Pro-dynorphin (also referred to as pro-enkephalin B) can be processed to produce dynorphin A, dynorphin B, α-neoendorphin, and β-neoendorphin. Beta-Neoendorphin is an endogenous opioid peptide. Beta-Neoendorphin is a hypothalamic “big” Leu-enkephalin of porcine origin. It shows activation of the Erk1/2, MMP-2 and MMP-9. The carboxypeptidase cleavage step is not rate limiting for the production of most neuroendocrine peptides, the exceptions being the conversion of α-neoendorphin into β-neoendorphin, which requires cleavage of a Pro-Lys bond, and the generation of rat β-endorphin 1-26, which requires cleavage of a C-terminal His-27 residue.
