Acylaminoacyl-peptide hydrolase (APEH)

Acylaminoacyl-peptide hydrolase (APEH) is a **serine protease enzyme** that catalyzes the removal of N-terminally acetylated amino acids from peptides and proteins (“exopeptidase” activity) and also degrades oxidized or glycated proteins at internal sites (“endopeptidase” activity)[1][2][3][4]. It is a homotetrameric protein of approximately 300 kDa in humans, with each subunit consisting of 732 amino acids[1][2]. APEH helps regulate protein homeostasis, especially under **oxidative stress**, by removing damaged or acetylated residues. The gene is located on chromosome 3p21 in humans and deletions or dysregulation are found in several carcinoma types[1][2]. APEH (also known as acylamino-acid-releasing enzyme or oxidized protein hydrolase) is evolutionarily conserved and plays a dual role in processing N-acetylated peptides and eliminating cytotoxic oxidized proteins, linking it to cellular aging, cancer progression, and the response to oxidative insults[3].

Other names

Acylamino-acid-releasing enzymeAAREAcyl-peptide hydrolaseAcylaminoacyl-peptidaseOxidized protein hydrolaseOPHACPHAPHD3F15S2D3S48EDNF15S2

Inhibition or modulation of APEH activity increases the level of N-terminal acetylated proteins and can affect cell proliferation and aging pathways[3]. Its endopeptidase and exopeptidase activities are targeted for potential modulation in cancer and proteostasis research[3].