Dynorphin/α-Neo-endorphin

Abstract Dynorphin and α-neo-endorphin are endogenous opioid peptides produced in a wide variety of regions of the central nervous system and other tissues such as the adrenal gland, spinal cord, testis, and anterior pituitary. They are generated from the precursor protein, prodynorphin, by posttranslational proteolytic cleavage. In mammals, prodynorphin contains three Leu-enkephalin sequences comprising YGGFL. This pentapeptide sequence is a core of the three prodynorphin-derived peptides. Among the three classical opioid receptors (δ-opioid receptor, κ-opioid receptor, and μ-opioid receptor, these peptides preferentially bind to κ-opioid receptors. Based on the localization of the κ-opioid receptor, dynorphins are involved in learning and memory, emotional control, and stress response, in addition to analgesic effects.