title: Acetylation of the NH2-terminal serine of prostaglandin synthetase by aspirin.
abstract: Aspirin (acetylsalicylic acid) inhibits prostaglandin synthesis by acetylating an active site portion of the enzyme, prostaglandin synthetase. In the current study, the site of acetylation has been demonstrated to be a seryl residue at the NH2 terminus of the enzyme. Purified [3H]acetyl enzyme was prepared from seminal vesicle homogenates treated with [acetyl-3H]aspirin. The [3H]acetate to protein bond was stable to hydroxylamine, indicating an N-acetyl linkage. The [3H]acetyl enzyme was fragmented sequentially with cyanogen bromide, trypsin, and pronase. The 3H material isolated from the pronase digest was identified as N-acetylserine. This finding indicates that the oxygenase portion of prostaglandin synthetase has an NH2-terminal serine which is involved in enzymatic activity and is susceptible to acetylation by aspirin.
mesh_terms: D000107:Acetylation; D000818:Animals; D001241:Aspirin; D002417:Cattle; D016861:Cyclooxygenase Inhibitors; D008297:Male; D010446:Peptide Fragments / Q000032:analysis; D012669:Seminal Vesicles / Q000201:enzymology; D012694:Serine; D012756:Sheep
chemical_list: D016861:Cyclooxygenase Inhibitors; D010446:Peptide Fragments; D012694:Serine; D001241:Aspirin