A novel bovine spinal cord endoprotease with high specificity for dynorphin B.
An endopeptidase that converts the opioid peptide dynorphin B (Tyr-Gly-Gly-Phe-Leu-Arg-aRg-Gln-Phe-Lys-Val-Val-Thr) to its bioactive fragment Leu-enkephalin-Arg6 was isolated from bovine spinal cord. The enzyme was purified about 230-fold from a concentrated spinal cord extract. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis, it stained as a protein of Mr 55,000. The purified enzyme is optimally active at around pH7 and has essential thiol groups. It appears to be highly specific for dynorphin B (Km = 11 microM) but not for alpha-neoendorphin or dynorphin A, two other opioids included in the prodynorphin precursor. From its specificity, molecular size, and inhibitory spectrum, this enzyme is different from other known dynorphin-converting or -degrading enzymes and appears to be a unique and novel endoprotease.
Silberring
J
J
Department of Pharmacology, University of Uppsala, Sweden.
Nyberg
F
F
D000595:Amino Acid Sequence; D000818:Animals; D002413:Cations, Divalent; D002417:Cattle; D002614:Chelating Agents / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004399:Dynorphins / Q000031:analogs & derivatives* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D004723:Endorphins / Q000378:metabolism*; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011480:Protease Inhibitors / Q000494:pharmacology; D013116:Spinal Cord / Q000201:enzymology*; D013379:Substrate Specificity; D013439:Sulfhydryl Reagents / Q000494:pharmacology
D002413:Cations, Divalent; D002614:Chelating Agents; D004723:Endorphins; D011480:Protease Inhibitors; D013439:Sulfhydryl Reagents; D004743:Enkephalin, Leucine; D004399:Dynorphins; C026768:enkephalin-Leu, Arg(6)-; C036200:rimorphin; D010450:Endopeptidases