title: Endopeptidase in human cerebrospinal fluid which cleaves proenkephalin B opioid peptides at consecutive basic amino acids.
abstract: An endopeptidase releasing the common N-terminal hexapeptide, (Leu)-enkephalin-Arg6, from dynorphins A and B, and alpha-neoendorphin was purified from human cerebrospinal fluid. Purification involved ion-exchange chromatography (DEAE-Sepharose CL-6B), hydrophobic interaction chromatography (phenyl-Sepharose CL-4B) and molecular sieving (Sephadex G-100). The enzyme showed molecular heterogeneity. A major fraction had an apparent molecular weight of about 40,000. It had an optimum activity in the pH range of 6-8. The conversion of dynorphin A was not affected by EDTA or iodoacetate but strongly reduced in the presence of phenylmethyl-sulphonyl fluoride, suggesting the enzyme is a serine protease.
authors.forename: F
authors.initials: F
authors.lastname: Nyberg
authors.forename: K
authors.initials: K
authors.lastname: Nordström
authors.forename: L
authors.initials: L
authors.lastname: Terenius
mesh_terms: D000596:Amino Acids; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004399:Dynorphins / Q000031:analogs & derivatives / Q000378:metabolism; D004723:Endorphins / Q000378:metabolism; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000032:analysis; D004745:Enkephalins / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D011498:Protein Precursors / Q000378:metabolism*; D011863:Radioimmunoassay; D012697:Serine Endopeptidases / Q000134:cerebrospinal fluid* / Q000302:isolation & purification; D015842:Serine Proteinase Inhibitors
chemical_list: D000596:Amino Acids; D004723:Endorphins; D004745:Enkephalins; D011498:Protein Precursors; D015842:Serine Proteinase Inhibitors; C029992:proenkephalin; D004743:Enkephalin, Leucine; C025681:alpha-neoendorphin; D004399:Dynorphins; C026768:enkephalin-Leu, Arg(6)-; C036200:rimorphin; D012697:Serine Endopeptidases; C054870:dynorphin-converting endopeptidase