphin-1 (EM-1), has been proposed to be the actual endogenousligand of this receptor (that is, rather than theendorphins).[1][2][3][4] Like EM-1, EM-2 producesanalgesia in animals, but whereas EM-1 is more prevalent in thebrain, EM-2 is more prevalent in thespinal cord.[1] In addition, the action of EM-2 differs from that of EM-1 somewhat, because EM-2 additionally induces the release ofdynorphin A and[Met]enkephalin in the spinal cord and brain by an unknownmechanism, which in turn activate theκ- andδ-opioid receptors, respectively, and a portion of the analgesic effects of EM-2 is dependent on this action.[5][6] Moreover, while EM-1 producesconditioned place preference, a measure ofdrug reward, EM-2 producesconditioned placeaversion, an effect which is dynorphin A-dependent.[6] Similarly to the case of EM-1, thegene encoding for EM-2 has not yet been identified.[4][7]
