A peptidyl alpha-amidation activity in chromaffin granules of bovine adrenal medulla.
Peptidyl alpha-amidation activity in bovine adrenal medulla has been localized in chromaffin granules by density gradient centrifugation. The activity was found to be both soluble and membrane-associated. Both enzymatic activities were stimulated by the addition of Cu2+ and ascorbate. The pH maximum for alpha-amidation in the chromaffin granules in pH 8.0-8.5. By gel filtration, the soluble enzyme activity appeared as a protein of approx. 40 kDa. It is suggested that this enzyme is involved in the carboxyl-terminal amidation of metorphamide, amidorphin and neuropeptide Y.
Bastiaensen
E
E
Department of Medicine, University of Antwerp (UIA), Wilrijk, Belgium.
De Potter
W
W
D000313:Adrenal Medulla / Q000201:enzymology*; D000818:Animals; D002417:Cattle; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D002837:Chromaffin Granules / Q000201:enzymology*; D002838:Chromaffin System / Q000201:enzymology*; D002850:Chromatography, Gel; D007700:Kinetics; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism; D006899:Mixed Function Oxygenases; D009097:Multienzyme Complexes; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000302:isolation & purification / Q000378:metabolism*
D008565:Membrane Proteins; D009097:Multienzyme Complexes; D006899:Mixed Function Oxygenases; C035189:peptidylglycine monooxygenase; D000587:Oxidoreductases Acting on CH-NH Group Donors