Processing of the oxytocin precursor: isolation of an exopeptidase from neurosecretory granules of bovine pituitaries.
The bovine pro-oxytocin precursor consists of the nonapeptide hormone and its neurophysin carrier protein that contains at its C-terminus a rudimentary processing signal, the single basic amino acid residue histidine. An exopeptidase has been isolated from neurosecretory granules of the bovine posterior pituitary that releases the supernumary histidine residue from the pro-hormone precursor. Based on its sensitivity to inhibitors and activators the enzyme has carboxypeptidase B-like properties with a pH optimum between 5.0 and 5.5.
Nörenberg
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U
Institut für Zellbiochemie und klinische Neurobiologie, Universitäts-Krankenhaus, Eppendorf, Hamburg, FRG.
Richter
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D
D000818:Animals; D043424:Carboxypeptidase B; D002268:Carboxypeptidases / Q000378:metabolism; D002413:Cations, Divalent; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003594:Cytoplasmic Granules / Q000201:enzymology*; D020689:Exopeptidases; D006639:Histidine / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D010121:Oxytocin / Q000031:analogs & derivatives* / Q000378:metabolism; D010447:Peptide Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D010904:Pituitary Gland, Posterior / Q000201:enzymology* / Q000648:ultrastructure; D011480:Protease Inhibitors; D014357:Trypsin / Q000378:metabolism
D002413:Cations, Divalent; D011480:Protease Inhibitors; D006639:Histidine; D010121:Oxytocin; C046278:oxytocin, Gly-Lys-Arg-; D002268:Carboxypeptidases; D020689:Exopeptidases; D010447:Peptide Hydrolases; D043424:Carboxypeptidase B; D014357:Trypsin