Zinc regulation of aminopeptidase B involved in neuropeptide production.
Aminopeptidase B (AP-B) is a metallopeptidase that removes basic residues from the N-termini of neuropeptide substrates in secretory vesicles. This study assessed zinc regulation of AP-B activity, since secretory vesicles contain endogenous zinc. AP-B was inhibited by zinc at concentrations typically present in secretory vesicles. Zinc effects were dependent on concentration, incubation time, and the molar ratio of zinc to enzyme. AP-B activity was recovered upon removal of zinc. AP-B with zinc became susceptible to degradation by trypsin, suggesting that zinc alters enzyme conformation. Zinc regulation demonstrates the metallopeptidase property of AP-B.
Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093-0744, United States.
Shin-Rong
SR
Hwang
Vivian
V
Hook
D000626:Aminopeptidases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D045727:Metalloexopeptidases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D009479:Neuropeptides / Q000096:biosynthesis*; D011487:Protein Conformation; D051381:Rats; D022142:Secretory Vesicles / Q000378:metabolism; D014357:Trypsin / Q000737:chemistry; D015032:Zinc / Q000378:metabolism* / Q000494:pharmacology
D009479:Neuropeptides; D045727:Metalloexopeptidases; D000626:Aminopeptidases; C019721:aminopeptidase B; D014357:Trypsin; D015032:Zinc