title: Pro-opiomelanocortin and pro-vasopressin converting enzyme in pituitary secretory vesicles.
abstract: Peptide hormones are synthesized from larger precursors by cleavages at paired basic residues. We have isolated a pro-hormone converting enzyme from bovine neural and intermediate lobe secretory vesicles that cleaves pro-vasopressin and pro-opiomelanocortin at Lys-Arg residues to yield vasopressin, and adrenocorticotropin/endorphin-related peptides, respectively. The enzyme from both lobes is an aspartyl protease of approximately 70,000 Da, is a glycoprotein and has an optimum pH range of 4.0-5.0. Present within the same secretory vesicles is an aminopeptidase B-like enzyme which is a metalloprotease that is inhibited by Co2+ and Zn2+. This enzyme may play a role in trimming off the N-terminal extended basic residues from peptides liberated by the pro-hormone converting enzyme.
authors.affiliation: Laboratory of Neurochemistry and Neuroimmunology, National Institute of Child Health and Human Development, Bethesda, MD 20892.
authors.forename: Y P
authors.initials: YP
authors.lastname: Loh
authors.forename: N P
authors.initials: NP
authors.lastname: Birch
authors.forename: M G
authors.initials: MG
authors.lastname: Castro
mesh_terms: D000818:Animals; D001127:Arginine Vasopressin; D002417:Cattle; D003594:Cytoplasmic Granules / Q000201:enzymology*; D010450:Endopeptidases / Q000378:metabolism*; D006801:Humans; D051379:Mice; D009479:Neuropeptides / Q000235:genetics; D009481:Neurophysins; D010121:Oxytocin; D010902:Pituitary Gland / Q000201:enzymology*; D010907:Pituitary Hormones / Q000235:genetics; D011333:Pro-Opiomelanocortin / Q000235:genetics / Q000378:metabolism*; D043484:Proprotein Convertases; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D014667:Vasopressins / Q000235:genetics / Q000378:metabolism
chemical_list: D009479:Neuropeptides; D009481:Neurophysins; D010907:Pituitary Hormones; D011498:Protein Precursors; D014667:Vasopressins; D001127:Arginine Vasopressin; D010121:Oxytocin; D011333:Pro-Opiomelanocortin; D010450:Endopeptidases; D043484:Proprotein Convertases