Acetylation

Abstract

Biologically active peptides and polypeptides are generated after proteolytic cleavage and other posttranslational modifications of precursor proteins. One of the most widely studied precursors is the prohormone precursor proopiomelanocortin (POMC), which gives rise to a number of peptide products with a range of biological activities. Interestingly, two of its posttranslational products (α-MSH and β-endorphin) belong to a very rare group of secreted, biologically active peptides that are acetylated. Acetylation of α-MSH enhances activity through increased biological stability, whereas acetylation abolishes activity of β-endorphin. These two peptides seem to have opposing roles in the regula..