Prodynorphin processing by rat CNS fractions and purified enzymes: Formation of Dynorphin A 1-8 by sulfhydryl-activated carboxypeptidase and peptidyl dipeptidase.

The conversion of selected prodynorphin fragments to form the octapeptide Dynorphin A 1-8 was studied in rat brain or spinal cord fractions, and the results compared to the action of purified carboxypeptidases and angiotension converting enzyme. The particulates were shown to convert Dynorphin A or 1-13 to the octapeptide as measured by radioimmunoassay, and by reverse phase high performance liquid chromatography. Detergent extracts of these particulates contained and enzyme converting 1-13 to 1-12 with release of C-terminal lysine, and active over a wide pH range of 4.