Peptidyl amidating enzyme
This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen.
I]d-Tyr-Val-Gly as substrate, a peptidyl-glycine α-amidating monooxygenase (PAM) was detected in islet secretory granule lysates.
The enzyme is active between p H 6.0 and 8.5 and exhibits maximal activity near p H 7.0.
Many peptide hormones and neuropeptides require an amidated carboxy terminal for full biological activity.
This reaction is carried out in two steps: hydroxylation of a C-terminal glycine and cleavage of the C N bond with the release of glyoxylate.
Other divalent metal ions and redox cofactors were tested and found to be inactive in the assay.