PAM

Bifunctional enzyme that catalyzes amidation of the C-terminus of proteins. Alpha-amidation is present at the C-terminus of many endocrine hormones and neuropeptides and is required for their activity. C-terminal amidation also takes place in response to protein fragmentation triggered by oxidative stress, promoting degradation of amidated protein fragments by the proteasome. Alpha-amidation involves two sequential reactions, both of which are catalyzed by separate catalytic domains of the enzyme. The first step, catalyzed by peptidyl alpha-hydroxylating monooxygenase (PHM) domain, is the copper-, ascorbate-, and O2- dependent stereospecific hydroxylation (with S stereochemistry) at the alpha-carbon (C-alpha) of the C-terminal glycine of the peptidylglycine substrate. The second step, catalyzed by the peptidylglycine amidoglycolate lyase (PAL) domain, is the zinc-dependent cleavage of the N-C-alpha bond, producing the alpha-amidated peptide and glyoxylate. Similarly, catalyzes the two-step conversion of an N-fatty acylglycine to a primary fatty acid amide and glyoxylate (By similarity)..

Function from UniProtKB (P19021), read 2026-09-23. CC BY 4.0.