Corticotropin (adrenocorticotropic hormone, ACTH) is a 39-amino acid polypeptide hormone produced and secreted by the pituitary gland. It is often produced in response to biological stress (along with corticotropin-releasing hormone). Its principal effects are increased production of androgens and cortisol. Corticotropin is processed from the precursor pro-opiomelanocortin (POMC). The enzyme that performs the cleavage of POMC to corticotropin is prohormone convertase 1 (PC1). In addition to corticotropin, POMC is processed into other small, biologically active fragments. These include lipotropins, melanocyte-stimulating hormone and endorphins.
serine-type endopeptidase activity of PC1:calcium cofactor [secretory granule lumen]