PAM (peptidylglycine alpha-amidating monooxygenase) is a bifunctional enzyme that catalyzes the C-terminal amidation of proteins, a critical post-translational modification required for the biological activity of many endocrine hormones and neuropeptides 1. The enzyme operates through two sequential reactions catalyzed by distinct domains: the PHM (peptidyl alpha-hydroxylating monooxygenase) domain performs copper-, ascorbate-, and oxygen-dependent stereospecific hydroxylation of the alpha-carbon of the C-terminal glycine residue, while the PAL (peptidylglycine amidoglycolate lyase) domain catalyzes zinc-dependent cleavage of the N-C-alpha bond to produce the alpha-amidated peptide and glyoxylate 1. Beyond hormone processing, PAM also responds to oxidative stress by promoting C-terminal amidation of protein fragments generated during cellular damage, facilitating their subsequent degradation by the proteasome 2. The enzyme additionally catalyzes the conversion of N-fatty acylglycines to primary fatty acid amides. PAM's dual catalytic mechanism and essential role in hormone maturation make it crucial for proper endocrine function and cellular stress responses.