In enzymology, a platelet-activating factor acetyltransferase is an enzyme that catalyzes the chemical reaction 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine + 1-organyl-2-lyso-sn-glycero-3-phospholipid ⇌ {\displaystyle \rightleftharpoons } 1-organyl-2-lyso-sn-glycero-3-phosphocholine + 1-alkyl-2-acetyl-sn-glycero-3-phospholipidThus, the two substrates of this enzyme are 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine and 1-organyl-2-lyso-sn-glycero-3-phospholipid, whereas its two products are 1-organyl-2-lyso-sn-glycero-3-phosphocholine and 1-alkyl-2-acetyl-sn-glycero-3-phospholipid. Wikipedia