Neuropeptides
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Dermorphin (Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2), a naturally occurring peptide isolated from arboreal frog skin, is endowed with outstanding structural and biological features. It has no structural community with the sequence of mammalian opioid peptides and is a unique example of a D-aminoacid containing peptide which is synthesized via ribosomal route. Dermorphin is the most potent of the opioid peptides or opiates in producing long lasting analgesia and catalepsy. ⋯ Identification was achieved by chromatographic comparison with synthetic standards and immunological analysis. A peptide behaving like authentic dermorphin was detected (2 ng/g) in rat small intestine. Immunoreactive species of higher Mr were also detected in the brain, adrenal glands and gastrointestinal tract, they may represent extended forms of dermorphin or homologous peptides.