Localization and characterization of aminopeptidase P in bovine adrenal medulla.
Aminopeptidase P (EC 3.4.11.9) is demonstrated for the first time in the cytosolic fraction of chromaffin cells of the bovine adrenal medulla. The enzyme is inhibited by metal chelators and by sulfhydryl-reactive agents, which suggests that both a tightly bound metal ion and a cysteine residue are necessary for enzymatic activity. Aminopeptidase P might be important for the modulation of the biological activity of neuropeptides. Its occurrence in the adrenal chromaffin cells provides a useful tool for studying the function of this unique proline-specific peptidase in neuropeptide processing and secretion.
Laboratory of Clinical Biochemistry, University of Antwerp, Wilrijk, Belgium.
G
G
Vanhoof
J
J
De Block
I
I
De Meester
S
S
Scharpé
W P
WP
De Potter
D000313:Adrenal Medulla / Q000201:enzymology*; D000626:Aminopeptidases / Q000032:analysis / Q000378:metabolism*; D000818:Animals; D018826:CD13 Antigens; D002413:Cations, Divalent / Q000494:pharmacology; D002417:Cattle; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D002837:Chromaffin Granules / Q000201:enzymology*; D003600:Cytosol / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011480:Protease Inhibitors / Q000494:pharmacology; D013347:Subcellular Fractions / Q000201:enzymology
D002413:Cations, Divalent; D011480:Protease Inhibitors; D000626:Aminopeptidases; D018826:CD13 Antigens