Dynorphin converting enzyme with unusual specificity from rat brain.
A rat brain membrane extract was shown to convert synthetic dynorphin B-29 ("leumorphin") to dynorphin B [dynorphin B-29-(1-13), "rimorphin"]. This represents a "single arginine cleavage" at Thr-Arg at positions 13 and 14 of the substrate. The product was identified by immunoprecipitation with a highly specific dynorphin B antiserum and by coelution with radiolabeled dynorphin B on reversed-phase high-performance liquid chromatography. The converting activity exhibits a pH optimum of 8. It is inhibited by a thiol protease inhibitor but not by inhibitors of cathepsin B or of serine proteases. It is inhibited by dynorphin A but not by various dynorphin A fragments. These results suggest that the converting activity is due to a novel thiol protease distinct from any known protease believed to function in the processing of biologically active peptides.
D000818:Animals; D001921:Brain / Q000201:enzymology*; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D004399:Dynorphins; D010450:Endopeptidases / Q000378:metabolism*; D004723:Endorphins / Q000378:metabolism*; D004745:Enkephalins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D010446:Peptide Fragments / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D011498:Protein Precursors / Q000378:metabolism; D051381:Rats; D013379:Substrate Specificity
D004723:Endorphins; D004745:Enkephalins; D010446:Peptide Fragments; D011480:Protease Inhibitors; D011498:Protein Precursors; D004399:Dynorphins; C026770:dynorphin (1-8); C033660:preproenkephalin; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; C063078:dynorphin converting enzyme