Processing of prodynorphin at single and paired basic residues in porcine neurointermediate lobe

The [Leu]enkephalin-containing peptides derived from prodynorphin have been quantitated in porcine neurointermediate lobe. Dynorphin-17, beta-neo-endorphin, [Leu]enkephalin, rimorphin and dynorphin-24 were found in highest concentrations (200-700 pmol/gm). No detectable amounts of the carboxyl terminal-extended rimorphin sequence (rimorphin 1-29) were observed, indicating that in addition to processing at paired basic residues, cleavage at the single Arg residue following rimorphin must be a major step in the processing of prodynorphin. Processing at Arg-Arg and/or Arg-Lys sequences to yield free [Leu]enkephalin also occurs to an appreciable extent in this tissue.